yingping wang

In situ cosmogenic 53Mn production rate from ancient low-denudation surface in tropic Brazil

Publisher: Elsevier BV

Date: 04-2010

DOI: 10.1016/J.NIMB.2009.10.135

Mycorrhizal fungi alleviate acidification‐induced phosphorus limitation: Evidence from a decade‐long field experiment of simulated acid deposition in a tropical forest in south China

Publisher: Wiley

Date: 03-2022

DOI: 10.1111/GCB.16135

Abstract: South China has been experiencing very high rate of acid deposition and severe soil acidification in recent decades, which has been proposed to exacerbate the regional ecosystem phosphorus (P) limitation. We conducted a 10‐year field experiment of simulated acid deposition to examine how acidification impacts seasonal changes of different soil P fractions in a tropical forest with highly acidic soils in south China. As expected, acid addition significantly increased occluded P pool but reduced the other more labile P pools in the dry season. In the wet season, however, acid addition did not change microbial P, soluble P and labile organic P pools. Acid addition significantly increased exchangeable Al 3+ and Fe 3+ and the activation of Fe oxides in both seasons. Different from the decline of microbial abundance in the dry season, acid addition increased ectomycorrhizal fungi and its ratio to arbuscular mycorrhiza fungi in the wet season, which significantly stimulated phosphomonoesterase activities and likely promoted the dissolution of occluded P. Our results suggest that, even in already highly acidic soils, the acidification‐induced P limitation could be alleviated by stimulating ectomycorrhizal fungi and phosphomonoesterase activities. The differential responses and microbial controls of seasonal soil P transformation revealed here should be implemented into ecosystem biogeochemical model for predicting plant productivity under future acid deposition scenarios.

Determination of seed moisture content in ginseng (Panax ginseng C.A. Mey)

Publisher: International Seed Testing Association

Date: 12-2014

DOI: 10.15258/SST.2014.42.3.10

Sensitivity of wheat growth to increased air temperature for different scenarios of ambient CO2 concentration and rainfall in Victoria, Australia - a simulation study

Publisher: Inter-Research Science Center

Date: 1992

DOI: 10.3354/CR002131

Comprehensive ecosystem model‐data synthesis using multiple data sets at two temperate forest free‐air CO₂ enrichment experiments: Model performance at ambient CO₂ concentration

Publisher: American Geophysical Union (AGU)

Date: 05-2014

DOI: 10.1002/2013JG002553

Supplementary material to Global carbon budget 2014

Publisher: Copernicus GmbH

Date: 21-09-2014

DOI: 10.5194/ESSDD-7-521-2014-SUPPLEMENT

Flood-flipped boulders: In-situ cosmogenic nuclide modeling of flood deposits in the monsoon tropics of Australia

Publisher: Geological Society of America

Date: 2015

DOI: 10.1130/G35856.1

Evaluating the simulated mean soil carbon transit times by Earth system models using observations

Publisher: Copernicus GmbH

Date: 27-02-2019

DOI: 10.5194/BG-16-917-2019

Abstract: Abstract. One known bias in current Earth system models (ESMs) is the underestimation of global mean soil carbon (C) transit time (τsoil), which quantifies the age of the C atoms at the time they leave the soil. However, it remains unclear where such underestimations are located globally. Here, we constructed a global database of measured τsoil across 187 sites to evaluate results from 12 ESMs. The observations showed that the estimated τsoil was dramatically shorter from the soil incubation studies in the laboratory environment (median = 4 years interquartile range = 1 to 25 years) than that derived from field in situ measurements (31 5 to 84 years) with shifts in stable isotopic C (13C) or the stock-over-flux approach. In comparison with the field observations, the multi-model ensemble simulated a shorter median (19 years) and a smaller spatial variation (6 to 29 years) of τsoil across the same site locations. We then found a significant and negative linear correlation between the in situ measured τsoil and mean annual air temperature. The underestimations of modeled τsoil are mainly located in cold and dry biomes, especially tundra and desert. Furthermore, we showed that one ESM (i.e., CESM) has improved its τsoil estimate by incorporation of the soil vertical profile. These findings indicate that the spatial variation of τsoil is a useful benchmark for ESMs, and we recommend more observations and modeling efforts on soil C dynamics in regions limited by temperature and moisture.

Effects of reducing dietary starch content by replacing barley grain with wheat dried distillers grains plus solubles in dairy cow rations on ovarian function

Publisher: American Dairy Science Association

Date: 04-2016

DOI: 10.3168/JDS.2015-10172

Abstract: Our objective was to evaluate the effects of dietary starch content, altered by partial substitution of dietary grain with wheat dried distillers grain with solubles (DDGS), on the interval from calving to first ovulation, concentrations of hormones and metabolites in plasma and follicular fluid, and granulosa cell gene expression in preovulatory follicles. Sixty lactating dairy cows were assigned to 1 of 2 diets from calving until 84d postpartum. Diets were formulated to contain either 17.3% rolled barley grain (29.2% starch) or 17.2% wheat DDGS (19.1% starch), with 43.0% barley silage and 21.6% rolled corn grain as the other major ingredients (dry matter basis). Transrectal ultrasonography was performed twice weekly to monitor ovarian dynamics from 7 ± 2d postpartum until ovulation or until 56d in milk, whichever occurred earlier. Plasma concentrations of insulin and insulin-like growth factor-1 (IGF-1) were determined in all 60 cows, and that of glucose, fatty acids, and urea in a subset of 24 cows, representing those in which the first ovulation occurred spontaneously within 5 wk postpartum. Estradiol (proestrus) and progesterone (12d postovulation) in plasma were also measured. Concentrations of insulin, IGF-1, glucose, fatty acids, and urea were determined in follicular fluid (wk 9), and the expression of LH receptor, estrogen receptor β, cytochrome P450 aromatase, and plasma type glutathione peroxidase genes measured in granulosa cells obtained from the preovulatory follicles at wk 9 postpartum in the subset of 24 cows. Diets did not alter the interval from calving to first ovulation (32.3 ± 2.5d), but a significantly lower proportion of cows on the DDGS diet (20%) ovulated multiple (≥ 2) follicles at the first ovulation than those on the barley grain diet (40%). The incidence of multiple ovulations tended to be lower at first insemination (10 vs. 21% for cows fed DDGS and barley grain diets, respectively). Mean plasma concentration of insulin was higher in cows fed the barley grain diet (2.5 vs 1.6 IU/mL), and a diet by time interaction was noted, with cows on the barley grain ration having higher insulin from wk 6 to 12 postpartum however, mean plasma IGF-1 concentration did not differ between dietary groups. In the subsets, mean plasma concentrations of metabolites or estradiol and progesterone were not affected by diet, parity, or diet by parity interactions. Cows on the DDGS diet had lower concentrations of IGF-I (69 vs. 108 ng/mL) and higher fatty acids (222 vs. 149 mEq/L) in the follicular fluid obtained from preovulatory follicles. Diet, parity, and diet by parity interactions did not affect the concentrations of insulin, glucose, urea, estradiol, and progesterone in follicular fluid. Diets did not alter the expression profiles of LHr, estrogen receptor β, CYP19, and GPx3 genes in granulosa cells. In summary, diets did not affect the interval from calving to first ovulation or granulosa cell gene expression. However, reducing dietary starch content by a partial replacement of dietary grain with wheat DDGS increased fatty acids in follicular fluid and reduced the concentrations of insulin in plasma, IGF-1 in follicular fluid, and the incidence of multiple ovulations.

Estimating regional terrestrial carbon fluxes for the Australian continent using a multiple-constraint approach. I. Using remotely sensed data and ecological observations of net primary production

Publisher: Stockholm University Press

Date: 04-2003

DOI: 10.1034/J.1600-0889.2003.00031.X

Microbial dynamics and soil physicochemical properties explain large-scale variations in soil organic carbon.

Publisher: Wiley

Date: 12-02-2020

DOI: 10.1111/GCB.14994

Abstract: First-order organic matter decomposition models are used within most Earth System Models (ESMs) to project future global carbon cycling these models have been criticized for not accurately representing mechanisms of soil organic carbon (SOC) stabilization and SOC response to climate change. New soil biogeochemical models have been developed, but their evaluation is limited to observations from laboratory incubations or few field experiments. Given the global scope of ESMs, a comprehensive evaluation of such models is essential using in situ observations of a wide range of SOC stocks over large spatial scales before their introduction to ESMs. In this study, we collected a set of in situ observations of SOC, litterfall and soil properties from 206 sites covering different forest and soil types in Europe and China. These data were used to calibrate the model MIMICS (The MIcrobial-MIneral Carbon Stabilization model), which we compared to the widely used first-order model CENTURY. We show that, compared to CENTURY, MIMICS more accurately estimates forest SOC concentrations and the sensitivities of SOC to variation in soil temperature, clay content and litter input. The ratios of microbial biomass to total SOC predicted by MIMICS agree well with independent observations from globally distributed forest sites. By testing different hypotheses regarding (using alternative process representations) the physicochemical constraints on SOC deprotection and microbial turnover in MIMICS, the errors of simulated SOC concentrations across sites were further decreased. We show that MIMICS can resolve the dominant mechanisms of SOC decomposition and stabilization and that it can be a reliable tool for predictions of terrestrial SOC dynamics under future climate change. It also allows us to evaluate at large scale the rapidly evolving understanding of SOC formation and stabilization based on laboratory and limited filed observation.

Delayed 10Be dilution in detrital quartz following extensive coseismic landsliding: A 2016 Kaikōura earthquake case study

Publisher: Elsevier BV

Date: 03-2022

DOI: 10.1016/J.EPSL.2022.117392

Greening of the Earth and its drivers

Publisher: Springer Science and Business Media LLC

Date: 25-04-2016

DOI: 10.1038/NCLIMATE3004

Tropical tall forests are more sensitive and vulnerable to drought than short forests

Publisher: Wiley

Date: 09-12-2021

DOI: 10.1111/GCB.16017

Abstract: Our limited understanding of the impacts of drought on tropical forests significantly impedes our ability in accurately predicting the impacts of climate change on this biome. Here, we investigated the impact of drought on the dynamics of forest canopies with different heights using time‐series records of remotely sensed Ku‐band vegetation optical depth (Ku‐VOD), a proxy of top‐canopy foliar mass and water content, and separated the signal of Ku‐VOD changes into drought‐induced reductions and subsequent non‐drought gains. Both drought‐induced reductions and non‐drought increases in Ku‐VOD varied significantly with canopy height. Taller tropical forests experienced greater relative Ku‐VOD reductions during drought and larger non‐drought increases than shorter forests, but the net effect of drought was more negative in the taller forests. Meta‐analysis of in situ hydraulic traits supports the hypothesis that taller tropical forests are more vulnerable to drought stress due to smaller xylem‐transport safety margins. Additionally, Ku‐VOD of taller forests showed larger reductions due to increased atmospheric dryness, as assessed by vapor pressure deficit, and showed larger gains in response to enhanced water supply than shorter forests. Including the height‐dependent variation of hydraulic transport in ecosystem models will improve the simulated response of tropical forests to drought.

Two-dimensional needle-area density distribution within the crowns of Pinus radiata

Publisher: Elsevier BV

Date: 05-1990

DOI: 10.1016/0378-1127(90)90172-8

Theory of edge states in systems with Rashba spin-orbit coupling

Publisher: American Physical Society (APS)

Date: 30-12-2004

DOI: 10.1103/PHYSREVB.70.235344

Soil production and transport on postorogenic desert hillslopes quantified with 10Be and 26Al

Publisher: Geological Society of America

Date: 02-01-2018

DOI: 10.1130/B31767.1

Global soil organic carbon changes and economic revenues with biochar application

Publisher: Wiley

Date: 24-12-2021

DOI: 10.1111/GCBB.12915

Abstract: Biochar has been proposed as a promising negative CO 2 emission technology to mitigate future climate change with the additional benefit of increasing agricultural production. However, the spatial responses of soil organic carbon (SOC) to biochar addition in cropland are still uncertain, and the economic feasibility of large‐scale biochar implementation remains unclear. Here, we analyzed the response of SOC to biochar addition using 389 paired field measurements. The results show that biochar addition significantly increased SOC by 45.8% on average with large regional variations. Using a random forest model trained with soil, climate, biotic, biochar, and management factors, we found that the response of SOC to biochar addition was mainly dependent on biochar application rates, initial SOC, edaphic (e.g., pH), and climatic (e.g., mean annual precipitation) variables. Combined with the predicted SOC changes to biochar addition on the global cropland, we assessed the revenue of the biochar system based on the current and potential pyrolysis plants in the world using the life‐cycle analysis. Net revenue of the currently existing 144 pyrolysis plants increases with larger plant capacity and higher carbon price. Potential revenue of building new plants is high in regions like America and Europe but low in regions with infertile soil, low crop residues availability, and inconvenient transportation. The global CO 2 removal of biochar application is 6.6 Tg CO 2 e (CO 2 equivalent) year −1 with a net revenue of $ 177 million dollars at a carbon price of $ 50 t −1 CO 2 for current pyrolysis plants with a biomass‐processing capacity of 20,000 t year −1 . Our study provides a full economic assessment of idealized biochar addition scenarios and identifies the locations with maximal potential revenues with new pyrolysis plants.

Responses of two nonlinear microbial models to warming or increased carbon input

Publisher: Copernicus GmbH

Date: 07-09-2015

DOI: 10.5194/BGD-12-14647-2015

Abstract: Abstract. A number of nonlinear microbial models of soil carbon decomposition have been developed. Some of them have been applied globally but have yet to be shown to realistically represent soil carbon dynamics in the field. Therefore a thorough analysis of their key differences will be very useful for the future development of these models. Here we compare two nonlinear microbial models of soil carbon decomposition: one is based on reverse Michaelis-Menten kinetics (model A) and the other on regular Michaelis-Menten kinetics (model B). Using a combination of analytic solutions and numerical simulations, we find that the oscillatory responses of carbon pools model A to a small perturbation in the initial pool sizes have a higher frequency and d s faster than model B. In response to soil warming, soil carbon always decreases in model A but likely decreases in cool regions and increases in warm regions in model B. Maximum CO2 efflux from soil carbon decomposition (Fmax) after an increased carbon addition decreases with an increase in soil temperature in both models, and the sensitivity of Fmax to the amount of carbon input increases with soil temperature in model A but decreases monotonically with an increase in soil temperature in model B. These differences in the responses to soil warming and carbon input between the two nonlinear models can be used to differentiate which model is more realistic with field or laboratory experiments. This will lead to a better understanding of the significance of soil microbial processes in the responses of soil carbon to future climate change at regional or global scales.

Repeatability of anogenital distance measurements from birth to maturity and at different physiological states in female Holstein cattle

Publisher: American Dairy Science Association

Date: 03-2022

DOI: 10.3168/JDS.2021-21419

Abstract: The inverse association between anogenital distance (AGD the distance from the center of the anus to the base of the clitoris) and fertility, its moderate heritability, and high variability reported in dairy cattle make AGD a promising candidate for further exploration as a reproductive phenotype. In addition to heritability, repeatability (i.e., consistency in measurements taken at different time points) is important for a reproductive phenotype to be considered useful in genetic selection. Therefore, our primary objective was to determine the repeatability of AGD from birth to breeding age (≈16 mo) in Holstein heifer calves, and during different stages of the estrous cycle, gestation, and lactation in Holstein cows. We also determined the associations among AGD, height (at the hip), and body weight (BW) at birth. In calves (n = 48), we recorded BW (kg) and height (cm) at birth and measured AGD (mm) at approximately 0, 2, 6, 9, 12, and 16 mo of age. In cows, AGD was measured at different stages of the estrous cycle (proestrus, estrus, metestrus and diestrus n = 20), gestation (30, 90, 180, and 270 d n = 78), and lactation (30-300 d in milk in 30-d increments n = 30). Calf height and BW at birth had a weak positive association with AGD at birth. The AGD increased linearly from birth to breeding age, but there was no association between the AGD at birth and at breeding age in heifers. Although any 2 consecutive AGD measurements were correlated, 6 mo was the earliest age at which AGD was moderately correlated (r = 0.41) with that of breeding-age heifers. The AGD was neither influenced by the different stages of estrous cycle nor lactation and remained highly repeatable (r ≥ 0.95). Although AGD measurements at 30, 90, and 180 d of gestation (126.9, 126.7, and 127.7 mm, respectively) were strongly correlated (r ≥ 0.97) with each other, AGD at 270 d of gestation (142.8 mm) differed from AGD at all earlier stages of gestation. In summary, AGD measured at birth did not reflect AGD at breeding age in heifers, but AGD measurements in cows had high repeatability at all stages of the estrous cycle, gestation, and lactation, except at 270 d of gestation. Therefore, AGD could be measured reliably at any of the aforesaid physiological states in cows due to its high repeatability, except during late gestation. The earliest gestational stage when pregnancy-associated increase in AGD occurred, however, could not be definitively established in the present study.

Using atmospheric CO₂ data to assess a simplified carbon-climate simulation for the 20th century

Publisher: Stockholm University Press

Date: 2006

DOI: 10.1111/J.1600-0889.2006.00198.X

Responses of soil buffering capacity to acid treatment in three typical subtropical forests

Publisher: Elsevier BV

Date: 09-2016

DOI: 10.1016/J.SCITOTENV.2016.04.198

Abstract: Elevated anthropogenic acid deposition can significantly affect forest ecosystem functioning by changing soil pH, nutrient balance, and chemical leaching and so on. These effects generally differ among different forests, and the dominant mechanisms for those observed responses often vary, depending on climate, soil conditions and vegetation types. Using soil monoliths (0-40cm) from pine forest (pioneer), coniferous and broadleaved mixed forest (transitional) and broadleaved forest (mature) in southern China, we conducted a leaching experiment with acid treatments at different pH levels (control: pH≈4.5 pH=3.5 pH=2.5). We found that pH3.5 treatment significantly reduced dissolved organic carbon (DOC) concentrations in leachate from the pioneer forest soil. pH2.5 treatment significantly increased concentrations of NO3(-), SO4(2-), Ca(2+), Mg(2+), Al(3+), Fe(3+) and DOC in leachate from the pioneer forest soil, and also concentrations of NO3(-), SO4(2-), Mg(2+), Al(3+), Fe(3+) and DOC in leachate from the transitional forest soil. All acid treatments had no significant effects on concentrations of these chemicals in leachate from the mature forest soil. The responses can be explained by the changes in soil pH, acid neutralizing capacity (ANC) and concentrations of Al and Fe. Our results showed that acid buffering capacity of the pioneer or transitional forest soil was lower than that of the mature forest soil. Therefore preserving mature forests in southern China is important for reducing the adverse impacts of high acid deposition on stream water quality at present and into the future.

Linear and nonlinear effects of dominant drivers on the trends in global and regional land carbon uptake: 1959 to 2013

Publisher: American Geophysical Union (AGU)

Date: 25-02-2016

DOI: 10.1002/2015GL067162

Cosmogenic evidence for limited local LGM glacial expansion, Denton Hills, Antarctica

Publisher: Elsevier BV

Date: 12-2017

DOI: 10.1016/J.QUASCIREV.2017.11.002

Nitrogen Deposition Maintains a Positive Effect on Terrestrial Carbon Sequestration in the 21st Century Despite Growing Phosphorus Limitation at Regional Scales

Publisher: American Geophysical Union (AGU)

Date: 06-2019

DOI: 10.1029/2018GB005952

Beryllium isotope signatures of ice shelves and sub-ice shelf circulation

Publisher: Elsevier BV

Date: 2019

DOI: 10.1016/J.EPSL.2018.10.004

A unifying framework for dinitrogen fixation in the terrestrial biosphere

Publisher: Springer Science and Business Media LLC

Date: 07-2008

DOI: 10.1038/NATURE07028

Abstract: Dinitrogen (N(2)) fixation is widely recognized as an important process in controlling ecosystem responses to global environmental change, both today and in the past however, significant discrepancies exist between theory and observations of patterns of N(2) fixation across major sectors of the land biosphere. A question remains as to why symbiotic N(2)-fixing plants are more abundant in vast areas of the tropics than in many of the mature forests that seem to be nitrogen-limited in the temperate and boreal zones. Here we present a unifying framework for terrestrial N(2) fixation that can explain the geographic occurrence of N(2) fixers across erse biomes and at the global scale. By examining trade-offs inherent in plant carbon, nitrogen and phosphorus capture, we find a clear advantage to symbiotic N(2) fixers in phosphorus-limited tropical savannas and lowland tropical forests. The ability of N(2) fixers to invest nitrogen into phosphorus acquisition seems vital to sustained N(2) fixation in phosphorus-limited tropical ecosystems. In contrast, modern-day temperatures seem to constrain N(2) fixation rates and N(2)-fixing species from mature forests in the high latitudes. We propose that an analysis that couples biogeochemical cycling and biophysical mechanisms is sufficient to explain the principal geographical patterns of symbiotic N(2) fixation on land, thus providing a basis for predicting the response of nutrient-limited ecosystems to climate change and increasing atmospheric CO(2).

Nonlinear interactions of land carbon cycle feedbacks in Earth System Models

Publisher: Wiley

Date: 05-11-2021

DOI: 10.1111/GCB.15953

Abstract: Carbon cycle feedbacks were often quantified through the carbon–concentration and carbon–climate feedbacks with the assumption of no significant interaction between the two feedbacks in most previous studies. Here we calculated the strength of the interactions between the two responses using simulations of models participated in the phase 6 of the Coupled Model Intercomparison Project (CMIP6). We found that the nonlinear interaction contributed 11% of the land–atmosphere carbon exchange on average with large intermodel variation (from −20% to +162%). This nonlinear interaction is largely driven by the pattern of net primary production (NPP), with shifts in heterotrophic respiration that d en the overall positive interactions from NPP. Photosynthetic rate per unit leaf area alone cannot adequately explain a wide variation of interactions in global NPP simulated by CMIP6 models. Plant respiration and processes that regulate leaf area are also important contributors to the interactions. Dominant factors that induce carbon–concentration and carbon–climate interactions are highly variable among models. One of those dominant factors is nutrient limitation. Using additional simulations of ACCESS‐ESM1.5 that include both nitrogen and phosphorus limitation, we found that the estimated interactions by ACCESS‐ESM1.5 with or without nutrient limitations covered the large intermodel variations among the CMIP6 models. It remains largely unknown how nutrient limitation complicates ecosystem's responses to simultaneously CO 2 fertilization and warming at the global scale. Our modeling results point to a potential important role of nutrients, especially phosphorus on the nonlinear interactions. Yet, more studies are needed on ecosystem responses to concurrent changes in nutrient availability, atmospheric CO 2 concentration, and warming.

CO₂ fertilization is spatially distinct from stomatal conductance reduction in controlling ecosystem water-use efficiency increase

Publisher: IOP Publishing

Date: 05-2022

DOI: 10.1088/1748-9326/AC6C9C

Abstract: It is well known that global ecosystem water-use efficiency (EWUE) has noticeably increased over the last several decades. However, it remains unclear how in idual environmental drivers contribute to EWUE changes, particularly from CO 2 fertilization and stomatal suppression effects. Using a satellite-driven water–carbon coupling model—Penman–Monteith–Leuning version 2 (PML-V2), we quantified in idual contributions from the observational drivers (atmospheric CO 2 , climate forcing, leaf area index (LAI), albedo and emissivity) across the globe over 1982–2014. The PML-V2 was well-calibrated and showed a good performance for simulating EWUE (with a determination coefficient ( R 2 ) of 0.56) compared to observational annual EWUE over 1982–2014 derived from global 95 eddy flux sites from the FLUXNET2015 dataset. Our results showed that global EWUE increasing trend (0.04 ± 0.004 gC mm −1 H 2 O decade −1 ) was largely contributed by increasing CO 2 (51%) and LAI (20%), but counteracted by climate forcing (−26%). Globally, the CO 2 fertilization effect on photosynthesis (23%) was similar to the CO 2 suppression effect on stomatal conductance (28%). Spatially, the fertilization effect dominated EWUE trend over semi-arid regions while the stomatal suppression effect controlled over tropical forests. These findings improve understanding of how environmental factors affect the long-term change of EWUE, and can help policymakers for water use planning and ecosystem management.

Development of a multi-method chronology spanning the Last Glacial Interval from Orakei maar lake, Auckland, New Zealand

Publisher: Copernicus GmbH

Date: 05-08-2020

DOI: 10.5194/GCHRON-2020-23

Abstract: Abstract. Northern New Zealand is an important site for understanding Last Glacial Interval (LGI) paleoclimate dynamics, since it is influenced by both tropical and polar climate systems which have varied in relative strength and timing of associated changes. The Auckland Volcanic Field maar lakes preserve these climatic influences on the regional paleoenvironment, as well as past volcanic eruptions, in their sedimentary infill. The sediment sequence infilling Orakei maar lake is continuous, laminated, high-resolution and provides a robust archive from which to investigate the dynamic nature of the northern New Zealand climate system over the LGI. Here we present the chronological framework for the Orakei maar sediment sequence. Our chronology was developed combining Bayesian age modelling of combined radiocarbon ages, tephrochronology of known-age rhyolitic tephra marker layers, 40Ar/39Ar-dated eruption age of a local basaltic volcano, luminescence dating (using post infrared-infrared stimulated luminescence, or pIR-IRSL), and the timing of the Lasch paleomagnetic excursion. We also investigated the application of meteoric (cosmogenic) Beryllium-10 variability to improve the age-depth model by complementing relative paleointensity measurements. However, the results were apparently influenced by some unaccounted catchment process and unable to reach satisfactory interpretation, apart from confirming the presence of the Lasch excursion, and therefore the 10Be data are not used in the production of the final age model. We have integrated our absolute chronology with tuning of the relative paleointensity record of the Earth’s magnetic field to a global reference curve (PISO-1500). The maar-forming phreatomagmatic eruption of the Orakei maar is now dated to 130,120 yr (95 % confidence range 128,665 to 131,560 yr). Our new chronology facilitates high-resolution paleoenvironmental reconstruction for northern New Zealand spanning the last ca. 130,000 years for the first time as most NZ records that spall all or parts of the LGI are fragmentary, low-resolution and poorly dated. Providing this chronological framework for LGI climate events inferred from the Orakei sequence is of paramount importance in the context of identification of leads and lags in different components of the Southern Hemisphere climate system as well as identification of Northern Hemisphere climate signals.

Australian desert dune fields initiated with Pliocene - Pleistocene global climatic shift

Publisher: Geological Society of America

Date: 2009

DOI: 10.1130/G25042A.1

GOLUM-CNP v1.0: a data-driven modeling of carbon, nitrogen and phosphorus cycles in major terrestrial biomes

Publisher: Copernicus GmbH

Date: 22-03-2018

DOI: 10.5194/GMD-2018-23

Abstract: Abstract. Global terrestrial nitrogen (N) and phosphorus (P) cycles are coupled to the global carbon (C) cycle for net primary production (NPP), plant C allocation and decomposition of soil organic matter, but N and P have distinct pathways of inputs and losses. Current C-nutrient models exhibit large uncertainties in their estimates of pool sizes, fluxes and turnover rates of nutrients, due to a lack of consistent global data for evaluating the models. In this study, we present a new model-data fusion framework called Global Observation-based Land-ecosystems Utilization Model of Carbon, Nitrogen and Phosphorus (GOLUM-CNP) that combines the CARbon DAta MOdel fraMework (CARDAMOM) data-constrained C-cycle analysis with spatially explicit data-driven estimates of N and P inputs and losses and with observed stoichiometric ratios. We calculated the steady-state N- and P-pool sizes and fluxes globally for large biomes. Our study showed that new N inputs from biological fixation and deposition supplied 20 % of total plant uptake in most forest ecosystems but accounted for smaller fractions in boreal forests and grasslands. New P inputs from atmospheric deposition and rock weathering supplied a much smaller fraction of total plant uptake than new N inputs, indicating that the terrestrial C sink may ultimately be constrained by low P. Nutrient-use efficiency, defined as the ratio of gross primary production (GPP) to plant nutrient uptake, can be diagnosed from our model results and compared between biomes. Tropical forests had the lowest N-use efficiency and the highest P-use efficiency of the forest biomes. An analysis of sensitivity and uncertainty indicated that the NPP-allocation fractions to leaves, roots and wood contributed the most to the uncertainties in the estimates of nutrient-use efficiencies. Correcting for biases in NPP-allocation fractions produced more plausible gradients of N- and P-use efficiencies from tropical to boreal ecosystems and highlighted the critical role of accurate measurements of C allocation for understanding the N and P cycles.

Dephasing and hyperfine interaction in carbon nanotube double quantum dots: The clean limit

Publisher: American Physical Society (APS)

Date: 21-11-2011

DOI: 10.1103/PHYSREVB.84.205449

A test of an optimal stomatal conductance scheme within the CABLE land surface model

Publisher: Copernicus GmbH

Date: 24-02-2015

DOI: 10.5194/GMD-8-431-2015

Abstract: Abstract. Stomatal conductance (gs) affects the fluxes of carbon, energy and water between the vegetated land surface and the atmosphere. We test an implementation of an optimal stomatal conductance model within the Community Atmosphere Biosphere Land Exchange (CABLE) land surface model (LSM). In common with many LSMs, CABLE does not differentiate between gs model parameters in relation to plant functional type (PFT), but instead only in relation to photosynthetic pathway. We constrained the key model parameter "g1", which represents plant water use strategy, by PFT, based on a global synthesis of stomatal behaviour. As proof of concept, we also demonstrate that the g1 parameter can be estimated using two long-term average (1960–1990) bioclimatic variables: (i) temperature and (ii) an indirect estimate of annual plant water availability. The new stomatal model, in conjunction with PFT parameterisations, resulted in a large reduction in annual fluxes of transpiration (~ 30% compared to the standard CABLE simulations) across evergreen needleleaf, tundra and C4 grass regions. Differences in other regions of the globe were typically small. Model performance against upscaled data products was not degraded, but did not noticeably reduce existing model–data biases. We identified assumptions relating to the coupling of the vegetation to the atmosphere and the parameterisation of the minimum stomatal conductance as areas requiring further investigation in both CABLE and potentially other LSMs. We conclude that optimisation theory can yield a simple and tractable approach to predicting stomatal conductance in LSMs.

Importance of background climate in determining impact of land-cover change on regional climate

Publisher: Springer Science and Business Media LLC

Date: 20-11-2011

DOI: 10.1038/NCLIMATE1294

Timing of Pleistocene glaciations in the High Atlas, Morocco: New 10Be and 36Cl exposure ages

Publisher: Elsevier BV

Date: 2018

DOI: 10.1016/J.QUASCIREV.2017.11.015

Global cooling intiated stony deserts in central Australia 2-4 Ma, dated by cosmogenic 21Ne-10Be

Publisher: Geological Society of America

Date: 2005

DOI: 10.1130/G21746.1

Relationship of anogenital distance with fertility in nulliparous Holstein heifers

Publisher: American Dairy Science Association

Date: 07-2021

DOI: 10.3168/JDS.2020-19940

Parameter estimation in surface exchange models using nonlinear inversion: how many parameters can we estimate and which measurements are most useful?

Publisher: Wiley

Date: 05-2001

DOI: 10.1046/J.1365-2486.2001.00434.X

Supplementary material to "Estimating global gross primary productivity using chlorophyll fluorescence and a data assimilation system with the BETHY-SCOPE model"

Publisher: Copernicus GmbH

Date: 21-06-2018

DOI: 10.5194/BG-2018-270-SUPPLEMENT

Charactering Light and Temperature Effects on Rice Grain Filling Using Extended Richards' Equation

Publisher: China Science Publishing & Media Ltd.

Date: 2014

DOI: 10.3724/SP.J.1006.2014.01776

Effects of 14-year continuous nitrogen addition on soil arylsulfatase and phosphodiesterase activities in a mature tropical forest

Publisher: Elsevier BV

Date: 06-2020

DOI: 10.1016/J.GECCO.2020.E00934

Predicting long‐term carbon sequestration in response to CO₂ enrichment: How and why do current ecosystem models differ?

Publisher: American Geophysical Union (AGU)

Date: 04-2015

DOI: 10.1002/2014GB004995

²⁶Al/¹⁰Be ratios reveal the source of river sediments in the Kimberley, NW Australia

Publisher: Wiley

Date: 05-12-2019

DOI: 10.1002/ESP.4744

Contribution of Litter Layer to Greenhouse Gas Fluxes between Atmosphere and Soil Varies with Forest Succession

Publisher: MDPI AG

Date: 31-03-2022

DOI: 10.3390/F13040544

Abstract: Surface litter layer strongly influences CO2, N2O, and CH4 fluxes (FCO2, FN2O, and FCH4) between the atmosphere and forest floor through litter decomposition (litter-internal, fL-L) or interactions between litter and mineral soil (litter-induced, fL-S). However, the relative contribution of fL-L or fL-S to these greenhouse gas (GHG) fluxes in forests at different succession stages remain unclear. We conducted a field experiment where surface litter was either removed (LR), left intact (CT), doubled (LD), or exchanged (LE) in a Masson pine forest (PF, early stage of succession) and an evergreen broadleaved forest (BF, climax of succession) at the Dinghushan Nature Reserve in southern China, and studied the responses of FCO2, FN2O, and FCH4 from August 2012 to July 2013. The results showed that both FCO2 and FN2O were increased by LD treatment with a greater increase in BF (41% for FCO2 and 30% for FN2O) and decreased by LR treatment with the greater decrease in PF (−61% for FCO2 and −58% for FN2O). LD treatment decreased FCH4 by 14% in PF and 6% in BF, and LR treatment increased FCH4 by 5% in PF and 18% in BF. fL-S contributed more to FCO2 (36%) and FN2O (45%) than fL-L in PF, whereas contributions of fL-L to FCO2 (41%) and FN2O (30%) were much bigger than fL-S in BF. The greater FCH4 in PF and BF resulted from the contributions of fL-L (−14%) and fL-S (−12%), respectively. Our results indicated that fL-L is the major source of GHG fluxes in BF, whereas fL-S dominates GHG fluxes in PF. The results provide a scientific reference for quantifying the contributions of fL-L and fL-S to GHG fluxes during the subtropical forest succession and should be considered in ecosystem models to predict global warming in the future.

Inhibitive Effects of Recent Exceeding Air Temperature Optima of Vegetation Productivity and Increasing Water Limitation on Photosynthesis Reversed Global Greening

Publisher: American Geophysical Union (AGU)

Date: 11-2022

DOI: 10.1029/2022EF002788

Abstract: Global terrestrial vegetation dynamics have been rapidly altered by climate change. A widespread vegetation greenness over a large part of the planet from the 1980s to early this century has been reported, whereas weakening of CO 2 fertilization effects and increasing climate extremes and the adverse impact of increasing rate of warming and severity of drought on vegetation growth were also reported. Earth system models project that the land carbon sink will decrease in size in response to an increase in warming during this century. How global vegetation is changing during this century in response to global warming and water availability across spatial and temporal scales remains uncertain. Our understanding of the widespread vegetation greening or browning processes and identifying the biogeochemical mechanisms remain incomplete. Here we use multiple long‐term satellite leaf area index (LAI) records to investigate vegetation growth trends from 1982 to 2018. We find that the widespread increase of growing‐season integrated LAI (greening) since 1980s was reversed ( p ‐value 0.05) around the year 2000 over 90% of the global vegetated area, and continued in only 10% of the global vegetated area. The reversal of greening trend was largely explained by the inhibitive effects of excessive optimal temperature on photosynthesis in most of the tropics and low latitudes, and by increasing water limitation (increasing in atmospheric vapor pressure deficit and decreasing in soil water availability) in the northern high latitudes ( °N). Overall, the reversal of greening trend since 2000 weakened the negative feedback of carbon sequestration on the climatic system and should be considered in the strategies for climate warming mitigation and adaptation. Our findings of the ersity of processes that drive browning across bioclimatic‐zones and ecosystems and of how those driving processes are changing would enhance our ability to project global future vegetation change and its climatic and abiotic consequences.

Greenhouse Gas Concentration and Volcanic Eruptions Controlled the Variability of Terrestrial Carbon Uptake Over the Last Millennium

Publisher: American Geophysical Union (AGU)

Date: 06-2019

DOI: 10.1029/2018MS001566

Inversion of diurnally varying synthetic CO₂: Network optimization for an Australian test case

Publisher: American Geophysical Union (AGU)

Date: 03-2004

DOI: 10.1029/2003GB002136

Forest management practices and policies exert strong impacts on the spatio-temporal variations of forest disturbance in Hunan Province, China over the last three decades

Publisher: Elsevier BV

Date: 09-2023

DOI: 10.1016/J.FORECO.2023.121167

Tracking the <sup>26</sup>Al/<sup>10</sup>Be source-area signal in sediment-routing systems of arid central Australia

Publisher: Copernicus GmbH

Date: 16-01-2018

DOI: 10.5194/ESURF-2017-76

Abstract: Abstract. Sediment-routing systems continuously transfer information and mass from eroding source areas to depositional sinks. Understanding how these systems alter environmental signals is critical when it comes to inferring source-area properties from the sedimentary record. We measure cosmogenic 10Be and 26Al along three large sediment-routing systems (~ 100,000 km2) in central Australia with the aim of tracking downstream variations in 26Al/10Be inventories and to identify the factors responsible. By comparing 56 new cosmogenic 10Be and 26Al measurements in stream sediments with matching data (n = 55) from source areas, we show that 26Al/10Be inventories in hillslope bedrock and soils set the benchmark for relative downstream modifications. Lithology is the primary determinant of erosion-rate variations in source areas and despite sediment mixing over hundreds of kilometres downstream a distinct lithological signal is retained. Postorogenic ranges yield catchment erosion rates of ~ 6–11 m/m.y. and silcrete-dominant areas erode as slow as ~ 0.2 m/m.y. 26Al/10Be inventories in stream-sediments reveal overall downstream-increasing minimum cumulative burial terms up to ~ 1.1 m.y. but more generally ~ 400–800 k.y. The magnitude of the burial signal correlates with increasing sediment cover downstream and reflects assimilation from storages with long exposure histories, such as alluvial fans, desert pavements, alluvial plains, and aeolian dunes. We propose that the tendency for large alluvial rivers to mask their 26Al/10Be source-area signal differs according to geomorphic setting. Signal preservation is favoured by i) high sediment supply rates, ii) high mean runoff, and iii) a thick sedimentary basin pile. Conversely, signal masking prevails in landscapes of i) low sediment supply, ii) discontinuous sediment flux, and iii) juxtaposition of sediment storages with notably different exposure histories.

Issues in Modelling Plant Ecosystem Responses to Elevated CO2: Interactions with Soil Nitrogen

Publisher: Wiley

Date: 10-10-2007

DOI: 10.1002/9780470988695.CH8

Anogenital distance is associated with postpartum estrous activity, intensity of estrous expression, ovulation, and progesterone concentrations in lactating Holstein cows

Publisher: American Dairy Science Association

Date: 10-2022

DOI: 10.3168/JDS.2022-21897

Abstract: The objectives of this retrospective observational study were to determine the associations of anogenital distance (AGD) with (a) postpartum estrous activity, (b) diameter of the preovulatory follicle, (c) intensity of estrous expression, (d) postestrus ovulation, (e) corpus luteum (CL) size, and (f) concentrations of progesterone at estrus and on d 7 after estrus. Lactating Holstein cows (n = 178 55 primiparous, 123 multiparous) were enrolled into the study during the first postpartum week. All cows were continuously monitored by a pedometer-based automated activity monitoring (AAM) system for estrus. Postpartum estrous activity was assessed using the AAM estrus alerts, in which cows with at least one true estrus alert (i.e., a relative increase in steps from each cow's baseline detected by the AAM and the presence of at least one follicle >15 mm, a CL 60 DIM, ovulation was determined by ultrasound at 24 h, 48 h, and 7 d after estrus, and blood s les were collected at estrus alert and on d 7 after estrus for progesterone analysis. The AGD was measured from the center of the anus to the base of the clitoris and classified as either short- or long-AGD using 2 cut-points of 148 mm (predictive of the probability of pregnancy to first insemination short-AGD, n = 115 long-AGD, n = 63) and 142 mm (the median AGD short-AGD, n = 90 long-AGD, n = 88). Regardless of the cut-point used, early postpartum estrous activity by 50 DIM (67 vs. 54%), duration of estrus (11.6 vs. 9.7 h), and preovulatory follicle diameter (20 vs. 19 mm) were greater in short-AGD than in long-AGD cows. Increased peak of activity at estrus in short-AGD cows (354 vs. 258% mean relative increase) was affected by an interaction between AGD and parity in which multiparous long-AGD cows had lesser relative increase in activity than primiparous cows (217 vs. 386%, respectively). Mean progesterone concentration at estrus was lesser in short-AGD (0.47 vs. 0.61 ng/mL) than in long-AGD cows. The ovulatory response at 24 h did not differ, but at 48 h (91 vs. 78%) and on d 7 after estrus (97 vs. 84%) it was greater in short-AGD cows. Although CL diameter on d 7 after estrus did not differ, short-AGD cows had greater progesterone concentration 7 d after estrus than long-AGD cows (4.1 vs. 3.2 ng/mL, respectively). In conclusion, greater proportions of short-AGD cows commenced estrous activity by 50 DIM, had larger preovulatory follicles, exhibited greater duration of estrus, had reduced progesterone concentration at estrus, had greater ovulation rates and progesterone concentration 7 d after estrus compared with long-AGD cows, with no difference in CL size between AGD groups. Because all the differences in physiological characteristics of short-AGD cows reported herein favor improved reproductive outcomes, we infer that these are factors contributing to improved fertility reported in short-AGD cows compared with long-AGD cows.

Improving land surface models with FLUXNET data

Publisher: Copernicus GmbH

Date: 30-07-2009

DOI: 10.5194/BG-6-1341-2009

Abstract: Abstract. There is a growing consensus that land surface models (LSMs) that simulate terrestrial biosphere exchanges of matter and energy must be better constrained with data to quantify and address their uncertainties. FLUXNET, an international network of sites that measure the land surface exchanges of carbon, water and energy using the eddy covariance technique, is a prime source of data for model improvement. Here we outline a multi-stage process for "fusing" (i.e. linking) LSMs with FLUXNET data to generate better models with quantifiable uncertainty. First, we describe FLUXNET data availability, and its random and systematic biases. We then introduce methods for assessing LSM model runs against FLUXNET observations in temporal and spatial domains. These assessments are a prelude to more formal model-data fusion (MDF). MDF links model to data, based on error weightings. In theory, MDF produces optimal analyses of the modelled system, but there are practical problems. We first discuss how to set model errors and initial conditions. In both cases incorrect assumptions will affect the outcome of the MDF. We then review the problem of equifinality, whereby multiple combinations of parameters can produce similar model output. Fusing multiple independent and orthogonal data provides a means to limit equifinality. We then show how parameter probability density functions (PDFs) from MDF can be used to interpret model validity, and to propagate errors into model outputs. Posterior parameter distributions are a useful way to assess the success of MDF, combined with a determination of whether model residuals are Gaussian. If the MDF scheme provides evidence for temporal variation in parameters, then that is indicative of a critical missing dynamic process. A comparison of parameter PDFs generated with the same model from multiple FLUXNET sites can provide insights into the concept and validity of plant functional types (PFT) – we would expect similar parameter estimates among sites sharing a single PFT. We conclude by identifying five major model-data fusion challenges for the FLUXNET and LSM communities: (1) to determine appropriate use of current data and to explore the information gained in using longer time series (2) to avoid confounding effects of missing process representation on parameter estimation (3) to assimilate more data types, including those from earth observation (4) to fully quantify uncertainties arising from data bias, model structure, and initial conditions problems and (5) to carefully test current model concepts (e.g. PFTs) and guide development of new concepts.

Estimating regional terrestrial carbon fluxes for the Australian continent using a multiple-constraint approach. II. The Atmospheric constraint

Publisher: Stockholm University Press

Date: 04-2003

DOI: 10.1034/J.1600-0889.2003.00030.X

Humanitarian Intervention and R2P

Publisher: Brill

Date: 08-04-2020

DOI: 10.1163/18754112-0220104019

Abstract: In this piece, Henderson looks to the shadow of Rwanda in terms of the concept of humanitarian intervention, and the evolution of the R2P doctrine. Tracing the re-examination of the conceptualisations of sovereignty and the principle of non-intervention that evolved after Rwanda, Henderson assesses the legal, normative, and institutional challenges that still attend the attainment of its goals. Henderson concludes on a note of cautious optimism: Although it is in no way a panacea, R2P – at the very least – raises the possibility that a greater range of measures may be taken in response to the commission, or anticipation of, atrocity crimes in the future. The legacy of Rwanda is the hope, reflected in R2P, that silence and idleness will never again be the international community’s response to genocide.

GOLUM-CNP v1.0: a data-driven modeling of carbon, nitrogen and phosphorus cycles in major terrestrial biomes

Publisher: Copernicus GmbH

Date: 27-09-2018

DOI: 10.5194/GMD-11-3903-2018

Abstract: Abstract. Global terrestrial nitrogen (N) and phosphorus (P) cycles are coupled to the global carbon (C) cycle for net primary production (NPP), plant C allocation, and decomposition of soil organic matter, but N and P have distinct pathways of inputs and losses. Current C-nutrient models exhibit large uncertainties in their estimates of pool sizes, fluxes, and turnover rates of nutrients, due to a lack of consistent global data for evaluating the models. In this study, we present a new model–data fusion framework called the Global Observation-based Land-ecosystems Utilization Model of Carbon, Nitrogen and Phosphorus (GOLUM-CNP) that combines the CARbon DAta MOdel fraMework (CARDAMOM) data-constrained C-cycle analysis with spatially explicit data-driven estimates of N and P inputs and losses and with observed stoichiometric ratios. We calculated the steady-state N- and P-pool sizes and fluxes globally for large biomes. Our study showed that new N inputs from biological fixation and deposition supplied % of total plant uptake in most forest ecosystems but accounted for smaller fractions in boreal forests and grasslands. New P inputs from atmospheric deposition and rock weathering supplied a much smaller fraction of total plant uptake than new N inputs, indicating the importance of internal P recycling within ecosystems to support plant growth. Nutrient-use efficiency, defined as the ratio of gross primary production (GPP) to plant nutrient uptake, were diagnosed from our model results and compared between biomes. Tropical forests had the lowest N-use efficiency and the highest P-use efficiency of the forest biomes. An analysis of sensitivity and uncertainty indicated that the NPP-allocation fractions to leaves, roots, and wood contributed the most to the uncertainties in the estimates of nutrient-use efficiencies. Correcting for biases in NPP-allocation fractions produced more plausible gradients of N- and P-use efficiencies from tropical to boreal ecosystems and highlighted the critical role of accurate measurements of C allocation for understanding the N and P cycles.

Space dispute resolution mechanism

Publisher: Springer Singapore

Date: 2021

DOI: 10.1007/978-981-15-8924-9_8

Geomorphic imprint of dynamic topography and intraplate tectonism in central Australia

Publisher: Copernicus GmbH

Date: 23-03-2020

DOI: 10.5194/EGUSPHERE-EGU2020-20252

Abstract: & & The mantle convection accompanying plate motion causes vertical movements of up to a few hundred metres at Earth& #8217 s surface over wavelengths of 10& sup& & /sup& & #8211 & sup& & /sup& km. This & em& dynamic topography& /em& appears to come and go at ~ 1& #8211 Myr timescales in areas that are often well away from plate margins, although its spatial and temporal characteristics are subject to ongoing debate. Since such motions are small and transient, discriminating convective signals from other drivers of relief generation and/or sediment dispersal remains tricky. An outstanding challenge is to detect these elusive, transient undulations from a tell-tale geomorphic imprint preserved in either drainage patterns or the stratigraphic record.& & & & In the intra-plate setting of central Australia, a 30 km long sinuous gorge is developed where the major regional drainage, Finke River, dissects a band of low hills. Remarkably, this gorge is intertwined with an abandoned and less deeply incised gorge that forms hanging junctions and shares similar width and sinuosity. This unusual overprinting of the two gorges remains unexplained.& & & & With an aim to investigate the history of the intertwined gorges, we measured cosmogenic & sup& & /sup& Be and & sup& & /sup& Al in fluvial gravels stored in the palaeovalley cutoffs. The gravels are remnants of major alluviation episodes that we surmise result from ongoing vertical motions associated with dynamic topography. We use a Markov chain Monte Carlo-based inversion model to test two hypotheses to explain the nuclide inventory contained within the stored fluvial gravels. In the first case, rapid alluviation and erosion since 1 Ma preserves the nuclide memory of the source area in the second, the nuclide memory is erased during long-term fluvial storage (& 5 Myr) and is restored during exhumation of the palaeovalley gravel-pile. The two hypotheses are therefore limiting-case scenarios that constrain overall fast versus slow landscape evolution, respectively. Our model results suggest that long-term burial decouples the source-area signal from nuclide abundances measured in the palaeovalley gravels. This casts events into a Miocene timescale.& &

Neural Error Regression Diagnosis (NERD): A Tool for Model Bias Identification and Prognostic Data Assimilation

Publisher: American Meteorological Society

Date: 02-2006

DOI: 10.1175/JHM479.1

Abstract: Data assimilation in the field of predictive land surface modeling is generally limited to using observational data to estimate optimal model states or restrict model parameter ranges. To date, very little work has attempted to systematically define and quantify error resulting from a model's inherent inability to simulate the natural system. This paper introduces a data assimilation technique that moves toward this goal by accounting for those deficiencies in the model itself that lead to systematic errors in model output. This is done using a supervised artificial neural network to “learn” and simulate systematic trends in the model output error. These simulations in turn are used to correct the model's output each time step. The technique is applied in two case studies, using fluxes of latent heat flux at one site and net ecosystem exchange (NEE) of carbon dioxide at another. Root-mean-square error (rmse) in latent heat flux per time step was reduced from 27.5 to 18.6 W m−2 (32%) and monthly from 9.91 to 3.08 W m−2 (68%). For NEE, rmse per time step was reduced from 3.71 to 2.70 μmol m−2 s−1 (27%) and annually from 2.24 to 0.11 μmol m−2 s−1 (95%). In both cases the correction provided significantly greater gains than single criteria parameter estimation on the same flux.

Deficiencies of Phenology Models in Simulating Spatial and Temporal Variations in Temperate Spring Leaf Phenology

Publisher: American Geophysical Union (AGU)

Date: 03-2022

DOI: 10.1029/2021JG006421

Abstract: Spring leaf phenology and its response to climate change have crucial effects on surface albedo, carbon balance, and the water cycle of terrestrial ecosystems. Based on long‐term (period 1963 – 2014) in situ observations of budburst date and leaf unfolding date of more than 300 deciduous woody species from 32 sites across the temperate zone in China, we conducted model‐data comparison of spatial and temporal variations for spring leaf phenology calculated using the phenology modules that were embed into 10 existing terrestrial ecosystem models. Our results suggested that ORganizing Carbon and Hydrology in Dynamic EcosystEms and Spatially Explicit In idual‐Based performed the best in reproducing the spatial patterns of spring leaf phenology, but tended to underestimate the temporal variations in responding to temperature warming, showing low interannual variability (IAV) and temperature sensitivity ( S T ). In contrast, the performances of Vegetation Integrated SImulator for Trace Gases were the best in modeling IAV and S T . BIOME3, Lund‐Potsdam‐Jena model, Joint UK Land Environment Simulator, BioGeochemical Cycles, Community Land Model, Integrated Biosphere Simulator, and Commonwealth Scientific and Industrial Research Organisation Atmosphere Biosphere Land Exchange Model failed to reproduce both the spatial and temporal patterns. Using temperature series (1960 – 2100) form Coupled Model Intercomparison Project Number 6 scenarios to force the 10 phenology modules, our results highlighted large uncertainties in predicting spring leaf phenology changes with the warming climate, and more work is required to deal with the deficiencies of phenology model parameters and algorithms.

Carbon balance of young birch trees grown in ambient and elevated atmospheric CO₂ concentrations

Publisher: Wiley

Date: 12-1998

DOI: 10.1046/J.1365-2486.1998.00170.X

OptIC project: An intercomparison of optimization techniques for parameter estimation in terrestrial biogeochemical models

Publisher: American Geophysical Union (AGU)

Date: 06-2007

DOI: 10.1029/2006JG000367

Implementation of an optimal stomatal conductance model in the Australian Community Climate Earth Systems Simulator (ACCESS1.3b)

Publisher: Copernicus GmbH

Date: 03-07-2015

DOI: 10.5194/GMDD-8-5235-2015

Abstract: Abstract. We implement a new stomatal conductance model, based on the optimality approach, within the Community Atmosphere Biosphere Land Exchange (CABLE) land surface model. Coupled land-atmosphere simulations are then performed using CABLE within the Australian Community Climate and Earth Systems Simulator (ACCESS) with prescribed sea surface temperatures. As in most land surface models, the default stomatal conductance scheme only accounts for differences in model parameters in relation to the photosynthetic pathway, but not in relation to plant functional types. The new scheme allows model parameters to vary by plant functional type, based on a global synthesis of observations of stomatal conductance under different climate regimes over a wide range of species. We show that the new scheme reduces the latent heat flux from the land surface over the boreal forests during the Northern Hemisphere summer by 0.5 to 1.0 mm day-1. This leads to warmer daily maximum and minimum temperatures by up to 1.0 °C and warmer extreme maximum temperatures by up to 1.5 °C. These changes generally improve the climate model's climatology and improve existing biases by 10–20 %. The change in the surface energy balance also affects net primary productivity and the terrestrial carbon balance. We conclude that the improvements in the global climate model which result from the new stomatal scheme, constrained by a global synthesis of experimental data, provide a valuable advance in the long-term development of the ACCESS modelling system.

Anti-Müllerian hormone in grazing dairy cows: Identification of factors affecting plasma concentration, relationship with phenotypic fertility, and genome-wide associations

Publisher: American Dairy Science Association

Date: 12-2019

DOI: 10.3168/JDS.2019-16979

Abstract: The objectives of this study were to (1) characterize the distribution and variability of plasma anti-Müllerian hormone (AMH) concentration (2) evaluate factors associated with phenotypic variation in plasma AMH (3) examine the associations between categories of plasma AMH and reproductive outcomes [pregnancy to first artificial insemination (P/AI), and pregnancy rates within 21, 42, and 84 d after the mating start date (MSD)] (4) estimate pedigree and genomic heritability for plasma AMH and (5) identify and validate SNP associated with phenotypic variation in plasma AMH. Plasma AMH concentration (pg/mL) was determined from a blood s le collected (mean ± standard deviation) 10 ± 2 d after first insemination at detected estrus (IDE) in 2,628 first- and second-parity Irish dairy cows. Overall, plasma AMH had a positively skewed distribution with mean (± standard deviation), median, minimum, and maximum concentrations of 326 ± 231, 268, 15, and 2,863 pg/mL, respectively. Plasma AMH was greatest for Jersey, followed by Holstein × Jersey, Holstein × Norwegian Red, and Holstein cows (410, 332, 284, and 257 pg/mL, respectively). Second-parity cows had greater plasma AMH than first-parity cows (333 vs. 301 pg/mL, respectively). S les collected at 7 and 8 d after first IDE had lesser plasma AMH than those collected on d 9, 10, 11, 12, and 13 after first IDE (291 and 297 vs. 317, 319, 331, 337, and 320 pg/mL). Plasma AMH was not associated with either body condition score at first IDE or the interval from calving to MSD. Cows were categorized into low (≤150 pg/mL n = 526 lowest 20%), intermediate (>150 to ≤461 pg/mL n = 1,576 intermediate 60%), and high AMH (>461 pg/mL n = 526 highest 20%) groups based on plasma AMH, and associations with reproductive outcomes were tested. Cows with high and intermediate plasma AMH had 1.42- and 1.51-times-greater odds of becoming pregnant within 84 d after the MSD than those with low plasma AMH (90.3 and 90.8 vs. 86.8%, respectively) however, P/AI and pregnancy rate within 21 and 42 d after the MSD did not differ among AMH categories. Plasma AMH was moderately heritable (pedigree heritability of 0.40 ± 0.06 and genomic heritability of 0.45 ± 0.05), and 68 SNP across Bos taurus autosomes 7 and 11 were associated with phenotypic variation in plasma AMH. Out of 68 SNP, 42 were located in a single quantitative trait locus on Bos taurus autosome 11 that harbored 6 previously identified candidate genes (NR5A1, HSPA5, CRB2, DENND1A, NDUFA8, and PTGS) linked to fertility-related phenotypes in dairy cows.

Plant above-ground biomass and litter quality drive soil microbial metabolic limitations during vegetation restoration of subtropical forests

Publisher: Springer Science and Business Media LLC

Date: 29-12-2022

DOI: 10.1007/S42832-022-0154-2

Introduction

Publisher: Springer Singapore

Date: 2021

DOI: 10.1007/978-981-15-8924-9_1

Examining soil carbon uncertainty in a global model: response of microbial decomposition to temperature, moisture and nutrient limitation

Publisher: Copernicus GmbH

Date: 08-11-2013

DOI: 10.5194/BG-10-7095-2013

Abstract: Abstract. Reliable projections of future climate require land–atmosphere carbon (C) fluxes to be represented realistically in Earth system models (ESMs). There are several sources of uncertainty in how carbon is parameterised in these models. First, while interactions between the C, nitrogen (N) and phosphorus (P) cycles have been implemented in some models, these lead to erse changes in land–atmosphere fluxes. Second, while the first-order parameterisation of soil organic matter decomposition is similar between models, formulations of the control of the soil physical state on microbial activity vary widely. For the first time, we address these sources of uncertainty simultaneously by implementing three soil moisture and three soil temperature respiration functions in an ESM that can be run with three degrees of biogeochemical nutrient limitation (C-only, C and N, and C and N and P). All 27 possible combinations of response functions and biogeochemical mode are equilibrated before transient historical (1850–2005) simulations are performed. As expected, implementing N and P limitation reduces the land carbon sink, transforming some regional sinks into net sources over the historical period. Meanwhile, regardless of which nutrient mode is used, various combinations of response functions imply a two-fold difference in the net ecosystem accumulation and a four-fold difference in equilibrated total soil C. We further show that regions with initially larger pools are more likely to become carbon sources, especially when nutrient availability limits the response of primary production to increasing atmospheric CO2. Simulating changes in soil C content therefore critically depends on both nutrient limitation and the choice of respiration functions.

Analysis and Simulation of Impact of Light and Temperature on Rice Tillering

Publisher: China Science Publishing & Media Ltd.

Date: 2016

DOI: 10.3724/SP.J.1006.2016.00082

Categorization of endometritis and its association with ovarian follicular growth and ovulation, reproductive performance, dry matter intake, and milk yield in dairy cattle

Publisher: Elsevier BV

Date: 10-2016

DOI: 10.1016/J.THERIOGENOLOGY.2016.06.003

Abstract: The objectives were to evaluate the effect of different categories of endometritis on follicular growth and ovulation, reproductive performance, dry matter intake (DMI), and milk yield (MY) in dairy cows. Lactating Holstein cows (n = 126) were examined for endometritis on 25 ± 1 day postpartum (DPP) using vaginoscopy, transrectal ultrasonography, and endometrial cytology to determine the presence and type of vaginal discharge, uterine fluid, and proportion of polymorphonuclear (PMN) cells, respectively. Cows that had mucopurulent vaginal discharge and/or presence of uterine fluid, no mucopurulent vaginal discharge or uterine fluid but 8% or more PMN, and mucopurulent vaginal discharge and/or uterine fluid and 8% or more of PMN were defined as having clinical (CLIN n = 45), cytological (CYTO n = 15), and clinical and cytological (CLINCYTO n = 30) endometritis, respectively. Cows that had none of the above pathological conditions were classified as unaffected (UNAF n = 36). The diameter of the largest follicle at first examination, intervals from calving to first dominant (diameter = 10 mm) follicle, preovulatory size (diameter = 16 mm) follicle, ovulation, presence of follicular cyst, and proportion of ovular cows at 35 and 65 DPP were recorded as the measures of follicular growth and ovulation. None of the ovarian follicular parameters analyzed was affected by categories of endometritis. The first service conception rate tended (P = 0.06) to differ among categories of endometritis cows that had CLIN and CLINCYTO endometritis were four times less likely to conceive to the first insemination compared to UNAF cows. Cows that had CLIN (hazard ratio: 0.52) and CLINCYTO (hazard ratio: 0.40) endometritis had decreased likelihood of pregnancy at 150 DPP compared to UNAF cows. Similarly, cows diagnosed as having CLINCYTO endometritis had decreased likelihood (hazard ratio: 0.48) of pregnancy at 250 DPP compared to UNAF cows. The DMI and MY up to 5 weeks postpartum were not affected by categories of endometritis. In summary, categories of endometritis as determined at 25 DPP did not affect follicular growth and ovulation, DMI, or MY. However, the combined (CLINCYTO endometritis) category had a negative impact on first service conception rate and subsequent services.

Soil Organic Carbon Stabilization Is Dominated by Non‐Sorptive Process Among the Subsoils From Different Parent Material

Publisher: American Geophysical Union (AGU)

Date: 03-2023

DOI: 10.1029/2022JG007286

Abstract: Soil parent material can strongly influence soil's physical and chemical properties, significantly affecting soil organic carbon (SOC) stabilization. However, the importance of different soil parent materials on the amount and composition of subsoil carbon in subtropical soils remains poorly qualified. Subsoil SOC (below A horizon) is chosen for this study because of its higher proportion of stable carbon than surface soils in A horizon. Here, we investigated the dependence of soil mineral‐associated organic carbon (MAOC) and its three mineral‐stabilized fractions on soil physical and chemical parameters (clay content, cation exchange capacity (CEC) and metal oxides) in the subsoil soil (B and C horizons) originating from three contrasting parent materials (sandshale, granite, limestone). The results showed that MAOC accounts for an average of 88% of total SOC, of which organo‐metal complexes (extracted with sodium pyrophosphate) are the dominant form at all three sites. MAOC and its three fractions were significantly correlated with soil clay, CEC, sodium pyrophosphate extractable Fe and oxalate extractable Fe concentrations ( P 0.05), which varied significantly with soil parent material. Since the sodium pyrophosphate plus oxalate‐ extracted mineral‐associated carbon accounted for more than 70% of MAOC, and the molar ratio between sodium pyrophosphate or oxalate‐ extracted mineral‐associated carbon and Fe (C:Fe) ranged from 2.7 to 17.1. The formation of Fe‐associated organic complex is dominated by co‐precipitation when C:Fe is . Therefore we conclude that non‐sorptive interactions with the mineral phase through co‐precipitation are the dominant mechanism for SOC stabilization in subtropical forest soils.

Scaling the estimate of maximum canopy conductance from patch to region and comparison of aircraft measurements.

Publisher: CABI Publishing

Date: 18-12-2003

DOI: 10.1079/9780851996776.0175

The response of ginseng grown on farmland to foliar-applied iron, zinc, manganese and copper

Publisher: Elsevier BV

Date: 02-2013

DOI: 10.1016/J.INDCROP.2012.12.047

Impact of the representation of stomatal conductance on model projections of heatwave intensity

Publisher: Springer Science and Business Media LLC

Date: 21-03-2016

DOI: 10.1038/SREP23418

Abstract: Stomatal conductance links plant water use and carbon uptake and is a critical process for the land surface component of climate models. However, stomatal conductance schemes commonly assume that all vegetation with the same photosynthetic pathway use identical plant water use strategies whereas observations indicate otherwise. Here, we implement a new stomatal scheme derived from optimal stomatal theory and constrained by a recent global synthesis of stomatal conductance measurements from 314 species, across 56 field sites. Using this new stomatal scheme, within a global climate model, subtantially increases the intensity of future heatwaves across Northern Eurasia. This indicates that our climate model has previously been under-predicting heatwave intensity. Our results have widespread implications for other climate models, many of which do not account for differences in stomatal water-use across different plant functional types and hence, are also likely under projecting heatwave intensity in the future.

The dominant role of semi-arid ecosystems in the trend and variability of the land CO ₂ sink

Publisher: American Association for the Advancement of Science (AAAS)

Date: 22-05-2015

DOI: 10.1126/SCIENCE.AAA1668

Abstract: The terrestrial biosphere absorbs about a quarter of all anthropogenic carbon dioxide emissions, but the amount that they take up varies from year to year. Why? Combining models and observations, Ahlström et al. found that marginal ecosystems—semiarid savannas and low-latitude shrublands—are responsible for most of the variability. Biological productivity in these semiarid regions is water-limited and strongly associated with variations in precipitation, unlike wetter tropical areas. Understanding carbon uptake by these marginal lands may help to improve predictions of variations in the global carbon cycle. Science , this issue p. 895

Bridge to the future: Important lessons from 20 years of ecosystem observations made by the OzFlux network

Publisher: Wiley

Date: 22-03-2022

DOI: 10.1111/GCB.16141

Abstract: In 2020, the Australian and New Zealand flux research and monitoring network, OzFlux, celebrated its 20 th anniversary by reflecting on the lessons learned through two decades of ecosystem studies on global change biology. OzFlux is a network not only for ecosystem researchers, but also for those ‘next users’ of the knowledge, information and data that such networks provide. Here, we focus on eight lessons across topics of climate change and variability, disturbance and resilience, drought and heat stress and synergies with remote sensing and modelling. In distilling the key lessons learned, we also identify where further research is needed to fill knowledge gaps and improve the utility and relevance of the outputs from OzFlux. Extreme climate variability across Australia and New Zealand (droughts and flooding rains) provides a natural laboratory for a global understanding of ecosystems in this time of accelerating climate change. As evidence of worsening global fire risk emerges, the natural ability of these ecosystems to recover from disturbances, such as fire and cyclones, provides lessons on adaptation and resilience to disturbance. Drought and heatwaves are common occurrences across large parts of the region and can tip an ecosystem's carbon budget from a net CO 2 sink to a net CO 2 source. Despite such responses to stress, ecosystems at OzFlux sites show their resilience to climate variability by rapidly pivoting back to a strong carbon sink upon the return of favourable conditions. Located in under‐represented areas, OzFlux data have the potential for reducing uncertainties in global remote sensing products, and these data provide several opportunities to develop new theories and improve our ecosystem models. The accumulated impacts of these lessons over the last 20 years highlights the value of long‐term flux observations for natural and managed systems. A future vision for OzFlux includes ongoing and newly developed synergies with ecophysiologists, ecologists, geologists, remote sensors and modellers.

The Arms Trade Treaty: Responsibility to Protect in Action?

Publisher: Brill

Date: 18-04-2017

DOI: 10.1163/1875984X-00902003

Abstract: This paper argues that the influence of R2P can be seen in many subtle, yet significant, ways throughout the Arms Trade Treaty, from the language used to the obligations imposed on States Parties. The Arms Trade Treaty indicates that R2P is influencing decision making and contributing to the protection of populations from atrocity crimes by obliging States Parties to explicitly consider the consequences of their arms transfers. In addition, the Arms Trade Treaty has increased our understanding of R2P by confirming that R2P involves a range of measures and includes restraint by States in refusing to transfer arms in situations where atrocity crimes are being committed, which may temper concerns about R2P being rebranded as assistance.

Assessing the design and power of capture-recapture studies to estimate demographic parameters for the Endangered Oceania humpback whale population

Publisher: Inter-Research Science Center

Date: 09-2015

DOI: 10.3354/ESR00686

The timing of deglaciation from mountain summits to cirques in Wales: 10Be and 26Al exposure dates from Cadair Idris

Publisher: Copernicus GmbH

Date: 04-03-2021

DOI: 10.5194/EGUSPHERE-EGU21-10398

Abstract: & & Cosmogenic & sup& & /sup& Be and & sup& & /sup& Al exposure ages from 20 erratic s les collected from Cadair Idris (893 m), a mountain in southern Snowdonia, Wales, provide evidence for the timing of deglaciation from summits to cirques at the end of the Late Pleistocene. The summit of the mountain is characterised by intensely modified frost-shattered surfaces that have long been identified as a representing a former nunatak. Numerous glacially-transported quartz boulders on the highest ground indicate that ice overran the summit at some point in the Pleistocene. Two quartz boulders, one with preserved striations, s led at c. 856 m near the summit of Cadair Idris yielded consistent & sup& & /sup& Be and & sup& & /sup& Al paired exposure ages of 75 ka to 60 ka (using a high-latitude sea level & sup& & /sup& Be spallation production rate of 4.20 at/g/y, scaled by the Lal/Stone scheme). A glacially polished bedrock quartzite outcrop at 735 m gave an age of 17.5 ka. Immediately below this, cirque and down-valley recessional moraine ages, covering an elevation of 480 m to 350 m ranged from 10 to 15 ka respectively.& & & & These results confirm that Cadair Idris was overridden by the Welsh Ice Cap during marine isotope stage (MIS) 4, when ice was thicker than at the global last glacial maximum (LGM) in MIS 2. This is consistent with findings from northern Snowdonia. The highest Welsh summits, including Cadair Idris, emerged above a thinning Welsh Ice Cap (British Irish Ice Sheet) during the transition from MIS 4 to 3. The summit area above ~800 m then stood as nunataks above the LGM ice sheet surface in MIS 2. The Welsh Ice Cap then rapidly thinned over Cadair Idris at& ~20-17 ka& based on ages from high-level ice-moulded bedrockThis is supported by more new ages from high-level paired erratics and bedrock s les on several other mountains throughout Snowdonia,& leading to a phase of alpine-style deglaciation. Valley glaciers initiated their retreat up-valley from ~17 to 14 ka after Heinrich Event 1. A later phase of glacier stabilisation or still stand formation produced classic cirque moraines near the rim of a present cirque lake basin (480 m elevation) yielding & sup& & /sup& Be ages of 13-10 ka during the Younger Dryas.& &

Towards improvement of aluminium assay in quartz for in situ cosmogenic 26Al analysis at ANSTO

Publisher: Elsevier BV

Date: 10-2015

DOI: 10.1016/J.NIMB.2015.07.120

Increasing phosphorus limitation along three successional forests in southern China

Publisher: Springer Science and Business Media LLC

Date: 11-07-2012

DOI: 10.1007/S11104-012-1355-8

Reply to comment by François Bourges et al. on “Carbon uptake by karsts in the Houzhai Basin, southwest China”

Publisher: American Geophysical Union (AGU)

Date: 04-07-2012

DOI: 10.1029/2012JG002060

Cumulative propagule pressure exerted by escaped pet parrots

Publisher: Wiley

Date: 23-01-2023

DOI: 10.1111/1365-2664.14341

Abstract: The global pet trade provides a pathway for introduced species to invade new environments. Most studies use trade data as an indirect proxy for propagule pressure exerted by the pet trade. Instead, we quantify the reported rate of loss of captive birds, assess factors that might influence this rate, simulate the survival and retrieval of birds and the overall cumulative propagule pressure exerted by pet birds on the environment. We used online listings of lost birds to estimate the propagule pressure that the pet trade exerts on the establishment of introduced bird species in Aotearoa–New Zealand. Listings from two popular websites were monitored daily for over 3.5 years, and information was recorded on the frequency, location, species composition and characteristics of the loss events. We investigated a range of factors that may influence the rate of loss events, such as season and human population size. We also developed a simulation approach to investigate the cumulative propagule pressure in Auckland, New Zealand's largest city. A total of 1205 birds and at least 33 species were reported lost nationwide during our monitoring period, 92% of which were parrots. We found that the reported loss rate was higher in areas of higher human population size and median income, and lower in the winter months. Simulation results predict that in any given month in Auckland there is an average of at least 491 escaped birds, including 136 potential breeding pairs, and for seven species the chance that at least one locality has a male/female pair at large exceeds 80%. Synthesis and applications . Online listings of lost pets provide an excellent source of data from which to identify species with high propagule pressure in specific localities. We identified escaped parrot species as a high‐risk invasion pathway, as they contribute to a high and consistent propagule pressure. A preventative approach, by banning the sale of these species, is the most appropriate pest management strategy for reducing the probability of establishment and potential impact.

A Model of Wheat Grain Growth and Its Applications to Different Temperature and Carbon Dioxide Levels

Publisher: CSIRO Publishing

Date: 1995

DOI: 10.1071/PP9950843

Abstract: Kernel growth after anthesis is simulated as a function of the potential kernel growth rate, current photosynthate production and mobilisation of stored reserves. The potential growth rate of the kernel is simulated as two temperature-sensitive processes, cell production and cell growth. The difference between the potential and actual growth rates of the kernel depends on the carbon supply to the free space of the kernel endosperm, while the carbon supply is itself affected by the actual kernel growth rate. Sensitivity analysis showed that the growth rate of the grain per plant is most sensitive to the potential growth rate of the kernel and number of kernels per plant. This model is able to simulate the observed rates of grain growth and leaf senescence from anthesis to physiological maturity for wheat plants grown in two CO2 concentrations. The simulated temperature response of grain growth agrees well with the experimenal observations.

Magnetic breakdown of cyclotron orbits in systems with Rashba and Dresselhaus spin-orbit coupling

Publisher: American Physical Society (APS)

Date: 18-09-2008

DOI: 10.1103/PHYSREVB.78.115312

Phosphorus addition promotes plant nitrogen uptake mainly via enhancing microbial activities: A global meta-analysis

Publisher: Elsevier BV

Date: 08-2023

DOI: 10.1016/J.APSOIL.2023.104927

Do land surface models need to include differential plant species responses to drought? Examining model predictions across a mesic-xeric gradient in Europe

Publisher: Copernicus GmbH

Date: 21-12-2015

DOI: 10.5194/BG-12-7503-2015

Abstract: Abstract. Future climate change has the potential to increase drought in many regions of the globe, making it essential that land surface models (LSMs) used in coupled climate models realistically capture the drought responses of vegetation. Recent data syntheses show that drought sensitivity varies considerably among plants from different climate zones, but state-of-the-art LSMs currently assume the same drought sensitivity for all vegetation. We tested whether variable drought sensitivities are needed to explain the observed large-scale patterns of drought impact on the carbon, water and energy fluxes. We implemented data-driven drought sensitivities in the Community Atmosphere Biosphere Land Exchange (CABLE) LSM and evaluated alternative sensitivities across a latitudinal gradient in Europe during the 2003 heatwave. The model predicted an overly abrupt onset of drought unless average soil water potential was calculated with dynamic weighting across soil layers. We found that high drought sensitivity at the most mesic sites, and low drought sensitivity at the most xeric sites, was necessary to accurately model responses during drought. Our results indicate that LSMs will over-estimate drought impacts in drier climates unless different sensitivity of vegetation to drought is taken into account.

Quantifying the effects of elevated CO2 on water budgets by combining FACE data with an ecohydrological model

Publisher: Wiley

Date: 05-03-2014

DOI: 10.1002/ECO.1478

A refinement to the two-leaf model for calculating canopy photosynthesis

Publisher: Elsevier BV

Date: 03-2000

DOI: 10.1016/S0168-1923(99)00165-3

Commercial and Military Uses of Outer Space

Publisher: Springer Singapore

Date: 2021

DOI: 10.1007/978-981-15-8924-9

Modeling biochar effects on soil organic carbon on croplands in the MIMICS (MIcrobial-MIneral Carbon Stabilization) model

Publisher: Copernicus GmbH

Date: 10-07-2023

DOI: 10.5194/GMD-2023-114

Abstract: Abstract. Biochar application in croplands aims to sequester carbon and improve soil quality, but its impact on soil organic carbon (SOC) dynamics is not represented in most land models used for assessing land-based climate mitigation, therefore we are unable to quantify the effect of biochar applications under different climate conditions or land management. To fill this gap, here we implemented a submodel to represent biochar into a microbial decomposition model named MIMICS (MIcrobial-MIneral Carbon Stabilization). We first calibrate MIMICS with new representations of density-dependent microbial turnover rate, adsorption of available organic carbon on mineral soil particles, and soil moisture effects on decomposition using global field measured cropland SOC at 58 sites. The calibration of MIMICS leads to an increase in explained spatial variation of SOC from 38 % in the default version to 47 %–52 % in the updated model with new representations. We further integrate biochar in MIMICS resolving its effect on microbial decomposition and SOC sorption/desorption and optimize two biochar-related parameters in these processes using 134 paired SOC measurements with and without biochar addition. The MIMICS-biochar version can generally reproduce the short-term (≤ 6 yr) and long-term (8 yr) SOC changes after adding biochar (mean addition rate: 25.6 t ha-1) (R2 = 0.65 and 0.84) with a low root mean square error (RMSE = 3.61 and 3.31 g kg-1). Our study incorporates sorption and soil moisture processes into MIMICS and extends its capacity to simulate biochar decomposition, providing a useful tool to couple with dynamic land models to evaluate the effectiveness of biochar applications on removing CO2 from the atmosphere.

Potential CO2-Enhanced Carbon Storage by the Terrestrial Biosphere

Publisher: CSIRO Publishing

Date: 1992

DOI: 10.1071/BT9920641

Abstract: Geochemical models that deduce latitudinal source/sink relationships of atmospheric CO2 suggest that, in tropical regions, there is almost zero net exchange of CO2 between the atmosphere and the terrestrial biosphere. The implication is that CO2-enhanced carbon storage (CO2-ECS) by tropical biomes is negating the output of CO2 from deforestation. We describe here a 10-biome model for CO2-ECS, in which carbon accumulation in living vegetation is coupled to the Rothamsted soil carbon model. A biotic growth factor (β) was used to describe the relationship between literature estimates of net primary production (NPP) and atmospheric CO2 concentration. Using β = 0.3 as a reference state, CO2-ECS by the global biosphere in 1990 was 1.1 Gt. When more appropriate values of β were used (derived from a theoretical response of vegetation to increasing temperature and CO2), CO2-ECS was 1.3 Gt, of which tropical biomes accounted for 0.7 Gt. There are many uncertainties in this (and other) models total CO2-ECS is particularly sensitive to changes in NPP. Unless published surveys have underestimated tropical NPP by a factor of about 2, then it is unlikely that CO2-ECS could have negated the 1.5-3.0 Gt of carbon that are estimated to have been emitted by tropical deforestation in 1990.

Modelling evapotranspiration during precipitation deficits: identifying critical processes in a land surface model

Publisher: Copernicus GmbH

Date: 21-06-2016

DOI: 10.5194/HESS-20-2403-2016

Abstract: Abstract. Surface fluxes from land surface models (LSMs) have traditionally been evaluated against monthly, seasonal or annual mean states. The limited ability of LSMs to reproduce observed evaporative fluxes under water-stressed conditions has been previously noted, but very few studies have systematically evaluated these models during rainfall deficits. We evaluated latent heat fluxes simulated by the Community Atmosphere Biosphere Land Exchange (CABLE) LSM across 20 flux tower sites at sub-annual to inter-annual timescales, in particular focusing on model performance during seasonal-scale rainfall deficits. The importance of key model processes in capturing the latent heat flux was explored by employing alternative representations of hydrology, leaf area index, soil properties and stomatal conductance. We found that the representation of hydrological processes was critical for capturing observed declines in latent heat during rainfall deficits. By contrast, the effects of soil properties, LAI and stomatal conductance were highly site-specific. Whilst the standard model performs reasonably well at annual scales as measured by common metrics, it grossly underestimates latent heat during rainfall deficits. A new version of CABLE, with a more physically consistent representation of hydrology, captures the variation in the latent heat flux during seasonal-scale rainfall deficits better than earlier versions, but remaining biases point to future research needs. Our results highlight the importance of evaluating LSMs under water-stressed conditions and across multiple plant functional types and climate regimes.

Mathematical models of the photosynthetic response of tree stands to rising CO₂ concentrations and temperatures

Publisher: Wiley

Date: 1993

DOI: 10.1111/J.1365-3040.1993.TB00839.X

Tradeoff of CO2 and CH4 emissions from global peatlands under water-table drawdown

Publisher: Springer Science and Business Media LLC

Date: 07-06-2021

DOI: 10.1038/S41558-021-01059-W

The land surface model component of ACCESS: description and impact on the simulated surface climatology

Publisher: Bureau of Meteorology, Australia

Date: 03-2013

DOI: 10.22499/2.6301.005

Ice surface lowering of Skelton Glacier, Transantarctic Mountains, since the Last Glacial Maximum: Implications for retreat of grounded ice in the western Ross Sea

Publisher: Elsevier BV

Date: 06-2020

DOI: 10.1016/J.QUASCIREV.2020.106305

Transit times and mean ages for nonautonomous and autonomous compartmental systems

Publisher: Springer Science and Business Media LLC

Date: 04-2016

DOI: 10.1007/S00285-016-0990-8

Geometry-induced enhancement factor improvement in covered-gold-nanorod-dimer antennas

Publisher: Royal Society of Chemistry (RSC)

Date: 2021

DOI: 10.1039/D1RA00285F

Abstract: Designs with gold covering far from the gap area applied on nanorod-dimer antennas can enable hybrid electrical and SERS detection. Simulations show promising and robust increasement of the enhancement factor with respect to the uncovered dimer.

Nitrogen allocation and carbon isotope fractionation in relation to intercepted radiation and position in a young Pinus radiata D. Don tree

Publisher: Wiley

Date: 08-1998

DOI: 10.1046/J.1365-3040.1998.00314.X

Dominant regions and drivers of the variability of the global land carbon sink across timescales

Publisher: Wiley

Date: 08-05-2018

DOI: 10.1111/GCB.14275

Abstract: Net biome productivity (NBP) dominates the observed large variation of atmospheric CO

A Two-Big-Leaf Model for Canopy Temperature, Photosynthesis, and Stomatal Conductance

Publisher: American Meteorological Society

Date: 06-2004

DOI: 10.1175/1520-0442(2004)017<2281:ATMFCT>2.0.CO;2

Joint structural and physiological control on the interannual variation in productivity in a temperate grassland: A data-model comparison.

Publisher: Wiley

Date: 08-05-2018

DOI: 10.1111/GCB.14274

Abstract: Given the important contributions of semiarid region to global land carbon cycle, accurate modeling of the interannual variability (IAV) of terrestrial gross primary productivity (GPP) is important but remains challenging. By decomposing GPP into leaf area index (LAI) and photosynthesis per leaf area (i.e., GPP_leaf), we investigated the IAV of GPP and the mechanisms responsible in a temperate grassland of northwestern China. We further assessed six ecosystem models for their capabilities in reproducing the observed IAV of GPP in a temperate grassland from 2004 to 2011 in China. We observed that the responses to LAI and GPP_leaf to soil water significantly contributed to IAV of GPP at the grassland ecosystem. Two of six models with prescribed LAI simulated of the observed IAV of GPP quite well, but still underestimated the variance of GPP_leaf, therefore the variance of GPP. In comparison, simulated pattern by the other four models with prognostic LAI differed significantly from the observed IAV of GPP. Only some models with prognostic LAI can capture the observed sharp decline of GPP in drought years. Further analysis indicated that accurately representing the responses of GPP_leaf and leaf stomatal conductance to soil moisture are critical for the models to reproduce the observed IAV of GPP_leaf. Our framework also identified that the contributions of LAI and GPP_leaf to the observed IAV of GPP were relatively independent. We conclude that our framework of decomposing GPP into LAI and GPP_leaf has a significant potential for facilitating future model intercomparison, benchmarking and optimization should be adopted for future data-model comparisons.

A model inter-comparison study to examine limiting factors in modelling Australian tropical savannas

Publisher: Copernicus GmbH

Date: 02-12-2015

DOI: 10.5194/BGD-12-18999-2015

Abstract: Abstract. Savanna ecosystems are one of the most dominant and complex terrestrial biomes that derives from a distinct vegetative surface comprised of co-dominant tree and grass populations. While these two vegetation types co-exist functionally, demographically they are not static, but are dynamically changing in response to environmental forces such as annual fire events and rainfall variability. Modelling savanna environments with the current generation of terrestrial biosphere models (TBMs) has presented many problems, particularly describing fire frequency and intensity, phenology, leaf biochemistry of C3 and C4 photosynthesis vegetation, and root water uptake. In order to better understand why TBMs perform so poorly in savannas, we conducted a model inter-comparison of 6 TBMs and assessed their performance at simulating latent energy (LE) and gross primary productivity (GPP) for five savanna sites along a rainfall gradient in northern Australia. Performance in predicting LE and GPP was measured using an empirical benchmarking system, which ranks models by their ability to utilise meteorological driving information to predict the fluxes. On average, the TBMs performed as well as a multi-linear regression of the fluxes against solar radiation, temperature and vapour pressure deficit, but were outperformed by a more complicated nonlinear response model that also included the leaf area index (LAI). This identified that the TBMs are not fully utilising their input information effectively in determining savanna LE and GPP, and highlights that savanna dynamics cannot be calibrated into models and that there are problems in underlying model processes. We identified key weaknesses in a model's ability to simulate savanna fluxes and their seasonal variation, related to the representation of vegetation by the models and root water uptake. We underline these weaknesses in terms of three critical areas for development. First, prescribed tree-rooting depths must be deep enough, enabling the extraction of deep soil water stores to maintain photosynthesis and transpiration during the dry season. Second, models must treat grasses as a co-dominant interface for water and carbon exchange, rather than a secondary one to trees. Third, models need a dynamic representation of LAI that encompasses the dynamic phenology of savanna vegetation and its response to rainfall interannual variability. We believe this study is the first to assess how well TBMs simulate savanna ecosystems, and that these results will be used to improve the representation of savannas ecosystems in future global climate model studies.

Global Carbon Sequestration Is Highly Sensitive to Model‐Based Formulations of Nitrogen Fixation

Publisher: American Geophysical Union (AGU)

Date: 2020

DOI: 10.1029/2019GB006296

A search for predictive understanding of plant responses to elevated [CO₂]

Publisher: Wiley

Date: 02-1999

DOI: 10.1046/J.1365-2486.1999.00215.X

Enhanced peak growth of global vegetation and its key mechanisms

Publisher: Springer Science and Business Media LLC

Date: 12-11-2018

DOI: 10.1038/S41559-018-0714-0

Abstract: The annual peak growth of vegetation is critical in characterizing the capacity of terrestrial ecosystem productivity and shaping the seasonality of atmospheric CO

Role contribution of biological nitrogen fixation to future terrestrial net land carbon accumulation under warming condition at centennial scale

Publisher: Elsevier BV

Date: 11-2018

DOI: 10.1016/J.JCLEPRO.2018.08.089

Ecosystem carbon transit versus turnover times in response to climate warming and rising atmospheric CO&lt;sub&gt;2&lt;/sub&gt; concentration

Publisher: Copernicus GmbH

Date: 02-05-2018

DOI: 10.5194/BG-2018-175

Abstract: Abstract. Ecosystem carbon (C) transit time is a critical diagnostic parameter to characterize land C sequestration. This parameter has different variants in literatures, including a commonly used turnover time. However, neither of them has been carefully examined under transient C dynamics in response to climate change. In this study, we estimated both C turnover time as defined by the conventional stock-over-flux (i.e., Olson method) and mean C transit time as defined by the mean age of C mass leaving the system (i.e., Rasmussen method). We incorporated them into Community Atmosphere-Biosphere-Land Exchange model (CABLE) to estimate C turnover time and transit time, respectively, in response to climate warming and rising atmospheric [CO2]. Modeling analysis showed that both C turnover time and transit time increased with climate warming but decreased with rising atmospheric [CO2]. The increase of C turnover time with warming was estimated to be 2.4 years with Olson method whereas the transit time increased by 11.8 years with Rasmussen method. The decrease with rising atmospheric [CO2] was estimated to be 3.8 years with Olson method and 5.5 years with Rasmussen method. Our analysis based on Rasmussen method showed that 65 % of the increase in global mean C transit time with climate warming results from the depletion of fast-turnover C pool. The remaining 35 % increase results from accompanied changes in compartment C age structures. Similarly, the decrease in mean C transit time with rising atmospheric [CO2] results approximately equally from replenishment of C into fast-turnover C pool and subsequent decrease in compartment C age structure. Greatly different from the Rasmussen method, the Olsen method, which does not account for changes in either C age structure or composition of respired C, underestimated impacts of either warming or rising atmospheric [CO2] on C diagnostic time and potentially lead to biases in estimating land C sequestration.

Nutrient Limitations Lead to a Reduced Magnitude of Disequilibrium in the Global Terrestrial Carbon Cycle

Publisher: American Geophysical Union (AGU)

Date: 05-2022

DOI: 10.1029/2021JG006764

Abstract: The terrestrial carbon (C) cycle is shifting to a state of dynamic disequilibrium under a rapid global climate change. However, the magnitude of such disequilibrium is inherently hard to measure directly. Abundant studies have revealed that the availability of nutrients, particularly nitrogen (N) and phosphorus (P), constrains ecosystem productivity and carbon stocks across the globe. However, whether and how nutrient limitation affects the disequilibrium magnitude of the terrestrial C cycle ( X p ) has never been evaluated. Here, we developed an approach by combining a process‐based numerical model and an analytical framework to evaluate the role of nutrient limitation on X p . We found that nutrient limitation did have significant impacts on the X p . Over the modeled period of 1901–2013, absolute change in X p was 497.6 PgC under the C‐only run, while it decreased to 155.6 and 124.3 PgC under N and NP limitations, respectively. To understand the underlying reasons, we further disaggregated the changes of X p into changes in steady‐state C storage and transit C storage with the former being decomposed into a productivity‐driven change, an ecosystem‐C‐residence‐time‐driven ( τ E ‐driven) change, and a change induced by productivity‐ τ E interactions. We found that nutrient constrained the increase in X p primarily by d ening the productivity‐driven changes in the steady‐state C storage. Reductions in the productivity‐driven term under N and NP limitations accounted for 94.7% and 94.9%, respectively, of the reductions in the steady‐state C storage. These results indicate that nutrient limitations have profound impacts on future climate‐biosphere feedback by reducing the disequilibrium magnitude of the terrestrial C cycle.

Nitrogen constraints on terrestrial carbon uptake: Implications for the global carbon‐climate feedback

Publisher: American Geophysical Union (AGU)

Date: 12-2009

DOI: 10.1029/2009GL041009

Large diurnal compensatory effects mitigate the response of Amazonian forests to atmospheric warming and drying

Publisher: American Association for the Advancement of Science (AAAS)

Date: 26-05-2023

DOI: 10.1126/SCIADV.ABQ4974

Abstract: Photosynthesis and evapotranspiration in Amazonian forests are major contributors to the global carbon and water cycles. However, their diurnal patterns and responses to atmospheric warming and drying at regional scale remain unclear, hindering the understanding of global carbon and water cycles. Here, we used proxies of photosynthesis and evapotranspiration from the International Space Station to reveal a strong depression of dry season afternoon photosynthesis (by 6.7 ± 2.4%) and evapotranspiration (by 6.1 ± 3.1%). Photosynthesis positively responds to vapor pressure deficit (VPD) in the morning, but negatively in the afternoon. Furthermore, we projected that the regionally depressed afternoon photosynthesis will be compensated by their increases in the morning in future dry seasons. These results shed new light on the complex interplay of climate with carbon and water fluxes in Amazonian forests and provide evidence on the emerging environmental constraints of primary productivity that may improve the robustness of future projections.

Matrix Approach to Land Carbon Cycle Modeling

Publisher: American Geophysical Union (AGU)

Date: 07-2022

DOI: 10.1029/2022MS003008

Abstract: Land ecosystems contribute to climate change mitigation by taking up approximately 30% of anthropogenically emitted carbon. However, estimates of the amount and distribution of carbon uptake across the world's ecosystems or biomes display great uncertainty. The latter hinders a full understanding of the mechanisms and drivers of land carbon uptake, and predictions of the future fate of the land carbon sink. The latter is needed as evidence to inform climate mitigation strategies such as afforestation schemes. To advance land carbon cycle modeling, we have developed a matrix approach. Land carbon cycle models use carbon balance equations to represent carbon exchanges among pools. Our approach organizes this set of equations into a single matrix equation without altering any processes of the original model. The matrix equation enables the development of a theoretical framework for understanding the general, transient behavior of the land carbon cycle. While carbon input and residence time are used to quantify carbon storage capacity at steady state, a third quantity, carbon storage potential, integrates fluxes with time to define dynamic disequilibrium of the carbon cycle under global change. The matrix approach can help address critical contemporary issues in modeling, including pinpointing sources of model uncertainty and accelerating spin‐up of land carbon cycle models by tens of times. The accelerated spin‐up liberates models from the computational burden that hinders comprehensive parameter sensitivity analysis and assimilation of observational data to improve model accuracy. Such computational efficiency offered by the matrix approach enables substantial improvement of model predictions using ever‐increasing data availability. Overall, the matrix approach offers a step change forward for understanding and modeling the land carbon cycle.

Grasslands may be more reliable carbon sinks than forests in California

Publisher: IOP Publishing

Date: 07-2018

DOI: 10.1088/1748-9326/AACB39

The impact of changing the land surface scheme in ACCESS(v1.0/1.1) on the surface climatology

Publisher: Copernicus GmbH

Date: 23-08-2016

DOI: 10.5194/GMD-9-2771-2016

Abstract: Abstract. The Community Atmosphere Biosphere Land Exchange (CABLE) model has been coupled to the UK Met Office Unified Model (UM) within the existing framework of the Australian Community Climate and Earth System Simulator (ACCESS), replacing the Met Office Surface Exchange Scheme (MOSES). Here we investigate how features of the CABLE model impact on present-day surface climate using ACCESS atmosphere-only simulations. The main differences attributed to CABLE include a warmer winter and a cooler summer in the Northern Hemisphere (NH), earlier NH spring runoff from snowmelt, and smaller seasonal and diurnal temperature ranges. The cooler NH summer temperatures in canopy-covered regions are more consistent with observations and are attributed to two factors. Firstly, CABLE accounts for aerodynamic and radiative interactions between the canopy and the ground below this placement of the canopy above the ground eliminates the need for a separate bare ground tile in canopy-covered areas. Secondly, CABLE simulates larger evapotranspiration fluxes and a slightly larger daytime cloud cover fraction. Warmer NH winter temperatures result from the parameterization of cold climate processes in CABLE in snow-covered areas. In particular, prognostic snow density increases through the winter and lowers the diurnally resolved snow albedo variable snow thermal conductivity prevents early winter heat loss but allows more heat to enter the ground as the snow season progresses liquid precipitation freezing within the snowpack delays the building of the snowpack in autumn and accelerates snow melting in spring. Overall we find that the ACCESS simulation of surface air temperature benefits from the specific representation of the turbulent transport within and just above the canopy in the roughness sublayer as well as the more complex snow scheme in CABLE relative to MOSES.

A two-leaf model for canopy conductance, photosynthesis and partitioning of available energy. II. Comparison with measurements

Publisher: Elsevier BV

Date: 05-1998

DOI: 10.1016/S0168-1923(98)00074-4

Noble gases in the Finero phlogopite-peridotites, western Italian Alps

Publisher: Elsevier BV

Date: 30-09-2005

DOI: 10.1016/J.EPSL.2005.07.005

Limitations of nitrogen and phosphorous on the terrestrial carbon uptake in the 20th century

Publisher: American Geophysical Union (AGU)

Date: 11-2011

DOI: 10.1029/2011GL049244

Increasing sensitivity of terrestrial nitrous oxide emissions to precipitation variations

Publisher: IOP Publishing

Date: 12-2022

DOI: 10.1088/2752-5295/ACA2D1

Abstract: Nitrous oxide (N 2 O), a major greenhouse gas and ozone-depleting agent, is generated over land mostly from two key biochemical processes—nitrification and denitrification. Nitrifying and denitrifying N 2 O production occurs preferably under alternative oxic and anoxic conditions, which are closely linked with variations in water filled soil pores, and thus indirectly with precipitation. We show here that the interannual anomalies in the annual growth rate of the global land N 2 O emissions are significantly ( P 0.001) correlated with precipitation anomalies, with an overall sensitivity ( α PRE , changes of land N 2 O emission variations per precipitation anomalies) of 2.50 ± 0.98 Tg N 2 O–N per 100 mm of precipitation across the global land (1998–2016). The sensitivity ( α PRE ) and precipitation-driven N 2 O anomalies increased during 1998–2016, partly due to increased nitrogen inputs to agricultural lands and enhanced precipitation anomalies. Spatially, we find that the α PRE increases with aridity. We predict a larger α PRE under future climate conditions (with radiative forcing levels of 4.5, 7.0 and 8.5 Wm −2 ) by the year 2100 if nitrogen fertilization follows the present practice.

Quantifying the biophysical effects of forests on local air temperature using a novel three-layered land surface energy balance model

Publisher: Elsevier BV

Date: 11-2019

DOI: 10.1016/J.ENVINT.2019.105080

Abstract: The well-documented energy balance dynamics within forest ecosystems are poorly implemented in studies of the biophysical effects of forests. This results in limitations to the accurate quantification of forest cooling/warming on local air temperature. Taking into consideration the forest air space, this study proposes a three-layered (canopy, forest air space and soil [CAS]) land surface energy balance model to simulate air temperature within forest spaces (T

Compensatory water effects link yearly global land CO2 sink changes to temperature

Publisher: Springer Science and Business Media LLC

Date: 2017

DOI: 10.1038/NATURE20780

Abstract: Large interannual variations in the measured growth rate of atmospheric carbon dioxide (CO

SIRIUS Performance: 10Be, 26Al and 36Cl measurements at ANSTO

Publisher: Elsevier BV

Date: 09-2019

DOI: 10.1016/J.NIMB.2019.02.009

The carbon cycle in the Australian Community Climate and Earth System Simulator (ACCESS-ESM1) – Part 1: Model description and pre-industrial simulation

Publisher: Copernicus GmbH

Date: 18-09-2015

DOI: 10.5194/GMDD-8-8063-2015

Abstract: Abstract. Earth System Models (ESMs) that incorporate carbon-climate feedbacks represent the present state of the art in climate modelling. Here, we describe the Australian Community Climate and Earth System Simulator (ACCESS)-ESM1 that combines existing ocean and land carbon models into the physical climate model to simulate exchanges of carbon between the land, atmosphere and ocean. The land carbon model can optionally include both nitrogen and phosphorous limitation on the land carbon uptake. The ocean carbon model simulates the evolution of nitrate, oxygen, dissolved inorganic carbon, alkalinity and iron with one class of phytoplankton and zooplankton. From two multi-centennial simulations of the pre-industrial period with different land carbon model configurations, we evaluate the equilibration of the carbon cycle and present the spatial and temporal variability in key carbon exchanges. For the land carbon cycle, leaf area index is simulated reasonably, and seasonal carbon exchange is well represented. Interannual variations of land carbon exchange are relatively large, driven by variability in precipitation and temperature. We find that the response of the ocean carbon cycle shows reasonable agreement with observations and very good agreement with existing Coupled Model Intercomparison Project (CMIP5) models. While our model over estimates surface nitrate values, the primary productivity agrees well with observations. Our analysis highlights some deficiencies inherent in the carbon models and where the carbon simulation is negatively impacted by known biases in the underlying physical model. We conclude the study with a brief discussion of key developments required to further improve the realism of our model simulation.

Carbon cycle confidence and uncertainty: Exploring variation among soil biogeochemical models

Publisher: Wiley

Date: 27-11-2017

DOI: 10.1111/GCB.13979

Abstract: Emerging insights into factors responsible for soil organic matter stabilization and decomposition are being applied in a variety of contexts, but new tools are needed to facilitate the understanding, evaluation, and improvement of soil biogeochemical theory and models at regional to global scales. To isolate the effects of model structural uncertainty on the global distribution of soil carbon stocks and turnover times we developed a soil biogeochemical testbed that forces three different soil models with consistent climate and plant productivity inputs. The models tested here include a first‐order, microbial implicit approach ( CASA ‐ CNP ), and two recently developed microbially explicit models that can be run at global scales ( MIMICS and CORPSE ). When forced with common environmental drivers, the soil models generated similar estimates of initial soil carbon stocks (roughly 1,400 Pg C globally, 0–100 cm), but each model shows a different functional relationship between mean annual temperature and inferred turnover times. Subsequently, the models made ergent projections about the fate of these soil carbon stocks over the 20 th century, with models either gaining or losing over 20 Pg C globally between 1901 and 2010. Single‐forcing experiments with changed inputs, temperature, and moisture suggest that uncertainty associated with freeze‐thaw processes as well as soil textural effects on soil carbon stabilization were larger than direct temperature uncertainties among models. Finally, the models generated distinct projections about the timing and magnitude of seasonal heterotrophic respiration rates, again reflecting structural uncertainties that were related to environmental sensitivities and assumptions about physicochemical stabilization of soil organic matter. By providing a computationally tractable and numerically consistent framework to evaluate models we aim to better understand uncertainties among models and generate insights about factors regulating the turnover of soil organic matter.

Soil–Atmosphere Trace Gas Exchange in Semiarid and Arid Zones

Publisher: Wiley

Date: 03-2008

DOI: 10.2134/JEQ2006.0445

Abstract: A review is presented on trace gas exchange of CH4, CO, N2O, and NOx arising from agriculture and natural sources in the world's semiarid and arid zones due to soil processes. These gases are important contributors to the radiative forcing and the chemistry of the atmosphere. Quantitative information is summarized from the available studies. Between 5 and 40% of the global soil-atmosphere exchange for these gases (CH4, CO, N2O, and NOx) may occur in semiarid and arid zones, but for each of these gases there are fewer than a dozen studies to support the in idual estimates, and these are from a limited number of locations. Significant differences in the biophysical and chemical processes controlling these trace gas exchanges are identified through the comparison of semiarid and arid zones with the moist temperate or wet/dry savanna land regions. Therefore, there is a poorly quantified understanding of the contribution of these regions to the global trace gas cycles and atmospheric chemistry. More importantly, there is a poor understanding of the feedback between these exchanges, global change, and regional land use and air pollution issues. A set of research issues is presented.

Influence of Shoot Structure on the Photosynthesis of Sitka Spruce (Picea sitchensis)

Publisher: JSTOR

Date: 08-1993

DOI: 10.2307/2390031

Preliminary results of CoQtz-N: A quartz reference material for terrestrial in-situ cosmogenic 10Be and 26Al measurements

Publisher: Elsevier BV

Date: 10-2019

DOI: 10.1016/J.NIMB.2019.04.073

Extraction and purification of quartz in rock using hot phosphoric acid for in situ cosmogenic exposure dating

Publisher: Elsevier BV

Date: 2013

DOI: 10.1016/J.NIMB.2012.08.037

A model of biogeochemical cycles of carbon, nitrogen, and phosphorus including symbiotic nitrogen fixation and phosphatase production

Publisher: American Geophysical Union (AGU)

Date: 03-2007

DOI: 10.1029/2006GB002797

Complex band structure eigenvalue method adapted to Floquet systems: topological superconducting wires as a case study

Publisher: IOP Publishing

Date: 18-12-2013

DOI: 10.1088/0953-8984/26/3/035301

Abstract: For systems that can be modeled as a single-particle lattice extended along a privileged direction, such as, for ex le, quantum wires, the so-called eigenvalue method provides full information about the propagating and evanescent modes as a function of energy. This complex band structure method can be applied either to lattices consisting of an infinite succession of interconnected layers described by the same local Hamiltonian or to superlattices: systems in which the spatial periodicity involves more than one layer. Here, for time-dependent systems subject to a periodic driving, we present an adapted version of the superlattice scheme capable of obtaining the Floquet states and the Floquet quasienergy spectrum. Within this scheme the time periodicity is treated as existing along a spatial dimension added to the original system. The solutions at a single energy for the enlarged artificial system provide the solutions of the original Floquet problem. The method is suited for arbitrary periodic excitations, including strong and anharmonic drivings. We illustrate the capabilities of the methods for both time-independent and time-dependent systems by discussing: (a) topological superconductors in multimode quantum wires with spin-orbit interaction and (b) microwave driven quantum dots in contact with a topological superconductor.

Seasonal responses of terrestrial ecosystem water‐use efficiency to climate change

Publisher: Wiley

Date: 23-03-2016

DOI: 10.1111/GCB.13180

Abstract: Ecosystem water-use efficiency (EWUE) is an indicator of carbon-water interactions and is defined as the ratio of carbon assimilation (GPP) to evapotranspiration (ET). Previous research suggests an increasing long-term trend in annual EWUE over many regions and is largely attributed to the physiological effects of rising CO2 . The seasonal trends in EWUE, however, have not yet been analyzed. In this study, we investigate seasonal EWUE trends and responses to various drivers during 1982-2008. The seasonal cycle for two variants of EWUE, water-use efficiency (WUE, GPP/ET), and transpiration-based WUE (WUEt , the ratio of GPP and transpiration), is analyzed from 0.5° gridded fields from four process-based models and satellite-based products, as well as a network of 63 local flux tower observations. WUE derived from flux tower observations shows moderate seasonal variation for most latitude bands, which is in agreement with satellite-based products. In contrast, the seasonal EWUE trends are not well captured by the same satellite-based products. Trend analysis, based on process-model factorial simulations separating effects of climate, CO2 , and nitrogen deposition (NDEP), further suggests that the seasonal EWUE trends are mainly associated with seasonal trends of climate, whereas CO2 and NDEP do not show obvious seasonal difference in EWUE trends. About 66% grid cells show positive annual WUE trends, mainly over mid- and high northern latitudes. In these regions, spring climate change has lified the effect of CO2 in increasing WUE by more than 0.005 gC m(-2) mm(-1) yr(-1) for 41% pixels. Multiple regression analysis further shows that the increase in springtime WUE in the northern hemisphere is the result of GPP increasing faster than ET because of the higher temperature sensitivity of GPP relative to ET. The partitioning of annual EWUE to seasonal components provides new insight into the relative sensitivities of GPP and ET to climate, CO2, and NDEP.

Linking plant lignin components or microbial necromass to soil organic carbon accumulation across different forest types

Publisher: Research Square Platform LLC

Date: 20-12-2022

DOI: 10.21203/RS.3.RS-2353062/V1

Abstract: Slow cycling organic matter such as plant lignin components or microbial necromass play important roles in soil organic carbon (SOC) accumulation, but their relatively importance are rarely quantified or have been under debate in forest ecosystems. While the traditional hypothesis holds that low-quality litter inputs generally favor more SOC accumulation by selectively storing recalcitrant lignin components, an emerging hypothesis highlights high-quality litter inputs effectively promoting more SOC formation due to faster microbial decomposition leading to more necromass products. Here, we compiled and analyzed a global database of plant lignin components (lignin phenols as biomarker 126 in idual sties) and microbial necromass (amino sugars as biomarker 137 in idual sties) together with SOC in surface mineral soils across coniferous, broad-leaved and mixed forests that represent different litter-quality inputs. Results showed that amino sugars were insignificant predictor for SOC variations across different forest types. SOC contents increased with lignin phenols, but lignin phenols were significantly higher in broad-leaved and mixed forests than in coniferous forests. Therefore, our findings challenge both traditional and emerging hypotheses, and provide new insights for future research on the mechanisms of SOC formation and stabilization from plant and microbial pathways.

Geometry-Assisted Topological Transitions in Spin Interferometry

Publisher: American Physical Society (APS)

Date: 30-12-2019

DOI: 10.1103/PHYSREVLETT.123.266804

A comparative analysis of simulated and observed photosynthetic CO 2 uptake in two coniferous forest canopies

Publisher: Oxford University Press (OUP)

Date: 07-2006

DOI: 10.1093/TREEPHYS/26.7.845

Abstract: Gross canopy photosynthesis (P(g)) can be simulated with canopy models or retrieved from turbulent carbon dioxide (CO2) flux measurements above the forest canopy. We compare the two estimates and illustrate our findings with two case studies. We used the three-dimensional canopy model MAESTRA to simulate P(g) of two spruce forests differing in age and structure. Model parameter acquisition and model sensitivity to selected model parameters are described, and modeled results are compared with independent flux estimates. Despite higher photon fluxes at the site, an older German Norway spruce (Picea abies L. (Karst.)) canopy took up 25% less CO2 from the atmosphere than a young Scottish Sitka spruce (Picea sitchensis (Bong.) Carr.) plantation. The average magnitudes of P(g) and the differences between the two canopies were satisfactorily represented by the model. The main reasons for the different uptake rates were a slightly smaller quantum yield and lower absorptance of the Norway spruce stand because of a more clumped canopy structure. The model did not represent the scatter in the turbulent CO2 flux densities, which was of the same order of magnitude as the non-photosynthetically-active-radiation-induced biophysical variability in the simulated P(g). Analysis of residuals identified only small systematic differences between the modeled flux estimates and turbulent flux measurements at high vapor pressure saturation deficits. The merits and limitations of comparative analysis for quality evaluation of both methods are discussed. From this analysis, we recommend use of both parameter sets and model structure as a basis for future applications and model development.

Multi-decadal trends in global terrestrial evapotranspiration and its components

Publisher: Springer Science and Business Media LLC

Date: 11-01-2016

DOI: 10.1038/SREP19124

Abstract: Evapotranspiration (ET) is the process by which liquid water becomes water vapor and energetically this accounts for much of incoming solar radiation. If this ET did not occur temperatures would be higher, so understanding ET trends is crucial to predict future temperatures. Recent studies have reported prolonged declines in ET in recent decades, although these declines may relate to climate variability. Here, we used a well-validated diagnostic model to estimate daily ET during 1981–2012 and its three components: transpiration from vegetation (E t ), direct evaporation from the soil (E s ) and vaporization of intercepted rainfall from vegetation (E i ). During this period, ET over land has increased significantly ( p 0.01), caused by increases in E t and E i , which are partially counteracted by E s decreasing. These contrasting trends are primarily driven by increases in vegetation leaf area index, dominated by greening. The overall increase in E t over land is about twofold of the decrease in E s . These opposing trends are not simulated by most Coupled Model Intercomparison Project phase 5 (CMIP5) models and highlight the importance of realistically representing vegetation changes in earth system models for predicting future changes in the energy and water cycle.

Asymmetric Responses of Primary Productivity to Altered Precipitation Simulated by Ecosystem Models across Three Longterm Grassland Sites

Publisher: Copernicus GmbH

Date: 31-01-2018

DOI: 10.5194/BG-2018-53

Abstract: Abstract. Changes in precipitation variability are known to influence grassland growth. Field measurements of aboveground net primary productivity (ANPP) in temperate grasslands suggest that both positive and negative asymmetric responses to changes in precipitation may occur. Under normally variable precipitation regimes, wet years typically result in ANPP gains being larger than ANPP declines in dry years (positive asymmetry), whereas increases in ANPP are lower in magnitude in extreme wet years compared to reductions during extreme drought (negative asymmetry). Whether ecosystem models that couple carbon-water system in grasslands are capable of simulating these non-symmetrical ANPP responses is an unresolved question. In this study, we evaluated the simulated responses of temperate grassland primary productivity to scenarios of altered precipitation with fourteen ecosystem models at three sites, Shortgrass Steppe (SGS), Konza Prairie (KNZ) and Stubai Valley meadow (STU), spanning a rainfall gradient from dry to moist. We found that: (1) Gross primary productivity (GPP), NPP, ANPP and belowground NPP (BNPP) showed concave-down nonlinear response curves to altered precipitation in all the models, but with different curvatures and mean values. (2) The slopes of spatial relationships (across sites) between modeled primary productivity and precipitation were steeper than the temporal slopes obtained from inter-annual variations, consistent with empirical data. (3) The asymmetry of the responses of modeled primary productivity under normal inter-annual precipitation variability differed among models, and the median of the model-ensemble suggested a negative asymmetry across the three sites, in contrast to empirical studies. (4) The median sensitivity of modeled productivity to rainfall consistently suggested greater negative impacts with reduced precipitation than positive effects with increased precipitation under extreme conditions. This study indicates that most models overestimate the extent of negative drought effects and/or underestimate the impacts of increased precipitation on primary productivity under normal climate conditions, highlighting the need for improving eco-hydrological processes in models.

Recent leveling off of vegetation greenness and primary production reveals the increasing soil water limitations on the greening Earth

Publisher: Elsevier BV

Date: 07-2021

DOI: 10.1016/J.SCIB.2021.02.023

Supplementary material to "Simulation of soil carbon dynamics in Australia under a framework that better connects spatially explicit data with Rᴏᴛʜ C"

Publisher: Copernicus GmbH

Date: 21-07-2020

DOI: 10.5194/BG-2020-150-SUPPLEMENT

Uncertainty and Emergent Constraints on Enhanced Ecosystem Carbon Stock by Land Greening

Publisher: American Geophysical Union (AGU)

Date: 05-2023

DOI: 10.1029/2022MS003397

Abstract: Significant land greening since the 1980s has been detected through satellite observation, forest inventory, and Earth system modeling. However, whether and to what extent global land greening enhances ecosystem carbon stock remains uncertain. Here, using 40 global models, we first detected a positive correlation between the terrestrial ecosystem carbon stock and leaf area index (LAI) over time. Then, we diagnose the source of uncertainty of simulated the sensitivities of ecosystem carbon stock to LAI based on a traceability analysis. We found that the sensitivity of gross primary productivity (GPP) to LAI is the largest contributor to the model uncertainty in more than 60% of the vegetated grids. Using the ensemble of four long‐term global data sets of GPP and three satellite LAI products from 1982 to 2014, we provided an emergent constraint on the ecosystem carbon stock increase as 0.75 ± 0.46 kg C m −2 per unit LAI over global land areas. Furthermore, the biome‐based results reveal that the tropical forest regions have the highest inter‐model variation and model bias. Overall, this study identifies the uncertainty source and provides constrained estimates of the greening effect on ecosystem carbon stock at the global scale.

Rainfall manipulation experiments as simulated by terrestrial biosphere models: Where do we stand?

Publisher: Wiley

Date: 18-03-2020

DOI: 10.1111/GCB.15024

Tracking the &lt;sup&gt;10&lt;/sup&gt;Be–&lt;sup&gt;26&lt;/sup&gt;Al source-area signal in sediment-routing systems of arid central Australia

Publisher: Copernicus GmbH

Date: 07-05-2018

DOI: 10.5194/ESURF-6-329-2018

Abstract: Abstract. Sediment-routing systems continuously transfer information and mass from eroding source areas to depositional sinks. Understanding how these systems alter environmental signals is critical when it comes to inferring source-area properties from the sedimentary record. We measure cosmogenic 10Be and 26Al along three large sediment-routing systems (∼ 100 000 km2) in central Australia with the aim of tracking downstream variations in 10Be–26Al inventories and identifying the factors responsible for these variations. By comparing 56 new cosmogenic 10Be and 26Al measurements in stream sediments with matching data (n= 55) from source areas, we show that 10Be–26Al inventories in hillslope bedrock and soils set the benchmark for relative downstream modifications. Lithology is the primary determinant of erosion-rate variations in source areas and despite sediment mixing over hundreds of kilometres downstream, a distinct lithological signal is retained. Post-orogenic ranges yield catchment erosion rates of ∼ 6–11 m Myr−1 and silcrete-dominant areas erode as slow as ∼ 0.2 m Myr−1. 10Be–26Al inventories in stream sediments indicate that cumulative-burial terms increase downstream to mostly ∼ 400–800 kyr and up to ∼ 1.1 Myr. The magnitude of the burial signal correlates with increasing sediment cover downstream and reflects assimilation from storages with long exposure histories, such as alluvial fans, desert pavements, alluvial plains, and aeolian dunes. We propose that the tendency for large alluvial rivers to mask their 10Be–26Al source-area signal differs according to geomorphic setting. Signal preservation is favoured by (i) high sediment supply rates, (ii) high mean runoff, and (iii) a thick sedimentary basin pile. Conversely, signal masking prevails in landscapes of (i) low sediment supply and (ii) juxtaposition of sediment storages with notably different exposure histories.

Detection and attribution of vegetation greening trend in China over the last 30 years

Publisher: Wiley

Date: 08-01-2015

DOI: 10.1111/GCB.12795

Abstract: The reliable detection and attribution of changes in vegetation growth is a prerequisite for the development of strategies for the sustainable management of ecosystems. This is an extraordinary challenge. To our knowledge, this study is the first to comprehensively detect and attribute a greening trend in China over the last three decades. We use three different satellite-derived Leaf Area Index (LAI) datasets for detection as well as five different process-based ecosystem models for attribution. Rising atmospheric CO2 concentration and nitrogen deposition are identified as the most likely causes of the greening trend in China, explaining 85% and 41% of the average growing-season LAI trend (LAIGS) estimated by satellite datasets (average trend of 0.0070 yr(-1), ranging from 0.0035 yr(-1) to 0.0127 yr(-1)), respectively. The contribution of nitrogen deposition is more clearly seen in southern China than in the north of the country. Models disagree about the contribution of climate change alone to the trend in LAIGS at the country scale (one model shows a significant increasing trend, whereas two others show significant decreasing trends). However, the models generally agree on the negative impacts of climate change in north China and Inner Mongolia and the positive impact in the Qinghai-Xizang plateau. Provincial forest area change tends to be significantly correlated with the trend of LAIGS (P < 0.05), and marginally significantly (P = 0.07) correlated with the residual of LAIGS trend, calculated as the trend observed by satellite minus that estimated by models through considering the effects of climate change, rising CO2 concentration and nitrogen deposition, across different provinces. This result highlights the important role of China's afforestation program in explaining the spatial patterns of trend in vegetation growth.

Minimising risks for South Australia's legal interns

Publisher: SAGE Publications

Date: 18-05-2023

DOI: 10.1177/1037969X231164731

Abstract: Australia’s legal profession is currently undergoing a long-awaited reckoning as professional representative bodies, law firms and courts craft solutions to the embedded culture of sexual harassment. But what of the other exclusionary and inequitable practices in legal workplaces? This article considers a project to minimise the myriad risks for legal interns in South Australia. By educating both law students and placement hosts about interns’ rights, and how lawyers from a range of backgrounds can be supported to succeed, we hope to facilitate equitable and successful participation in legal work experience for a new generation of erse and inclusive practitioners.

Challenging terrestrial biosphere models with data from the long‐term multifactor Prairie Heating and CO₂ Enrichment experiment

Publisher: Wiley

Date: 06-03-2017

DOI: 10.1111/GCB.13643

Abstract: Multifactor experiments are often advocated as important for advancing terrestrial biosphere models (TBMs), yet to date, such models have only been tested against single-factor experiments. We applied 10 TBMs to the multifactor Prairie Heating and CO

Supplementary material to &quot;Modelling evapotranspiration during precipitation deficits: identifying critical processes in a land surface model&quot;

Publisher: Copernicus GmbH

Date: 21-10-2015

DOI: 10.5194/HESSD-12-10789-2015-SUPPLEMENT

Nitrous oxide emissions from a legume pasture and the influences of liming and urine addition

Publisher: Elsevier BV

Date: 15-03-2010

DOI: 10.1016/J.AGEE.2009.10.013

Supplementary material to &quot;Ecosystem carbon transit versus turnover times in response to climate warming and rising atmospheric CO&lt;sub&gt;2&lt;/sub&gt; concentration&q

Publisher: Copernicus GmbH

Date: 02-05-2018

DOI: 10.5194/BG-2018-175-SUPPLEMENT

A novel silvicultural model for increasing biopolymer production from Eucommia ulmoides Oliver trees

Publisher: Elsevier BV

Date: 03-2013

DOI: 10.1016/J.INDCROP.2012.06.001

A model inter-comparison study to examine limiting factors in modelling Australian tropical savannas

Publisher: Copernicus GmbH

Date: 03-06-2016

DOI: 10.5194/BG-13-3245-2016

Abstract: Abstract. The savanna ecosystem is one of the most dominant and complex terrestrial biomes, deriving from a distinct vegetative surface comprised of co-dominant tree and grass populations. While these two vegetation types co-exist functionally, demographically they are not static but are dynamically changing in response to environmental forces such as annual fire events and rainfall variability. Modelling savanna environments with the current generation of terrestrial biosphere models (TBMs) has presented many problems, particularly describing fire frequency and intensity, phenology, leaf biochemistry of C3 and C4 photosynthesis vegetation, and root-water uptake. In order to better understand why TBMs perform so poorly in savannas, we conducted a model inter-comparison of six TBMs and assessed their performance at simulating latent energy (LE) and gross primary productivity (GPP) for five savanna sites along a rainfall gradient in northern Australia. Performance in predicting LE and GPP was measured using an empirical benchmarking system, which ranks models by their ability to utilise meteorological driving information to predict the fluxes. On average, the TBMs performed as well as a multi-linear regression of the fluxes against solar radiation, temperature and vapour pressure deficit but were outperformed by a more complicated nonlinear response model that also included the leaf area index (LAI). This identified that the TBMs are not fully utilising their input information effectively in determining savanna LE and GPP and highlights that savanna dynamics cannot be calibrated into models and that there are problems in underlying model processes. We identified key weaknesses in a model's ability to simulate savanna fluxes and their seasonal variation, related to the representation of vegetation by the models and root-water uptake. We underline these weaknesses in terms of three critical areas for development. First, prescribed tree-rooting depths must be deep enough, enabling the extraction of deep soil-water stores to maintain photosynthesis and transpiration during the dry season. Second, models must treat grasses as a co-dominant interface for water and carbon exchange rather than a secondary one to trees. Third, models need a dynamic representation of LAI that encompasses the dynamic phenology of savanna vegetation and its response to rainfall interannual variability. We believe that this study is the first to assess how well TBMs simulate savanna ecosystems and that these results will be used to improve the representation of savannas ecosystems in future global climate model studies.

Evaluating surface water cycle simulated by the Australian community land surface model (CABLE) across different spatial and temporal domains

Publisher: American Meteorological Society

Date: 08-2013

DOI: 10.1175/JHM-D-12-0123.1

Abstract: The terrestrial water cycle in the Australian Community Atmosphere Biosphere Land Exchange (CABLE) model has been evaluated across a range of temporal and spatial domains. A series of offline experiments were conducted using the forcing data from the second Global Soil Wetness Project (GSWP-2) for the period of 1986–95, but with its default parameter settings. Results were compared against GSWP-2 multimodel ensembles and a range of observationally driven datasets. CABLE-simulated global mean evapotranspiration (ET) and runoff agreed well with the GSWP-2 multimodel climatology and observations, and the spatial variations of ET and runoff across 150 large catchments were well captured. Nevertheless, at regional scales it underestimated ET in the tropics and had some significant runoff errors. The model sensitivity to a number of selected parameters is further examined. Results showed some significant model uncertainty caused by its sensitivity to soil wilting point as well as to the root water uptaking efficiency and canopy water storage parameters. The sensitivity was large in tropical rain forest and midlatitude forest regions, where the uncertainty caused by the model parameters was comparable to a large part of its difference against the GSWP-2 multimodel mean. Furthermore, the discrepancy among the CABLE perturbation experiments caused by its sensitivity to model parameters was equivalent to about 20%–40% of the intermodel difference among the GSWP-2 models, which was primarily caused by different model structure rocesses. Although such results are model dependent, they suggest that soil/vegetation parameters could be another source of uncertainty in estimating global surface energy and water budgets.

Modelling evapotranspiration during precipitation deficits: identifying critical processes in a land surface model

Publisher: Copernicus GmbH

Date: 21-10-2015

DOI: 10.5194/HESSD-12-10789-2015

Abstract: Abstract. Surface fluxes from land surface models (LSM) have traditionally been evaluated against monthly, seasonal or annual mean states. The limited ability of LSMs to reproduce observed evaporative fluxes under water-stressed conditions has been previously noted, but very few studies have systematically evaluated these models during rainfall deficits. We evaluated latent heat flux simulated by the Community Atmosphere Biosphere Land Exchange (CABLE) LSM across 20 flux tower sites at sub-annual to inter-annual time scales, in particular focusing on model performance during seasonal-scale rainfall deficits. The importance of key model processes in capturing the latent heat flux are explored by employing alternative representations of hydrology, leaf area index, soil properties and stomatal conductance. We found that the representation of hydrological processes was critical for capturing observed declines in latent heat during rainfall deficits. By contrast, the effects of soil properties, LAI and stomatal conductance are shown to be highly site-specific. Whilst the standard model performs reasonably well at annual scales as measured by common metrics, it grossly underestimates latent heat during rainfall deficits. A new version of CABLE, with a more physically consistent representation of hydrology, captures the variation in the latent heat flux during seasonal-scale rainfall deficits better than earlier versions but remaining biases point to future research needs. Our results highlight the importance of evaluating LSMs under water-stressed conditions and across multiple plant functional types and climate regimes.

Evolution of sandstone peak‐forest landscapes – insights from quantifying erosional processes with cosmogenic nuclides

Publisher: Wiley

Date: 21-11-2017

DOI: 10.1002/ESP.4273

Sign change of linear Dresselhaus spin-orbit interaction observed in Aharonov-Casher spin interference (Conference Presentation)

Publisher: SPIE

Date: 10-09-2019

DOI: 10.1117/12.2528568

Global patterns and drivers of soil total phosphorus concentration

Publisher: Copernicus GmbH

Date: 12-07-2021

DOI: 10.5194/ESSD-2021-166

Abstract: Abstract. Soils represent the largest phosphorus (P) reserves on land and determining the amount is a critical first step for identifying sites where ecosystem functioning is potentially limited by P availability. However, global patterns and predictors of soil total P concentration remain poorly understood. To address this knowledge gap, we constructed a database of the total P concentration of 5,275 distributed globally natural soils. We quantified the relative importance of 13 soil-forming variables in predicting soil total P concentration and then made further predictions at the global scale using a random forest approach. Soil total P concentration varied significantly among parent material types, soil orders, biomes, and continents, and ranged widely from 1.4 to 9,630.0 (median 430.0 and mean 570.0) mg kg−1 across the globe. About two-thirds (65 %) of the global variation was accounted for by the 13 variables that we selected, among which soil organic carbon concentration, parent material, mean annual temperature, and soil sand content were the most important. While global predictions of soil total P concentration increased significantly with latitude, they varied largely among regions with similar latitudes due to regional differences in parent material, topography, and/or climate conditions. Global soil P stocks (excluding Antarctica) were estimated to be 26.8 ± 3.1 (mean ± standard deviation) Pg and 62.2 ± 8.9 Pg (1 Pg = 1 × 1015 g) in the topsoil (0–30 cm) and subsoil (30–100 cm), respectively. Our global map of soil total P concentration as well as the underlying drivers of soil total P concentration can be used to constraint Earth system models that represent the P cycle and to inform quantification of global soil P availability. Raw datasets and global maps generated in this study are available at 0.6084/m9.figshare.14583375 (He et al., 2021).

Spin Hall effect in clean two-dimensional electron gases with Rashba spin-orbit coupling

Publisher: American Physical Society (APS)

Date: 31-03-2006

DOI: 10.1103/PHYSREVB.73.115342

Plant Feedback Aggravates Soil Organic Carbon Loss Associated With Wind Erosion in Northwest China

Publisher: American Geophysical Union (AGU)

Date: 04-2019

DOI: 10.1029/2018JG004804

Climate and food supply

Publisher: Springer Science and Business Media LLC

Date: 09-1994

DOI: 10.1038/371025A0

Improving the responses of the Australian community land surface model (CABLE) to seasonal drought

Publisher: American Geophysical Union (AGU)

Date: 11-10-2012

DOI: 10.1029/2012JG002038

The response of soil respiration to precipitation change is asymmetric and differs between grasslands and forests

Publisher: Wiley

Date: 2019

DOI: 10.1111/GCB.15270

Modeling permafrost thaw and ecosystem carbon cycle under annual and seasonal warming at an Arctic tundra site in Alaska

Publisher: American Geophysical Union (AGU)

Date: 06-2014

DOI: 10.1002/2013JG002569

Direct cosmogenic nuclide isochron burial dating of early Acheulian stone tools at the T69 Complex (FLK West, Olduvai Bed II, Tanzania)

Publisher: Elsevier BV

Date: 04-2022

DOI: 10.1016/J.JHEVOL.2022.103155

Evaluation of 11 terrestrial carbon–nitrogen cycle models against observations from two temperate Free‐Air CO₂ Enrichment studies

Publisher: Wiley

Date: 28-01-2014

DOI: 10.1111/NPH.12697

Abstract: We analysed the responses of 11 ecosystem models to elevated atmospheric [ CO 2 ] (e CO 2 ) at two temperate forest ecosystems ( D uke and Oak Ridge National Laboratory ( ORNL ) F ree‐ A ir CO 2 E nrichment ( FACE ) experiments) to test alternative representations of carbon ( C )–nitrogen ( N ) cycle processes. We decomposed the model responses into component processes affecting the response to e CO 2 and confronted these with observations from the FACE experiments. Most of the models reproduced the observed initial enhancement of net primary production ( NPP ) at both sites, but none was able to simulate both the sustained 10‐yr enhancement at D uke and the declining response at ORNL : models generally showed signs of progressive N limitation as a result of lower than observed plant N uptake. Nonetheless, many models showed qualitative agreement with observed component processes. The results suggest that improved representation of above‐ground–below‐ground interactions and better constraints on plant stoichiometry are important for a predictive understanding of e CO 2 effects. Improved accuracy of soil organic matter inventories is pivotal to reduce uncertainty in the observed C – N budgets. The two FACE experiments are insufficient to fully constrain terrestrial responses to eCO 2 , given the complexity of factors leading to the observed erging trends, and the consequential inability of the models to explain these trends. Nevertheless, the ecosystem models were able to capture important features of the experiments, lending some support to their projections.

Supplementary material to "A model inter-comparison study to examine limiting factors in modelling Australian tropical savannas"

Publisher: Copernicus GmbH

Date: 02-12-2015

DOI: 10.5194/BGD-12-18999-2015-SUPPLEMENT

Supplementary material to &quot;GOLUM-CNP v1.0: a data-driven modeling of carbon, nitrogen and phosphorus cycles in major terrestrial biomes&quot;

Publisher: Copernicus GmbH

Date: 22-03-2018

DOI: 10.5194/GMD-2018-23-SUPPLEMENT

Temperature dependence of ecosystem carbon, nitrogen and phosphorus residence times differs between subtropical and temperate forests in China

Publisher: Elsevier BV

Date: 11-2022

DOI: 10.1016/J.AGRFORMET.2022.109165

The Dependence of Ecosystem Water Use Partitioning on Vegetation Productivity at the Inter-Annual Time Scale

Publisher: American Geophysical Union (AGU)

Date: 20-08-2021

DOI: 10.1029/2020JD033756

Abstract: The dependence of inter‐annual ecosystem evapotranspiration (ET) partitioning on vegetation dynamics is crucial for understanding the long term coupling relationship between the water and carbon cycles. The objective of this study was to determine the spatial variation of ET partitioning ( T /ET) and the inter‐annual dependencies of T /ET on vegetation gross primary productivity (GPP). The investigation was conducted at the global scale based on seven global datasets and at the point scale at 37 flux sites. The spatial variations of T /ET were ided into three phases, that is, the rapidly increasing phase (P1), slowly increasing phase (P2), and decreasing phase (P3), which were located in arid and cold regions, temperate regions, and tropical rainforest regions, respectively. The three‐phase spatial variations were primarily driven by the different spatial variations of the two water use pathways (i.e., transpiration, T and evaporation, E ) in ecosystems with different productivity levels. In P1 and P2 ecosystems, the inter‐annual dependencies of T /ET on GPP were mostly positive, and in P3 ecosystems, it was mostly negative. This revealed a significantly decreased dependence as GPP increased, which was attributed to the different dependencies of T and E on GPP. Based on the effects of GPP on ET under climate variations (represented by precipitation, P ), ET had the smallest inter‐annual variations in most of global vegetated grid cells due to the joint regulation of T and E by GPP and P . This study highlights the significant role of vegetation productivity in regulating inter‐annual ET partitioning, and improves understandings on the coupled water‐carbon cycles.

Strong Nonlinearity of Land Climate‐Carbon Cycle Feedback Under a High CO₂ Growth Scenario

Publisher: American Geophysical Union (AGU)

Date: 2023

DOI: 10.1029/2021EF002499

Abstract: Projections of future climate change for given CO 2 and other greenhouse gas emission scenarios depend on the response of global climate‐carbon cycle feedback, which consists of carbon‐concentration feedback (e.g., CO 2 physiology effect on land carbon sink) and carbon‐climate feedback (e.g., CO 2 radiative effect on land carbon sink). Previous studies have assumed no significant interaction between these two feedbacks within the Earth system. This study quantifies the interaction of these two feedbacks, or the nonlinear feedback on land using the fully, biogeochemically, and radiatively coupled simulations under a 1% yr −1 CO 2 increase path from nine Earth system models of the Coupled Model Intercomparison Project Phase 6 (CMIP6). The results show that the nonlinear feedback is 1.64 ± 2.92 × 10 −2 GtC ppm −1 K −1 at the end of 140‐year simulation with a quadrupling CO 2 (4 × CO 2 ), where its strength is 11% ± 18% of the carbon‐concentration feedback or −27% ± 49% of the carbon‐climate feedback on land. Compared to previous assumptions that did not consider this interaction, the nonlinear feedback contributes about 8% ± 12% of the land carbon increase accumulated at the 4 × CO 2 . The nonlinear feedback largely results from the combined effect of increased CO 2 ‐induced additional fertilization effect on warming‐induced additional leaf area index and vegetation productivity over the Northern Hemisphere. The magnitude of the nonlinear feedback on land decreases with an increase in atmospheric CO 2 or warming under the high emission scenario. This study highlights the significance of land nonlinear climate‐carbon cycle feedback in increasing land carbon sink and slowing down future climate change.

Warming and redistribution of nitrogen inputs drive an increase in terrestrial nitrous oxide emission factor

Publisher: Springer Science and Business Media LLC

Date: 25-07-2022

DOI: 10.1038/S41467-022-32001-Z

Abstract: Anthropogenic nitrogen inputs cause major negative environmental impacts, including emissions of the important greenhouse gas N 2 O. Despite their importance, shifts in terrestrial N loss pathways driven by global change are highly uncertain. Here we present a coupled soil-atmosphere isotope model (IsoTONE) to quantify terrestrial N losses and N 2 O emission factors from 1850-2020. We find that N inputs from atmospheric deposition caused 51% of anthropogenic N 2 O emissions from soils in 2020. The mean effective global emission factor for N 2 O was 4.3 ± 0.3% in 2020 (weighted by N inputs), much higher than the surface area-weighted mean (1.1 ± 0.1%). Climate change and spatial redistribution of fertilisation N inputs have driven an increase in global emission factor over the past century, which accounts for 18% of the anthropogenic soil flux in 2020. Predicted increases in fertilisation in emerging economies will accelerate N 2 O-driven climate warming in coming decades, unless targeted mitigation measures are introduced.

Spatially asynchronous changes in strength and stability of terrestrial net ecosystem productivity

Publisher: Copernicus GmbH

Date: 28-02-2020

DOI: 10.5194/BG-2020-26

Abstract: Abstract. Multiple lines of evidence have demonstrated the persistence of global land carbon (C) sink during the past several decades. However, both annual net ecosystem productivity (NEP) and its inter-annual variation (IAVNEP) keep varying over space. Thus, identifying local indicators for the spatially varying NEP and IAVNEP is critical for locating the major and sustainable C sinks on the land. Here, based on a machine-learning-derived database, we first showed that the variations of NEP and IAVNEP are spatially asynchronous. Then, based on daily NEP observations from eddy covariance sites, we found robust logarithmic correlation between annual NEP and ratio of total CO2 exchanges during net uptake (U) and release (R) periods (i.e., U/R). The cross-site variation of mean annual NEP can be linearly indicated by ln(U/R), while the spatial distribution of IAVNEP was well indicated by the slope (i.e., β) of the demonstrated logarithmic correlation. Among biomes, for ex le, forests and croplands had the largest U/R ratio (1.06 ± 0.83) and β (473 ± 112 g C m−2 yr−1), indicating the highest NEP and IAVNEP in forests and croplands, respectively. We further showed that the spatial variations of NEP and IAVNEP were both underestimated by the machine-learning-based and process-based global models. Overall, this study underscores the asynchronously changes in the strength and stability of land C sinks over space, and provides two simple local indicators for their intricate spatial variations. These indicators could be helpful for locating the persistent terrestrial C sinks and provides valuable constraints for improving the simulation of land-atmospheric C exchanges.

Amazon forest response to CO2 fertilization dependent on plant phosphorus acquisition

Publisher: Springer Science and Business Media LLC

Date: 05-08-2019

DOI: 10.1038/S41561-019-0404-9

A new member of cosmogenic nuclide, manganese-53: the first application in the iron-rich semiarid landscape in the Pilbara region, northwest Australia

Publisher: Elsevier BV

Date: 11-2012

DOI: 10.1016/J.QUAINT.2012.08.153

Transient dynamics of terrestrial carbon storage: mathematical foundation and its applications

Publisher: Copernicus GmbH

Date: 12-01-2017

DOI: 10.5194/BG-14-145-2017

Abstract: Abstract. Terrestrial ecosystems have absorbed roughly 30 % of anthropogenic CO2 emissions over the past decades, but it is unclear whether this carbon (C) sink will endure into the future. Despite extensive modeling and experimental and observational studies, what fundamentally determines transient dynamics of terrestrial C storage under global change is still not very clear. Here we develop a new framework for understanding transient dynamics of terrestrial C storage through mathematical analysis and numerical experiments. Our analysis indicates that the ultimate force driving ecosystem C storage change is the C storage capacity, which is jointly determined by ecosystem C input (e.g., net primary production, NPP) and residence time. Since both C input and residence time vary with time, the C storage capacity is time-dependent and acts as a moving attractor that actual C storage chases. The rate of change in C storage is proportional to the C storage potential, which is the difference between the current storage and the storage capacity. The C storage capacity represents instantaneous responses of the land C cycle to external forcing, whereas the C storage potential represents the internal capability of the land C cycle to influence the C change trajectory in the next time step. The influence happens through redistribution of net C pool changes in a network of pools with different residence times. Moreover, this and our other studies have demonstrated that one matrix equation can replicate simulations of most land C cycle models (i.e., physical emulators). As a result, simulation outputs of those models can be placed into a three-dimensional (3-D) parameter space to measure their differences. The latter can be decomposed into traceable components to track the origins of model uncertainty. In addition, the physical emulators make data assimilation computationally feasible so that both C flux- and pool-related datasets can be used to better constrain model predictions of land C sequestration. Overall, this new mathematical framework offers new approaches to understanding, evaluating, diagnosing, and improving land C cycle models.

Dune-field chronology in the Simpson Desert, revealed by cosmogenic nuclide and luminescence dating

Publisher: Elsevier BV

Date: 11-2012

DOI: 10.1016/J.QUAINT.2012.08.152

Unpaired Floquet Majorana fermions without magnetic fields

Publisher: American Physical Society (APS)

Date: 18-03-2013

DOI: 10.1103/PHYSREVB.87.115420

A global model of carbon, nitrogen and phosphorus cycles for the terrestrial biosphere

Publisher: Copernicus GmbH

Date: 23-07-2010

DOI: 10.5194/BG-7-2261-2010

Abstract: Abstract. Carbon storage by many terrestrial ecosystems can be limited by nutrients, predominantly nitrogen (N) and phosphorus (P), in addition to other environmental constraints, water, light and temperature. However the spatial distribution and the extent of both N and P limitation at the global scale have not been quantified. Here we have developed a global model of carbon (C), nitrogen (N) and phosphorus (P) cycles for the terrestrial biosphere. Model estimates of steady state C and N pool sizes and major fluxes between plant, litter and soil pools, under present climate conditions, agree well with various independent estimates. The total amount of C in the terrestrial biosphere is 2767 Gt C, and the C fractions in plant, litter and soil organic matter are 19%, 4% and 77%. The total amount of N is 135 Gt N, with about 94% stored in the soil, 5% in the plant live biomass, and 1% in litter. We found that the estimates of total soil P and its partitioning into different pools in soil are quite sensitive to biochemical P mineralization. The total amount of P (plant biomass, litter and soil) excluding occluded P in soil is 17 Gt P in the terrestrial biosphere, 33% of which is stored in the soil organic matter if biochemical P mineralization is modelled, or 31 Gt P with 67% in soil organic matter otherwise. This model was used to derive the global distribution and uncertainty of N or P limitation on the productivity of terrestrial ecosystems at steady state under present conditions. Our model estimates that the net primary productivity of most tropical evergreen broadleaf forests and tropical savannahs is reduced by about 20% on average by P limitation, and most of the remaining biomes are N limited N limitation is strongest in high latitude deciduous needle leaf forests, and reduces its net primary productivity by up to 40% under present conditions.

Global patterns and drivers of soil total phosphorus concentration

Publisher: Copernicus GmbH

Date: 20-12-2021

DOI: 10.5194/ESSD-13-5831-2021

Abstract: Abstract. Soil represents the largest phosphorus (P) stock in terrestrial ecosystems. Determining the amount of soil P is a critical first step in identifying sites where ecosystem functioning is potentially limited by soil P availability. However, global patterns and predictors of soil total P concentration remain poorly understood. To address this knowledge gap, we constructed a database of total P concentration of 5275 globally distributed (semi-)natural soils from 761 published studies. We quantified the relative importance of 13 soil-forming variables in predicting soil total P concentration and then made further predictions at the global scale using a random forest approach. Soil total P concentration varied significantly among parent material types, soil orders, biomes, and continents and ranged widely from 1.4 to 9630.0 (median 430.0 and mean 570.0) mg kg−1 across the globe. About two-thirds (65 %) of the global variation was accounted for by the 13 variables that we selected, among which soil organic carbon concentration, parent material, mean annual temperature, and soil sand content were the most important ones. While predicted soil total P concentrations increased significantly with latitude, they varied largely among regions with similar latitudes due to regional differences in parent material, topography, and/or climate conditions. Soil P stocks (excluding Antarctica) were estimated to be 26.8 ± 3.1 (mean ± standard deviation) Pg and 62.2 ± 8.9 Pg (1 Pg = 1 × 1015 g) in the topsoil (0–30 cm) and subsoil (30–100 cm), respectively. Our global map of soil total P concentration as well as the underlying drivers of soil total P concentration can be used to constraint Earth system models that represent the P cycle and to inform quantification of global soil P availability. Raw datasets and global maps generated in this study are available at 0.6084/m9.figshare.14583375 (He et al., 2021).

Transient Dynamics of Terrestrial Carbon Storage: Mathematical foundation and Numeric Examples

Publisher: Copernicus GmbH

Date: 16-09-2016

DOI: 10.5194/BG-2016-377

Abstract: Abstract. Terrestrial ecosystems absorb roughly 30 % of anthropogenic CO2 emissions since preindustrial era, but it is unclear whether this carbon (C) sink will endure into the future. Despite extensive modeling, experimental, and observational studies, what fundamentally determines transient dynamics of terrestrial C storage under climate change is still not very clear. Here we develop a new framework for understanding transient dynamics of terrestrial C storage through mathematical analysis and numerical experiments. Our analysis indicates that the ultimate force driving ecosystem C storage change is the C storage capacity, which is jointly determined by ecosystem C input (e.g., net primary production, NPP) and residence time. Since both C input and residence time vary with time, the C storage capacity is time-dependent and acts as a moving attractor that actual C storage chases. The rate of change in C storage is proportional to the C storage potential, the difference between the current storage and the storage capacity. The C storage capacity represents instantaneous responses of the land C cycle to external forcing, whereas the C storage potential represents the internal capability of the land C cycle to influence the C change trajectory in the next time step. The influence happens through redistribution of net C pool changes in a network of pools with different residence times. Moreover, this and our other studies have demonstrated that one matrix equation can exactly replicate simulations of most land C cycle models (i.e., physical emulators). As a result, simulation outputs of those models can be placed into a three-dimensional (3D) parameter space to measure their differences. The latter can be decomposed into traceable components to track the origins of model uncertainty. Moreover, the emulators make data assimilation computationally feasible so that both C flux- and pool-related datasets can be used to better constrain model predictions of land C sequestration. We also propose that the C storage potential be the targeted variable for research, market trading, and government negotiation for C credits.

Adaptive Carbon Allocation by Plants Enhances the Terrestrial Carbon Sink

Publisher: Springer Science and Business Media LLC

Date: 13-06-2017

DOI: 10.1038/S41598-017-03574-3

Abstract: Carbon allocation is one of the most important physiological processes to optimize the plant growth, which exerts a strong influence on ecosystem structure and function, with potentially large implications for the global carbon budget. However, it remains unclear how the carbon allocation pattern has changed at global scale and impacted terrestrial carbon uptake. Based on the Community Atmosphere Biosphere Land Exchange (CABLE) model, this study shows the increasing partitioning ratios to leaf and wood and reducing ratio to root globally from 1979 to 2014. The results imply the plant optimizes carbon allocation and reaches its maximum growth by allocating more newly acquired photosynthate to leaves and wood tissues. Thus, terrestrial vegetation has absorbed 16% more carbon averagely between 1979 and 2014 through adjusting their carbon allocation process. Compared with the fixed carbon allocation simulation, the trend of terrestrial carbon sink from 1979 to 2014 increased by 34% in the adaptive carbon allocation simulation. Our study highlights carbon allocation, associated with climate change, needs to be mapped and incorporated into terrestrial carbon cycle estimates.

Charge and spin transport in nanoscopic structures with spin–orbit coupling

Publisher: Elsevier BV

Date: 10-2006

DOI: 10.1016/J.PHYSB.2006.05.033

Arms control and space security

Publisher: Springer International Publishing

Date: 2020

DOI: 10.1007/978-3-030-22786-9_135-1

Quantification and attribution of errors in the simulated annual gross primary production and latent heat fluxes by two global land surface models

Publisher: American Geophysical Union (AGU)

Date: 16-08-2016

DOI: 10.1002/2015MS000583

Polariton-driven phonon laser

Publisher: Springer Science and Business Media LLC

Date: 11-09-2020

DOI: 10.1038/S41467-020-18358-Z

Abstract: Efficient generation of phonons is an important ingredient for a prospective electrically-driven phonon laser. Hybrid quantum systems combining cavity quantum electrodynamics and optomechanics constitute a novel platform with potential for operation at the extremely high frequency range (30–300 GHz). We report on laser-like phonon emission in a hybrid system that optomechanically couples polariton Bose-Einstein condensates (BECs) with phonons in a semiconductor microcavity. The studied system comprises GaAs/AlAs quantum wells coupled to cavity-confined optical and vibrational modes. The non-resonant continuous wave laser excitation of a polariton BEC in an in idual trap of a trap array, induces coherent mechanical self-oscillation, leading to the formation of spectral sidebands displaced by harmonics of the fundamental 20 GHz mode vibration frequency. This phonon “lasing” enhances the phonon occupation five orders of magnitude above the thermal value when tunable neighbor traps are red-shifted with respect to the pumped trap BEC emission at even harmonics of the vibration mode. These experiments, supported by a theoretical model, constitute the first demonstration of coherent cavity optomechanical phenomena with exciton polaritons, paving the way for new hybrid designs for quantum technologies, phonon lasers, and phonon-photon bidirectional translators.

Parameter optimization for carbon and water fluxes in two global land surface models based on surrogate modelling

Publisher: Wiley

Date: 26-01-2018

DOI: 10.1002/JOC.5428

Detection of spin polarized currents in quantum point contacts via transverse electron focusing

Publisher: American Physical Society (APS)

Date: 23-02-2007

DOI: 10.1103/PHYSREVB.75.085321

Two automatic chamber techniques for measuring soil-atmosphere exchanges of trace gases and results of their use in the oasis field experiment

Publisher: Aspendale, CSIRO Atmospheric Research

Date: 2001

DOI: 10.4225/08/5863FED59F826

Climate tipping point of nitrogen fixation

Publisher: Springer Science and Business Media LLC

Date: 07-03-2022

DOI: 10.1038/S41477-022-01116-Y

Space resource activities and the evolution of international space law

Publisher: Elsevier BV

Date: 10-2023

DOI: 10.1016/J.ACTAASTRO.2023.06.009

Soil Organic Carbon Stabilization in the Three Subtropical Forests: Importance of Clay and Metal Oxides

Publisher: American Geophysical Union (AGU)

Date: 10-2019

DOI: 10.1029/2018JG004995

Comparisons of field measurements of carbon dioxide and nitrous oxide fluxes with model simulations for a legume pasture in southeast Australia

Publisher: American Geophysical Union (AGU)

Date: 12-1997

DOI: 10.1029/97JD02063

Traceable components of terrestrial carbon storage capacity in biogeochemical models

Publisher: Wiley

Date: 25-03-2013

DOI: 10.1111/GCB.12172

Abstract: Biogeochemical models have been developed to account for more and more processes, making their complex structures difficult to be understood and evaluated. Here, we introduce a framework to decompose a complex land model into traceable components based on mutually independent properties of modeled biogeochemical processes. The framework traces modeled ecosystem carbon storage capacity (Xss ) to (i) a product of net primary productivity (NPP) and ecosystem residence time (τE ). The latter τE can be further traced to (ii) baseline carbon residence times (τ'E ), which are usually preset in a model according to vegetation characteristics and soil types, (iii) environmental scalars (ξ), including temperature and water scalars, and (iv) environmental forcings. We applied the framework to the Australian Community Atmosphere Biosphere Land Exchange (CABLE) model to help understand differences in modeled carbon processes among biomes and as influenced by nitrogen processes. With the climate forcings of 1990, modeled evergreen broadleaf forest had the highest NPP among the nine biomes and moderate residence times, leading to a relatively high carbon storage capacity (31.5 kg cm(-2) ). Deciduous needle leaf forest had the longest residence time (163.3 years) and low NPP, leading to moderate carbon storage (18.3 kg cm(-2) ). The longest τE in deciduous needle leaf forest was ascribed to its longest τ'E (43.6 years) and small ξ (0.14 on litter/soil carbon decay rates). Incorporation of nitrogen processes into the CABLE model decreased Xss in all biomes via reduced NPP (e.g., -12.1% in shrub land) or decreased τE or both. The decreases in τE resulted from nitrogen-induced changes in τ'E (e.g., -26.7% in C3 grassland) through carbon allocation among plant pools and transfers from plant to litter and soil pools. Our framework can be used to facilitate data model comparisons and model intercomparisons via tracking a few traceable components for all terrestrial carbon cycle models. Nevertheless, more research is needed to develop tools to decompose NPP and transient dynamics of the modeled carbon cycle into traceable components for structural analysis of land models.

Low-dose natural prostaglandin F2α (dinoprost) at timed insemination improves conception rate in dairy cattle

Publisher: Elsevier BV

Date: 03-2015

DOI: 10.1016/J.THERIOGENOLOGY.2014.10.034

Abstract: The primary objective was to determine if low doses of PGF2α (dinoprost) given intramuscularly (im) concurrent with timed artificial insemination (TAI) would improve conception rates in dairy cattle. A secondary objective was to determine if body condition score (BCS) and parity would influence conception rates, either independently or in interaction with PGF2α treatment. In experiment I, 307 lactating Holstein cows were randomly assigned to receive either 5-mg PGF2α im (PGF2α treated, n = 154) or 0-mg PGF2α (control, n = 153) at TAI (Day 0). Blood s les were obtained on Days -10, -3, 0, and 7 to determine plasma progesterone (P4) concentrations. Pregnancy was confirmed 30 to 32 days after insemination by transrectal ultrasonography. In experiment II, 451 cows were randomly assigned to receive either 10-mg PGF2α im (PGF2α treated, n = 226) or 0-mg PGF2α (control, n = 225) at TAI, and pregnancy was confirmed 45 to 50 days after TAI by palpation per rectum. Pregnancy data were analyzed by CATMOD (SAS). In experiment I, PGF2α treatment, BCS, and parity did not affect conception rate (35.7% vs. 37.0% for PGF2α treated vs. control P > 0.05). However, in experiment II, conception rates were higher in cows given 10-mg PGF2α than those in control cows (45.8% vs. 36.0% P < 0.05), in cows with high BCS than in cows with low BCS (52.1% vs. 30.4% P < 0.01), and in primiparous than in multiparous cows (47.6% vs. 34.4% P < 0.01), but their interaction with PGF2α treatment did not affect conception rates. In summary, 5 mg of PGF2α given im concurrent with TAI failed to enhance conception rate in lactating dairy cows, whereas 10 mg of PGF2α significantly increased conception rate.

Significant effects of precipitation frequency on soil respiration and its components—A global synthesis

Publisher: Wiley

Date: 02-12-2022

DOI: 10.1111/GCB.16532

Abstract: Global warming intensifies the hydrological cycle, which results in changes in precipitation regime (frequency and amount), and will likely have significant impacts on soil respiration ( R s ). Although the responses of R s to changes in precipitation amount have been extensively studied, there is little consensus on how R s will be affected by changes in precipitation frequency (PF) across the globe. Here, we synthesized the field observations from 296 published papers to quantify the effects of PF on R s and its components using meta‐analysis. Our results indicated that the effects of PF on R s decreased with an increase in background mean annual precipitation. When the data were grouped by climate conditions, increased PF showed positive effects on R s under the arid condition but not under the semi‐humid or humid conditions, whereas decreased PF suppressed R s across all the climate conditions. The positive effects of increased PF mainly resulted from the positive response of heterotrophic respiration under the arid condition while the negative effects of decreased PF were mainly attributed to the reductions in root biomass and respiration. Overall, our global synthesis provided for the first time a comprehensive analysis of the ergent effects of PF on R s and its components across climate regions. This study also provided a framework for understanding and modeling responses of ecosystem carbon cycling to global precipitation change.

Implementation of an optimal stomatal conductance scheme in the Australian Community Climate Earth Systems Simulator (ACCESS1.3b)

Publisher: Copernicus GmbH

Date: 08-12-2015

DOI: 10.5194/GMD-8-3877-2015

Abstract: Abstract. We implement a new stomatal conductance scheme, based on the optimality approach, within the Community Atmosphere Biosphere Land Exchange (CABLEv2.0.1) land surface model. Coupled land–atmosphere simulations are then performed using CABLEv2.0.1 within the Australian Community Climate and Earth Systems Simulator (ACCESSv1.3b) with prescribed sea surface temperatures. As in most land surface models, the default stomatal conductance scheme only accounts for differences in model parameters in relation to the photosynthetic pathway but not in relation to plant functional types. The new scheme allows model parameters to vary by plant functional type, based on a global synthesis of observations of stomatal conductance under different climate regimes over a wide range of species. We show that the new scheme reduces the latent heat flux from the land surface over the boreal forests during the Northern Hemisphere summer by 0.5–1.0 mm day−1. This leads to warmer daily maximum and minimum temperatures by up to 1.0 °C and warmer extreme maximum temperatures by up to 1.5 °C. These changes generally improve the climate model's climatology of warm extremes and improve existing biases by 10–20 %. The bias in minimum temperatures is however degraded but, overall, this is outweighed by the improvement in maximum temperatures as there is a net improvement in the diurnal temperature range in this region. In other regions such as parts of South and North America where ACCESSv1.3b has known large positive biases in both maximum and minimum temperatures (~ 5 to 10 °C), the new scheme degrades this bias by up to 1 °C. We conclude that, although several large biases remain in ACCESSv1.3b for temperature extremes, the improvements in the global climate model over large parts of the boreal forests during the Northern Hemisphere summer which result from the new stomatal scheme, constrained by a global synthesis of experimental data, provide a valuable advance in the long-term development of the ACCESS modelling system.

Estimating global gross primary productivity using chlorophyll fluorescence and a data assimilation system with the BETHY-SCOPE model

Publisher: Copernicus GmbH

Date: 18-03-2019

DOI: 10.5194/BG-2019-83

Abstract: Abstract. This paper presents the assimilation of solar-induced chlorophyll fluorescence (SIF) into a terrestrial biosphere model to estimate the gross uptake of carbon through photosynthesis (GPP). We use the BETHY-SCOPE model to simulate both GPP and SIF using a process-based formulation, going beyond a simple linear scaling between the two. We then use satellite SIF data from the Orbiting Carbon Observatory-2 (OCO-2) for 2015 in the data assimilation system to constrain model biophysical parameters and GPP. The assimilation results in considerable improvement in the fit between model and observed SIF, despite a limited capability to fit regions with large seasonal variability in SIF. The SIF assimilation increases global GPP by 31 % to 167 ± 5 Pg C yr−1 and shows an improvement in the global distribution of productivity relative to independent estimates, but a large difference in magnitude. This change in global GPP is driven by an overall increase in photosynthetic light-use efficiency across almost all biomes and more minor, regionally distinct changes in APAR. This process-based data assimilation opens up new pathways to the effective utilization of satellite SIF data to improve our understanding of the global carbon cycle.

Global patterns and drivers of phosphorus fractions in natural soils

Publisher: Copernicus GmbH

Date: 11-10-2023

DOI: 10.5194/BG-20-4147-2023

Reliable, robust and realistic: The three R's of next-generation land-surface modelling

Publisher: Copernicus GmbH

Date: 29-05-2015

DOI: 10.5194/ACP-15-5987-2015

Abstract: Abstract. Land-surface models (LSMs) are increasingly called upon to represent not only the exchanges of energy, water and momentum across the land–atmosphere interface (their original purpose in climate models), but also how ecosystems and water resources respond to climate, atmospheric environment, land-use and land-use change, and how these responses in turn influence land–atmosphere fluxes of carbon dioxide (CO2), trace gases and other species that affect the composition and chemistry of the atmosphere. However, the LSMs embedded in state-of-the-art climate models differ in how they represent fundamental aspects of the hydrological and carbon cycles, resulting in large inter-model differences and sometimes faulty predictions. These "third-generation" LSMs respect the close coupling of the carbon and water cycles through plants, but otherwise tend to be under-constrained, and have not taken full advantage of robust hydrological parameterizations that were independently developed in offline models. Benchmarking, combining multiple sources of atmospheric, biospheric and hydrological data, should be a required component of LSM development, but this field has been relatively poorly supported and intermittently pursued. Moreover, benchmarking alone is not sufficient to ensure that models improve. Increasing complexity may increase realism but decrease reliability and robustness, by increasing the number of poorly known model parameters. In contrast, simplifying the representation of complex processes by stochastic parameterization (the representation of unresolved processes by statistical distributions of values) has been shown to improve model reliability and realism in both atmospheric and land-surface modelling contexts. We provide ex les for important processes in hydrology (the generation of runoff and flow routing in heterogeneous catchments) and biology (carbon uptake by species- erse ecosystems). We propose that the way forward for next-generation complex LSMs will include: (a) representations of biological and hydrological processes based on the implementation of multiple internal constraints (b) systematic application of benchmarking and data assimilation techniques to optimize parameter values and thereby test the structural adequacy of models and (c) stochastic parameterization of unresolved variability, applied in both the hydrological and the biological domains.

Geomorphic imprints of dynamic topography and intraplate tectonism in central Australia

Publisher: Copernicus GmbH

Date: 04-03-2021

DOI: 10.5194/EGUSPHERE-EGU21-9165

Abstract: & & The Finke River in central Australia is counted among the world& #8217 s oldest drainage systems, raising the prospect that it holds a geomorphic record relevant to testing ideas about the role of sub-lithospheric mantle flow in shaping the Australian landscape. The Finke& #8217 s upper reaches preserve an enigmatic set of intertwined active and relict gorges that suggest a complex history of incision, aggradation and re-incision. We measured cosmogenic & sup& & /sup& Be and & sup& & /sup& Al in fluvial gravels stored in the gorges, and we applied a Markov chain Monte Carlo-based inversion model to test two limiting-case hypotheses about the timing of the gravel deposition and exhumation. Our results suggest that the nuclide memory contained within the gravels was essentially erased during protracted sediment storage. Previous studies attribute landscape evolution to the intensified post-Miocene aridity in tune with the perception that central Australia experienced limited deformation during the Cenozoic. However, the close correlation between drainage network patterns and the gravity field leads us to propose, instead, that incision/aggradation phases in the upper Finke are driven by a flexural response (at ~10& sup& & /sup& km length scales) to extreme uncompensated loads embedded in the crust. Further, we suggest that dynamic mantle processes have deformed the central Australian topography over longer (~10& sup& & /sup& km) wavelengths via the in-situ stress field, with horizontal stress variations of order 1& #8211 MPa. Acting together, these crustal and sub-lithospheric structures have imposed to-and-fro tilting on the Finke, triggering the phases of incision/aggradation on a million-year timescale that created the unusual intertwined bedrock gorges. The litude of topographic responses in the upper Finke to inferred variations in end-loading on the plate helps resolve an ongoing debate about the effective elastic thickness of the central Australian lithosphere to no more than 35 km.& &

Responses of two nonlinear microbial models to warming and increased carbon input

Publisher: Copernicus GmbH

Date: 18-02-2016

DOI: 10.5194/BG-13-887-2016

Abstract: Abstract. A number of nonlinear microbial models of soil carbon decomposition have been developed. Some of them have been applied globally but have yet to be shown to realistically represent soil carbon dynamics in the field. A thorough analysis of their key differences is needed to inform future model developments. Here we compare two nonlinear microbial models of soil carbon decomposition: one based on reverse Michaelis–Menten kinetics (model A) and the other on regular Michaelis–Menten kinetics (model B). Using analytic approximations and numerical solutions, we find that the oscillatory responses of carbon pools to a small perturbation in their initial pool sizes d en faster in model A than in model B. Soil warming always decreases carbon storage in model A, but in model B it predominantly decreases carbon storage in cool regions and increases carbon storage in warm regions. For both models, the CO2 efflux from soil carbon decomposition reaches a maximum value some time after increased carbon input (as in priming experiments). This maximum CO2 efflux (Fmax) decreases with an increase in soil temperature in both models. However, the sensitivity of Fmax to the increased amount of carbon input increases with soil temperature in model A but decreases monotonically with an increase in soil temperature in model B. These differences in the responses to soil warming and carbon input between the two nonlinear models can be used to discern which model is more realistic when compared to results from field or laboratory experiments. These insights will contribute to an improved understanding of the significance of soil microbial processes in soil carbon responses to future climate change.

Using models to guide field experiments: a priori predictions for the CO₂ response of a nutrient‐ and water‐limited native Eucalypt woodland

Publisher: Wiley

Date: 09-05-2016

DOI: 10.1111/GCB.13268

Abstract: The response of terrestrial ecosystems to rising atmospheric CO2 concentration (Ca ), particularly under nutrient-limited conditions, is a major uncertainty in Earth System models. The Eucalyptus Free-Air CO2 Enrichment (EucFACE) experiment, recently established in a nutrient- and water-limited woodland presents a unique opportunity to address this uncertainty, but can best do so if key model uncertainties have been identified in advance. We applied seven vegetation models, which have previously been comprehensively assessed against earlier forest FACE experiments, to simulate a priori possible outcomes from EucFACE. Our goals were to provide quantitative projections against which to evaluate data as they are collected, and to identify key measurements that should be made in the experiment to allow discrimination among alternative model assumptions in a postexperiment model intercomparison. Simulated responses of annual net primary productivity (NPP) to elevated Ca ranged from 0.5 to 25% across models. The simulated reduction of NPP during a low-rainfall year also varied widely, from 24 to 70%. Key processes where assumptions caused disagreement among models included nutrient limitations to growth feedbacks to nutrient uptake autotrophic respiration and the impact of low soil moisture availability on plant processes. Knowledge of the causes of variation among models is now guiding data collection in the experiment, with the expectation that the experimental data can optimally inform future model improvements.

New Forest Aboveground Biomass Maps of China Integrating Multiple Datasets

Publisher: MDPI AG

Date: 23-07-2021

DOI: 10.3390/RS13152892

Abstract: Mapping the spatial variation of forest aboveground biomass (AGB) at the national or regional scale is important for estimating carbon emissions and removals and contributing to global stocktake and balancing the carbon budget. Recently, several gridded forest AGB products have been produced for China by integrating remote sensing data and field measurements, yet significant discrepancies remain among these products in their estimated AGB carbon, varying from 5.04 to 9.81 Pg C. To reduce this uncertainty, here, we first compiled independent, high-quality field measurements of AGB using a systematic and consistent protocol across China from 2011 to 2015. We applied two different approaches, an optimal weighting technique (WT) and a random forest regression method (RF), to develop two observationally constrained hybrid forest AGB products in China by integrating five existing AGB products. The WT method uses a linear combination of the five existing AGB products with weightings that minimize biases with respect to the field measurements, and the RF method uses decision trees to predict a hybrid AGB map by minimizing the bias and variance with respect to the field measurements. The forest AGB stock in China was 7.73 Pg C for the WT estimates and 8.13 Pg C for the RF estimates. Evaluation with the field measurements showed that the two hybrid AGB products had a lower RMSE (29.6 and 24.3 Mg/ha) and bias (−4.6 and −3.8 Mg/ha) than all five participating AGB datasets. Our study demonstrated both the WT and RF methods can be used to harmonize existing AGB maps with field measurements to improve the spatial variability and reduce the uncertainty of carbon stocks. The new spatial AGB maps of China can be used to improve estimates of carbon emissions and removals at the national and subnational scales.

Microbial carbon use efficiency promotes global soil carbon storage

Publisher: Springer Science and Business Media LLC

Date: 24-05-2023

DOI: 10.1038/S41586-023-06042-3

Abstract: Soils store more carbon than other terrestrial ecosystems 1,2 . How soil organic carbon (SOC) forms and persists remains uncertain 1,3 , which makes it challenging to understand how it will respond to climatic change 3,4 . It has been suggested that soil microorganisms play an important role in SOC formation, preservation and loss 5–7 . Although microorganisms affect the accumulation and loss of soil organic matter through many pathways 4,6,8–11 , microbial carbon use efficiency (CUE) is an integrative metric that can capture the balance of these processes 12,13 . Although CUE has the potential to act as a predictor of variation in SOC storage, the role of CUE in SOC persistence remains unresolved 7,14,15 . Here we examine the relationship between CUE and the preservation of SOC, and interactions with climate, vegetation and edaphic properties, using a combination of global-scale datasets, a microbial-process explicit model, data assimilation, deep learning and meta-analysis. We find that CUE is at least four times as important as other evaluated factors, such as carbon input, decomposition or vertical transport, in determining SOC storage and its spatial variation across the globe. In addition, CUE shows a positive correlation with SOC content. Our findings point to microbial CUE as a major determinant of global SOC storage. Understanding the microbial processes underlying CUE and their environmental dependence may help the prediction of SOC feedback to a changing climate.

A comparison of two algorithms for estimating carbon dioxide emissions after forest clearing

Publisher: Elsevier BV

Date: 1997

DOI: 10.1016/S1364-8152(97)00010-8

Effect of the excitation setup in the improved enhancement factor of covered-gold-nanorod-dimer antennas

Publisher: Royal Society of Chemistry (RSC)

Date: 2022

DOI: 10.1039/D2CP03124H

Abstract: Covering nanorod-dimers (for contacting them) breaks the antenna top/bottom symmetry. Excitations coming from the top, bottom, or odd/even superposition of both, change the optimal dimensions for maximizing the SERS enhancement factor at the gap.

Divergent predictions of carbon storage between two global land models: attribution of the causes through traceability analysis

Publisher: Copernicus GmbH

Date: 27-08-2015

DOI: 10.5194/ESDD-6-1579-2015

Abstract: Abstract. Representations of the terrestrial carbon cycle in land models are becoming increasingly complex. It is crucial to develop approaches for critical assessment of the complex model properties in order to understand key factors contributing to models' performance. In this study, we applied a traceability analysis, which decomposes carbon cycle models into traceable components, to two global land models (CABLE and CLM-CASA') to diagnose the causes of their differences in simulating ecosystem carbon storage capacity. Driven with similar forcing data, the CLM-CASA' model predicted ~ 31 % larger carbon storage capacity than the CABLE model. Since ecosystem carbon storage capacity is a product of net primary productivity (NPP) and ecosystem residence time (τE), the predicted difference in the storage capacity between the two models results from differences in either NPP or τE or both. Our analysis showed that CLM-CASA' simulated 37 % higher NPP than CABLE due to higher rates of carboxylation (Vcmax) in CLM-CASA'. On the other hand, τE, which was a function the baseline carbon residence time (τ'E) and environmental effect on carbon residence time, was on average 11 years longer in CABLE than CLM-CASA'. The difference in τE was mainly found to be caused by longer τ'E in CABLE than CLM-CASA'. This difference in τE was mainly caused by longer τ'E of woody biomass (23 vs. 14 years in CLM-CASA') and higher proportion of NPP allocated to woody biomass (23 vs. 16 %). Differences in environmental effects on carbon residence times had smaller influences on differences in ecosystem carbon storage capacities compared to differences in NPP and τ'E. Overall the traceability analysis is an effective method for identifying sources of variations between the two models.

Supplementary material to &quot;Spatially asynchronous changes in strength and stability of terrestrial net ecosystem productivity&quot;

Publisher: Copernicus GmbH

Date: 28-02-2020

DOI: 10.5194/BG-2020-26-SUPPLEMENT

Development of a spatially explicit inventory of methane emissions from Australia and its verification using atmospheric concentration data

Publisher: Elsevier BV

Date: 10-2002

DOI: 10.1016/S1352-2310(02)00589-7

Challenging Intraplate&#160;Orogens: from geomorphology to lithospheric dynamic. The French Massif Central Case study

Publisher: Copernicus GmbH

Date: 23-03-2020

DOI: 10.5194/EGUSPHERE-EGU2020-8547

Abstract: & & & span& & span& In the 60& #8217 s, the formulation of the plate tectonic theory changed our understanding of the Earth dynamics. Aiming at explaining the earth first order kinematics, this primary theory of plate tectonic assumed rigid plates, a necessity to efficiently transfer stress from one boundary to another.& & /span& & /span& & & & & & span& & span& If successful to explain, at first order, the plate-boundary evolutions, this theory fails when compared to the unpredicted but identified deformation located inside the plate-domains: the intraplate orogens. Indeed, the intraplate regions are thought to be slowly, if at all, deforming. Therefore, it is expected that intraplate regions do not show important finite deformation, that is to say, no mountains. Some intraplate regions, however, have important relief: the Snowy Mountains (Australia), the Ural Mountains (Russia) or the Massif Central (France) for ex les. Traditionally, such regions are interpreted as old structures that are slowly eroded, interpretations that are most of the time weakly constrained.& & /span& & /span& & & & & & & & & & & span& & span& Our study is aiming at providing stronger constraints and then a better understanding of such challenging area that are the intraplate orogen domains. Because direct measurements of deformations (e.g. GNSS: Global Navigation Satellite System or InSAR: Interferometric Synthetic Aperture Radar) are most of the time below the precision level, it is necessary to derive this information from the landscape evolution. To do so, terrestrial cosmogenic nuclide (TCN) technics are a key method, allowing to constraint the temporal landscape evolution. Classically, two TCN-based approaches are used to quantify the landscape evolution rate: burial ages and watershed-wide denudation rates, based on measurement in quartz sediment of 10Be and 26Al concentrations, two radioactive cosmogenic isotopes.& /span& & /span& & & & & & & & & & & span& & span& Using the Massif Central (France) as study area, we show that this region is currently deforming.& /span& & /span& & & & & & span& & span& From new geochronological constraints and a geomorphometric study, we propose that the region undergoes an active uplift encompassing the last c.a. 4 Ma. It can be explained by the combination of at least two phenomena: the first one is the uplift triggering event, that has yet to be clearly identified, and the second one: the erosional isostatic adjustment enhancing the first one and possibly continuing after the end of the first one.& & /span& & /span& & &

Legal and Ethical Planetary Protection Frameworks for Crewed Missions

Publisher: Springer Nature Singapore

Date: 2023

DOI: 10.1007/978-981-19-9462-3_5

Biogeographic variation in evergreen conifer needle longevity and impacts on boreal forest carbon cycle projections

Publisher: Proceedings of the National Academy of Sciences

Date: 15-09-2014

DOI: 10.1073/PNAS.1216054110

Abstract: How evergreen tree needle longevity varies from south to north in the boreal biome is poorly quantified and therefore ignored in vegetation and earth system models. This is problematic, because needle longevity translates directly into needle turnover rate and profoundly affects carbon cycling in both nature and computer models. Herein we present data for five widespread boreal conifers, including pines and spruces, from sites along a 2,000-km gradient. For each species, in iduals in colder, more northern environments had longer needle life span, highlighting its importance to evergreen ecological success. Incorporating biogeography of needle longevity into a global model improved predictions of forest productivity and carbon cycling and identified specific problems for models that ignore such variability.

CSR/ESG in Commercial Space Operations and the Artemis Accords

Publisher: Springer Nature Singapore

Date: 2023

DOI: 10.1007/978-981-19-9462-3_7

Returning humans to the Moon

Publisher: Springer Nature Singapore

Date: 2023

DOI: 10.1007/978-981-19-9462-3_1

Ten years of warming increased plant-derived carbon accumulation in an East Asian monsoon forest

Publisher: Springer Science and Business Media LLC

Date: 12-08-2022

DOI: 10.1007/S11104-022-05642-8

Coupling a terrestrial biogeochemical model to the common land model

Publisher: Springer Science and Business Media LLC

Date: 19-08-2011

DOI: 10.1007/S00376-010-0131-Z

Spin dynamics under the influence of elliptically rotating fields: Extracting the field topology from time-averaged quantities

Publisher: American Physical Society (APS)

Date: 27-05-2021

DOI: 10.1103/PHYSREVE.103.052139

New cosmogenic nuclide dating laboratory in CENIEH, Spain

Publisher: Copernicus GmbH

Date: 28-03-2022

DOI: 10.5194/EGUSPHERE-EGU22-12056

Abstract: & & Centro Nacional de Investigaci& #243 n sobre la Evoluci& #243 n Humana (or National Research Centre on Human Evolution, CENIEH) is located in Burgos, northern Spain. The centre is dedicated to human evolution research worldwide, including Atapuerca, a world heritage archaeological site where the oldest human fossil in Europe to date have been discovered. To support the needs of characterising geological and sedimentological context of archaeological sites, the institute also features a wide range of geological analysis (e.g., Laser diffraction grain size analyser, XRD, XRF, Raman Spectroscopy, SEM, Micro CT, Digital mapping and 3D analysis) and geochronology laboratories (including palaeomagnetism, OSL, ESR and U-series). In 2020, a new cosmogenic nuclide dating research line has initiated to strengthen the existing geochronological capabilities in the centre, particularly, at timescales of early-mid Pleistocene and beyond. To date, we have established a procedure for routine quartz separation and & sup& & /sup& Be-& sup& & /sup& Al extraction. Current projects include & sup& & /sup& Be-& sup& & /sup& Al burial/isochron dating of cave deposits, fluvial terraces and artefacts in the context of archaeological and landscape evolution research. In this paper, we present a general setup of the laboratory, its capacity and current projects as well as future prospective.& &

Aerodynamic resistance and Bowen ratio explain the biophysical effects of forest cover on understory air and soil temperatures at the global scale

Publisher: Elsevier BV

Date: 10-2021

DOI: 10.1016/J.AGRFORMET.2021.108615

Disentangling the effects of vapor pressure deficit on northern terrestrial vegetation productivity

Publisher: American Association for the Advancement of Science (AAAS)

Date: 09-08-2023

DOI: 10.1126/SCIADV.ADF3166

Abstract: The impact of atmospheric vapor pressure deficit (VPD) on plant photosynthesis has long been acknowledged, but large interactions with air temperature (T) and soil moisture (SM) still hinder a complete understanding of the influence of VPD on vegetation production across various climate zones. Here, we found a erging response of productivity to VPD in the Northern Hemisphere by excluding interactive effects of VPD with T and SM. The interactions between VPD and T/SM not only offset the potential positive impact of warming on vegetation productivity but also lifies the negative effect of soil drying. Notably, for high-latitude ecosystems, there occurs a pronounced shift in vegetation productivity’s response to VPD during the growing season when VPD surpasses a threshold of 3.5 to 4.0 hectopascals. These results yield previously unknown insights into the role of VPD in terrestrial ecosystems and enhance our comprehension of the terrestrial carbon cycle’s response to global warming.

Effects of prepartum oilseed supplements on subclinical endometritis, pro- and anti-inflammatory cytokine transcripts in endometrial cells and postpartum ovarian function in dairy cows

Publisher: CSIRO Publishing

Date: 2017

DOI: 10.1071/RD15334

Abstract: Postpartum uterine infections affect ovarian function and delay ovulation in cattle. As dietary fats can affect immune cell function, we investigated the influence of prepartum diets on postpartum uterine inflammatory status (UIS) as assessed 25 ± 1 days postpartum by endometrial cytology (normal: ≤8% polymorphonuclear cells (PMN) vs subclinical endometritis (SCE): % PMN) and associations between SCE, pro- and anti-inflammatory cytokine gene expression and ovarian function. During the last 5 weeks of gestation, dairy cows received a diet supplemented with 8% rolled sunflower (n = 10) or canola seed (n = 9) or no oilseed (n = 9). Ovaries were scanned until 35 days postpartum. Prepartum diets did not influence SCE, but a preovulatory-size follicle developed sooner (P ≤ 0.05), the interval to first ovulation was shorter and the proportion of cows ovulating within 35 days postpartum was greater in the sunflower seed group. Although mRNA expression of cytokines was not affected by diet, cows with SCE had higher (P ≤ 0.05) expression of interleukin-1β (IL1B), interleukin-8 (CXCL8), IL10 and tumour necrosis factor-α (TNF) than normal cows. The interval (mean ± s.e.m.) from calving to preovulatory-size follicle was shorter (P ≤ 0.05) in normal (13.2 ± 0.9 days) than SCE cows (18.7 ± 1.4 days). In summary, a prepartum diet supplemented with sunflower seed positively influenced postpartum ovarian function without affecting UIS or pro- and anti-inflammatory cytokine gene expression in endometrial cells.

A test of an optimal stomatal conductance scheme within the CABLE Land Surface Model

Publisher: Copernicus GmbH

Date: 15-10-2014

DOI: 10.5194/GMDD-7-6845-2014

Abstract: Abstract. Stomatal conductance (gs) affects the fluxes of carbon, energy and water between the vegetated land surface and the atmosphere. We test an implementation of an optimal stomatal conductance model within the Community Atmosphere Biosphere Land Exchange (CABLE) land surface model (LSM). In common with many LSMs, CABLE does not differentiate between gs model parameters in relation to plant functional type (PFT), but instead only in relation to photosynthetic pathway. We therefore constrained the key model parameter "g1" which represents a plants water use strategy by PFT based on a global synthesis of stomatal behaviour. As proof of concept, we also demonstrate that the g1 parameter can be estimated using two long-term average (1960–1990) bioclimatic variables: (i) temperature and (ii) an indirect estimate of annual plant water availability. The new stomatal models in conjunction with PFT parameterisations resulted in a large reduction in annual fluxes of transpiration (~ 30% compared to the standard CABLE simulations) across evergreen needleleaf, tundra and C4 grass regions. Differences in other regions of the globe were typically small. Model performance when compared to upscaled data products was not degraded, though the new stomatal conductance scheme did not noticeably change existing model-data biases. We conclude that optimisation theory can yield a simple and tractable approach to predicting stomatal conductance in LSMs.

A small climate-amplifying effect of climate-carbon cycle feedback

Publisher: Springer Science and Business Media LLC

Date: 19-05-2021

DOI: 10.1038/S41467-021-22392-W

Abstract: The climate-carbon cycle feedback is one of the most important climate- lifying feedbacks of the Earth system, and is quantified as a function of carbon-concentration feedback parameter ( β ) and carbon-climate feedback parameter ( γ ). However, the global climate- lifying effect from this feedback loop (determined by the gain factor, g ) has not been quantified from observations. Here we apply a Fourier analysis-based carbon cycle feedback framework to the reconstructed records from 1850 to 2017 and 1000 to 1850 to estimate β and γ . We show that the β -feedback varies by less than 10% with an average of 3.22 ± 0.32 GtC ppm −1 for 1880–2017, whereas the γ -feedback increases from −33 ± 14 GtC K −1 on a decadal scale to −122 ± 60 GtC K −1 on a centennial scale for 1000–1850. Feedback analysis further reveals that the current lification effect from the carbon cycle feedback is small ( g is 0.01 ± 0.05), which is much lower than the estimates by the advanced Earth system models ( g is 0.09 ± 0.04 for the historical period and is 0.15 ± 0.08 for the RCP8.5 scenario), implying that the future allowable CO 2 emissions could be 9 ± 7% more. Therefore, our findings provide new insights about the strength of climate-carbon cycle feedback and about observational constraints on models for projecting future climate.

Correlations among leaf traits provide a significant constraint on the estimate of global gross primary production

Publisher: American Geophysical Union (AGU)

Date: 10-10-2012

DOI: 10.1029/2012GL053461

Supplementary material to "Do land surface models need to include differential plant species responses to drought? Examining model predictions across a latitudinal gradient in Europe"

Publisher: Copernicus GmbH

Date: 06-08-2015

DOI: 10.5194/BGD-12-12349-2015-SUPPLEMENT

Forest water use and water use efficiency at elevated CO₂: a model‐data intercomparison at two contrasting temperate forest FACE sites

Publisher: Wiley

Date: 25-03-2013

DOI: 10.1111/GCB.12164

Abstract: Predicted responses of transpiration to elevated atmospheric CO2 concentration (eCO2 ) are highly variable amongst process-based models. To better understand and constrain this variability amongst models, we conducted an intercomparison of 11 ecosystem models applied to data from two forest free-air CO2 enrichment (FACE) experiments at Duke University and Oak Ridge National Laboratory. We analysed model structures to identify the key underlying assumptions causing differences in model predictions of transpiration and canopy water use efficiency. We then compared the models against data to identify model assumptions that are incorrect or are large sources of uncertainty. We found that model-to-model and model-to-observations differences resulted from four key sets of assumptions, namely (i) the nature of the stomatal response to elevated CO2 (coupling between photosynthesis and stomata was supported by the data) (ii) the roles of the leaf and atmospheric boundary layer (models which assumed multiple conductance terms in series predicted more decoupled fluxes than observed at the broadleaf site) (iii) the treatment of canopy interception (large intermodel variability, 2-15%) and (iv) the impact of soil moisture stress (process uncertainty in how models limit carbon and water fluxes during moisture stress). Overall, model predictions of the CO2 effect on WUE were reasonable (intermodel μ = approximately 28% ± 10%) compared to the observations (μ = approximately 30% ± 13%) at the well-coupled coniferous site (Duke), but poor (intermodel μ = approximately 24% ± 6% observations μ = approximately 38% ± 7%) at the broadleaf site (Oak Ridge). The study yields a framework for analysing and interpreting model predictions of transpiration responses to eCO2 , and highlights key improvements to these types of models.

Where does the carbon go? A model–data intercomparison of vegetation carbon allocation and turnover processes at two temperate forest free‐air CO₂ enrichment sites

Publisher: Wiley

Date: 21-05-2014

DOI: 10.1111/NPH.12847

Abstract: Elevated atmospheric CO 2 concentration ( eCO 2 ) has the potential to increase vegetation carbon storage if increased net primary production causes increased long‐lived biomass. Model predictions of eCO 2 effects on vegetation carbon storage depend on how allocation and turnover processes are represented. We used data from two temperate forest free‐air CO 2 enrichment ( FACE ) experiments to evaluate representations of allocation and turnover in 11 ecosystem models. Observed eCO 2 effects on allocation were dynamic. Allocation schemes based on functional relationships among biomass fractions that vary with resource availability were best able to capture the general features of the observations. Allocation schemes based on constant fractions or resource limitations performed less well, with some models having unintended outcomes. Few models represent turnover processes mechanistically and there was wide variation in predictions of tissue lifespan. Consequently, models did not perform well at predicting eCO 2 effects on vegetation carbon storage. Our recommendations to reduce uncertainty include: use of allocation schemes constrained by biomass fractions careful testing of allocation schemes and synthesis of allocation and turnover data in terms of model parameters. Data from intensively studied ecosystem manipulation experiments are invaluable for constraining models and we recommend that such experiments should attempt to fully quantify carbon, water and nutrient budgets.

A semi-analytical solution to accelerate spin-up of a coupled carbon and nitrogen land model to steady state

Publisher: Copernicus GmbH

Date: 11-10-2012

DOI: 10.5194/GMD-5-1259-2012

Abstract: Abstract. The spin-up of land models to steady state of coupled carbon–nitrogen processes is computationally so costly that it becomes a bottleneck issue for global analysis. In this study, we introduced a semi-analytical solution (SAS) for the spin-up issue. SAS is fundamentally based on the analytic solution to a set of equations that describe carbon transfers within ecosystems over time. SAS is implemented by three steps: (1) having an initial spin-up with prior pool-size values until net primary productivity (NPP) reaches stabilization, (2) calculating quasi-steady-state pool sizes by letting fluxes of the equations equal zero, and (3) having a final spin-up to meet the criterion of steady state. Step 2 is enabled by averaged time-varying variables over one period of repeated driving forcings. SAS was applied to both site-level and global scale spin-up of the Australian Community Atmosphere Biosphere Land Exchange (CABLE) model. For the carbon-cycle-only simulations, SAS saved 95.7% and 92.4% of computational time for site-level and global spin-up, respectively, in comparison with the traditional method (a long-term iterative simulation to achieve the steady states of variables). For the carbon–nitrogen coupled simulations, SAS reduced computational cost by 84.5% and 86.6% for site-level and global spin-up, respectively. The estimated steady-state pool sizes represent the ecosystem carbon storage capacity, which was 12.1 kg C m−2 with the coupled carbon–nitrogen global model, 14.6% lower than that with the carbon-only model. The nitrogen down-regulation in modeled carbon storage is partly due to the 4.6% decrease in carbon influx (i.e., net primary productivity) and partly due to the 10.5% reduction in residence times. This steady-state analysis accelerated by the SAS method can facilitate comparative studies of structural differences in determining the ecosystem carbon storage capacity among biogeochemical models. Overall, the computational efficiency of SAS potentially permits many global analyses that are impossible with the traditional spin-up methods, such as ensemble analysis of land models against parameter variations.

Effects of dietary butyrate supplementation and oral nonsteroidal antiinflammatory drug administration on uterine inflammation and interval to first ovulation in postpartum dairy cows

Publisher: American Dairy Science Association

Date: 09-2022

DOI: 10.3168/JDSC.2022-0207

A meta-analysis of 1,119 manipulative experiments on terrestrial carbon-cycling responses to global change

Publisher: Springer Science and Business Media LLC

Date: 19-08-2019

DOI: 10.1038/S41559-019-0958-3

Abstract: Direct quantification of terrestrial biosphere responses to global change is crucial for projections of future climate change in Earth system models. Here, we synthesized ecosystem carbon-cycling data from 1,119 experiments performed over the past four decades concerning changes in temperature, precipitation, CO

Lowland river responses to intraplate tectonism and climate forcing quantified with luminescence and cosmogenic 10Be

Publisher: Elsevier BV

Date: 03-2013

DOI: 10.1016/J.EPSL.2013.02.007

Repeated megafloods from glacial Lake Vitim, Siberia, to the Arctic Ocean over the past 60,000 years

Publisher: Elsevier BV

Date: 05-2018

DOI: 10.1016/J.QUASCIREV.2018.03.005

Supplementary material to &quot;Leaf Area Index identified as a major source of variability in modelled CO&lt;sub&gt;2&lt;/sub&gt; fertilization&quot;

Publisher: Copernicus GmbH

Date: 08-05-2018

DOI: 10.5194/BG-2018-213-SUPPLEMENT

Diagnosing the impacts of climate extremes on the interannual variations of carbon fluxes of a subtropical evergreen mixed forest

Publisher: Elsevier BV

Date: 09-2021

DOI: 10.1016/J.AGRFORMET.2021.108507

Estimating parameters in a land‐surface model by applying nonlinear inversion to eddy covariance flux measurements from eight FLUXNET sites

Publisher: Wiley

Date: 07-08-2006

DOI: 10.1111/J.1365-2486.2006.01225.X

Bedrock Weathering Controls on Terrestrial Carbon‐Nitrogen‐Climate Interactions

Publisher: American Geophysical Union (AGU)

Date: 10-2021

DOI: 10.1029/2020GB006933

Abstract: Anthropogenic nitrogen deposition is widely considered to increase CO 2 sequestration by land plants on a global scale. Here, we demonstrate that bedrock nitrogen weathering contributes significantly more to nitrogen‐carbon interactions than anthropogenic nitrogen deposition. This working hypothesis is based on the introduction of empirical results into a global biogeochemical simulation model over the time period of the mid‐1800s to the end of the 21st century. Our findings suggest that rock nitrogen inputs have contributed roughly 2–11 times more to plant CO 2 capture than nitrogen deposition inputs since pre‐industrial times. Climate change projections based on RCP 8.5 show that rock nitrogen inputs and biological nitrogen fixation contribute 2–5 times more to terrestrial carbon uptake than anthropogenic nitrogen deposition though year 2101. Future responses of rock N inputs on plant CO 2 capture rates are more signficant at higher latitudes and in mountainous environments, where geological and climate factors promote higher rock weathering rates. The enhancement of plant CO 2 uptake via rock nitrogen weathering partially resolves nitrogen‐carbon discrepancies in Earth system models and offers an alternative explanation for lack of progressive nitrogen limitation in the terrestrial biosphere. We conclude that natural N inputs impart major control over terrestrial CO 2 sequestration in Earth’s ecosystems.

Supplementary material to &quot;Evaluating the simulated mean soil carbon transit times by Earth system models using observations&quot;

Publisher: Copernicus GmbH

Date: 15-08-2018

DOI: 10.5194/BG-2018-342-SUPPLEMENT

Antagonistic and additive interactions dominate the responses of belowground carbon-cycling processes to nitrogen and phosphorus additions

Publisher: Elsevier BV

Date: 05-2021

DOI: 10.1016/J.SOILBIO.2021.108216

Quantifying the impacts of vegetation changes on catchment storage‐discharge dynamics using paired‐catchment data

Publisher: American Geophysical Union (AGU)

Date: 07-2017

DOI: 10.1002/2017WR020600

Par Absorption and Its Relation to Above-Ground Dry Matter Production of Sitka Spruce

Publisher: JSTOR

Date: 08-1991

DOI: 10.2307/2404567

Model simulations of spatial distributions and daily totals of photosynthesis in Eucalyptus grandis canopies

Publisher: Springer Science and Business Media LLC

Date: 12-1991

DOI: 10.1007/BF00317711

Divergent predictions of carbon storage between two global land models: attribution of the causes through traceability analysis

Publisher: Copernicus GmbH

Date: 29-07-2016

DOI: 10.5194/ESD-7-649-2016

Abstract: Abstract. Representations of the terrestrial carbon cycle in land models are becoming increasingly complex. It is crucial to develop approaches for critical assessment of the complex model properties in order to understand key factors contributing to models' performance. In this study, we applied a traceability analysis which decomposes carbon cycle models into traceable components, for two global land models (CABLE and CLM-CASA′) to diagnose the causes of their differences in simulating ecosystem carbon storage capacity. Driven with similar forcing data, CLM-CASA′ predicted ∼ 31 % larger carbon storage capacity than CABLE. Since ecosystem carbon storage capacity is a product of net primary productivity (NPP) and ecosystem residence time (τE), the predicted difference in the storage capacity between the two models results from differences in either NPP or τE or both. Our analysis showed that CLM-CASA′ simulated 37 % higher NPP than CABLE. On the other hand, τE, which was a function of the baseline carbon residence time (τ′E) and environmental effect on carbon residence time, was on average 11 years longer in CABLE than CLM-CASA′. This difference in τE was mainly caused by longer τ′E of woody biomass (23 vs. 14 years in CLM-CASA′), and higher proportion of NPP allocated to woody biomass (23 vs. 16 %). Differences in environmental effects on carbon residence times had smaller influences on differences in ecosystem carbon storage capacities compared to differences in NPP and τ′E. Overall, the traceability analysis showed that the major causes of different carbon storage estimations were found to be parameters setting related to carbon input and baseline carbon residence times between two models.

Explicitly representing soil microbial processes in Earth system models

Publisher: American Geophysical Union (AGU)

Date: 10-2015

DOI: 10.1002/2015GB005188

More replenishment than priming loss of soil organic carbon with additional carbon input

Publisher: Springer Science and Business Media LLC

Date: 09-08-2018

DOI: 10.1038/S41467-018-05667-7

Abstract: Increases in carbon (C) inputs to soil can replenish soil organic C (SOC) through various mechanisms. However, recent studies have suggested that the increased C input can also stimulate the decomposition of old SOC via priming. Whether the loss of old SOC by priming can override C replenishment has not been rigorously examined. Here we show, through data–model synthesis, that the magnitude of replenishment is greater than that of priming, resulting in a net increase in SOC by a mean of 32% of the added new C. The magnitude of the net increase in SOC is positively correlated with the nitrogen-to-C ratio of the added substrates. Additionally, model evaluation indicates that a two-pool interactive model is a parsimonious model to represent the SOC decomposition with priming and replenishment. Our findings suggest that increasing C input to soils likely promote SOC accumulation despite the enhanced decomposition of old C via priming.

Carbon balance in the tundra, boreal forest and humid tropical forest during climate change: scaling up from leaf physiology and soil carbon dynamics

Publisher: Wiley

Date: 10-1995

DOI: 10.1111/J.1365-3040.1995.TB00631.X

Challenges and opportunities in modelling savanna ecosystems

Publisher: Copernicus GmbH

Date: 11-05-2016

DOI: 10.5194/BG-2016-190

Abstract: Abstract. The savanna complex is a highly erse global biome that occurs within the seasonally dry tropical to sub-tropical equatorial latitudes. Savannas are open-canopy environments that encompass a broad demographic continuum, often characterised by a dynamically changing dominance between C3-tree and C4-grass vegetation, where frequent environmental disturbances such as fire modulates the balance between ephemeral and perennial life forms. Climate change is projected to result in significant changes to the savanna floristic structure, with increases to woody biomass expected through CO2 fertilisation in mesic savannas and increased tree mortality expected through increased rainfall interannual variability in xeric savannas. The complex interaction between vegetation and climate that occurs in savannas has traditionally challenged current-generation terrestrial biosphere models (TBMs), which aim to simulate the interaction between the atmosphere and the land-surface to predict responses of vegetation to changing in environmental forcing. In this review, we examine whether TBMs are able to adequately represent savanna dynamics and what implications potential deficiencies may have for climate change projection scenarios that rely on these models. We start by highlighting the defining characteristic traits and behaviours of savanna, how these differ across continents, and how this information is (or is not) represented in the structural framework of many TBMs. We highlight three dynamic processes that we believe directly affect the water-use and productivity of the savanna system, namely: phenology root-water access and fire dynamics. Following this, we discuss how these processes are represented in many current generation TBMs and whether they are suitable for simulating savanna dynamics. Finally, we give an overview of how eddy-covariance observations in combination with other data sources, can be used in model benchmarking and inter-comparison frameworks to diagnose the performance of TBMs in this environment and formulate roadmaps for future development. Our investigation reveals that many TBMs systematically misrepresent phenology, effects of fire and root-water access (if they are considered at all) and that these should be critical areas for future development. Furthermore, such processes must not be static (i.e. prescribed behaviour), but be capable of responding to the changing environmental conditions in order to emulate the dynamic behaviour of savannas. Without such developments, however, TBMs will have limited predictive capability in making the critical projections needed to understand how savannas will respond to future global change.

Global patterns of plant root colonization intensity by mycorrhizal fungi explained by climate and soil chemistry

Publisher: Wiley

Date: 08-01-2015

DOI: 10.1111/GEB.12272

Supplementary material to &quot;Asymmetric Responses of Primary Productivity to Altered Precipitation Simulated by Ecosystem Models across Three Longterm Grassland Sites&quot;

Publisher: Copernicus GmbH

Date: 31-01-2018

DOI: 10.5194/BG-2018-53-SUPPLEMENT

Change in terrestrial ecosystem water‐use efficiency over the last three decades

Publisher: Wiley

Date: 20-03-2015

DOI: 10.1111/GCB.12873

Abstract: Defined as the ratio between gross primary productivity (GPP) and evapotranspiration (ET), ecosystem-scale water-use efficiency (EWUE) is an indicator of the adjustment of vegetation photosynthesis to water loss. The processes controlling EWUE are complex and reflect both a slow evolution of plants and plant communities as well as fast adjustments of ecosystem functioning to changes of limiting resources. In this study, we investigated EWUE trends from 1982 to 2008 using data-driven models derived from satellite observations and process-oriented carbon cycle models. Our findings suggest positive EWUE trends of 0.0056, 0.0007 and 0.0001 g C m(-2) mm(-1) yr(-1) under the single effect of rising CO2 ('CO2 '), climate change ('CLIM') and nitrogen deposition ('NDEP'), respectively. Global patterns of EWUE trends under different scenarios suggest that (i) EWUE-CO2 shows global increases, (ii) EWUE-CLIM increases in mainly high latitudes and decreases at middle and low latitudes, (iii) EWUE-NDEP displays slight increasing trends except in west Siberia, eastern Europe, parts of North America and central Amazonia. The data-driven MTE model, however, shows a slight decline of EWUE during the same period (-0.0005 g C m(-2) mm(-1) yr(-1) ), which differs from process-model (0.0064 g C m(-2) mm(-1) yr(-1) ) simulations with all drivers taken into account. We attribute this discrepancy to the fact that the nonmodeled physiological effects of elevated CO2 reducing stomatal conductance and transpiration (TR) in the MTE model. Partial correlation analysis between EWUE and climate drivers shows similar responses to climatic variables with the data-driven model and the process-oriented models across different ecosystems. Change in water-use efficiency defined from transpiration-based WUEt (GPP/TR) and inherent water-use efficiency (IWUEt , GPP×VPD/TR) in response to rising CO2 , climate change, and nitrogen deposition are also discussed. Our analyses will facilitate mechanistic understanding of the carbon-water interactions over terrestrial ecosystems under global change.

Warming and redistribution of N inputs drive long-term increase in terrestrial N2O emission factor

Publisher: Research Square Platform LLC

Date: 20-01-2022

DOI: 10.21203/RS.3.RS-1177877/V1

Abstract: Anthropogenic nitrogen inputs cause major negative environmental impacts, including emissions of the important greenhouse gas N2O. Despite their importance, changes in terrestrial N loss pathways driven by global change and spatial redistribution of N inputs are highly uncertain. We present a novel coupled soil-atmosphere isotope model (IsoTONE) to quantify terrestrial N losses and N2O emission factors from 1850-2020, initialised using a global dataset of natural soil δ15N, and optimized with a tropospheric timeseries of N2O isotopic composition using a Bayesian framework. N inputs from atmospheric deposition caused the majority (51%) of anthropogenic N2O emissions from soils in 2020. Long-term growth in emissions was driven by fertilization and deposition, however biological fixation caused subdecadal variability in emissions. N2O emission factors (EF) show large spatial variability due to climate and soil parameters. The mean effective global EF for N2O (weighted by N inputs) was 4.3±0.3% in 2020, much higher than the land surface area-weighted mean (1.1±0.1%). Climate change and redistribution of fertilisation have driven an increase in global EF over the past century, which accounts for 18% of the anthropogenic soil flux in 2020. Predicted increases in fertilisation in emerging economies will accelerate N2O-driven climate warming in coming decades, unless targeted mitigation measures focussing on fertiliser management and reduced N deposition are introduced.

The impact on the surface climatology from changing the land surface scheme in the ACCESS(v1.0/1.1) climate model

Publisher: Copernicus GmbH

Date: 03-2016

DOI: 10.5194/GMD-2016-35

Abstract: Abstract. The Community Atmosphere Biosphere Land Exchange (CABLE) model has been coupled to the UK Met Office Unified Model (UM) within the existing framework of the Australian Community Climate and Earth System Simulator (ACCESS), replacing the Met Office Surface Exchange Scheme (MOSES). Here we investigate how features of the CABLE model impact on present day surface climate using ACCESS atmosphere-only simulations. The main differences attributed to CABLE include a warmer winter and a cooler summer in the Northern Hemisphere (NH), earlier NH spring runoff from snowmelt, and smaller seasonal and diurnal temperature ranges. Cooler NH summer temperatures in canopy covered areas are attributed to two factors. Firstly CABLE accounts for aerodynamic and radiative interactions between the canopy and the ground below this placement of canopy above the ground eliminates the need for a separate bare ground tile in canopy covered areas. Secondly, CABLE produces larger evapotranspiration fluxes and slightly larger daytime cloud cover fraction. Warmer NH winter temperatures result from the parameterization of cold climate processes in CABLE in snow covered areas. In particular prognostic snow density increases through the winter and lowers diurnally resolved snow albedo variable snow thermal conductivity prevents early winter heat loss but allows more heat to enter the ground as the snow season progresses liquid precipitation freezing within the snowpack delays the building of the snow pack in autumn and accelerates snow melting in spring.

Spatial changes in nitrogen inputs drive short- and long-term variability in global N2O emissions

Publisher: Copernicus GmbH

Date: 27-03-2022

DOI: 10.5194/EGUSPHERE-EGU22-1150

Abstract: & & Anthropogenic activities, particularly fertilisation, have resulted in significant increases in nitrogen in soils globally, leading to negative environmental impacts including eutrophication, acidification, poor air quality, and emissions of the important greenhouse gas N& sub& & /sub& O. Potential changes in terrestrial N loss pathways driven by global change and spatial redistribution of N inputs are highly uncertain. We present a novel coupled soil-atmosphere isotope model (IsoTONE & strong& ISO& /strong& topic & strong& T& /strong& racing & strong& O& /strong& f & strong& N& /strong& itrogen in the & strong& E& /strong& nvironment) to quantify terrestrial N losses and N& sub& & /sub& O emissions and emission factors for the period 1850-2020. The soil module is initialised using a global isoscape of natural soil & #948 & sup& & /sup& N values generated from measurement data using an artificial neural network. The model is optimized within a Bayesian framework using a high precision tropospheric time series of N& sub& & /sub& O isotopic composition as well as emission factor measurements from many sites across the globe.& & & & N inputs from atmospheric deposition caused the majority (51% 3.6& #177 .3 Tg N& sub& & /sub& O-N a& sup& -1& /sup& ) of total anthropogenic N& sub& & /sub& O emissions from soils (7.1& #177 .9 Tg N& sub& & /sub& O-N a& sup& -1& /sup& ) in 2020. Growth in total and anthropogenic soil N& sub& & /sub& O emissions over the past century was driven by both fertilization and deposition, however N inputs from biological fixation were responsible for subdecadal variability in emissions. N& sub& & /sub& O emission factors show large spatial variability due to climate and soil parameters. The mean global EF for N& sub& & /sub& O weighted by N inputs was 4.3& #177 .3% in 2020, much higher than the land surface area-weighted mean of 1.1& #177 .1%, as a large proportion of N inputs were in regions with relatively high emission factors. Climate warming as well as redistribution of fertilisation inputs have led to an increase in global EF for N& sub& & /sub& O over the past century these additional emissions account for 18% of the total anthropogenic soil flux in 2020. Predicted increases in fertilisation in emerging economies will accelerate N& sub& & /sub& O-driven climate warming in the coming decades, unless targeted mitigation measures focussing on fertiliser management in developing regions are introduced.& &

Responses of LAI to rainfall explain contrasting sensitivities to carbon uptake between forest and non-forest ecosystems in Australia

Publisher: Springer Science and Business Media LLC

Date: 15-09-2017

DOI: 10.1038/S41598-017-11063-W

Abstract: Non-forest ecosystems (predominant in semi-arid and arid regions) contribute significantly to the increasing trend and interannual variation of land carbon uptake over the last three decades, yet the mechanisms are poorly understood. By analysing the flux measurements from 23 ecosystems in Australia, we found the the correlation between gross primary production (GPP) and ecosystem respiration (R e ) was significant for non-forest ecosystems, but was not for forests. In non-forest ecosystems, both GPP and R e increased with rainfall, and, consequently net ecosystem production (NEP) increased with rainfall. In forest ecosystems, GPP and R e were insensitive to rainfall. Furthermore sensitivity of GPP to rainfall was dominated by the rainfall-driven variation of LAI rather GPP per unit LAI in non-forest ecosystems, which was not correctly reproduced by current land models, indicating that the mechanisms underlying the response of LAI to rainfall should be targeted for future model development.

Soil–atmosphere exchange of CH₄, CO, N₂O and NO_x and the effects of land‐use change in the semiarid Mallee system in Southeastern Australia

Publisher: Wiley

Date: 08-2010

DOI: 10.1111/J.1365-2486.2010.02161.X

Nitrogen and phosphorous limitation reduces the effects of land use change on land carbon uptake or emission

Publisher: IOP Publishing

Date: 2015

DOI: 10.1088/1748-9326/10/1/014001

Correcting the Response of Maximum Leaf Photosynthetic Rate to Tempera-tures in Crop Models

Publisher: China Science Publishing & Media Ltd.

Date: 2018

DOI: 10.3724/SP.J.1006.2018.00750

Can the stomatal response to higher atmospheric carbon dioxide explain the unusual temperatures during the 2002 Murray-Darling Basin drought?

Publisher: American Geophysical Union (AGU)

Date: 16-01-2010

DOI: 10.1029/2009JD012767

First quantitative evidences of ghost-rock karstification controlling regional karst geometry

Publisher: Copernicus GmbH

Date: 23-03-2020

DOI: 10.5194/EGUSPHERE-EGU2020-9099

Abstract: & & Although more and more processes are discussed and discovered on the genesis and evolution of cave systems, the tiered karsts are often explained by a control of the base level evolution. In this classical model, the horizontal galleries are explained by a stability of the base level elevation. To the contrary, the shafts and network segments with steep slopes are related to incision periods with a base level lowering.& & & & We use Terrestrial Cosmogenic Nuclide Geochronology to estimate burial ages of alluvium trapped in several caves of the Larzac plateau in Southern France. All the s les are collected in horizontal cave levels, sometimes located between steeper segments. Some caves are opened in river gorge walls, while others are located below the Larzac plateau not farther than 5km away from the river gorges.& & & & The burial ages for the caves opening in the gorges are consistent with the incision rates given for the area and could be interpreted using the classical model. However, the cave within the plateau show a horizontal level with alluvium deposited 200m above the caves in the gorge with the same burial ages (~1 Myr). Since then, new shafts have been opened without alluvium and are hydrologically connected to the river by deeper[jfr1]& hypogenic galleries. The cave morphologies and the geochronological data suggest that the classical model fails to explain the horizontal levels in cave below the plateau. We postulate that the geometry of the caves in these limestone and dolomite plateaus are related to a previous period of ghost-rock and alteration roots formations. Without the opening of an efficient connection between this primokarst and the valley, no alluvium can flow through the cave. Therefore, we think that our burial ages constrain the emptying of the ghost-rocks leading to the genesis of the cave where water and possibly alluvium can flow through. Furthermore, these new finding explain why the horizontal levels in the caves are not clearly related to horizontal markers in the surface geomorphology and why large shafts (& m) exist in the area without evidences of long periods of base level stability followed by large drop of the regional base level.& & & & & & & & & & / & & / & & / &

A tale of two bogs - new 10Be production rates from UK and NZ calibrated by basal 14C ages&#160;

Publisher: Copernicus GmbH

Date: 04-03-2021

DOI: 10.5194/EGUSPHERE-EGU21-14132

Abstract: & & Cosmogenic production rates (PRs) are the essential conversion factor between AMS cosmogenic concentrations and absolute exposure ages. The accuracy of cosmogenic glacial chronologies and reliability in their comparison to other paleoclimate systems & is largely contingent on the precision and accuracy of the adopted production rate. This is particularly critical in determining past glacial geochronologies at the scale of millennial temporal resolution. Most PR calibrations are carried out at deglaciation sites where radiocarbon provides the independent chronometric control usually based on 14C ages in basal sediments or varves& from lake or bog cores which is assumed to represent the minimum age for glacial retreat. Under these conditions and hence provide PRs as maximum values. Given that today most AMS facilities can deliver 10-Be, 26-Al and 36-Cl data with total analytical errors less than 2% ( for 10 ka exposure), the precision of a PR remains largely dependent & on the error in the independent chronology and accuracy of AMS standards. The history over the past 20 years of the ever-decreasing value of & SLHL 10-Be cosmogenic spallation PRs & from initial estimates of about 7 atoms/g/a to the current& & #8216 accepted& #8216 (global average) values of ~4 atoms/g/a,& & is an interesting story in itself and demonstrates the complexity in such determinations. & & & & & Over the past few years new web-based calculators are now available to calculate uniformly new production rates from either new data or combinations of any set of published data (CRONUS-Earth, CRONUS-UW, CosmoCalc, ICE-D, CREp). This delivers a means by which new production rates can be seamlessly integrated and compared using identical constants, methods and statistics that were used to generate (currently accepted) global average or regional production rates.& & & & & For the British Isles, there are a number of 10-Be reference sites that give PRs (Lm scheme) between 3.89& #177 % & atoms/g/a & (Putnam, QG, v50, 2019) to 4.20& #177 % atoms/g/a (Small, JQS, v30, 2015) which convert to 3.95 and 4.28, respectively, using datasets in the ICE-D calculator). This difference in 10-Be spallation PRs has recently raised some debate and challenges for the timing of the local-LGM and demise of the British Ice Sheet. This work provides a new & British Isles site specific 10Be PR from the & Arenig Mountains in North Wales where radiocarbon dating of basal sediments from a bog core associated with a series of nearby cirque moraines provides independent age control.& Similarly in the South Island of New Zealand, the current accepted 10Be PR is 3.76& #177 % (Putnam, QG 2009 converts to 3.94& #177 % using ICE-D) and is the only available PR that is used for these southern hemispheric glacial sites. This work provides a new Australasian site specific 10Be PR from Arthurs Pass retreat moraines where radiocarbon dating of basal sediments from three cores extracted from a bog impounded by the moraine provides independent age control.& & &

Using indirect methods to constrain symbiotic nitrogen fixation rates: a case study from an Amazonian rain forest

Publisher: Springer Science and Business Media LLC

Date: 05-12-2009

DOI: 10.1007/S10533-009-9392-Y

Effects of Aerosols on Gross Primary Production from Ecosystems to the Globe

Publisher: MDPI AG

Date: 08-06-2022

DOI: 10.3390/RS14122759

Abstract: Aerosols affect the gross primary productivity (GPP) of plants by absorbing and scattering solar radiation. However, it is still an open question whether and to what extent the effects of aerosol on the diffuse fraction (Df) can enhance GPP globally. We quantified the aerosol diffuse fertilization effect (DFE) and incorporated it into a light use efficiency (LUE) model, EC-LUE. The new model is driven by aerosol optical depth (AOD) data and is referred to as AOD-LUE. The eddy correlation variance (EC) of the FLUXNET2015 dataset was used to calibrate and validate the model. The results showed that the newly developed AOD-LUE model improved the performance in simulating GPP across all ecosystem types (R2 from 0.6 to 0.68), with the highest performance for mixed forest (average R2 from 0.71 to 0.77) and evergreen broadleaf forest (average R2 from 0.34 to 0.45). The maximum LUE of diffuse photosynthetic active radiation (PAR) (3.61 g C m−2 MJ−1) was larger than that of direct PAR (1.68 g C m−2 MJ−1) through parameter optimization, indicating that the aerosol DFE seriously affects the estimation of GPP, and the separation of diffuse PAR and direct PAR in the GPP model is necessary. In addition, we used AOD-LUE to quantify the impact of aerosol on GPP. Specifically, aerosols impaired GPP in closed shrub (CSH) by 6.45% but enhanced the GPP of grassland (GRA) and deciduous broadleaf forest (DBF) by 3.19% and 2.63%, respectively. Our study stresses the importance of understanding aerosol-radiation interactions and incorporating aerosol effects into regional and global GPP models.

Microbial Activity and Root Carbon Inputs Are More Important than Soil Carbon Diffusion in Simulating Soil Carbon Profiles

Publisher: American Geophysical Union (AGU)

Date: 04-2021

DOI: 10.1029/2020JG006205

Estimating global gross primary productivity using chlorophyll fluorescence and a data assimilation system with the BETHY-SCOPE model

Publisher: Copernicus GmbH

Date: 21-06-2018

DOI: 10.5194/BG-2018-270

Abstract: Abstract. This paper presents the assimilation of solar-induced chlorophyll fluorescence (SIF) into a terrestrial biosphere model to estimate the gross uptake of carbon through photosynthesis (GPP). We use the BETHY-SCOPE model to simulate both GPP and SIF in a process-based manner, going beyond a simple linear scaling between the two. We then use satellite SIF data from the Orbiting Carbon Observatory-2 (OCO-2) for 2015 in the data assimilation system to constrain model GPP. The assimilation results in considerable improvement between model and observed SIF, despite difficulties in simulating large SIF values due partly to uncertainties in the prescribed LAI. SIF-optimized global GPP increases by 7 % to 137 ± 6 PgCyr−1 and shows improvement in its global distribution relative to independent estimates. This change in global GPP is driven by an overall decline in APAR and increase in the light-use efficiency of photosynthesis across almost all ecosystems. This process-based data assimilation opens up new pathways to the effective utilization of satellite SIF data that will improve our understanding of the global carbon cycle.

ACCESS Datasets for CMIP6: Methodology & Idealised Experiments

Publisher: CSIRO Publishing

Date: 14-07-2022

DOI: 10.1071/ES21031

Abstract: The Australian Community Climate and Earth System Simulator (ACCESS) has contributed to the World Climate Research Programme’s Coupled Model Intercomparison Project Phase 6 (CMIP6) using two fully coupled model versions (ACCESS-CM2 and ACCESS-ESM1.5) and two ocean–sea-ice model versions (1° and 0.25° resolution versions of ACCESS-OM2). The fully coupled models differ primarily in the configuration and version of their atmosphere components (including the aerosol scheme), with smaller differences in their sea-ice and land model versions. Additionally, ACCESS-ESM1.5 includes biogeochemistry in the land and ocean components and can be run with an interactive carbon cycle. CMIP6 comprises core experiments and associated thematic Model Intercomparison Projects (MIPs). This paper provides an overview of the CMIP6 submission, including the methods used for the preparation of input forcing datasets and the post-processing of model output, along with a comprehensive list of experiments performed, detailing their initialisation, duration, ensemble number and computational cost. A small selection of model output is presented, focusing on idealised experiments and their variants at global scale. Differences in the climate simulation of the two coupled models are highlighted. ACCESS-CM2 produces a larger equilibrium climate sensitivity (4.7°C) than ACCESS-ESM1.5 (3.9°C), likely a result of updated atmospheric parameterisation in recent versions of the atmospheric component of ACCESS-CM2. The idealised experiments run with ACCESS-ESM1.5 show that land and ocean carbon fluxes respond to both changing atmospheric CO2 and to changing temperature. ACCESS data submitted to CMIP6 are available from the Earth System Grid Federation (0.22033/ESGF/CMIP6.2281 and 0.22033/ESGF/CMIP6.2288). The information provided in this paper should facilitate easier use of these significant datasets by the broader climate community.

A two-leaf model for canopy conductance, photosynthesis and partitioning of available energy I:

Publisher: Elsevier BV

Date: 05-1998

DOI: 10.1016/S0168-1923(98)00061-6

Evaluating Global Land Surface Models in CMIP5: Analysis of Ecosystem Water- and Light-Use Efficiencies and Rainfall Partitioning

Publisher: American Meteorological Society

Date: 20-03-2018

DOI: 10.1175/JCLI-D-16-0177.1

Abstract: Water and carbon fluxes simulated by 12 Earth system models (ESMs) that participated in phase 5 of the Coupled Model Intercomparison Project (CMIP5) over several recent decades were evaluated using three functional constraints that are derived from both model simulations, or four global datasets, and 736 site-year measurements. Three functional constraints are ecosystem water-use efficiency (WUE), light-use efficiency (LUE), and the partitioning of precipitation P into evapotranspiration (ET) and runoff based on the Budyko framework. Although values of these three constraints varied significantly with time scale and should be quite conservative if being averaged over multiple decades, the results showed that both WUE and LUE simulated by the ensemble mean of 12 ESMs were generally lower than the site measurements. Simulations by the ESMs were generally consistent with the broad pattern of energy-controlled ET under wet conditions and soil water-controlled ET under dry conditions, as described by the Budyko framework. However, the value of the parameter in the Budyko framework ω, obtained from fitting the Budyko curve to the ensemble model simulation (1.74), was larger than the best-fit value of ω to the observed data (1.28). Globally, the ensemble mean of multiple models, although performing better than any in idual model simulations, still underestimated the observed WUE and LUE, and overestimated the ratio of ET to P, as a result of overestimation in ET and underestimation in gross primary production (GPP). The results suggest that future model development should focus on improving the algorithms of the partitioning of precipitation into ecosystem ET and runoff, and the coupling of water and carbon cycles for different land-use types.

Eighteen‐year nitrogen addition does not increase plant phosphorus demand in a nitrogen‐saturated tropical forest

Publisher: Wiley

Date: 25-05-2023

DOI: 10.1111/1365-2745.14118

Abstract: Nitrogen (N) deposition usually increases plant tissue N concentrations and thus phosphorus (P) demand in young and/or N‐limited forests, but the N deposition effect on plant P demand has rarely been assessed in N‐saturated forests. Impacts of 18‐year external N additions (Control: 0, Low N: 50, Moderate N:100 and High N: 150 kg N ha −1 year −1 ) on leaf P of four plant life‐forms (tree, shrub, herb and liana), P fractions of bulk and rhizosphere soils were examined in a N‐saturated mature tropical forest in southern China. Leaf N, P and N: P ratios of all plant life‐forms remained stable under three N additions. Among soil P fractions, moderate labile organic P increased by 25%–33% across three N additions and soil total P was increased by 11.76% under Low N, and 8.87% under High N, compared with the control. The PLS‐PM results showed that path coefficient of microbial community to available P significantly increased and of inorganic P to available P significantly decreased under N additions than control. N additions improved soil P availability through microbe‐mediated P transformation: Low N significantly increased soil microbial taxonomic ersity, and a higher microbial ersity could enlarge the sources of nutrient acquisition and stimulate decomposition of recalcitrant organic matters while High N significantly decreased soil microbial taxonomic ersity, the remaining microorganisms that were screened by N‐rich environments had the characteristics of resisting the N addition effects and maintained efficient P acquisition. Synthesis. Our findings provide a novel line of evidence that long‐term N deposition did not increase plant P demand in a N‐saturated mature tropical forest. The underlying mechanism is that plants did not increase N uptakes therefore nor increase P uptakes (a stable leaf N: P stoichiometry) in an already N‐saturated ecosystem. Different N addition rates regulated soil P transformation via microbial community transition. These findings help improve the understanding of plant P acquisition and modelling of biogeochemical N–P cycling and vegetation productivity in N‐rich forest ecosystems, particularly considering the fact that chronic N deposition may likely lead to soil N richness and even saturation of many forests in the future.

History of Australian aridity: Chronology in the evolution of arid landscapes

Publisher: Geological Society of London

Date: 2010

DOI: 10.1144/SP346.8

Supplementary material to &quot;Global patterns and drivers of soil total phosphorus concentration&quot;

Publisher: Copernicus GmbH

Date: 12-07-2021

DOI: 10.5194/ESSD-2021-166-SUPPLEMENT

Geometric vector potentials from nonadiabatic spin dynamics

Publisher: American Physical Society (APS)

Date: 27-07-2017

DOI: 10.1103/PHYSREVB.96.035312

Mean leaf angles for the ellipsoidal inclination angle distribution

Publisher: Elsevier BV

Date: 09-1988

DOI: 10.1016/0168-1923(88)90057-3

Toward a Global Model for Soil Inorganic Phosphorus Dynamics: Dependence of Exchange Kinetics and Soil Bioavailability on Soil Physicochemical Properties

Publisher: American Geophysical Union (AGU)

Date: 03-2022

DOI: 10.1029/2021GB007061

Abstract: The representation of phosphorus (P) cycling in global land models remains quite simplistic, particularly on soil inorganic phosphorus. For ex le, sorption and desorption remain unresolved and their dependence on soil physical and chemical properties is ignored. Empirical parameter values are usually based on expert knowledge or data from few sites with debatable global representativeness in most global land models. To overcome these issues, we compiled from data of inorganic soil P fractions and calculated the fraction of added P remaining in soil solution over time of 147 soil s les to optimize three parameters in a model of soil inorganic P dynamics. The calibrated model performed well ( r 2 0.7 for 122 soil s les). Model parameters vary by several orders of magnitude, and correlate with soil P fractions of different inorganic pools, soil organic carbon and oxalate extractable metal oxide concentrations among the soil s les. The modeled bioavailability of soil P depends on, not only, the desorption rates of labile and sorbed pool, inorganic phosphorus fractions, the slope of P sorbed against solution P concentration, but also on the ability of biological uptake to deplete solution P concentration and the time scale. The model together with the empirical relationships of model parameters on soil properties can be used to quantify bioavailability of soil inorganic P on various timescale especially when coupled within global land models.

Carbon uptake by karsts in the Houzhai Basin, southwest China

Publisher: American Geophysical Union (AGU)

Date: 22-10-2011

DOI: 10.1029/2011JG001686

Modelling of land nutrient cycles: recent progress and future development

Publisher: Faculty Opinions Ltd

Date: 02-06-2021

DOI: 10.12703/R/10-53

Spatial changes in nitrogen inputs drive short- and long-term variability in global nitrous oxide&#160;emissions

Publisher: Copernicus GmbH

Date: 03-03-2021

DOI: 10.5194/EGUSPHERE-EGU21-804

Abstract: & & Anthropogenic activities, particularly fertilisation, have resulted in significant increases in reactive nitrogen (& em& r& /em& N) in soils globally, leading to eutrophication, acidification, poor air quality, and emissions of the important greenhouse gas N& sub& & /sub& O. Understanding the partitioning of & em& r& /em& N losses into different environmental compartments is critical to mitigate negative impacts, however, loss pathways are poorly quantified, and potential changes driven by climate warming and societal shifts are highly uncertain. We present a coupled soil-atmosphere isotope model (IsoTONE & strong& ISO& /strong& topic & strong& T& /strong& racing & strong& O& /strong& f & strong& N& /strong& itrogen in the & strong& E& /strong& nvironment) to partition & em& r& /em& N losses into leaching, harvest, NH& sub& & /sub& volatilization, and production of NO, N& sub& & /sub& and N& sub& & /sub& O based on a global dataset of soil & #948 & sup& & /sup& N, as well as numerous other geoclimatic and experimental datasets. The model was optimized in a Bayesian framework using a time series of N& sub& & /sub& O mixing ratios and isotopic compositions since the preindustrial era, as well as a global dataset of N& sub& & /sub& O emission factors (EF). The posterior model results showed that the total anthropogenic flux in 2020 (7.8 Tg N& sub& & /sub& O-N a& sup& -1& /sup& ) was dominated by indirect emissions resulting from N deposition, while the growth rate and trend in anthropogenic N& sub& & /sub& O was driven by both direct N fertilisation and deposition inputs. In contrast, inputs from fixation N drive natural N& sub& & /sub& O emissions, and were responsible for subdecadal interannual variability in total emissions.& & & & Total N gas (N& sub& & /sub& O + NO + N& sub& & /sub& ) production and N& sub& & /sub& O losses were strongly dependent on geoclimate and thus spatially variable, therefore the spatial pattern of N inputs strongly impacted resulting EFs and total N& sub& & /sub& O emissions. The area-weighted global EF for N& sub& & /sub& O was 1% & of anthropogenic N inputs in 2020, similar to the current IPCC default of 1.4%, however the N input-weighted global EF was 4.3%. Shifts in fertilisation inputs from the temperate Northern hemisphere towards warmer regions with higher EFs such as India and China have led to accelerating N& sub& & /sub& O emissions (1.02& #177 .7 Tg N& sub& & /sub& O-N a& sup& -1& /sup& ). In addition, N& sub& & /sub& O emissions have increased over the past decades due to climate warming (0.76& #177 .4 Tg N& sub& & /sub& O-N a& sup& -1& /sup& ). Predicted increases in fertilisation in India and Africa in the coming decades could further accelerate N& sub& & /sub& O-driven climate warming, unless mitigation measures are implemented to increase fertiliser N use efficiency and reduce N& sub& & /sub& O emission factors.& &

Supplementary material to &quot;The carbon cycle in the Australian Community Climate and Earth System Simulator (ACCESS-ESM1) – Part 1: Model description and pre-industrial simulation&quot;

Publisher: Copernicus GmbH

Date: 18-09-2015

DOI: 10.5194/GMDD-8-8063-2015-SUPPLEMENT

Climate mitigation from vegetation biophysical feedbacks during the past three decades

Publisher: Springer Science and Business Media LLC

Date: 22-05-2017

DOI: 10.1038/NCLIMATE3299

Using research networks to create the comprehensive datasets needed to assess nutrient availability as a key determinant of terrestrial carbon cycling

Publisher: IOP Publishing

Date: 07-12-2018

DOI: 10.1088/1748-9326/AAEAE7

Supplementary material to Global patterns and drivers of phosphorus pools in natural soils

Publisher: Copernicus GmbH

Date: 24-02-2023

DOI: 10.5194/BG-2023-22-SUPPLEMENT

Estimates of soil respiration and net primary production of three forests at different succession stages in South China

Publisher: Wiley

Date: 05-2006

DOI: 10.1111/J.1365-2486.2006.01141.X

Geomorphic imprints of lithospheric flexure in central Australia

Publisher: Elsevier BV

Date: 04-2022

DOI: 10.1016/J.EPSL.2022.117456

The impact of nitrogen and phosphorous limitation on the estimated terrestrial carbon balance and warming of land use change over the last 156 yr

Publisher: Copernicus GmbH

Date: 08-05-2013

DOI: 10.5194/ESDD-4-507-2013

Abstract: Abstract. We examine the impact of land use and land cover change (LULCC) over the period from 1850 to 2005 using an Earth System Model that incorporates nitrogen and phosphorous limitation on the terrestrial carbon cycle. We compare the estimated CO2 emissions and warming from land use change in a carbon only version of the model with those from simulations including nitrogen and phosphorous limitation. If we omit nutrients, our results suggest LULCC cools on the global average by about 0.1 °C. Including nutrients reduces this cooling to ~ 0.05 °C. Our results also suggest LULCC has a major impact on total land carbon over the period 1850–2005. In carbon only simulations, the inclusion of LULCC decreases the total additional land carbon stored in 2005 from around 210 Pg C to 85 Pg C. Including nitrogen and phosphorous limitation also decreases the scale of the terrestrial carbon sink to 80 Pg C. In particular, adding LULCC on top of the nutrient limited simulations changes the sign of the terrestrial carbon flux from a sink to a source (12 Pg C). The CO2 emission from LULCC from 1850 to 2005 is estimated to be 130 Pg C for carbon only simulation, or 97 Pg C if nutrient limitation is accounted for in our model. The difference between these two estimates of CO2 emissions from LULCC largely results from the weaker response of photosynthesis to increased CO2 and smaller carbon pool sizes, and therefore lower carbon loss from plant and wood product carbon pools under nutrient limitation. We suggest that nutrient limitation should be accounted in simulating the effects of LULCC on the past climate and on the past and future carbon budget.

Growing‐season temperature and precipitation are independent drivers of global variation in xylem hydraulic conductivity

Publisher: Wiley

Date: 10-12-2019

DOI: 10.1111/GCB.14929

Abstract: Stem xylem‐specific hydraulic conductivity ( K S ) represents the potential for plant water transport normalized by xylem cross section, length, and driving force. Variation in K S has implications for plant transpiration and photosynthesis, growth and survival, and also the geographic distribution of species. Clarifying the global‐scale patterns of K S and its major drivers is needed to achieve a better understanding of how plants adapt to different environmental conditions, particularly under climate change scenarios. Here, we compiled a xylem hydraulics dataset with 1,186 species‐at‐site combinations (975 woody species representing 146 families, from 199 sites worldwide), and investigated how K S varied with climatic variables, plant functional types, and biomes. Growing‐season temperature and growing‐season precipitation drove global variation in K S independently. Both the mean and the variation in K S were highest in the warm and wet tropical regions, and lower in cold and dry regions, such as tundra and desert biomes. Our results suggest that future warming and redistribution of seasonal precipitation may have a significant impact on species functional ersity, and is likely to be particularly important in regions becoming warmer or drier, such as high latitudes. This highlights an important role for K S in predicting shifts in community composition in the face of climate change.

Supplementary material to &quot;Tracking the &lt;sup&gt;26&lt;/sup&gt;Al/&lt;sup&gt;10&lt;/sup&gt;Be source-area signal in sediment-routing systems of arid central

Publisher: Copernicus GmbH

Date: 16-01-2018

DOI: 10.5194/ESURF-2017-76-SUPPLEMENT

Cover Image

Publisher: Wiley

Date: 09-03-2018

DOI: 10.1002/ESP.4368

The CSIRO Mk3L climate system model v1.0 coupled to the CABLE land surface scheme v1.4b: evaluation of the control climatology

Publisher: Copernicus GmbH

Date: 08-12-2011

DOI: 10.5194/GMD-4-1115-2011

Abstract: Abstract. The CSIRO Mk3L climate system model, a reduced-resolution coupled general circulation model, has previously been described in this journal. The model is configured for millennium scale or multiple century scale simulations. This paper reports the impact of replacing the relatively simple land surface scheme that is the default parameterisation in Mk3L with a sophisticated land surface model that simulates the terrestrial energy, water and carbon balance in a physically and biologically consistent way. An evaluation of the new model's near-surface climatology highlights strengths and weaknesses, but overall the atmospheric variables, including the near-surface air temperature and precipitation, are simulated well. The impact of the more sophisticated land surface model on existing variables is relatively small, but generally positive. More significantly, the new land surface scheme allows an examination of surface carbon-related quantities including net primary productivity which adds significantly to the capacity of Mk3L. Overall, results demonstrate that this reduced-resolution climate model is a good foundation for exploring long time scale phenomena. The addition of the more sophisticated land surface model enables an exploration of important Earth System questions including land cover change and abrupt changes in terrestrial carbon storage.

The lifetime of interlayer breathing modes of few-layer 2H-MoSe₂ membranes

Publisher: Royal Society of Chemistry (RSC)

Date: 2019

DOI: 10.1039/C9NR02447F

Abstract: Investigation of the decay processes leading to the phonon lifetime of optically excited vibrational modes of few-layer MoSe 2 membranes.

Systematic Bias in Land Surface Models

Publisher: American Meteorological Society

Date: 10-2007

DOI: 10.1175/JHM628.1

Abstract: A neural network–based flux correction technique is applied to three land surface models. It is then used to show that the nature of systematic model error in simulations of latent heat, sensible heat, and the net ecosystem exchange of CO2 is shared between different vegetation types and indeed different models. By manipulating the relationship between the dataset used to train the correction technique and that used to test it, it is shown that as much as 45% of per-time-step model root-mean-square error in these flux outputs is due to systematic problems in those model processes insensitive to changes in vegetation parameters. This is shown in the three land surface models using flux tower measurements from 13 sites spanning 2 vegetation types. These results suggest that efforts to improve the representation of fundamental processes in land surface models, rather than parameter optimization, are the key to the development of land surface model ability.

Characterization of the variability and repeatability of gonadotropin-releasing hormone–induced luteinizing hormone responses in dairy cows within a synchronized ovulation protocol

Publisher: American Dairy Science Association

Date: 08-2017

DOI: 10.3168/JDS.2016-12529

Abstract: The primary objective was to determine the variability and repeatability of GnRH-induced LH responses. The secondary objective was to evaluate the associations among plasma LH, FSH, estradiol (E2), and progesterone (P4) concentrations. One hundred lactating Holstein cows (35 primiparous, 65 multiparous) were initially subjected to a presynchronization protocol (d 0, PGF

Simulation of soil carbon dynamics in Australia under a framework that better connects spatially explicit data with Rᴏᴛʜ C

Publisher: Copernicus GmbH

Date: 21-07-2020

DOI: 10.5194/BG-2020-150

Abstract: Abstract. We simulated soil organic carbon (C) dynamics across Australia with the Rothamsted carbon model (Rᴏᴛʜ C) under a framework that connects new spatially-explicit soil measurements and data with the model. Doing so helped to bridge the disconnection that exists between datasets used to inform the model and the processes that it depicts. Under this framework, we compiled continental-scale datasets and pre-processed, standardised and configured them to the required spatial and temporal resolutions. We then calibrated Rᴏᴛʜ C and run simulations to predict the baseline soil organic C stocks and composition in the 0–0.3 m layer at 4,043 sites in cropping, modified grazing, native grazing, and natural environments across Australia. The Rᴏᴛʜ C model uses measured C fractions, the particulate, humus, and resistant organic C (POC, HOC and ROC, respectively) to represent the three main C pools in its structure. The model explained 97–98 % of the variation in measured total organic C in soils under cropping and grazing, and 65 % in soils under natural environments. We optimised the model at each site and experimented with different amounts of C inputs to predict the potential for C accumulation in a 100-year simulation. With an annual increase of 1 Mg C ha−1 in C inputs, the model predicted a potential soil C increase of 13.58 (interquartile range 12.19–15.80), 14.21 (12.38–16.03), and 15.57 (12.07–17.82) Mg C ha−1 under cropping, modified grazing and native grazing, and 3.52 (3.15–4.09) Mg C ha−1 under natural environments. Soils under native grazing were the most potentially vulnerable to C decomposition and loss, while soils under natural environments were the least vulnerable. An empirical assessment of the controls on the C change showed that climate, pH, total N, the C:N ratio, and cropping were the most important controls on POC change. Clay content and climate were dominant controls on HOC change. Consistent and explicit soil organic C simulations improve confidence in the model's predictions, contributing to the development of sustainable soil management under global change.

Oscillatory behavior of two nonlinear microbial models of soil carbon decomposition

Publisher: Copernicus GmbH

Date: 16-12-2013

DOI: 10.5194/BGD-10-19661-2013

Abstract: Abstract. A number of nonlinear models have recently been proposed for simulating soil carbon decomposition. Their predictions of soil carbon responses to fresh litter input and warming differ significantly from conventional linear models. Using both stability analysis and numerical simulations, we showed that two of those nonlinear models (a two-pool model and a three-pool model) exhibit d ed oscillatory responses to small perturbations. Stability analysis showed the frequency of oscillation is proportional to √ (& varepsilon −1−1)Ks/Vs in the two-pool model, and to √ (& varepsilon −1−1)Kl/Vl in the three-pool model, where & varepsilon is microbial growth efficiency, Ks and Kl are the half saturation constants of soil and litter carbon, respectively, and Vs and Vl are the maximal rates of carbon decomposition per unit of microbial biomass for soil and litter carbon, respectively. For both models, the oscillation has a period between 5 and 15 yr depending on other parameter values, and has smaller litude at soil temperatures between 0 °C to 15 °C. In addition, the equilibrium pool sizes of litter or soil carbon are insensitive to carbon inputs in the nonlinear model, but are proportional to carbon input in the conventional linear model. Under warming, the microbial biomass and litter carbon pools simulated by the nonlinear models can increase or decrease, depending whether & varepsilon varies with temperature. In contrast, the conventional linear models always simulate a decrease in both microbial and litter carbon pools with warming. Based on the evidence available, we concluded that the oscillatory behavior and insensitivity of soil carbon to carbon input in the nonlinear models are unrealistic. We recommend that a better model for capturing the soil carbon dynamics over decadal to centennial timescales would combine the sensitivity of the conventional models to carbon influx with the flexible response to warming of the nonlinear model.

Incorporation of plant traits in a land surface model helps explain the global biogeographical distribution of major forest functional types

Publisher: Wiley

Date: 13-11-2016

DOI: 10.1111/GEB.12535

Recent increases in terrestrial carbon uptake at little cost to the water cycle

Publisher: Springer Science and Business Media LLC

Date: 24-07-2017

DOI: 10.1038/S41467-017-00114-5

Abstract: Quantifying the responses of the coupled carbon and water cycles to current global warming and rising atmospheric CO 2 concentration is crucial for predicting and adapting to climate changes. Here we show that terrestrial carbon uptake (i.e. gross primary production) increased significantly from 1982 to 2011 using a combination of ground-based and remotely sensed land and atmospheric observations. Importantly, we find that the terrestrial carbon uptake increase is not accompanied by a proportional increase in water use (i.e. evapotranspiration) but is largely (about 90%) driven by increased carbon uptake per unit of water use, i.e. water use efficiency. The increased water use efficiency is positively related to rising CO 2 concentration and increased canopy leaf area index, and negatively influenced by increased vapour pressure deficits. Our findings suggest that rising atmospheric CO 2 concentration has caused a shift in terrestrial water economics of carbon uptake.

Global carbon budget 2014

Publisher: Copernicus GmbH

Date: 21-09-2014

DOI: 10.5194/ESSDD-7-521-2014

Abstract: Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe datasets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates, consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics and cement production data, respectively, while emissions from Land-Use Change (ELUC), mainly deforestation, are based on combined evidence from land-cover change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent Dynamic Global Vegetation Models forced by observed climate, CO2 and land cover change (some including nitrogen-carbon interactions). We compare the variability and mean land and ocean fluxes to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1σ, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2004–2013), EFF was 8.9 ± 0.4 GtC yr−1, ELUC 0.9 ± 0.5 GtC yr−1, GATM 4.3 ± 0.1 GtC yr−1, SOCEAN 2.6 ± 0.5 GtC yr−1, and SLAND 2.9 ± 0.8 GtC yr−1. For year 2013 alone, EFF grew to 9.9 ± 0.5 GtC yr−1, 2.3% above 2012, contining the growth trend in these emissions. ELUC was 0.9 ± 0.5 GtC yr−1, GATM was 5.4 ± 0.2 GtC yr−1, SOCEAN was 2.9 ± 0.5 GtC yr−1 and SLAND was 2.5 ± 0.9 GtC yr−1. GATM was high in 2013 reflecting a steady increase in EFF and smaller and opposite changes between SOCEAN and SLAND compared to the past decade (2004–2013). The global atmospheric CO2 concentration reached 395.31 ± 0.10 ppm averaged over 2013. We estimate that EFF will increase by 2.5% (1.3–3.5%) to 10.1 ± 0.6 GtC in 2014 (37.0 ± 2.2 GtCO2 yr−1), 65% above emissions in 1990, based on projections of World Gross Domestic Product and recent changes in the carbon intensity of the economy. From this projection of EFF and assumed constant ELUC for 2014, cumulative emissions of CO2 will reach about 545 ± 55 GtC (2000 ± 200 GtCO2) for 1870–2014, about 75% from EFF and 25% from ELUC. This paper documents changes in the methods and datasets used in this new carbon budget compared with previous publications of this living dataset (Le Quéré et al., 2013, 2014). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP_2014). Italic font highlights significant methodological changes and results compared to the Le Quéré et al. (2014) manuscript that accompanies the previous version of this living data.

A comparison of three different canopy radiation models commonly used in plant modelling

Publisher: CSIRO Publishing

Date: 2003

DOI: 10.1071/FP02117

Abstract: Three radiation models are compared. They are the two-stream approximation, Goudriaan's radiation model and Beer's law. If direct beam and diffuse radiation are considered separately with the appropriate extinction coefficients, Beer's law can be used to estimate the fraction of absorbed visible radiation quite accurately, as compared with the other two models. However, Beer's law always overestimates the fraction of absorbed near-infrared radiation because of the significant loss of scattered radiation in the near-infrared radiation waveband the error can be up to 50%, compared with the two-stream approximation. The error is systematic and is not reduced by integrating over a day or longer. It can be even larger if absorption of direct beam and diffuse radiation are not considered separately. Compared with the two-stream approximation, Goudriaan's model underestimates the amount of absorbed visible and near-infrared radiation, and consequently net photosynthesis, and overestimates sensible heat fluxes of the canopy when Goudriaan's model is used to estimate the amount of radiation absorbed by sunlit and shaded leaves within a canopy in the CSIRO Biosphere Model. However, the mean differences in the calculated hourly fluxes of net canopy photosynthesis, latent and sensible heat are less than 5% for a wheat crop during the whole growing season.

Assessing the response of soil carbon in Australia to changing inputs and climate using a consistent modelling framework

Publisher: Copernicus GmbH

Date: 22-09-2021

DOI: 10.5194/BG-18-5185-2021

Abstract: Abstract. Land use and management practices affect the response of soil organic carbon (C) to global change. Process-based models of soil C are useful tools to simulate C dynamics, but it is important to bridge any disconnect that exists between the data used to inform the models and the processes that they depict. To minimise that disconnect, we developed a consistent modelling framework that integrates new spatially explicit soil measurements and data with the Rothamsted carbon model (Roth C) and simulates the response of soil organic C to future climate change across Australia. We compiled publicly available continental-scale datasets and pre-processed, standardised and configured them to the required spatial and temporal resolutions. We then calibrated Roth C and ran simulations to estimate the baseline soil organic C stocks and composition in the 0–0.3 m layer at 4043 sites in cropping, modified grazing, native grazing and natural environments across Australia. We used data on the C fractions, the particulate, mineral-associated and resistant organic C (POC, MAOC and ROC, respectively) to represent the three main C pools in the Roth C model's structure. The model explained 97 %–98 % of the variation in measured total organic C in soils under cropping and grazing and 65 % in soils under natural environments. We optimised the model at each site and experimented with different amounts of C inputs to simulate the potential for C accumulation under constant climate in a 100-year simulation. With an annual increase of 1 Mg C ha−1 in C inputs, the model simulated a potential soil C increase of 13.58 (interquartile range 12.19–15.80), 14.21 (12.38–16.03) and 15.57 (12.07–17.82) Mg C ha−1 under cropping, modified grazing and native grazing and 3.52 (3.15–4.09) Mg C ha−1 under natural environments. With projected future changes in climate (+1.5, 2 and 5.0 ∘C) over 100 years, the simulations showed that soils under natural environments lost the most C, between 3.1 and 4.5 Mg C ha−1, while soils under native grazing lost the least, between 0.4 and 0.7 Mg C ha−1. Soil under cropping lost between 1 and 2.7 Mg C ha−1, while those under modified grazing showed a slight increase with temperature increases of 1.5 ∘C, but with further increases of 2 and 5 ∘C the median loss of TOC was 0.28 and 3.4 Mg C ha−1, respectively. For the different land uses, the changes in the C fractions varied with changes in climate. An empirical assessment of the controls on the C change showed that climate, pH, total N, the C : N ratio and cropping were the most important controls on POC change. Clay content and climate were dominant controls on MAOC change. Consistent and explicit soil organic C simulations improve confidence in the model's estimations, facilitating the development of sustainable soil management under global change.

Spatial variations in terrestrial net ecosystem productivity and its local indicators

Publisher: Copernicus GmbH

Date: 09-12-2020

DOI: 10.5194/BG-17-6237-2020

Abstract: Abstract. Multiple lines of evidence have demonstrated the persistence of global land carbon (C) sink during the past several decades. However, both annual net ecosystem productivity (NEP) and its inter-annual variation (IAVNEP) keep varying over space. Thus, identifying local indicators for the spatially varying NEP and IAVNEP is critical for locating the major and sustainable C sinks on land. Here, based on daily NEP observations from FLUXNET sites and large-scale estimates from an atmospheric-inversion product, we found a robust logarithmic correlation between annual NEP and seasonal carbon uptake–release ratio (i.e. U ∕ R). The cross-site variation in mean annual NEP could be logarithmically indicated by U ∕ R, while the spatial distribution of IAVNEP was associated with the slope (i.e. β) of the logarithmic correlation between annual NEP and U ∕ R. Among biomes, for ex le, forests and croplands had the largest U ∕ R ratio (1.06 ± 0.83) and β (473 ± 112 g C m−2 yr−1), indicating the highest NEP and IAVNEP in forests and croplands, respectively. We further showed that these two simple indicators could directly infer the spatial variations in NEP and IAVNEP in global gridded NEP products. Overall, this study provides two simple local indicators for the intricate spatial variations in the strength and stability of land C sinks. These indicators could be helpful for locating the persistent terrestrial C sinks and provide valuable constraints for improving the simulation of land–atmospheric C exchanges.

Global patterns and climate drivers of water‐use efficiency in terrestrial ecosystems deduced from satellite‐based datasets and carbon cycle models

Publisher: Wiley

Date: 23-12-2015

DOI: 10.1111/GEB.12411

Reliable, robust and realistic: The three R's of next-generation land surface modelling

Publisher: Copernicus GmbH

Date: 26-09-2014

DOI: 10.5194/ACPD-14-24811-2014

Abstract: Abstract. Land surface models (LSMs) are increasingly called upon to represent not only the exchanges of energy, water and momentum across the land-atmosphere interface (their original purpose in climate models), but also how ecosystems and water resources respond to climate and atmospheric environment, and how these responses in turn influence land-atmosphere fluxes of carbon dioxide (CO2), trace gases and other species that affect the composition and chemistry of the atmosphere. However, the LSMs embedded in state-of-the-art climate models differ in how they represent fundamental aspects of the hydrological and carbon cycles, resulting in large inter-model differences and sometimes faulty predictions. These "third-generation" LSMs respect the close coupling of the carbon and water cycles through plants, but otherwise tend to be under-constrained, and have not taken full advantage of robust hydrological parameterizations that were independently developed in offline models. Benchmarking, combining multiple sources of atmospheric, biospheric and hydrological data, should be a required component of LSM development, but this field has been relatively poorly supported and intermittently pursued. Moreover, benchmarking alone is not sufficient to ensure that models improve. Increasing complexity may increase realism but decrease reliability and robustness, by increasing the number of poorly known model parameters. In contrast, simplifying the representation of complex processes by stochastic parameterization (the representation of unresolved processes by statistical distributions of values) has been shown to improve model reliability and realism in both atmospheric and land-surface modelling contexts. We provide ex les for important processes in hydrology (the generation of runoff and flow routing in heterogeneous catchments) and biology (carbon uptake by species- erse ecosystems). We propose that the way forward for next-generation complex LSMs will include: (a) representations of biological and hydrological processes based on the implementation of multiple internal constraints (b) systematic application of benchmarking and data assimilation techniques to optimize parameter values and thereby test the structural adequacy of models and (c) stochastic parameterization of unresolved variability, applied in both the hydrological and the biological domains.

Characterization of anogenital distance and its relationship to fertility in lactating Holstein cows

Publisher: American Dairy Science Association

Date: 12-2017

DOI: 10.3168/JDS.2017-13033

Abstract: Anogenital distance (AGD) serves as a marker for prenatal androgenization, reproductive development, and fertility in humans and rodents. The primary objectives of this observational study in lactating dairy cows were to (1) characterize the distribution and variability of AGD, (2) determine the relationship among AGD and potential postnatal AGD determinants of age and height, and (3) evaluate the associations between AGD and pregnancy to first artificial insemination (P/AI) and cumulative pregnancy by 250 d in milk (DIM) within parity groups (first, second, and third+ parities). The secondary objective was to evaluate the association between AGD and testosterone concentrations. The AGD (mm), age (yr), and height at hip (cm) at the time of AGD determination, and aforesaid reproductive outcomes were determined in 921 Holstein cows (first, second, and third+ parity n = 360, 256, and 305, respectively). Plasma concentrations of testosterone were determined in a subset of 93 cows. Overall, AGD had a normal distribution and high variability [mean (±standard deviation) 131.0 ± 12.2 mm], was weakly associated with cow age and height (coefficient of determination = 0.09 and 0.04, respectively), and had an inverse relationship with P/AI in first- and second-parity cows, but not in third+ parity cows. For every 1 mm increase in AGD, the odds of P/AI decreased by 3.4 and 2.4% for first- and second-parity cows, respectively. The optimal AGD threshold to predict probability of P/AI was 127.1 mm for both first- (sensitivity: 66.4 specificity: 56.6%) and second-parity cows (sensitivity: 46.0 specificity: 70.4%). Accordingly, first- and second-parity cows were categorized into either short or long AGD (≤ or >127.1 mm), and associations with reproductive outcomes were evaluated. First-parity cows with long AGD had lower P/AI (30.9 vs. 53.6%) and decreased likelihood (hazard ratio: 0.68) of pregnancy by 250 DIM than those with short AGD. Similarly, second-parity cows with long AGD had reduced P/AI (28.3 vs. 44.4%) and a tendency for decreased likelihood (hazard ratio: 0.76) of pregnancy by 250 DIM than in cows with short AGD. The association between AGD and testosterone was weak and nonsignificant. In summary, AGD in Holstein cows was normally distributed, highly variable, and weakly associated with age and height. Besides, AGD had an inverse relationship with P/AI and cumulative pregnancy by 250 DIM in first- and second-parity cows however, such a relationship was not evident in older (third+ parity) cows.

Corrigendum to “Nitrous oxide emissions from a legume-pasture and the influences of liming and urine addition” [Agric. Ecosyst. Environ. 136 (2010) 262–272]

Publisher: Elsevier BV

Date: 08-2016

DOI: 10.1016/J.AGEE.2016.05.021

Humanitarian intervention and R2P

Publisher: Brill | Nijhoff

Date: 22-11-2022

DOI: 10.1163/9789004430129_019

Different patterns of ecosystem carbon accumulation between a young and an old-growth subtropical forest in Southern China

Publisher: Springer Science and Business Media LLC

Date: 26-03-2011

DOI: 10.1007/S11258-011-9914-2

Simulation of optimal development for spring wheat at two locations in southern Australia under present and changed climate conditions

Publisher: Elsevier BV

Date: 03-1996

DOI: 10.1016/0168-1923(95)02271-6

Land and ocean nutrient and carbon cycle interactions

Publisher: Elsevier BV

Date: 10-2010

DOI: 10.1016/J.COSUST.2010.05.009

Estimating Aboveground Carbon Dynamic of China Using Optical and Microwave Remote-Sensing Datasets from 2013 to 2019

Publisher: American Association for the Advancement of Science (AAAS)

Date: 2023

DOI: 10.34133/REMOTESENSING.0005

Abstract: Over the past 2 to 3 decades, Chinese forests are estimated to act as a large carbon sink, yet the magnitude and spatial patterns of this sink differ considerably among studies. Using 3 microwave (L- and X-band vegetation optical depth [VOD]) and 3 optical (normalized difference vegetation index, leaf area index, and tree cover) remote-sensing vegetation products, this study compared the estimated live woody aboveground biomass carbon (AGC) dynamics over China between 2013 and 2019. Our results showed that tree cover has the highest spatial consistency with 3 published AGC maps (mean correlation value R = 0.84), followed by L-VOD ( R = 0.83), which outperform the other VODs. An AGC estimation model was proposed to combine all indices to estimate the annual AGC dynamics in China during 2013 to 2019. The performance of the AGC estimation model was good (root mean square error = 0.05 Pg C and R 2 = 0.90 with a mean relative uncertainty of 9.8% at pixel scale [0.25°]). Results of the AGC estimation model showed that carbon uptake by the forests in China was about +0.17 Pg C year −1 from 2013 to 2019. At the regional level, provinces in southwest China including Guizhou (+22.35 Tg C year −1 ), Sichuan (+14.49 Tg C year −1 ), and Hunan (+11.42 Tg C year −1 ) provinces had the highest carbon sink rates during 2013 to 2019. Most of the carbon-sink regions have been afforested recently, implying that afforestation and ecological engineering projects have been effective means for carbon sequestration in these regions.

The carbon cycle in the Australian Community Climate and Earth System Simulator (ACCESS-ESM1) - Part 1: Model description and pre-industrial simulation

Publisher: Copernicus GmbH

Date: 06-07-2017

DOI: 10.5194/GMD-10-2567-2017

Abstract: Abstract. Earth system models (ESMs) that incorporate carbon–climate feedbacks represent the present state of the art in climate modelling. Here, we describe the Australian Community Climate and Earth System Simulator (ACCESS)-ESM1, which comprises atmosphere (UM7.3), land (CABLE), ocean (MOM4p1), and sea-ice (CICE4.1) components with OASIS-MCT coupling, to which ocean and land carbon modules have been added. The land carbon model (as part of CABLE) can optionally include both nitrogen and phosphorous limitation on the land carbon uptake. The ocean carbon model (WOMBAT, added to MOM) simulates the evolution of phosphate, oxygen, dissolved inorganic carbon, alkalinity and iron with one class of phytoplankton and zooplankton. We perform multi-centennial pre-industrial simulations with a fixed atmospheric CO2 concentration and different land carbon model configurations (prescribed or prognostic leaf area index). We evaluate the equilibration of the carbon cycle and present the spatial and temporal variability in key carbon exchanges. Simulating leaf area index results in a slight warming of the atmosphere relative to the prescribed leaf area index case. Seasonal and interannual variations in land carbon exchange are sensitive to whether leaf area index is simulated, with interannual variations driven by variability in precipitation and temperature. We find that the response of the ocean carbon cycle shows reasonable agreement with observations. While our model overestimates surface phosphate values, the global primary productivity agrees well with observations. Our analysis highlights some deficiencies inherent in the carbon models and where the carbon simulation is negatively impacted by known biases in the underlying physical model and consequent limits on the applicability of this model version. We conclude the study with a brief discussion of key developments required to further improve the realism of our model simulation.

Improving the ability of the photochemical reflectance index to track canopy light use efficiency through differentiating sunlit and shaded leaves

Publisher: Elsevier BV

Date: 06-2017

DOI: 10.1016/J.RSE.2017.03.012

Accounting for female reproductive cycles in a superpopulation capture–recapture framework

Publisher: Wiley

Date: 10-2013

DOI: 10.1890/12-1657.1

Abstract: Superpopulation capture-recapture models are useful for estimating the abundance of long-lived, migratory species because they are able to account for the fluid nature of annual residency at migratory destinations. Here we extend the superpopulation POPAN model to explicitly account for heterogeneity in capture probability linked to reproductive cycles (POPAN-tau). This extension has potential application to a range of species that have temporally variable life stages (e.g., non-annual breeders such as albatrosses and baleen whales) and results in a significant reduction in bias over the standard POPAN model. We demonstrate the utility of this model in simultaneously estimating abundance and annual population growth rate (lamda) in the New Zealand (NZ) southern right whale (Eubalaena australis) from 1995 to 2009. DNA profiles were constructed for the in idual identification of more than 700 whales, s led during two sets of winter expeditions in 1995-1998 and 2006-2009. Due to differences in recapture rates between sexes, only sex-specific models were considered. The POPAN-tau models, which explicitly account for a decrease in capture probability in non-calving years, fit the female data set significantly better than do standard superpopulation models (deltaAIC > 25). The best POPAN-tau model (AIC) gave a super-population estimate of 1162 females for 1995-2009 (95% CL 921, 1467) and an estimated annual increase of 5% (95% CL--2%, 13%). The best model (AIC) gave a superpopulation estimate of 1007 males (95% CL 794, 1276) and an estimated annual increase of 7% (95% CL 5%, 9%) for 1995-2009. Combined, the total superpopulation estimate for 1995-2009 was 2169 whales (95% CL 1836, 2563). Simulations suggest that failure to account for the effect of reproductive status on the capture probability would result in a substantial positive bias (+19%) in female abundance estimates.

Global patterns and drivers of phosphorus pools in natural soils

Publisher: Copernicus GmbH

Date: 24-02-2023

DOI: 10.5194/BG-2023-22

Abstract: Abstract. Most phosphorus (P) in soils is unavailable for direct biological uptake as it is locked within primary or secondary mineral particles, adsorbed to mineral surfaces, or immobilized inside of organic material. Deciphering the composition of different P pools in soil is critical for understanding P bioavailability and its underlying dynamics. However, widely used global estimates of different soil P pools are based on a dataset containing few measurements in which many regions or soil types are unrepresented. This poses a major source of uncertainty in assessments that rely on these estimates to quantify soil P constraints on biological activity controlling global food production and terrestrial carbon balance. To address this issue, we consolidated a database of six major soil P pools containing 1857 entries from globally distributed (semi-)natural soils and 11 related environmental variables. The P pools (labile inorganic P (Pi), labile organic P (Po), moderately labile Pi, moderately labile Po, primary mineral P, and occluded P) were measured using a sequential P fractionation method. Using the database, we trained random forest regression models for each of the P pools and captured observed variation with R2 higher than 60 %. We identified total soil P concentration as the most important predictor of all soil P pool concentrations, except for primary mineral P concentration, which is primarily controlled by soil pH. When expressed in relative concentrations (i.e., as a proportion of total P), the model showed that soil pH is the most important predictor for proportions of all soil P pools, except for labile Pi proportion, which is primarily controlled by soil depth. Using the trained random forest models, we predicted soil P pools’ distributions in natural systems at a resolution of 0.5° × 0.5°. Our global maps of different P pools in soils as well as the pools’ underlying drivers can inform assessments of the role of natural P availability for ecosystem productivity, climate change mitigation, and the functioning of the Earth system.

Leaf Area Index identified as a major source of variability in modelled CO&lt;sub&gt;2&lt;/sub&gt; fertilization

Publisher: Copernicus GmbH

Date: 08-05-2018

DOI: 10.5194/BG-2018-213

Abstract: Abstract. The concentration-carbon feedback factor (β), also called the CO2 fertilization effect, is a key unknown in climate-carbon cycle projections. A better understanding of model mechanisms that govern terrestrial ecosystem responses to elevated CO2 is urgently needed to enable a more accurate prediction of future terrestrial carbon sink. We calculated CO2 fertilization effects at various hierarchical levels from leaf biochemical reaction, leaf photosynthesis, canopy gross primary production (GPP), net primary production (NPP), to ecosystem carbon storage (cpool), for seven C3 vegetation types in response to increasing CO2 under RCP 8.5 scenario, using the Community Atmosphere Biosphere Land Exchange model (CABLE). Our results show that coefficient of variation (CV) for the CABLE model among the seven vegetation types is 0.15–0.13 for the biochemical level β, 0.13–0.16 for the leaf-level β, 0.48 for the βGPP, 0.45 for the βNPP, and 0.58 for the βcpool. The low variation of the leaf-level β is consistent with a theoretical analysis that leaf photosynthetic sensitivity to increasing CO2 concentration is almost an invariant function. In CABLE, the major jump in CV of β values from leaf- to canopy- and ecosystem-levels results from ergence in modelled leaf area index (LAI) within and among the vegetation types. The correlations of βGPP, βNPP, or βcpool with βLAI are very high in CABLE. Overall, our results indicate that modelled LAI is a key factor causing the ergence in β values in CABLE model. It is therefore urgent to constrain processes that regulate LAI dynamics in order to better represent the response of ecosystem productivity to increasing CO2 in Earth System Models.

Modifying Existing Forest Growth Models to Take Account of Effects of Elevated CO2

Publisher: CSIRO Publishing

Date: 1992

DOI: 10.1071/BT9920657

Abstract: Most published process models of the growth of forest stands are concerned predominantly with either tree physiology or nutrient cycling, concentrating respectively on photosynthetic carbon gain and allocation, or on decomposition and nutrient uptake processes. Mechanistic formulations of direct CO2 effects on photosynthesis have been incorporated in some physiology-based models, whereas modifications incorporating direct CO2 effects in nutrient-driven models have usually been more empirical. Physiology-based models predict considerable CO2-fertiliser effects, while nutrient driven models tend to be less sensitive to elevated ambient CO2 concentration (Ca). This paper describes how effects of elevated Ca can be incorporated in these various types of forest growth models. The magnitude of the simulated response to elevated Ca varies markedly depending on a particular model's spatial and temporal resolution and on which processes are incorporated. Two physiology- based models of forest canopy processes (MAESTRO and BIOMASS) and a plant-soil model (G'DAY) are considered here. MAESTRO and BIOMASS incorporate mechanistic descriptions of the biochemical basis of photosynthesis by C3 plants, while G'DAY contains a simplified formulation but includes soil processes. All three models are used to simulate the response to an instantaneous doubling of Ca. Simulations of MAESTRO and BIOMASS show that on a clear day total canopy photsynthesis is temperature-dependent with increases of approximately 10, 45 and 70% at 10. 25 and 40°C respectively. A simulation for a stand of Pinus radiata growing with abundant water and nutrients and mean annual day-time temperature of 14.8°C shows an increase of 25% in annual canopy photosynthesis. On nutrient-limited sites plant responses to elevated Ca are constrained by feedbacks associated with rates of decomposition and nutrient cycling. According to the G'DAY model, which incorporates these feedbacks, an instantaneous doubling of Ca leads to a 27% initial productivity increase lasting less than a decade and a more modest increase of 8% sustained in the long term.

Benchmarking global land surface models against observed mean annual runoff from 150 large basins

Publisher: Elsevier BV

Date: 11-2012

DOI: 10.1016/J.JHYDROL.2012.09.002

The Australian Earth System Model: ACCESS-ESM1.5

Publisher: CSIRO Publishing

Date: 24-08-2020

DOI: 10.1071/ES19035

Abstract: The Australian Community Climate and Earth System Simulator (ACCESS) has been extended to include land and ocean carbon cycle components to form an Earth System Model (ESM). The current version, ACCESS-ESM1.5, has been mainly developed to enable Australia to participate in the Coupled Model Intercomparison Project Phase 6 (CMIP6) with an ESM version. Here we describe the model components and changes to the previous version, ACCESS-ESM1. We use the 500-year pre-industrial control run to highlight the stability of the physical climate and the carbon cycle. The long spin-up, negligible drift in temperature and small pre-industrial net carbon fluxes (0.02 and 0.08 PgC year−1 for land and ocean respectively) highlight the suitability of ACCESS-ESM1.5 to explore modes of variability in the climate system and coupling to the carbon cycle. The physical climate and carbon cycle for the present day have been evaluated using the CMIP6 historical simulation by comparing against observations and ACCESS-ESM1. Although there is generally little change in the climate simulation from the earlier model, many aspects of the carbon simulation are improved. An assessment of the climate response to CO2 forcing indicates that ACCESS-ESM1.5 has an equilibrium climate sensitivity of 3.87°C.

Spin interferometry in anisotropic spin-orbit fields

Publisher: American Physical Society (APS)

Date: 21-03-2018

DOI: 10.1103/PHYSREVB.97.125423

The CSIRO Atmosphere Biosphere Land Exchange (CABLE) model for use in climate models and as an offline model

Publisher: Aspendale, Vic., CSIRO Marine and Atmospheric Research

Date: 2006

DOI: 10.4225/08/58615C6A9A51D

Asymmetric influence of forest cover gain and loss on land surface temperature

Publisher: Springer Science and Business Media LLC

Date: 08-2023

DOI: 10.1038/S41558-023-01757-7

Using ecosystem experiments to improve vegetation models

Publisher: Springer Science and Business Media LLC

Date: 21-05-2015

DOI: 10.1038/NCLIMATE2621

Harmonization of land-use scenarios for the period 1500–2100: 600 years of global gridded annual land-use transitions, wood harvest, and resulting secondary lands

Publisher: Springer Science and Business Media LLC

Date: 09-08-2011

DOI: 10.1007/S10584-011-0153-2

Decadal biomass increment in early secondary succession woody ecosystems is increased by CO2 enrichment

Publisher: Springer Science and Business Media LLC

Date: 14-02-2019

DOI: 10.1038/S41467-019-08348-1

Abstract: Increasing atmospheric CO 2 stimulates photosynthesis which can increase net primary production (NPP), but at longer timescales may not necessarily increase plant biomass. Here we analyse the four decade-long CO 2 -enrichment experiments in woody ecosystems that measured total NPP and biomass. CO 2 enrichment increased biomass increment by 1.05 ± 0.26 kg C m −2 over a full decade, a 29.1 ± 11.7% stimulation of biomass gain in these early-secondary-succession temperate ecosystems. This response is predictable by combining the CO 2 response of NPP (0.16 ± 0.03 kg C m −2 y −1 ) and the CO 2 -independent, linear slope between biomass increment and cumulative NPP (0.55 ± 0.17). An ensemble of terrestrial ecosystem models fail to predict both terms correctly. Allocation to wood was a driver of across-site, and across-model, response variability and together with CO 2 -independence of biomass retention highlights the value of understanding drivers of wood allocation under ambient conditions to correctly interpret and predict CO 2 responses.

Spin-orbit-induced chirality of Andreev states in Josephson junctions

Publisher: American Physical Society (APS)

Date: 28-12-2012

DOI: 10.1103/PHYSREVB.86.214519

Asynchronous glaciations in arid continental climate

Publisher: Elsevier BV

Date: 02-2018

DOI: 10.1016/J.QUASCIREV.2017.12.001

Pregnancy per artificial insemination and pregnancy loss in lactating dairy cows of a single herd following timed artificial insemination or insemination at detected estrus

Publisher: Canadian Science Publishing

Date: 09-2015

DOI: 10.4141/CJAS-2014-122

Abstract: Thangavelu, G., Gobikrushanth, M., Colazo, M. G. and Ambrose, D. J. 2015. Pregnancy per artificial insemination and pregnancy loss in lactating dairy cows of a single herd following timed artificial insemination or insemination at detected estrus. Can. J. Anim. Sci. 95: 383–388. The objective of this retrospective study was to determine the factors affecting pregnancy per artificial insemination (P/AI) and pregnancy loss in lactating dairy cattle. Breeding records (n=1466) for 5 consecutive years were evaluated from one dairy herd. The effects of type of breeding [timed artificial insemination (TAI n=1246) vs. insemination at detected estrus (IDE n=220)], parity (primiparous vs. multiparous), body condition score (BCS low ≤2.5 vs. high .5), year, season (summer vs. other seasons) and fertility group (high fertile vs. low fertile ≥3 inseminations), on P/AI and pregnancy loss (i.e., late embryonic/early fetal loss, abortion and stillbirth) were determined using the GLIMMIX procedures of SAS software. Pregnancy per AI was influenced by type of breeding and season. Pregnancy per AI was lower (P .05) in cows that were TAI (28.7%) than IDE (37.1%) and during summer (30.3%) than other seasons of the year (35.5%). Pregnancy loss was higher (P .05) in low BCS (9.1%) than in high BCS (1.9%) cows. However, parity, year, and fertility group affected neither P/AI nor pregnancy loss.

Growth and water use of wheat under present and future levels of CO2

Publisher: Society of Agricultural Meteorology of Japan

Date: 1993

DOI: 10.2480/AGRMET.48.807

Simulation of soil carbon dynamics in Australia with {\sc Roth C}

Publisher: Copernicus GmbH

Date: 28-04-2021

DOI: 10.5194/ISMC2021-91

Abstract: & & We simulated soil organic carbon (C) dynamics across Australia with the Rothamsted carbon model ({\\sc Roth C}) by connecting new spatially-explicit soil measurements and data with the model. This helped us to bridge the disconnection that exists between datasets used to inform the model and the processes that it depicts. We compiled publicly available continental-scale datasets and pre-processed, standardised and configured them to the required spatial and temporal resolutions. We then calibrated {\\sc Roth C} and run simulations to estimate the baseline soil organic C stocks and composition in the 0--0.3~m layer at 4,043 sites in cropping, modified grazing, native grazing, and natural environments across Australia. We used data on the C fractions, the particulate, mineral associated, and resistant organic C (POC, MAOC and ROC, respectively) to represent the three main C pools in the {\\sc Roth C} model's structure.& span class=& quot Apple-converted-space& quot & & & /span& The model explained 97--98\\% of the variation in measured total organic C in soils under cropping and grazing, and 65\\% in soils under natural environments. We optimised the model at each site and experimented with different amounts of C inputs to simulate the potential for C accumulation under constant and chainging climate in a 100-year simulation. Soils under native grazing were the most potentially vulnerable to C decomposition and loss, while soils under natural environments were the least vulnerable. An empirical assessment of the controls on the C change showed that climate, pH, total N, the C:N ratio, and cropping were the most important controls on POC change. Clay content and climate were dominant controls on MAOC change. Consistent and explicit soil organic C simulations improve confidence in the model's estimations, contributing to the development of sustainable soil management under global change.& span class=& quot Apple-converted-space& quot & & & /span& & &

Circuit-QED with phase-biased Josephson weak links

Publisher: American Physical Society (APS)

Date: 12-01-2021

DOI: 10.1103/PHYSREVRESEARCH.3.013036

Carbon turnover gets wet

Publisher: Springer Science and Business Media LLC

Date: 12-2022

DOI: 10.1038/S41561-022-01098-8

A review of applications of model-data fusion to studies of terrestrial carbon fluxes at different scales

Publisher: Elsevier BV

Date: 11-2009

DOI: 10.1016/J.AGRFORMET.2009.07.009

Incorporating root hydraulic redistribution and compensatory water uptake in the Common Land Model: Effects on site level and global land modeling

Publisher: American Geophysical Union (AGU)

Date: 17-07-2017

DOI: 10.1002/2016JD025744

Do land surface models need to include differential plant species responses to drought? Examining model predictions across a latitudinal gradient in Europe

Publisher: Copernicus GmbH

Date: 06-08-2015

DOI: 10.5194/BGD-12-12349-2015

Abstract: Abstract. Future climate change has the potential to increase drought in many regions of the globe, making it essential that land surface models (LSMs) used in coupled climate models, realistically capture the drought responses of vegetation. Recent data syntheses show that drought sensitivity varies considerably among plants from different climate zones, but state-of-the-art LSMs currently assume the same drought sensitivity for all vegetation. We tested whether variable drought sensitivities are needed to explain the observed large-scale patterns of drought impact. We implemented data-driven drought sensitivities in the Community Atmosphere Biosphere Land Exchange (CABLE) LSM and evaluated alternative sensitivities across a latitudinal gradient in Europe during the 2003 heatwave. The model predicted an overly abrupt onset of drought unless average soil water potential was calculated with dynamic weighting across soil layers. We found that high drought sensitivity at the northernmost sites, and low drought sensitivity at the southernmost sites, was necessary to accurately model responses during drought. Our results indicate that LSMs will over-estimate drought impacts in drier climates unless different sensitivity of vegetation to drought is taken into account.

Soil organic matter is important for acid buffering and reducing aluminum leaching from acidic forest soils

Publisher: Elsevier BV

Date: 11-2018

DOI: 10.1016/J.CHEMGEO.2018.10.009

Asymmetric responses of primary productivity to altered precipitation simulated by ecosystem models across three long-term grassland sites

Publisher: Copernicus GmbH

Date: 11-06-2018

DOI: 10.5194/BG-15-3421-2018

Abstract: Abstract. Field measurements of aboveground net primary productivity (ANPP) in temperate grasslands suggest that both positive and negative asymmetric responses to changes in precipitation (P) may occur. Under normal range of precipitation variability, wet years typically result in ANPP gains being larger than ANPP declines in dry years (positive asymmetry), whereas increases in ANPP are lower in magnitude in extreme wet years compared to reductions during extreme drought (negative asymmetry). Whether the current generation of ecosystem models with a coupled carbon–water system in grasslands are capable of simulating these asymmetric ANPP responses is an unresolved question. In this study, we evaluated the simulated responses of temperate grassland primary productivity to scenarios of altered precipitation with 14 ecosystem models at three sites: Shortgrass steppe (SGS), Konza Prairie (KNZ) and Stubai Valley meadow (STU), spanning a rainfall gradient from dry to moist. We found that (1) the spatial slopes derived from modeled primary productivity and precipitation across sites were steeper than the temporal slopes obtained from inter-annual variations, which was consistent with empirical data (2) the asymmetry of the responses of modeled primary productivity under normal inter-annual precipitation variability differed among models, and the mean of the model ensemble suggested a negative asymmetry across the three sites, which was contrary to empirical evidence based on filed observations (3) the mean sensitivity of modeled productivity to rainfall suggested greater negative response with reduced precipitation than positive response to an increased precipitation under extreme conditions at the three sites and (4) gross primary productivity (GPP), net primary productivity (NPP), aboveground NPP (ANPP) and belowground NPP (BNPP) all showed concave-down nonlinear responses to altered precipitation in all the models, but with different curvatures and mean values. Our results indicated that most models overestimate the negative drought effects and/or underestimate the positive effects of increased precipitation on primary productivity under normal climate conditions, highlighting the need for improving eco-hydrological processes in those models in the future.

Evaluating the simulated mean soil carbon transit times by Earth system models using observations

Publisher: Copernicus GmbH

Date: 15-08-2018

DOI: 10.5194/BG-2018-342

Abstract: Abstract. One known bias in current Earth system models (ESMs) is the underestimation of global mean soil carbon (C) transit time (τsoil), which quantifies the mean age of the C atoms at the time they leave the soil. However, it remains unclear where such underestimations are located globally. Here, we constructed a global database of measured τsoil across 187 sites to evaluated results from twelve ESMs. The observations showed that the estimated τsoil was dramatically shorter from the soil incubations studies in the laboratory environment (median as 4 with the interquartile range of 1–25 years) than that derived from field in-situ measurements (31 with 5–84 years) with the shifts of stable isotopic C (13C) or the stock-over-flux approach. In comparison with the field observations, the multi-model ensemble simulated a shorter median (19 years) and a smaller spatial variation (interquartile range of 6–28 years) of τsoil across the same site locations. We then found a significant and negative linear correlation between the in-situ measured τsoil and mean annual air temperature, and the underestimations of modeled τsoil are mainly located in cold and dry biomes especially tundra and desert. Furthermore, we showed that one ESM (i.e., CESM) has improved its τsoil estimate by incorporation of the soil vertical profile. These findings indicate that the spatial variation of τsoil is a useful benchmark for ESMs, and we recommend more observation and modeling efforts on soil C dynamics in hydrothermal limited regions.

Soil organic carbon and nutrient losses resulted from spring dust emissions in Northern China

Publisher: Elsevier BV

Date: 09-2019

DOI: 10.1016/J.ATMOSENV.2019.06.043

Description and validation of an array model — MAESTRO

Publisher: Elsevier BV

Date: 07-1990

DOI: 10.1016/0168-1923(90)90112-J

Atrocity crimes and international law

Publisher: Routledge

Date: 07-09-2022

DOI: 10.4324/9781003220893

Interactive effects of nitrogen and phosphorus additions on plant growth vary with ecosystem type

Publisher: Springer Science and Business Media LLC

Date: 08-05-2019

DOI: 10.1007/S11104-019-04119-5

Global Patterns in Net Primary Production Allocation Regulated by Environmental Conditions and Forest Stand Age: A Model‐Data Comparison

Publisher: American Geophysical Union (AGU)

Date: 07-2019

DOI: 10.1029/2018JG004777

Abstract: The allocation of net primary production (NPP) to different plant structures, such as leaves, wood, and fine roots, plays an important role in the terrestrial carbon cycle. However, the biogeographical patterns of NPP allocation are not well understood. We constructed a global database of forest NPP to investigate the observed spatial patterns of forest NPP allocation, as influenced by environmental drivers and forest stand age. We then examined whether dynamic global vegetation models (DGVMs) could capture these allocation patterns. The NPP allocation response to variations in temperature or precipitation was often opposite in leaves and fine roots, a finding consistent with the functional balance theory for allocation. The observed allocation to fine roots decreased with increasing temperature and precipitation. The observed allocation to wood and leaves decreased with forest stand age. The simulated allocation with five DGVMs was compared with the observations. The five models captured the spatial gradient of lower allocation to fine roots with increasing temperature and precipitation but did not capture coincident gradients in allocation to wood and leaves. None of the five models adequately represented the changes in allocation with forest stand age. Specifically, the models did not reproduce the decrease in allocation to wood and leaves and the increase in allocation to fine roots with increasing forest stand age. An accurate simulation of NPP allocation requires more realistic representation of multiple processes that are closely related to allocation. The NPP allocation database can be used to develop DGVMs.

Nitrogen and phosphorous limitations significantly reduce future allowable CO₂ emissions

Publisher: American Geophysical Union (AGU)

Date: 28-01-2014

DOI: 10.1002/2013GL058352

Three-dimensional trapping of light with light in semiconductor planar microcavities

Publisher: American Physical Society (APS)

Date: 29-05-2019

DOI: 10.1103/PHYSREVB.99.195308

Dephasing and hyperfine interaction in carbon nanotubes double quantum dots: Disordered case

Publisher: American Physical Society (APS)

Date: 18-05-2012

DOI: 10.1103/PHYSREVB.85.195441

A framework for benchmarking land models

Publisher: Copernicus GmbH

Date: 09-10-2012

DOI: 10.5194/BG-9-3857-2012

Abstract: Abstract. Land models, which have been developed by the modeling community in the past few decades to predict future states of ecosystems and climate, have to be critically evaluated for their performance skills of simulating ecosystem responses and feedback to climate change. Benchmarking is an emerging procedure to measure performance of models against a set of defined standards. This paper proposes a benchmarking framework for evaluation of land model performances and, meanwhile, highlights major challenges at this infant stage of benchmark analysis. The framework includes (1) targeted aspects of model performance to be evaluated, (2) a set of benchmarks as defined references to test model performance, (3) metrics to measure and compare performance skills among models so as to identify model strengths and deficiencies, and (4) model improvement. Land models are required to simulate exchange of water, energy, carbon and sometimes other trace gases between the atmosphere and land surface, and should be evaluated for their simulations of biophysical processes, biogeochemical cycles, and vegetation dynamics in response to climate change across broad temporal and spatial scales. Thus, one major challenge is to select and define a limited number of benchmarks to effectively evaluate land model performance. The second challenge is to develop metrics of measuring mismatches between models and benchmarks. The metrics may include (1) a priori thresholds of acceptable model performance and (2) a scoring system to combine data–model mismatches for various processes at different temporal and spatial scales. The benchmark analyses should identify clues of weak model performance to guide future development, thus enabling improved predictions of future states of ecosystems and climate. The near-future research effort should be on development of a set of widely acceptable benchmarks that can be used to objectively, effectively, and reliably evaluate fundamental properties of land models to improve their prediction performance skills.

Spin resonance under topological driving fields

Publisher: IOP Publishing

Date: 06-06-2017

DOI: 10.1088/1367-2630/AA723A

The impact of nitrogen and phosphorous limitation on the estimated terrestrial carbon balance and warming of land use change over the last 156 yr

Publisher: Copernicus GmbH

Date: 16-09-2013

DOI: 10.5194/ESD-4-333-2013

Abstract: Abstract. We examine the impact of land use and land cover change (LULCC) over the period from 1850 to 2005 using an Earth system model that incorporates nitrogen and phosphorous limitation on the terrestrial carbon cycle. We compare the estimated CO2 emissions and warming from land use change in a carbon-only version of the model with those from simulations, including nitrogen and phosphorous limitation. If we omit nutrients, our results suggest LULCC cools on the global average by about 0.1 °C. Including nutrients reduces this cooling to ~ 0.05 °C. Our results also suggest LULCC has a major impact on total land carbon over the period 1850–2005. In carbon-only simulations, the inclusion of LULCC decreases the total additional land carbon stored in 2005 from around 210 Pg C to 85 Pg C. Including nitrogen and phosphorous limitation also decreases the scale of the terrestrial carbon sink to 80 Pg C. Shown as corresponding fluxes, adding LULCC on top of the nutrient-limited simulations changes the sign of the terrestrial carbon flux from a sink to a source (12 Pg C). The CO2 emission from LULCC from 1850 to 2005 is estimated to be 130 Pg C for carbon only simulation, or 97 Pg C if nutrient limitation is accounted for in our model. The difference between these two estimates of CO2 emissions from LULCC largely results from the weaker response of photosynthesis to increased CO2 and smaller carbon pool sizes, and therefore lower carbon loss from plant and wood product carbon pools under nutrient limitation. We suggest that nutrient limitation should be accounted for in simulating the effects of LULCC on the past climate and on the past and future carbon budget.

Oscillatory behavior of two nonlinear microbial models of soil carbon decomposition

Publisher: Copernicus GmbH

Date: 07-04-2014

DOI: 10.5194/BG-11-1817-2014

Abstract: Abstract. A number of nonlinear models have recently been proposed for simulating soil carbon decomposition. Their predictions of soil carbon responses to fresh litter input and warming differ significantly from conventional linear models. Using both stability analysis and numerical simulations, we showed that two of those nonlinear models (a two-pool model and a three-pool model) exhibit d ed oscillatory responses to small perturbations. Stability analysis showed the frequency of oscillation is proportional to √(& varepsilon −1−1) Ks/Vs in the two-pool model, and to √(& varepsilon −1−1) Kl/Vl in the three-pool model, where & varepsilon is microbial growth efficiency, Ks and Kl are the half saturation constants of soil and litter carbon, respectively, and /Vs and /Vl are the maximal rates of carbon decomposition per unit of microbial biomass for soil and litter carbon, respectively. For both models, the oscillation has a period of between 5 and 15 years depending on other parameter values, and has smaller litude at soil temperatures between 0 and 15 °C. In addition, the equilibrium pool sizes of litter or soil carbon are insensitive to carbon inputs in the nonlinear model, but are proportional to carbon input in the conventional linear model. Under warming, the microbial biomass and litter carbon pools simulated by the nonlinear models can increase or decrease, depending whether & varepsilon varies with temperature. In contrast, the conventional linear models always simulate a decrease in both microbial and litter carbon pools with warming. Based on the evidence available, we concluded that the oscillatory behavior and insensitivity of soil carbon to carbon input are notable features in these nonlinear models that are somewhat unrealistic. We recommend that a better model for capturing the soil carbon dynamics over decadal to centennial timescales would combine the sensitivity of the conventional models to carbon influx with the flexible response to warming of the nonlinear model.

Hydrologic connectivity drives extremes and high variability in vegetation productivity across Australian arid and semi-arid ecosystems

Publisher: Elsevier BV

Date: 04-2022

DOI: 10.1016/J.RSE.2022.112937

Non-uniform seasonal warming regulates vegetation greening and atmospheric CO ₂ amplification over northern lands

Publisher: IOP Publishing

Date: 27-11-2018

DOI: 10.1088/1748-9326/AAE9AD

Global patterns and substrate‐based mechanisms of the terrestrial nitrogen cycle

Publisher: Wiley

Date: 02-03-2016

DOI: 10.1111/ELE.12591

Abstract: Nitrogen (N) deposition is impacting the services that ecosystems provide to humanity. However, the mechanisms determining impacts on the N cycle are not fully understood. To explore the mechanistic underpinnings of N impacts on N cycle processes, we reviewed and synthesised recent progress in ecosystem N research through empirical studies, conceptual analysis and model simulations. Experimental and observational studies have revealed that the stimulation of plant N uptake and soil retention generally diminishes as N loading increases, while dissolved and gaseous losses of N occur at low N availability but increase exponentially and become the dominant fate of N at high loading rates. The original N saturation hypothesis emphasises sequential N saturation from plant uptake to soil retention before N losses occur. However, biogeochemical models that simulate simultaneous competition for soil N substrates by multiple processes match the observed patterns of N losses better than models based on sequential competition. To enable better prediction of terrestrial N cycle responses to N loading, we recommend that future research identifies the response functions of different N processes to substrate availability using manipulative experiments, and incorporates the measured N saturation response functions into conceptual, theoretical and quantitative analyses.

Linkage of microbial living communities and residues to soil organic carbon accumulation along a forest restoration gradient in southern China

Publisher: Elsevier BV

Date: 20-08-2021

DOI: 10.1186/S40663-021-00334-8

Abstract: Forest restoration has been considered an effective method to increase soil organic carbon (SOC), whereas it remains unclear whether long-term forest restoration will continuously increase SOC. Such large uncertainties may be mainly due to the limited knowledge on how soil microorganisms will contribute to SOC accumulation over time. We simultaneously documented SOC, total phospholipid fatty acids (PLFAs), and amino sugars (AS) content across a forest restoration gradient with average stand ages of 14, 49, 70, and 90 years in southern China. The SOC and AS continuously increased with stand age. The ratio of fungal PLFAs to bacterial PLFAs showed no change with stand age, while the ratio of fungal AS to bacterial AS significantly increased. The total microbial residue-carbon (AS-C) accounted for 0.95–1.66 % in SOC across all forest restoration stages, with significantly higher in fungal residue-C (0.68–1.19 %) than bacterial residue-C (0.05–0.11 %). Furthermore, the contribution of total AS-C to SOC was positively correlated with clay content at 0–10 cm soil layer but negatively related to clay content at 10–20 cm soil layer. These findings highlight the significant contribution of AS-C to SOC accumulation along forest restoration stages, with ergent contributions from fungal residues and bacterial residues. Soil clay content with stand age significantly affects the ergent contributions of AS-C to SOC at two different soil layers.

Global and regional coupled climate sensitivity to the parameterization of rainfall interception

Publisher: Springer Science and Business Media LLC

Date: 10-06-2010

DOI: 10.1007/S00382-010-0862-7

Down‐regulation of tissue N:P ratios in terrestrial plants by elevated CO₂

Publisher: Wiley

Date: 12-2015

DOI: 10.1890/15-0217.1

Abstract: Increasing atmospheric CO2 concentrations generally alter element stoichiometry in plants. However, a comprehensive evaluation of the elevated CO2 impact on plant nitrogen: phosphorus (N:P) ratios and the underlying mechanism has not been conducted. We synthesized the results from 112 previously published studies using meta-analysis to evaluate the effects of elevated CO2 on the N:P ratio of terrestrial plants and to explore the underlying mechanism based on plant growth and soil P dynamics. Our results show that terrestrial plants grown under elevated CO2 had lower N:P ratios in both above- and belowground biomass across different ecosystem types. The response ratio for plant N:P was negatively correlated with the response ratio for plant growth in croplands and grasslands, and showed a stronger relationship for P than for N. In addition, the CO2-induced down-regulation of plant N:P was accompanied by 19.3% and 4.2% increases in soil phosphatase activity and labile P, respectively, and a 10.1% decrease in total soil P. Our results show that down-regulation of plant N:P under elevated CO2 corresponds with accelerated soil P cycling. These findings should be useful for better understanding of terrestrial plant stoichiometry in response to elevated CO2 and of the underlying mechanisms affecting nutrient dynamics under climate change.

The Evolution of the Principle of Non-intervention?

Publisher: Brill

Date: 04-10-2019

DOI: 10.1163/1875984X-01104002

Abstract: This paper analyses the overt provision of assistance to opposition groups in the contemporary conflicts in Libya and Syria. Applying an R2P lens to this new and emerging State practice, the paper argues that R2P has served as the inspiration for a re-aligned conceptualisation of the limits of State responses to atrocity crimes, charting a way forward for the international community which is at once sensitive to State sovereignty but also responsive to humanitarian imperatives.

Supplementary material to Modeling biochar effects on soil organic carbon on croplands in the MIMICS (MIcrobial-MIneral Carbon Stabilization) model

Publisher: Copernicus GmbH

Date: 10-07-2023

DOI: 10.5194/GMD-2023-114-SUPPLEMENT

Anomalous Josephson Current in Junctions with Spin Polarizing Quantum Point Contacts

Publisher: American Physical Society (APS)

Date: 02-09-2008

DOI: 10.1103/PHYSREVLETT.101.107001

Afghanistan's forgotten boys

Publisher: Brill

Date: 11-08-2022

DOI: 10.1163/1875984X-14030003

Abstract: This article critically examines the pluralistic legal environment of Afghanistan, security sector reform processes engaged in by the international community, and the dismissal of the practice of bacha bazi as a cultural issue, which combined to allow the sexual abuse and exploitation of young boys to continue with impunity. The article calls for the United Nations and the international community to show strong, ethical, and transparent leadership on child protection within future mission mandates as a practical implementation of the secondary duty under the responsibility to protect (R2P).

Development of a multi-method chronology spanning the Last Glacial Interval from Orakei maar lake, Auckland, New Zealand

Publisher: Copernicus GmbH

Date: 15-12-2020

DOI: 10.5194/GCHRON-2-367-2020

Abstract: Abstract. Northern New Zealand is an important location for understanding Last Glacial Interval (LGI) palaeoclimate dynamics, since it is influenced by both tropical and polar climate systems which have varied in relative strength and timing. Sediments from the Auckland Volcanic Field maar lakes preserve records of such large-scale climatic influences on regional palaeo-environment changes, as well as past volcanic eruptions. The sediment sequence infilling Orakei maar lake is continuous, laminated, and rapidly deposited, and it provides a high-resolution (sedimentation rate above ∼ 1 m kyr−1) archive from which to investigate the dynamic nature of the northern New Zealand climate system over the LGI. Here we present the chronological framework for the Orakei maar sediment sequence. Our chronology was developed using Bayesian age modelling of combined radiocarbon ages, tephrochronology of known-age rhyolitic tephra marker layers, 40Ar∕39Ar-dated eruption age of a local basaltic volcano, luminescence dating (using post-infrared–infrared stimulated luminescence, or pIR-IRSL), and the timing of the Lasch palaeomagnetic excursion. We have integrated our absolute chronology with tuning of the relative palaeo-intensity record of the Earth's magnetic field to a global reference curve (PISO-1500). The maar-forming phreatomagmatic eruption of the Orakei maar is now dated to 132 305 years (95 % confidence range: 131 430 to 133 180 years). Our new chronology facilitates high-resolution palaeo-environmental reconstruction for northern New Zealand spanning the last ca. 130 000 years for the first time as most NZ records that span all or parts of the LGI are fragmentary, low-resolution, and poorly dated. Providing this chronological framework for LGI climate events inferred from the Orakei sequence is of paramount importance in the context of identification of leads and lags in different components of the Southern Hemisphere climate system as well as identification of Northern Hemisphere climate signals.

Dynamics of pre- and post-insemination progesterone profiles and insemination outcomes determined by an in-line milk analysis system in primiparous and multiparous Canadian Holstein cows

Publisher: Elsevier BV

Date: 10-2017

DOI: 10.1016/J.THERIOGENOLOGY.2017.05.024

Abstract: The objective was to evaluate in-line milk progesterone (mP4) data to determine dynamics of pre- and post-insemination mP4 profiles and their associations with parity and outcomes of artificial insemination (AI) in Holstein cows. Milk progesterone (ng/mL) was quantified at pre-determined time points before and after AI through an automated in-line milk analysis system (Herd Navigator™, DeLaval International, Tumba, Sweden). Only AI (∼d0 n = 605) preceded by an mP4-decline (at least two s les of mP4 ≥5 ng/mL followed by at least one s le <5 ng/mL d-2) were evaluated. Maximum mP4 attained between d-15 and d-2 (PrePeak), d-2, d5, d10, d14, maximum mP4 attained within 21d post-AI (PostPeak), and rate-of-daily-change between mP4 time points (ng/mL/d) were analyzed. Primiparous and multiparous cows were classified by AI outcomes based on post-AI mP4 profiles into three groups: (1) non-pregnant (OPEN mP4-decline ≤ 30d post-AI), (2) presumed-pregnant (PREG no mP4-decline until 55d post-AI), and (3) presumed-pregnancy loss (P-LOSS mP4-decline between 31 and 55d post-AI). For profile comparisons, smoothed mP4 data were analyzed using mixed linear models. Primiparous cows had greater (P < 0.01) mP4 than multiparous cows at d5 (4.6 ± 0.2 vs. 2.8 ± 0.1), 10 (11.1 ± 0.4 vs. 7.6 ± 0.2), 14 (19.7 ± 0.4 vs. 16.1 ± 0.3) and PostPeak (23.5 ± 0.3 vs. 21.7 ± 0.2). The rate-of-daily-change was greater (P < 0.01) in primiparous than in multiparous cows from d-2 to 5 (+0.2 ± 0.03 vs. -0.1 ± 0.02) and from d5 to 10 (+1.2 ± 0.05 vs. +0.9 ± 0.03), but lesser (P < 0.01) from d14 to PostPeak (+0.9 ± 0.09 vs. +1.3 ± 0.06). In primiparous cows, mP4 in PREG was greater at d10 and PostPeak than OPEN (11.1 ± 0.5 and 24.2 ± 0.5 vs. 9.6 ± 0.4 and 22.3 ± 0.4, respectively, P < 0.04), but lesser at d5 than P-LOSS (4.4 ± 0.3 vs. 5.7 ± 0.4, P = 0.04). In multiparous cows, mP4 at d-2 was lesser in PREG than OPEN and P-LOSS (3.2 ± 0.1 vs. 3.4 ± 0.04 and 3.5 ± 0.1, respectively, P ≤ 0.03), but greater at d10, d14 and PostPeak in PREG than in OPEN (8.2 ± 0.4, 16.8 ± 0.5 and 22.7 ± 0.4 vs. 6.9 ± 0.3, 14.8 ± 0.3 and 19.7 ± 0.2, respectively, P < 0.01). Multiparous PREG cows had greater rate-of-daily-change in mP4 than OPEN cows from d5 to 10 and from d10 to 14 (+1.0 ± 0.06 and +2.2 ± 0.11 vs. +0.8 ± 0.04 and +1.9 ± 0.08, respectively, P < 0.03). Overall post-AI mP4 increased faster and were greater in primiparous than in multiparous cows. Based on in-line mP4 profiles, greater mP4 levels near time of AI (d-2 in multiparous and d5 in primiparous cows) and lesser mP4 beyond d10 were negatively associated with a successful pregnancy.

Associations between anogenital distance and measures of fertility in lactating North American Holstein cows: A validation study

Publisher: American Dairy Science Association

Date: 07-2022

DOI: 10.3168/JDS.2021-20827

Abstract: Anogenital distance (AGD) has been defined in dairy cows as the distance from the center of the anus to the base of the clitoris. Initial reports on nulliparous Holstein heifers and first- and second-parity Holstein cows have found inverse relationships between AGD and measures of fertility. Our primary objective was to determine the relationship between AGD and measures of fertility in a larger population of North American Holstein cows to validate our previous finding that AGD is inversely related to fertility. Secondary objectives were to determine the associations between AGD and parity, and milk yield. Using digital calipers, we measured AGD in 4,709 Holstein cows [mean ± standard deviation (SD) parity 2.3 ± 1.4 days in milk (DIM) 154 ± 94 305-d mature equivalent (ME) milk yield 13,759 ± 2,188 kg] from 18 herds in Western Canada and 1 herd in the USA. Anogenital distance (mm) was normally distributed with a mean (±SD) of 132 ± 12, ranging from 95 to 177, and a median of 133. Anogenital distance was linearly but inversely associated with pregnancy to first artificial insemination (P/AI1). For every 1-mm increase in AGD, the estimated probability of P/AI1 decreased by 0.8%. The optimum AGD cut-point that predicted probability of P/AI1 with sensitivity and specificity of 45 and 55%, respectively, was 129 mm. Consequently, data were categorized into either short (≤129) or long (>129) AGD groups across parities, and associations between AGD, parity (first, second, and third+), and fertility measures were determined. Rates of P/AI1 were greater (36 vs. 30%) in short- than in long-AGD cows short-AGD cows required fewer AI per conception (2.3 vs. 2.4) and had fewer days open (137 vs. 142), and a greater proportion of short-AGD cows (67 vs. 64%) was pregnant by 150 DIM compared with long-AGD cows. The rates of pregnancy up to 150 (hazard ratio of 0.91) and 250 DIM (hazard ratio of 0.93) were smaller in long- than in short-AGD cows. Anogenital distance had a weak positive association with both parity (r = 0.22) and 305-d ME milk yield (r = 0.04). Results indicate an inverse relationship between AGD and measures of fertility in lactating cows, validating our earlier report. We infer that although selecting cows for short AGD is expected to have an adverse effect on milk yield, the anticipated gain in fertility will outweigh the small decline in milk yield, strengthening the potential of AGD as a novel reproductive phenotype for use in future breeding programs to improve fertility.

Global carbon budget 2014

Publisher: Copernicus GmbH

Date: 08-05-2015

DOI: 10.5194/ESSD-7-47-2015

Abstract: Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics, and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates, consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics and cement production data, respectively, while emissions from land-use change (ELUC), mainly deforestation, are based on combined evidence from land-cover-change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models forced by observed climate, CO2, and land-cover-change (some including nitrogen–carbon interactions). We compare the mean land and ocean fluxes and their variability to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1σ, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2004–2013), EFF was 8.9 ± 0.4 GtC yr−1, ELUC 0.9 ± 0.5 GtC yr−1, GATM 4.3 ± 0.1 GtC yr−1, SOCEAN 2.6 ± 0.5 GtC yr−1, and SLAND 2.9 ± 0.8 GtC yr−1. For year 2013 alone, EFF grew to 9.9 ± 0.5 GtC yr−1, 2.3% above 2012, continuing the growth trend in these emissions, ELUC was 0.9 ± 0.5 GtC yr−1, GATM was 5.4 ± 0.2 GtC yr−1, SOCEAN was 2.9 ± 0.5 GtC yr−1, and SLAND was 2.5 ± 0.9 GtC yr−1. GATM was high in 2013, reflecting a steady increase in EFF and smaller and opposite changes between SOCEAN and SLAND compared to the past decade (2004–2013). The global atmospheric CO2 concentration reached 395.31 ± 0.10 ppm averaged over 2013. We estimate that EFF will increase by 2.5% (1.3–3.5%) to 10.1 ± 0.6 GtC in 2014 (37.0 ± 2.2 GtCO2 yr−1), 65% above emissions in 1990, based on projections of world gross domestic product and recent changes in the carbon intensity of the global economy. From this projection of EFF and assumed constant ELUC for 2014, cumulative emissions of CO2 will reach about 545 ± 55 GtC (2000 ± 200 GtCO2) for 1870–2014, about 75% from EFF and 25% from ELUC. This paper documents changes in the methods and data sets used in this new carbon budget compared with previous publications of this living data set (Le Quéré et al., 2013, 2014). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP_2014).

Isotopic identification of nitrogen hotspots across natural terrestrial ecosystems

Publisher: Copernicus GmbH

Date: 23-08-2012

DOI: 10.5194/BG-9-3287-2012

Abstract: Abstract. Nitrogen (N) influences local biological processes, ecosystem productivity, the composition of the atmospheric-climate system, and the human endeavour as a whole. Here we use natural variations in N isotopes, coupled with two models, to trace global pathways of N loss from the land to the water and atmosphere. We show that denitrification accounts for approximately 35 % of total N losses from the natural soil, with NO, N2O, and N2 fluxes equal to 15.7 ± 4.7 Tg N yr−1, 10.2 ± 3.0 Tg N yr−1, and 21.0 ± 6.1 Tg N yr−1, respectively. Our analysis points to tropical regions as the major "hotspot" of nitrogen export from the terrestrial biosphere, accounting for 71 % of global N losses from the natural land surface. The poorly studied Congo Basin is further identified as one of the major natural sources of atmospheric N2O. Extra-tropical areas, by contrast, lose a greater fraction of N via leaching pathways (~77 % of total N losses) than do tropical biomes, likely contributing to N limitations of CO2 uptake at higher latitudes. Our results provide an independent constraint on global models of the N cycle among different regions of the unfertilized biosphere.

Influence of crown structural properties on PAR absorption, photosynthesis, and transpiration in Sitka spruce: application of a model (MAESTRO)

Publisher: Oxford University Press (OUP)

Date: 12-1990

DOI: 10.1093/TREEPHYS/7.1-2-3-4.297

Abstract: The structure of a tree crown can be described by the spatial distribution, inclination, and orientation of all the phytoelements (leaves, twigs, branches, trunk, etc.), and their geometric properties. The following four structural properties have been studied in relation to radiation absorption, photosynthesis, and transpiration using a simulation model named MAESTRO: crown shape, total area of leaves and their spatial distribution within the tree crown, and the leaf inclination angle distribution. It was found that the total area of leaves and their spatial distribution within the tree crown are far more important than the other two properties for radiation absorption, photosynthesis, and transpiration.

Ecosystem carbon transit versus turnover times in response to climate warming and rising atmospheric CO&lt;sub&gt;2&lt;/sub&gt; concentration

Publisher: Copernicus GmbH

Date: 07-11-2018

DOI: 10.5194/BG-15-6559-2018

Abstract: Abstract. Ecosystem carbon (C) transit time is a critical diagnostic parameter to characterize land C sequestration. This parameter has different variants in the literature, including a commonly used turnover time. However, we know little about how different transit time and turnover time are in representing carbon cycling through multiple compartments under a non-steady state. In this study, we estimate both C turnover time as defined by the conventional stock over flux and mean C transit time as defined by the mean age of C mass leaving the system. We incorporate them into the Community Atmosphere Biosphere Land Exchange (CABLE) model to estimate C turnover time and transit time in response to climate warming and rising atmospheric [CO2]. Modelling analysis shows that both C turnover time and transit time increase with climate warming but decrease with rising atmospheric [CO2]. Warming increases C turnover time by 2.4 years and transit time by 11.8 years in 2100 relative to that at steady state in 1901. During the same period, rising atmospheric [CO2] decreases C turnover time by 3.8 years and transit time by 5.5 years. Our analysis shows that 65 % of the increase in global mean C transit time with climate warming results from the depletion of fast-turnover C pool. The remaining 35 % increase results from accompanied changes in compartment C age structures. Similarly, the decrease in mean C transit time with rising atmospheric [CO2] results approximately equally from replenishment of C into fast-turnover C pool and subsequent decrease in compartment C age structure. Greatly different from the transit time, the turnover time, which does not account for changes in either C age structure or composition of respired C, underestimated impacts of warming and rising atmospheric [CO2] on C diagnostic time and potentially led to deviations in estimating land C sequestration in multi-compartmental ecosystems.

An efficient method for global parameter sensitivity analysis and its applications to the Australian community land surface model (CABLE)

Publisher: Elsevier BV

Date: 12-2013

DOI: 10.1016/J.AGRFORMET.2013.04.003

Toward more realistic projections of soil carbon dynamics by Earth system models

Publisher: American Geophysical Union (AGU)

Date: 2016

DOI: 10.1002/2015GB005239

Leaf area index identified as a major source of variability in modeled CO&lt;sub&gt;2&lt;/sub&gt; fertilization

Publisher: Copernicus GmbH

Date: 19-11-2018

DOI: 10.5194/BG-15-6909-2018

Abstract: Abstract. The concentration–carbon feedback (β), also called the CO2 fertilization effect, is a key unknown in climate–carbon-cycle projections. A better understanding of model mechanisms that govern terrestrial ecosystem responses to elevated CO2 is urgently needed to enable a more accurate prediction of future terrestrial carbon sink. We conducted C-only, carbon–nitrogen (C–N) and carbon–nitrogen–phosphorus (C–N–P) simulations of the Community Atmosphere Biosphere Land Exchange model (CABLE) from 1901 to 2100 with fixed climate to identify the most critical model process that causes ergence in β. We calculated CO2 fertilization effects at various hierarchical levels from leaf biochemical reaction and leaf photosynthesis to canopy gross primary production (GPP), net primary production (NPP), and ecosystem carbon storage (cpool) for seven C3 plant functional types (PFTs) in response to increasing CO2 under the RCP 8.5 scenario. Our results show that β values at biochemical and leaf photosynthesis levels vary little across the seven PFTs, but greatly erge at canopy and ecosystem levels in all simulations. The low variation of the leaf-level β is consistent with a theoretical analysis that leaf photosynthetic sensitivity to increasing CO2 concentration is almost an invariant function. In the CABLE model, the major jump in variation of β values from leaf levels to canopy and ecosystem levels results from ergence in modeled leaf area index (LAI) within and among PFTs. The correlation of βGPP, βNPP, or βcpool each with βLAI is very high in all simulations. Overall, our results indicate that modeled LAI is a key factor causing the ergence in β in the CABLE model. It is therefore urgent to constrain processes that regulate LAI dynamics in order to better represent the response of ecosystem productivity to increasing CO2 in Earth system models.

Underestimated Interannual Variability of Terrestrial Vegetation Production by Terrestrial Ecosystem Models

Publisher: American Geophysical Union (AGU)

Date: 04-2023

DOI: 10.1029/2023GB007696

Abstract: Vegetation gross primary production (GPP) is the largest terrestrial carbon flux and plays an important role in regulating the carbon sink. Current terrestrial ecosystem models (TEMs) are indispensable tools for evaluating and predicting GPP. However, to which degree the TEMs can capture the interannual variability (IAV) of GPP remains unclear. With large data sets of remote sensing, in situ observations, and predictions of TEMs at a global scale, this study found that the current TEMs substantially underestimate the GPP IAV in comparison to observations at global flux towers. Our results also showed the larger underestimations of IAV in GPP at nonforest ecosystem types than forest types, especially in arid and semiarid grassland and shrubland. One cause of the underestimation is that the IAV in GPP predicted by models is strongly dependent on canopy structure, that is, leaf area index (LAI), and the models underestimate the changes of canopy physiology responding to climate change. On the other hand, the simulated interannual variations of LAI are much less than the observed. Our results highlight the importance of improving TEMs by precisely characterizing the contribution of canopy physiological changes on the IAV in GPP and of clarifying the reason for the underestimated IAV in LAI. With these efforts, it may be possible to accurately predict the IAV in GPP and the stability of the global carbon sink in the context of global climate change.

Supplementary material to &quot;Estimating global gross primary productivity using chlorophyll fluorescence and a data assimilation system with the BETHY-SCOPE model&quot;

Publisher: Copernicus GmbH

Date: 18-03-2019

DOI: 10.5194/BG-2019-83-SUPPLEMENT

Estimating global gross primary productivity using chlorophyll fluorescence and a data assimilation system with the BETHY-SCOPE model

Publisher: Copernicus GmbH

Date: 13-08-2019

DOI: 10.5194/BG-16-3069-2019

Abstract: Abstract. This paper presents the assimilation of solar-induced chlorophyll fluorescence (SIF) into a terrestrial biosphere model to estimate the gross uptake of carbon through photosynthesis (GPP). We use the BETHY-SCOPE model to simulate both GPP and SIF using a process-based formulation, going beyond a simple linear scaling between the two. We then use satellite SIF data from the Orbiting Carbon Observatory-2 (OCO-2) for 2015 in the data assimilation system to constrain model biophysical parameters and GPP. The assimilation results in considerable improvement in the fit between model and observed SIF, despite a limited capability to fit regions with large seasonal variability in SIF. The SIF assimilation increases global GPP by 31 % to 167±5 Pg C yr−1 and shows an improvement in the global distribution of productivity relative to independent estimates, but a large difference in magnitude. This change in global GPP is driven by an overall increase in photosynthetic light-use efficiency across almost all biomes and more minor, regionally distinct changes in APAR. This process-based data assimilation opens up new pathways to the effective utilization of satellite SIF data to improve our understanding of the global carbon cycle.

Diagnosing errors in a land surface model (CABLE) in the time and frequency domains

Publisher: American Geophysical Union (AGU)

Date: 29-03-2011

DOI: 10.1029/2010JG001385

Imaging Transverse Electron Focusing in Semiconducting Heterostructures with Spin-Orbit Coupling

Publisher: Springer Netherlands

Date: 2008

DOI: 10.1007/978-1-4020-8512-3_11

Diffusion of 15N-labelled N2O into soil columns: a promising method to examine the fate of N2O in subsoils

Publisher: Elsevier BV

Date: 06-2006

DOI: 10.1016/J.SOILBIO.2005.11.002

Million-year lag times in a post-orogenic sediment conveyor

Publisher: American Association for the Advancement of Science (AAAS)

Date: 19-06-2020

DOI: 10.1126/SCIADV.AAZ8845

Abstract: Reworking of old sediment in the Murray-Darling implies alteration of environmental signals traveling from source to sink.

Machine learning for accelerating process‐based computation of land biogeochemical cycles

Publisher: Wiley

Date: 10-02-2023

DOI: 10.1111/GCB.16623

Abstract: Global change ecology nowadays embraces ever‐growing large observational datasets (big‐data) and complex mathematical models that track hundreds of ecological processes (big‐model). The rapid advancement of the big‐data‐big‐model has reached its bottleneck: high computational requirements prevent further development of models that need to be integrated over long time‐scales to simulate the distribution of ecosystems carbon and nutrient pools and fluxes. Here, we introduce a machine‐learning acceleration (MLA) tool to tackle this grand challenge. We focus on the most resource‐consuming step in terrestrial biosphere models (TBMs): the equilibration of biogeochemical cycles (spin‐up), a prerequisite that can take up to 98% of the computational time. Through three members of the ORCHIDEE TBM family part of the IPSL Earth System Model, including versions that describe the complex interactions between nitrogen, phosphorus and carbon that do not have any analytical solution for the spin‐up, we show that an unoptimized MLA reduced the computation demand by 77%–80% for global studies via interpolating the equilibrated state of biogeochemical variables for a subset of model pixels. Despite small biases in the MLA‐derived equilibrium, the resulting impact on the predicted regional carbon balance over recent decades is minor. We expect a one‐order of magnitude lower computation demand by optimizing the choices of machine learning algorithms, their settings, and balancing the trade‐off between quality of MLA predictions and need for TBM simulations for training data generation and bias reduction. Our tool is agnostic to gridded models (beyond TBMs), compatible with existing spin‐up acceleration procedures, and opens the door to a wide variety of future applications, with complex non‐linear models benefit most from the computational efficiency.

Increased atmospheric vapor pressure deficit reduces global vegetation growth

Publisher: American Association for the Advancement of Science (AAAS)

Date: 02-08-2019

DOI: 10.1126/SCIADV.AAX1396

Abstract: Global vegetation greening trend stalled after the late 1990s due to increased atmospheric water demand.

Challenges and opportunities in land surface modelling of savanna ecosystems

Publisher: Copernicus GmbH

Date: 24-10-2017

DOI: 10.5194/BG-14-4711-2017

Abstract: Abstract. The savanna complex is a highly erse global biome that occurs within the seasonally dry tropical to sub-tropical equatorial latitudes and are structurally and functionally distinct from grasslands and forests. Savannas are open-canopy environments that encompass a broad demographic continuum, often characterised by a changing dominance between C3-tree and C4-grass vegetation, where frequent environmental disturbances such as fire modulates the balance between ephemeral and perennial life forms. Climate change is projected to result in significant changes to the savanna floristic structure, with increases to woody biomass expected through CO2 fertilisation in mesic savannas and increased tree mortality expected through increased rainfall interannual variability in xeric savannas. The complex interaction between vegetation and climate that occurs in savannas has traditionally challenged terrestrial biosphere models (TBMs), which aim to simulate the interaction between the atmosphere and the land surface to predict responses of vegetation to changing in environmental forcing. In this review, we examine whether TBMs are able to adequately represent savanna fluxes and what implications potential deficiencies may have for climate change projection scenarios that rely on these models. We start by highlighting the defining characteristic traits and behaviours of savannas, how these differ across continents and how this information is (or is not) represented in the structural framework of many TBMs. We highlight three dynamic processes that we believe directly affect the water use and productivity of the savanna system: phenology, root-water access and fire dynamics. Following this, we discuss how these processes are represented in many current-generation TBMs and whether they are suitable for simulating savanna fluxes.Finally, we give an overview of how eddy-covariance observations in combination with other data sources can be used in model benchmarking and intercomparison frameworks to diagnose the performance of TBMs in this environment and formulate road maps for future development. Our investigation reveals that many TBMs systematically misrepresent phenology, the effects of fire and root-water access (if they are considered at all) and that these should be critical areas for future development. Furthermore, such processes must not be static (i.e. prescribed behaviour) but be capable of responding to the changing environmental conditions in order to emulate the dynamic behaviour of savannas. Without such developments, however, TBMs will have limited predictive capability in making the critical projections needed to understand how savannas will respond to future global change.

Sensitivity of net ecosystem exchange and heterotrophic respiration to parameterization uncertainty

Publisher: American Geophysical Union (AGU)

Date: 25-02-2013

DOI: 10.1029/2012JD018122

Gate-controlled anisotropy in Aharonov-Casher spin interference: Signatures of Dresselhaus spin-orbit inversion and spin phases

Publisher: American Physical Society (APS)

Date: 04-12-2018

DOI: 10.1103/PHYSREVB.98.245301

Tighten the Bolts and Nuts on GPP Estimations from Sites to the Globe: An Assessment of Remote Sensing Based LUE Models and Supporting Data Fields

Publisher: MDPI AG

Date: 06-01-2021

DOI: 10.3390/RS13020168

Abstract: Gross primary production (GPP) determines the amounts of carbon and energy that enter terrestrial ecosystems. However, the tremendous uncertainty of the GPP still hinders the reliability of GPP estimates and therefore understanding of the global carbon cycle. In this study, using observations from global eddy covariance (EC) flux towers, we appraised the performance of 24 widely used GPP models and the quality of major spatial data layers that drive the models. Results show that global GPP products generated by the 24 models varied greatly in means (from 92.7 to 178.9 Pg C yr−1) and trends (from −0.25 to 0.84 Pg C yr−1). Model structure differences (i.e., light use efficiency models, machine learning models, and process-based biophysical models) are an important aspect contributing to the large uncertainty. In addition, various biases in currently available spatial datasets have found (e.g., only 57% of the observed variation in photosynthetically active radiation at the flux tower locations was explained by the spatial dataset), which not only affect GPP simulation but more importantly hinder the simulation and understanding of the earth system. Moving forward, research into the efficacy of model structures and precision of input data may be more important for global GPP estimation.

Examining soil carbon uncertainty in a global model: response of microbial decomposition to temperature, moisture and nutrient limitation

Publisher: Copernicus GmbH

Date: 24-06-2013

DOI: 10.5194/BGD-10-10229-2013

Abstract: Abstract. Reliable projections of future climate require land–atmosphere carbon (C) fluxes to be represented realistically in Earth System Models. There are several sources of uncertainty in how carbon is parameterized in these models. First, while interactions between the C, nitrogen (N) and phosphorus (P) cycles have been implemented in some models, these lead to erse changes in land–atmosphere fluxes. Second, while the parameterization of soil organic matter decomposition is similar between models, formulations of the control of the soil physical state on microbial activity vary widely. We address these sources uncertainty by implementing three soil moisture (SMRF) and three soil temperature (STRF) respiration functions in an Earth System Model that can be run with three degrees of biogeochemical nutrient limitation (C-only, C and N, and C and N and P). All 27 possible combinations of a SMRF with a STRF and a biogeochemical mode are equilibrated before transient historical (1850–2005) simulations are performed. As expected, implementing N and P limitation reduces the land carbon sink, transforming some regions from net sinks to net sources over the historical period (1850–2005). Differences in the soil C balance implied by the various SMRFs and STRFs also change the sign of some regional sinks. Further, although the absolute uncertainty in global carbon uptake is reduced, the uncertainty due to the SMRFs and STRFs grows relative to the inter-annual variability in net uptake when N and P limitations are added. We also demonstrate that the equilibrated soil C also depend on the shape of the SMRF and STRF. Equilibration using different STRFs and SMRFs and nutrient limitation generates a six-fold range of global soil C that largely mirrors the range in available (17) CMIP5 models. Simulating the historical change in soil carbon therefore critically depends on the choice of STRF, SMRF and nutrient limitation, as it controls the equilibrated state to which transient conditions are applied. This direct effect of the representation of microbial decomposition in Earth System Models adds to recent concerns on the adequacy of these simple representations of very complex soil carbon processes.

Impacts of elevated CO2, climate change and their interactions on water budgets in four different catchments in Australia

Publisher: Elsevier BV

Date: 11-2014

DOI: 10.1016/J.JHYDROL.2014.09.020

Human Uses of Outer Space

Publisher: Springer Nature Singapore

Date: 2023

DOI: 10.1007/978-981-19-9462-3

Machine learning for accelerating process-based computation of land biogeochemical cycles

Publisher: Copernicus GmbH

Date: 15-05-2023

DOI: 10.5194/EGUSPHERE-EGU23-10692

Abstract: Global change ecology nowadays embraces ever-growing large observational datasets (big-data) and complex mathematical models that track hundreds of ecological processes (big-model). The rapid advancement of the big-data-big-model has reached its bottleneck: high computational requirements prevent further development of models that need to be integrated over long time scales to simulate the distribution of ecosystems carbon and nutrient pools and fluxes. Here we introduce a machine-learning acceleration (MLA) tool to tackle this grand challenge. We focus on the most resource-consuming step in terrestrial biosphere models (TBMs): the equilibration of biogeochemical cycles (spin-up), a prerequisite that can take up to 98% of the computational time. Through three members of the ORCHIDEE TBM family part of the IPSL Earth System Model, including versions that describe the complex interactions between nitrogen, phosphorus and carbon that do not have any analytical solution for the spin-up, we show that MLA reduced the computation demand by 77-80% & for global studies via interpolating the equilibrated state of biogeochemical variables for a subset of model pixels. Despite small biases in the MLA-derived equilibrium, the resulting impact on the predicted regional carbon balance over recent decades is minor. Our tool is agnostic to gridded models (beyond TBMs), compatible with existing spin-up acceleration procedures, and opens the door to a wide variety of future applications, with complex non-linear models benefit most from the computational efficiency.

Divergent responses of soil organic carbon accumulation to 14 years of nitrogen addition in two typical subtropical forests

Publisher: Elsevier BV

Date: 03-2020

DOI: 10.1016/J.SCITOTENV.2019.136104

Abstract: Developing an understanding of the response of soil organic carbon (SOC) to N addition is critical to quantify and predict the terrestrial carbon uptake under increasing N deposition in the future. However, results from field studies on the response of SOC content and composition to N addition are highly variable across different ecosystems. The interpretation of SOC responses to N addition are often complicated by the differences in climate, soil substrate and other factors. To address this question, we measured SOC and its components in adjacent broadleaved and coniferous subtropical forests after 14 years of N addition. SOC in the top 50 cm increased by 2.1 kg m

Mapping near-surface air temperature, pressure, relative humidity and wind speed over Mainland China with high spatiotemporal resolution

Publisher: Springer Science and Business Media LLC

Date: 16-07-2014

DOI: 10.1007/S00376-014-3190-8

Commonwealth Scientific And Industrial Research Organisation

Location: Australia

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University Of New South Wales

Location: Australia

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CSIRO Oceans And Atmosphere

Location: Australia

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The University Of Edinburgh

Location: United Kingdom of Great Britain and Northern Ireland

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CSIRO

Location: Australia

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CSIRO Clayton

Location: Australia

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Discovery Projects - Grant ID: DP130101566

Start Date: 2013

End Date: 06-2016

Amount: $527,500.00

Funder: Australian Research Council

ARC Centres Of Excellence - Grant ID: CE170100023

Start Date: 08-2017

End Date: 12-2024

Amount: $30,050,000.00

Funder: Australian Research Council

ARC Centres Of Excellence - Grant ID: CE1101028

Start Date: 07-2011

End Date: 06-2018

Amount: $21,400,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0774996

Start Date: 05-2007

End Date: 12-2010

Amount: $191,921.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0662887

Start Date: 2006

End Date: 11-2009

Amount: $240,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP210100420

Start Date: 10-2021

End Date: 10-2024

Amount: $431,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP210101600

Start Date: 08-2021

End Date: 08-2024

Amount: $450,000.00

Funder: Australian Research Council