ORCID Profile
0000-0002-8154-0097
Current Organisation
Swinburne University of Technology
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Plant Physiology | Plant Biology | Terrestrial Ecology | Global Change Biology | Ecology | Natural Resource Management | Management And Environment | Nutrition And Physiology | Groundwater Hydrology | Terrestrial Ecology | Landscape Ecology | Environmental Science and Management | Forestry Sciences | Land Capability And Soil Degradation | Ecosystem Function | Renewable Power and Energy Systems Engineering (excl. Solar Cells) | Atmospheric Sciences | Physical Geography and Environmental Geoscience | Biological Mathematics | Tree Improvement (Selection, Breeding And Genetic Engineering) | Environmental Impact Assessment | Climate Change Processes | Surfacewater Hydrology | Functional Materials | Materials Engineering | Palaeoecology | Surfacewater Hydrology | Soil Sciences | Crop and Pasture Production | Nanomaterials | Plant Cell and Molecular Biology | Plant Physiology | Tree Nutrition and Physiology | Forestry Fire Management | Sustainable Agricultural Development | Crop and Pasture Nutrition | Carbon Sequestration Science | Crop and Pasture Biochemistry and Physiology |
ANZSRC Socio-Economic Objective (SEO)
Land and water management | Climate change | Global climate change adaptation measures | Native forests | Forestry | Hardwood plantations | Softwood plantations | Biological sciences | Ecosystem Adaptation to Climate Change | Integrated (ecosystem) assessment and management | Native vegetation | Primary products from plants | Grain Legumes | Wheat | Management of Greenhouse Gas Emissions from Animal Production | Native Forests | Land and water management | Horticultural Crops not elsewhere classified | Forestry not elsewhere classified | Environmentally Sustainable Energy Activities not elsewhere classified | Forest and Woodlands Flora, Fauna and Biodiversity | Integrated (ecosystem) assessment and management | Climate Change Mitigation Strategies | Climate Change Adaptation Measures | Soybeans | Land and water management | Land and water management | Remnant vegetation and protected conservation areas | Integrated (ecosystem) assessment and management | Living resources (flora and fauna) | Rehabilitation of degraded sparseland | Management of Water Consumption by Plant Production | Management of Greenhouse Gas Emissions from Plant Production | Forest and Woodlands Soils | Forest and Woodlands Water Management
Related Links
Publications
Nocturnal water loss in mature subalpine Eucalyptus delegatensis tall open forests and adjacent E. pauciflora woodlands
Publisher: Wiley
Date: 12-10-2011
DOI: 10.1002/ECE3.44
Does triacylglycerol (TAG) serve a photoprotective function in plant leaves? An examination of leaf lipids under shading and drought
Publisher: Wiley
Date: 02-08-2017
DOI: 10.1111/PPL.12601
Continental and local climatic influences on hydrology of eucalypt‐Nothofagus ecosystems revealed by δ2H, δ13C, and δ18O of ecosystem sampl
Publisher: American Geophysical Union (AGU)
Date: 03-2010
DOI: 10.1029/2009WR007807
Potential for rural electrification based on biomass gasification in Cambodia
Publisher: Elsevier BV
Date: 09-2007
Decline of Eucalyptus tereticornis near bairnsdale, Victoria:Insect herbivory and nitrogen fractions in sap and foliage
Publisher: CSIRO Publishing
Date: 1995
DOI: 10.1071/BT9950039
Abstract: Eucalyptus tereticornis growing along roadsides and in pastures in eastern Victoria were often in poor health and were repeatedly defoliated by herbivorous insects. Epicormic buds sprouted following bouts of defoliation and the first epicormic leaves produced from such buds were rich in nitrogen and particularly in nitrogenous solutes such as proline compared with adult leaves. Xylem sap collected from declining trees was richer in nitrogenous solutes than that from healthy trees. Concentrations of total nitrogen and specific solutes in foliage were not closely related to pressure potential in shoots or to nitrogen availability in soil. In glasshouse-grown seedlings, foliar concentrations of total nitrogen and of a number of nitrogenous solutes were increased by reduced water availability. Chronic insect infestations and periodic insect outbreaks may be supported by high concentrations of nitrogenous solutes in sap and foliage, especially epicormic foliage, which in turn may be a response to drought or increasing salinity ('physiological drought').
Fire Eases Imbalances of Nitrogen and Phosphorus in Woody Plants
Publisher: Springer Science and Business Media LLC
Date: 06-03-2015
Temperature-dependent release of volatile organic compounds of eucalypts by direct analysis in real time (DART) mass spectrometry
Publisher: Wiley
Date: 25-06-2009
DOI: 10.1002/RCM.4133
Abstract: A method is described for the rapid identification of biogenic, volatile organic compounds (VOCs) emitted by plants, including the analysis of the temperature dependence of those emissions. Direct analysis in real time (DART) enabled ionization of VOCs from stem and leaf of several eucalyptus species including E. cinerea, E. citriodora, E. nicholii and E. sideroxylon. Plant tissues were placed directly in the gap between the DART ionization source skimmer and the capillary inlet of the time-of-flight (TOF) mass spectrometer. Temperature-dependent emission of VOCs was achieved by adjusting the temperature of the helium gas into the DART ionization source at 50, 100, 200 and 300 degrees C, which enabled direct evaporation of compounds, up to the onset of pyrolysis of plant fibres (i.e. cellulose and lignin). Accurate mass measurements facilitated by TOF mass spectrometry provided elemental compositions for the VOCs. A wide range of compounds was detected from simple organic compounds (i.e. methanol and acetone) to a series of monoterpenes (i.e. pinene, c hene, cymene, eucalyptol) common to many plant species, as well as several less abundant sesquiterpenes and flavonoids (i.e. naringenin, spathulenol, eucalyptin) with antioxidant and antimicrobial properties. The leaf and stem tissues for all four eucalypt species showed similar compounds. The relative abundances of methanol and ethanol were greater in stem wood than in leaf tissue suggesting that DART could be used to investigate the tissue-specific transport and emissions of VOCs.
Relations of sugar composition and δ13C in phloem sap to growth and physiological performance of Eucalyptus globulus (Labill)
Publisher: Wiley
Date: 05-07-2010
DOI: 10.1111/J.1365-3040.2010.02143.X
Abstract: We characterized differences in carbon isotopic content (delta(13)C) and sugar concentrations in phloem exudates from Eucalyptus globulus (Labill) plantations across a rainfall gradient in south-western Australia. Phloem sap delta(13)C and sugar concentrations varied with season and annual rainfall. Annual bole growth was negatively related to phloem sap delta(13)C during summer, suggesting a water limitation, yet was positively related in winter. We conclude that when water is abundant, variations in carboxylation rates become significant to overall growth. Concentrations of sucrose in phloem sap varied across sites by up to 600 mm, and raffinose by 300 mm. These compounds play significant roles in maintaining osmotic balance and facilitating carbon movement into the phloem, and their relative abundances contribute strongly to overall delta(13)C of phloem sap. Taken together, the delta(13)C and concentrations of specific sugars in phloem sap provide significant insights to functions supporting growth at the tree, site and landscape scale.
Diminishing CO2-driven gains in water-use efficiency of global forests
Publisher: Springer Science and Business Media LLC
Date: 27-04-2020
δ13C of wood in growth-rings indicates cambial activity of drought-stressed trees of Eucalyptus globulus
Publisher: Wiley
Date: 08-1998
Vessel diameter and related hydraulic traits of 31 Eucalyptus species arrayed along a gradient of water availability
Publisher: Wiley
Date: 06-2016
DOI: 10.1890/16-0147.1
Abstract: We present two comprehensive data sets that describe xylem vessel diameters and related sapwood traits for species of Eucalyptus from arid and semi-arid woodlands and forests in Australia. Between 2009 and 2014, sapwood of mature trees was s led in south-western, south-eastern and eastern Australia. One additional species was s led from tropical north-western Australia. The first data set describes s les collected from the basal stem section (130 cm above ground) of three in iduals of 31 species of which eight species were replicated at sites that differed in climatic conditions. The second data set describes vessel characteristics of three trees from each of 10 species that were s led at 8 m below the tree apex. The s led trees of these 10 species are also part of the first data set. In total, we report diameters (D) for over 25 100 vessels, from 494 digital images taken from 117 trees. We also report vessel frequencies, void-to-wood ratios, sapwood densities and hydraulically weighted vessel diameters (Dh). Supporting data of the first data set include tree diameter at breast height (130 cm above ground), tree height, s le locations, and summary climate data. In this data set, diameter of in idual vessels ranges from 10 to over 300 μm, and vessel frequency from 360 to 9070 vessels cm
The apparent feed-forward response to vapour pressure deficit of stomata in droughted, field-grown Eucalyptus globulus Labill
Publisher: Wiley
Date: 10-2004
Estimates of carbon storage in the aboveground biomass of victoria’s forests
Publisher: CSIRO Publishing
Date: 2100
DOI: 10.1071/BT9920631
Abstract: The pool of carbon in the world's forests is of similar magnitude to that in the atmosphere, yet little attention has been given to improving measures of carbon in terrestrial biomass. Much of the critical data for forest biomass on which models of global carbon cycling rely is, in fact, based on the accurate s ling of less than 100 ha of forest. Uncertainties in biomass estimation at the local and regional level may be responsible for much of the current speculation as to unidentified sinks for carbon. We have used a forest inventory (i.e. records of forest volume obtained for harvesting purposes) approach to quantify the biomass of forests in Victoria, Australia. Forests were analysed by type, age and region. Regression equations were developed for the accumulation of biomass with age across all productivity classes for each forest type. The mean carbon density for above-ground components of Victorian native forests is 157 tonnes ha-1 (t ha-1), although forest types range in mean carbon density from 250 to 18 t ha-1. Pinus radiata D. Don plantations in Victoria have a mean carbon density of 91 t ha-1 in the above-ground components. Total carbon stored in above-ground biomass is estimated to be 1.2 X 109 t. Rates of carbon fixation vary with forest age, species and site. Mountain ash (Eucalyptus regnans F. Muell.) forests fix around 9 t of carbon ha-1 annually during the first few years of growth, decreasing to 6 t ha-1 by age 10. Rates of carbon accumulation by other forests are generally less than this and, at the lower end of the range, box-ironbark forests, mallee and woodlands accumulate between 0.5 and 2 t ha-1 year-1. P. radiata plantations in Victoria will accumulate around 7 t carbon ha-1 year-1.
The Effect of Land-Use Change on Soil CH4 and N2O Fluxes: A Global Meta-Analysis
Publisher: Springer Science and Business Media LLC
Date: 11-03-2019
Quantifying and predicting spatio-temporal variability of soil CH 4 and N 2 O fluxes from a seemingly homogeneous Australian agricultural field
Publisher: Elsevier BV
Date: 03-2017
Differential effects of N, P and K on photosynthesis and partitioning of N in Pinus pinaster needles
Publisher: EDP Sciences
Date: 2005
Nutrient cycling and nitrogen mineralization in eucalypt forests of south-eastern Australia - I. Nutrient cycling and nitrogen turnover
Publisher: Springer Science and Business Media LLC
Date: 10-1986
DOI: 10.1007/BF02372482
Patterns of genetic variation in a group of parasites, the Australian reptile ticks
Publisher: Springer Science and Business Media LLC
Date: 12-1984
DOI: 10.1038/HDY.1984.112
31P-NMR identification of phosphorus compounds in neutral extracts of mountain ash (Eucalyptus regnans F. Muell.) soils
Publisher: Elsevier BV
Date: 1990
Nutrient cycling and nitrogen mineralization in eucalypt forests of south-eastern Australia - II. Indices of nitrogen mineralization
Publisher: Springer Science and Business Media LLC
Date: 10-1986
DOI: 10.1007/BF02372483
The redistribution of soil water by tree root systems
Publisher: Springer Science and Business Media LLC
Date: 03-07-1998
Abstract: Plant roots transfer water between soil layers of different water potential thereby significantly affecting the distribution and availability of water in the soil profile. We used a modification of the heat pulse method to measure sap flow in roots of Grevillea robusta and Eucalyptus camaldulensis and demonstrated a redistribution of soil water from deeper in the profile to dry surface horizons by the root system. This phenomenon, termed "hydraulic lift" has been reported previously. However, we also demonstrated that after the surface soils were rewetted at the break of season, water was transported by roots from the surface to deeper soil horizons - the reverse of the "hydraulic lift" behaviour described for other woody species. We suggest that "hydraulic redistribution" of water in tree roots is significant in maintaining root viability, facilitating root growth in dry soils and modifying resource availability.
Litter cover as an index of nitrogen availability in rehabilitated mine sites
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/SR99046
Abstract: The spatial heterogeneity of litter cover and bioavailability of nitrogen within a 9-year-old rehabilitated bauxite mine in south Western Australia was examined. Three replicate plots (6 m by 6 m) were each ided into 100 quadrats. Litter cover, vegetation distribution, and projected foliage cover were mapped, and litter (overstorey leaves, understorey leaves, and other assorted fractions) and soil (depth: 0–5, 5–10, and 10–30 cm) were s led from within each quadrat. Litter distribution reflected projected foliage cover, and accumulated within microtopographic depressions. Distribution of soil nitrate (NO3–) reflected the distribution of litter. The 15N natural abundance (d15N) values of soil (0–5 cm) and the understorey litter fraction were significantly correlated (R2 = 0.529, P 0.05), whereas carbon isotope composition (d13C) of soil (0–5 cm) was significantly correlated with the distribution of the assorted litter fraction (R2 = 0.296, P 0.05). It is concluded that site preparation practices that effect microtopography, such as contour ripping and revegetation along contours, will have a significant impact on nitrogen (N) distribution and bioavailability within rehabilitated mine sites.
Mineralisation of nitrogen in a chronosequence of rehabilitated bauxite mines
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/SR99047
Abstract: Mine site rehabilitation should aim to establish quickly and maintain the processes of nutrient cycling at rates comparable with, or approaching, those of native forests. Current management strategies for rehabilitating bauxite mines and other mine sites in Australia usually include planting fast-growing understorey species at high densities and applying fertiliser. We provide the first detailed study of nitrogen (N) availability and N transformations (mineralisation/immobilisation) in such rehabilitated mine sites. Mean concentrations of NO3– (0–5 cm) in a chronosequence (7, 13, 22, and 27 years old) of rehabilitated mine sites ranged from 0.5 to 1.3 kg/ha, and NH4+ from 4.0 to 9.5 kg/ha. In burnt and unburnt native jarrah (E. marginata Donn ex. Smith) forests adjacent to the mine site, mean NO3– concentrations in surface soil (0–5 cm) were 0.8 kg/ha (burnt) and 1.1 kg/ha (unburnt), and mean NH4+ concentrations were 6.8 kg/ha (burnt) and 7.8 kg/ha (unburnt). Concentration of NH4+ at 0–5 cm was strongly related to soil water content (R2 = 0.69, P 0.05) in rehabilitation sites, but not at 5–10 cm depth. Rates of N mineralisation (0–5 cm) in rehabilitation sites ranged from 34 to 52 kg/ha.year, of the same order as rates in native forest soil. In all rehabilitation and native forest sites, rates of N mineralisation were significantly related to rates of N-uptake at both 0–5 and 5–10 cm depth (R2 0.63, P 0.05). Soil C/N ratios (0–5 cm) in rehabilitation sites ranged from 22.4 to 38.8, and in native forests from 35.6 (burnt) to 40.3 (unburnt). Soil C/N ratios increased with depth in both rehabilitation and native forest sites (ranged from 31.2 to 51.6). Availability of water was the major determinant of nitrogen availability in this strongly Mediterranean climate.
Estimation of drought-related limitations to mid-rotation aged plantation grown Eucalyptus globulus by phloem sap analysis
Publisher: Elsevier BV
Date: 08-2008
Capillary electrophoresis for the determination of major amino acids and sugars in foliage: application to the nitrogen nutrition of sclerophyllous species
Publisher: Oxford University Press (OUP)
Date: 06-2000
DOI: 10.1093/JEXBOT/51.347.1147
Abstract: Amino acids and sugars are probably the most commonly measured solutes in plant fluids and tissue extracts. Chromatographic techniques used for the measurement of such solutes require complex derivatization procedures, analysis times are long and separate analyses are required for sugars and amino acids. Two methods were developed for the analysis of underivatized sugars and amino acids by capillary electrophoresis (CE). Separation of a range of sugars and amino acids was achieved in under 30 min, with good reproducibility and linearity. In general, there was close agreement between amino acid analyses by CE and HPLC with post-column derivatization. An alternative, more rapid method was optimized for the common neutral sugars. Separation of a mixture of fructose, glucose, sucrose, and fucose (internal standard) was achieved in less than 5 min. How the source of N applied (nitrate or ammonium) and its concentration (8.0 or 0.5 mM) affects the amino acid and sugar composition of leaves from Banksia grandis Willd. and Hakea prostrata R. Br. was investigated. The amino acid pool of Banksia and Hakea were dominated by seven amino acids (aspartic acid, glutamic acid, asparagine, glutamine, serine, proline, and arginine). Of these, asparagaine and glutamine dominated at low N-supply, whereas at high N-supply the concentration of arginine increased and dominated amino-N. Plants grown with nitrate had a greater concentration of proline relative to plants with ammonium. In Banksia the concentration of amides was greatest and arginine least with a nitrate N-source, whereas in Hakea amides were least and arginine greatest with nitrate N-source. The concentration of sugars was greater in Banksia than Hakea and in both species at greater N-supply.
Carbon and oxygen isotope composition of organic compounds in the phloem sap provides a short‐term measure for stomatal conductance of European beech (Fagus sylvatica L.)
Publisher: Wiley
Date: 07-2003
Seasonal water acquisition and redistribution in the Australian woody phreatophyte, Banksia prionotes
Publisher: Oxford University Press (OUP)
Date: 02-2000
Indices for characterising spatial variability of soil nitrogen semi-arid grasslands of northwestern Australia
Publisher: Elsevier BV
Date: 05-1999
Sensitivity of respiratory metabolism and efficiency to foliar nitrogen during growth and maintenance
Publisher: Wiley
Date: 07-02-2008
Litter accumulation and fire risks show direct and indirect climate-dependence at continental scale
Publisher: Springer Science and Business Media LLC
Date: 18-03-2023
DOI: 10.1038/S41467-023-37166-9
Abstract: Litter decomposition / accumulation are rate limiting steps in soil formation, carbon sequestration, nutrient cycling and fire risk in temperate forests, highlighting the importance of robust predictive models at all geographic scales. Using a data set for the Australian continent, we show that among a range of models, % of the variance in litter mass over a 40-year time span can be accounted for by a parsimonious model with elapsed time, and indices of aridity and litter quality, as independent drivers. Aridity is an important driver of variation across large geographic and climatic ranges while litter quality shows emergent properties of climate-dependence. Up to 90% of variance in litter mass for in idual forest types can be explained using models of identical structure. Results provide guidance for future decomposition studies. Algorithms reported here can significantly improve accuracy and reliability of predictions of carbon and nutrient dynamics and fire risk.
Novel mannose-sequestration technique reveals variation in subcellular orthophosphate pools do not explain the effects of phosphorus nutrition on photosynthesis in Eucalyptus globulus seedlings
Publisher: Wiley
Date: 08-11-2007
DOI: 10.1111/J.1469-8137.2007.02229.X
Abstract: Although only a small proportion of plant phosphorus (P) is used for photosynthesis, the relationships between P and photosynthesis can be strong. It was hypothesized, in this study, that variation in the allocation of orthophosphate (Pi) between active (cytoplasmic) and nonactive (vacuolar) pools would underpin differences in rates of photosynthesis in 4-month-old Eucalyptus globulus seedlings grown with a varying P supply. Photosynthetic biochemistry was assessed by the response of net photosynthesis to increasing intercellular [CO2]. Cytoplasmic Pi was sequestered as mannose 6-phosphate. Total P and the proportion of P as Pi were positively related to P supply. The ratios of active : stored Pi (10-24%) varied little over the range of treatments. Active Pi was positively related to P supply, as was photosynthesis (7 micromol CO2 m(-2) s(-1) with 0 mM P vs. 16 micromol CO2 m(-2) s(-1) with 0.32 mM P). Positive relationships between P supply and photosynthesis were explained best by leaf P content, not by active pools of Pi. The distribution of Pi between the vacuole and the cytoplasm had little impact on the photosynthetic phosphorus-use efficiency (PPUE), and reductions in cytoplasmic Pi had little effect on photosynthesis. Hence, PPUE is an unsuitable guide for assessing plant responses to increasingly unavailable P in the environment.
Diurnal patterns of water use in Eucalyptus victrix indicate pronounced desiccation-rehydration cycles despite unlimited water supply
Publisher: Oxford University Press (OUP)
Date: 10-09-2011
Abstract: Knowledge about nocturnal transpiration (E(night)) of trees is increasing and its impact on regional water and carbon balance has been recognized. Most of this knowledge has been generated in temperate or equatorial regions. Yet, little is known about E(night) and tree water use (Q) in semi-arid regions. We investigated the influence of atmospheric conditions on daytime (Q(day)) and nighttime water transport (Q(night)) of Eucalyptus victrix L.A.S. Johnson & K.D. Hill growing over shallow groundwater (not >1.5 m in depth) in semi-arid tropical Australia. We recorded Q(day) and Q(night) at different tree heights in conjunction with measurements of stomatal conductance (g(s)) and partitioned E(night) from refilling processes. Q of average-sized trees (200-400 mm diameter) was 1000-3000 l month(-1), but increased exponentially with diameter such that large trees (>500 mm diameter) used up to 8000 l month(-1). Q was remarkably stable across seasons. Water flux densities (J(s)) varied significantly at different tree heights during day and night. We show that g(s) remained significantly different from zero and E(night) was always greater than zero due to vapor pressure deficits (D) that remained >1.5 kPa at night throughout the year. Q(night) reached a maximum of 50% of Q(day) and was >0.03 mm h(-1) averaged across seasons. Refilling began during afternoon hours and continued well into the night. Q(night) eventually stabilized and closely tracked D(night). Coupling of Q(night) and D(night) was particularly strong during the wet season (R2 = 0.95). We suggest that these trees have developed the capacity to withstand a pronounced desiccation-rehydration cycle in a semi-arid environment. Such a cycle has important implications for local and regional hydrological budgets of semi-arid landscapes, as large nighttime water fluxes must be included in any accounting.
Mega-fires, inquiries and politics in the eucalypt forests of Victoria, south-eastern Australia
Publisher: Elsevier BV
Date: 04-2013
Photoprotective carotenoids and antioxidants are more affected by canopy position than by nitrogen supply in 21-year-old Pinus radiata
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/FP08124
Abstract: Photoprotection, light harvesting and light utilisation were investigated as a function of variation in N supply and canopy position in 21-year-old Pinus radiata D. Don. Chlorophyll fluorescence, gas exchange and photoprotective compounds were measured on lower, middle and upper canopy needles in trees receiving N fertiliser and in control trees not receiving N fertiliser. Irrespective of canopy height, additional N increased the light-harvesting capacity through greater contents of chlorophyll, neoxanthin and lutein, but did not affect light-utilisation processes, such as effective quantum yield of PSII or rates of net CO2 assimilation. Additional N fertiliser did not affect the concentrations of the measured photoprotective carotenoids (violaxanthin, antheraxanthin, zeaxanthin, α-carotene and β-carotene) or antioxidants (ascorbic acid, glutathione and α-tocopherol) however, carotenoids and antioxidants were strongly affected by canopy height and increased in concentration with increasing canopy height. The present study found that pools of photoprotective carotenoids and antioxidants were not driven by imbalances in light-harvesting and light-utilisation processes, but rather by gradients in light.
Testing the generality of above-ground biomass allometry across plant functional types at the continent scale
Publisher: Wiley
Date: 29-03-2016
DOI: 10.1111/GCB.13201
Abstract: Accurate ground-based estimation of the carbon stored in terrestrial ecosystems is critical to quantifying the global carbon budget. Allometric models provide cost-effective methods for biomass prediction. But do such models vary with ecoregion or plant functional type? We compiled 15 054 measurements of in idual tree or shrub biomass from across Australia to examine the generality of allometric models for above-ground biomass prediction. This provided a robust case study because Australia includes ecoregions ranging from arid shrublands to tropical rainforests, and has a rich history of biomass research, particularly in planted forests. Regardless of ecoregion, for five broad categories of plant functional type (shrubs multistemmed trees trees of the genus Eucalyptus and closely related genera other trees of high wood density and other trees of low wood density), relationships between biomass and stem diameter were generic. Simple power-law models explained 84-95% of the variation in biomass, with little improvement in model performance when other plant variables (height, bole wood density), or site characteristics (climate, age, management) were included. Predictions of stand-based biomass from allometric models of varying levels of generalization (species-specific, plant functional type) were validated using whole-plot harvest data from 17 contrasting stands (range: 9-356 Mg ha(-1) ). Losses in efficiency of prediction were <1% if generalized models were used in place of species-specific models. Furthermore, application of generalized multispecies models did not introduce significant bias in biomass prediction in 92% of the 53 species tested. Further, overall efficiency of stand-level biomass prediction was 99%, with a mean absolute prediction error of only 13%. Hence, for cost-effective prediction of biomass across a wide range of stands, we recommend use of generic allometric models based on plant functional types. Development of new species-specific models is only warranted when gains in accuracy of stand-based predictions are relatively high (e.g. high-value monocultures).
Mistletoes and their eucalypt hosts differ in the response of leaf functional traits to climatic moisture supply
Publisher: Springer Science and Business Media LLC
Date: 17-02-2021
Contrasts between Eucalyptus subgenera
Publisher: Wiley
Date: 10-2000
Sequential fractionation and characterisation (31P-NMR) of phosphorus-amended soils in Banksia integrifolia (L.f.) woodland and adjacent pasture
Publisher: Elsevier BV
Date: 02-2000
Mesophyll photosynthetic sensitivity to leaf water potential in Eucalyptus: a new dimension of plant adaptation to native moisture supply
Publisher: Wiley
Date: 02-04-2021
DOI: 10.1111/NPH.17304
Cytotoxic Mechanism of Supramolecular Helicates
Publisher: Elsevier BV
Date: 11-2016
Managing mixed Callitris-Eucalyptus forests for carbon and energy in central-eastern Australia
Publisher: Elsevier BV
Date: 09-2020
Distribution of N, Rubisco and photosynthesis in Pinus pinaster and acclimation to light
Publisher: Wiley
Date: 06-2001
Optimization of photosynthesis and stomatal conductance in the date palm Phoenix dactylifera during acclimation to heat and drought
Publisher: Wiley
Date: 29-07-2019
DOI: 10.1111/NPH.15923
Abstract: We studied acclimation of leaf gas exchange to differing seasonal climate and soil water availability in slow-growing date palm (Phoenix dactylifera) seedlings. We used an extended Arrhenius equation to describe instantaneous temperature responses of leaf net photosynthesis (A) and stomatal conductance (G), and derived physiological parameters suitable for characterization of acclimation (T
Characterization of photosynthetic acclimation in Phoenix dactylifera by a modified Arrhenius equation originally developed for leaf respiration
Publisher: Springer Science and Business Media LLC
Date: 09-01-2017
CO2, nitrogen deposition and a discontinuous climate response drive water use efficiency in global forests
Publisher: Springer Science and Business Media LLC
Date: 31-08-2021
DOI: 10.1038/S41467-021-25365-1
Abstract: Reduced stomatal conductance is a common plant response to rising atmospheric CO 2 and increases water use efficiency ( W ). At the leaf-scale, W depends on water and nitrogen availability in addition to atmospheric CO 2 . In hydroclimate models W is a key driver of rainfall, droughts, and streamflow extremes. We used global climate data to derive Aridity Indices (AI) for forests over the period 1965–2015 and synthesised those with data for nitrogen deposition and W derived from stable isotopes in tree rings. AI and atmospheric CO 2 account for most of the variance in W of trees across the globe, while cumulative nitrogen deposition has a significant effect only in regions without strong legacies of atmospheric pollution. The relation of aridity and W displays a clear discontinuity. W and AI are strongly related below a threshold value of AI ≈ 1 but are not related where AI 1. Tree ring data emphasise that effective demarcation of water-limited from non-water-limited behaviour of stomata is critical to improving hydrological models that operate at regional to global scales.
Hydraulic traits and water use of Eucalyptus on restored versus natural sites in a seasonally dry forest in southwestern Australia
Publisher: Elsevier BV
Date: 06-2012
Photographic exposure affects indirect estimation of leaf area in plantations of Eucalyptus globulus Labill
Publisher: Elsevier BV
Date: 02-2000
Evaluation of anion exchange membranes to estimate bioavailable phosphorus in native grasslands of semi-arid northwestern Australia
Publisher: Informa UK Limited
Date: 09-1999
Water and nutrient dynamics in surface roots and soils are not modified by short-term flooding of phreatophytic plants in a hyperarid desert
Publisher: Springer Science and Business Media LLC
Date: 2006
The tree-crop interface: The effects of root pruning in south-western Australia
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/EA02012
Abstract: This paper examines the effect severing lateral tree roots (root pruning) has on crop and tree growth and soil water content at 2 sites in the south-west of Western Australia. Crop and tree growth and soil water content were assessed in a Pinus pinaster windbreak system growing on 0.45–1.00 m of sand over clay, and crop growth was assessed adjacent to Eucalyptus globulus windbreaks growing on 4–5 m of sand. Crop yield was depressed by 23–52% within 2.5 times the tree height (H) of unpruned pines and by 44% within 2.5 H of pruned eucalypts. Depressed yields made cropping uneconomical within 1.5 H of the eucalypts and 1 H of the pines. Root pruning most improved crop yields where lateral tree roots were confined close to the soil surface and decreased in effectiveness as the depth to confining layer (clay) increased. Crop losses within 2.5 H of the pines were reduced from 39 to 14% in the year the trees were root pruned and were 25% 1 year after root pruning. Subsequent root pruning of the eucalypts did not improve crop yield. While root pruning severed lateral pine roots, tree growth was not significantly reduced. The principal cause of reduced crop yield near the trees appeared to be reduced soil moisture in the area occupied by tree roots. Competition for nutrients and light appeared to have little effect on crop yield. Root pruning can spatially separate tree and crop roots where the tree roots are confined close to the surface, and significantly improve crop yields without reducing tree growth.
Stomatal structure and physiology do not explain differences in water use among montane eucalypts
Publisher: Springer Science and Business Media LLC
Date: 12-02-2015
DOI: 10.1007/S00442-015-3252-3
Abstract: Understanding the regulation of water use at the whole-tree scale is critical to advancing the utility of physiological ecology, for ex le in its role in predictive hydrology of forested catchments. For three eucalypt species that dominate high-elevation catchments in south-eastern Australia, we examined if whole-tree water use could be related to three widely discussed regulators of water use: stomatal anatomy, sensitivity of stomata [i.e. stomatal conductance (g(s))] to environmental influences, and sapwood area. While daily tree water use varied sixfold among species, sap velocity and sapwood area varied in parallel. Combined, stomatal structure and physiology could not explain differences in species-specific water use. Species which exhibited the fastest (Eucalyptus delegatensis) and slowest (Eucalyptus pauciflora) rates of water use both exhibited greater capacity for physiological control of g(s) [indicated by sensitivity to vapour pressure deficit (VPD)] and a reduced capacity to limit g(s) anatomically [indicated by greater potential g(s) (g(max))]. Conversely, g(s) was insensitive to VPD and g(max) was lowest for Eucalyptus radiata, the species showing intermediate rates of water use. Improved knowledge of stomatal anatomy will help us to understand the capacity of species to regulate leaf-level water loss, but seems likely to remain of limited use for explaining rates of whole-tree water use in montane eucalypts at the catchment scale.
Broadacre crop yield in the lee of windbreaks in the medium and low rainfall areas of south-western Australia
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/EA02011
Abstract: In Western Australia, the paucity of documented information detailing crop yield in the lee of windbreaks is a constraint to the adoption of tree windbreaks in dryland farming systems. This paper presents grain yield data for crops growing in the lee of windbreaks in the medium to low rainfall areas of the south-west of Western Australia for 64 field years between 1994 and 1997. Two distinct areas were identified in the lee of windbreaks: a zone of reduced crop yield extending 3–5 times the windbreak height (H) from the trees (competition zone), and a zone of unchanged or improved yield extending 15–20 H (sheltered zone). Yield between 1 and 20 H was less than unsheltered yield in years with average rainfall, similar to unsheltered yield in years, or areas, with low rainfall and higher than unsheltered yield if the unsheltered crop was subjected to sandblasting. Changes in microclimate in shelter appeared to be of benefit in increasing crop yields in drier years or areas. Lupin yield was generally increased in the sheltered zone while cereal yield was generally unchanged. The rate of canopy development may be critical to crop response. In dry years, reduced wind speed in shelter reduced evaporation of soil moisture, increasing the amount of soil water available to establishing crops and reducing sandblasting damage. The principle benefit of windbreaks was their ability to reduce wind erosion and subsequent crop damage. As such, windbreaks are best regarded as a form of insurance.
Mega-fires, tipping points and ecosystem services: Managing forests and woodlands in an uncertain future
Publisher: Elsevier BV
Date: 04-2013
Eucalypt smoke and wildfires: Temperature dependent emissions of biogenic volatile organic compounds
Publisher: Elsevier BV
Date: 2009
Forests and Decarbonization – Roles of Natural and Planted Forests
Publisher: Frontiers Media SA
Date: 08-05-2020
Erratum to Eucalypt smoke and wildfires: Temperature dependent emissions of biogenic volatile organic compounds [Int. J. Mass Spectrom. 279 (2-3) (2009) 126-133] (DOI:10.1016/j.ijms.2008.10.027)
Publisher: Elsevier BV
Date: 04-2009
Ecotype adaptation and acclimation of leaf traits to rainfall in 29 species of 16-year-old Eucalyptus at two common gardens
Publisher: Wiley
Date: 24-10-2006
Non-suppressed conductivity detection of organic acids in plant tissue extracts by ion-exclusion chromatography with aromatic acid eluents
Publisher: Informa UK Limited
Date: 09-1998
Short‐term variation in the isotopic composition of organic matter allocated from the leaves to the stem of Pinus sylvestris: effects of photosynthetic and postphotosynthetic carbon isotope fra
Publisher: Wiley
Date: 21-08-2006
Solar UV upregulates photoprotection but slows photosynthesis in Subalpine Australian Plants
Publisher: Informa UK Limited
Date: 11-2017
DOI: 10.1657/AAAR0017-024
Synchrotron radiation induced X-ray emission studies of the antioxidant mechanism of the organoselenium drug ebselen
Publisher: Springer Science and Business Media LLC
Date: 11-02-2012
DOI: 10.1007/S00775-012-0879-Y
Abstract: Synchrotron radiation induced X-ray emission (SRIXE) spectroscopy was used to map the cellular uptake of the organoselenium-based antioxidant drug ebselen using differentiated ND15 cells as a neuronal model. The cellular SRIXE spectra, acquired using a hard X-ray microprobe beam (12.8-keV), showed a large enhancement of fluorescence at the K(α) line for Se (11.2-keV) following treatment with ebselen (10 μM) at time periods from 60 to 240 min. Drug uptake was quantified and ebselen was shown to induce time-dependent changes in cellular elemental content that were characteristic of oxidative stress with the efflux of K, Cl, and Ca species. The SRIXE cellular Se distribution map revealed that ebselen was predominantly localized to a discreet region of the cell which, by comparison with the K and P elemental maps, is postulated to correspond to the endoplasmic reticulum. On the basis of these findings, it is hypothesized that a major outcome of ebselen redox catalysis is the induction of cellular stress. A mechanism of action of ebselen is proposed that involves the cell responding to drug-induced stress by increasing the expression of antioxidant genes. This hypothesis is supported by the observation that ebselen also regulated the homeostasis of the transition metals Mn, Cu, Fe, and Zn, with increases in transition metal uptake paralleling known induction times for the expression of antioxidant metalloenzymes.
Nitrogen uptake by Eucalyptus regnans and Acacia spp. - preferences, resource overlap and energetic costs
Publisher: Oxford University Press (OUP)
Date: 19-01-2009
Abstract: In southeastern Australia, the overstory species Eucalyptus regnans F. Muell. commonly grows with either of the two leguminous understory trees, Acacia melanoxylon (R. Br. Ex Ait. f.) or Acacia dealbata (Link.). Our objective was to elucidate interactions between the dominant eucalypt and its companion acacias for nitrogen (N) sources. Use of stable N isotopes as tracers revealed that ammonium was the preferred soil N source for all species, nevertheless, total N uptake varied greatly among species. Studies with double-labeled ((13)C/(15)N) glutamine indicated the uptake of this form of organic N in small amounts by both E. regnans and the Acacia spp. These and other data imply that, in contrast to boreal forests, organic N is not a significant component of N nutrition in mountain ash forests. Field and laboratory studies provided evidence that N(2)-fixation capacity of acacias varies with stand development, with N-fixing species playing an important role in N nutrition during the early but not the mature stages of forest growth. An index of N-uptake efficiency - the amount of oxygen consumed per unit N taken up - was compared across four N sources and three species. Nitrate uptake was the least efficient form of N acquisition, especially compared with ammonium uptake which was up to 30-fold less costly. Efficiency of glutamine uptake was intermediate between that of ammonium and nitrate. Differences in uptake efficiency among N forms were most pronounced for the Acacia spp. and least for E. regnans. We conclude that an overlap in requirements among sympatric Acacia spp. and E. regnans for specific soil N sources can be bypassed because of changes in biochemical strategies of Acacia spp. triggered by increasing soil N concentrations during stand development. Further studies might elucidate whether this is a common feature of complex forest ecosystems, or a specialty of the interaction between eucalypts and acacias.
Combustion influences on natural abundance nitrogen isotope ratio in soil and plants following a wildfire in a sub-alpine ecosystem
Publisher: Springer Science and Business Media LLC
Date: 07-05-2013
DOI: 10.1007/S00442-013-2665-0
Abstract: This before-and-after-impact study uses the natural abundance N isotope ratio (δ(15)N) to investigate the effects of a wildfire on sub-alpine ecosystem properties and processes. We measured the (15)N signatures of soil, charred organic material, ash and foliage in three sub-alpine plant communities (grassland, heathland and woodland) in south-eastern Australia. Surface bulk soil was temporarily enriched in (15)N immediately after wildfire compared to charred organic material and ash in all plant communities. We associated the enrichment of bulk soil with fractionation of N during combustion and volatilization of N, a process that also explains the sequential enrichment of (15)N of unburnt leaves > ash > charred organic material in relation to duration and intensity of heating. The rapid decline in (15)N of bulk soil to pre-fire values indicates that depleted ash, containing considerable amounts of total N, was readily incorporated into the soil. Foliar δ(15)N also increased with values peaking 1 year post-fire. Foliar enrichment was foremost coupled with the release of enriched NH4(+) into the soil owing to isotopic discrimination during volatilization of soluble N and combustion of organic material. The mode of post-fire regeneration influenced foliar (15)N enrichment in two species indicating use of different sources of N following fire. The use of natural abundance of (15)N in soil, ash and foliage as a means of tracing transformation of N during wildfire has established the importance of combustion products as an important, albeit temporary source of inorganic N for plants regenerating after wildfire.
Quercitol links the physiology, taxonomy and evolution of 279 eucalypt species
Publisher: Wiley
Date: 16-06-2007
Regeneration of the legumes Acacia ancistrocarpa and Senna notabilis in the Pilbara region of Western Australia: mineral nutrition and carbon fractions
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/BT98095
Abstract: A large proportion of Australia’s rangelands is arid or semi-arid and is dominated by soils low in total phosphorus. Productivity is controlled chiefly by the season and distribution of rainfall, although fire plays a major role in determining species composition, especially of the scrublands in these regions. Two legumes, common to the Pilbara region of Western Australia, Acacia ancistrocarpa and Senna notabilis, regenerated quickly after fires in summer 1995–1996. We examined their growth, mineral nutrition and carbon fractions in relation to their role as possible feed for herbivores, both native and introduced, with and without added phosphorus both in the field and the glasshouse. In the field, both species showed no significant changes in concentrations of total phenolics, condensed tannins, non-structural carbohydrates or lignin in response to fertiliser addition. Both species accumulated nitrogen and phosphorus after summer rain but the allocation of those resources varied between species. In the glasshouse, the concentration of nitrogen in both species was not affected by phosphorus fertilisation but the concentration of phosphorus in foliage increased linearly as the amount of phosphorus increased. Phosphorus application resulted in an increase in the dry mass of both species. Both species are low in in vitro dry organic matter digestibility and maintain high concentrations of total phenolics, condensed tannins and lignin. All nutritional, including major minerals, and anti-nutritional components varied significantly with season.
Optimisation of fuel reduction burning regimes for carbon, water and vegetation outcomes
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.JENVMAN.2017.07.056
Abstract: Fire plays a critical role in bio ersity, carbon balance, soil erosion, and nutrient and hydrological cycles. While empirical evidence shows that fuel reduction burning can reduce the incidence, severity and extent of unplanned fires in Australia and elsewhere, the integration of environmental values into fire management operations is not well-defined and requires further research and development. In practice, the priority for fuel reduction burning is effective mitigation of risk to life and property. Environmental management objectives, including maintenance of high quality water, reduction of CO
Stable isotopes at natural abundance in terrestrial plant ecology and ecophysiology: An update
Publisher: Wiley
Date: 07-2001
DOI: 10.1055/S-2001-16454
Soil Respiration in Future Global Change Scenarios
Publisher: Springer Berlin Heidelberg
Date: 2011
Estimation of leaf area index in eucalypt forest with vertical foliage, using cover and fullframe fisheye photography
Publisher: Elsevier BV
Date: 04-2007
Application of an enthalpy balance model of the relation between growth and respiration to temperature acclimation of Eucalyptus globulus seedlings
Publisher: The Royal Society
Date: 22-07-2002
The Effects of Atmospheric Nitrogen Deposition on Terrestrial and Freshwater Biodiversity
Publisher: Springer Netherlands
Date: 2014
Causes and consequences of Eastern Australia’s 2019–20 season of mega-fires: A broader perspective
Publisher: Wiley
Date: 06-05-2020
DOI: 10.1111/GCB.15125
Gravity waves above a convective boundary layer: A comparison between wind-profiler observations and numerical simulations
Publisher: Wiley
Date: 2007
DOI: 10.1002/QJ.72
Rewetting and litter addition influence mineralisation and microbial communities in soils from a semi-arid intermittent stream
Publisher: Elsevier BV
Date: 2009
An analytical model of non-photorespiratory CO2 release in the light and dark in leaves of C3 species based on stoichiometric flux balance
Publisher: Wiley
Date: 07-10-2011
DOI: 10.1111/J.1365-3040.2010.02228.X
Abstract: Leaf respiration continues in the light but at a reduced rate. This inhibition is highly variable, and the mechanisms are poorly known, partly due to the lack of a formal model that can generate testable hypotheses. We derived an analytical model for non-photorespiratory CO₂ release by solving steady-state supply/demand equations for ATP, NADH and NADPH, coupled to a widely used photosynthesis model. We used this model to evaluate causes for suppression of respiration by light. The model agrees with many observations, including highly variable suppression at saturating light, greater suppression in mature leaves, reduced assimilatory quotient (ratio of net CO₂ and O₂ exchange) concurrent with nitrate reduction and a Kok effect (discrete change in quantum yield at low light). The model predicts engagement of non-phosphorylating pathways at moderate to high light, or concurrent with processes that yield ATP and NADH, such as fatty acid or terpenoid synthesis. Suppression of respiration is governed largely by photosynthetic adenylate balance, although photorespiratory NADH may contribute at sub-saturating light. Key questions include the precise diel variation of anabolism and the ATP : 2e⁻ ratio for photophosphorylation. Our model can focus experimental research and is a step towards a fully process-based model of CO₂ exchange.
A metallic cobalt electrode for the indirect potentiometric determination of calcium and magnesium in natural waters using flow injection analysis
Publisher: Elsevier BV
Date: 11-1998
DOI: 10.1016/S0039-9140(98)00170-2
Abstract: A flow injection analysis of Ca(2+) and Mg(2+) using indirect potentiometric detection in natural waters is proposed, where Ca(2+) or Mg(2+) are injected into a buffer carrier containing phosphate, resulting in the formation of Ca(3)(PO(4))(2) or Mg(3)(PO(4))(2). The consequent reduction in free phosphate in the carrier solution is detected using a metallic cobalt wire electrode. Indirect electrode response was used and the experimental conditions affecting electrode response were optimized. Responses were linear in the concentration range 5x10(-4) to 5x10(-3) M with a detection limit of 1x10(-5) M in 20 mM phosphate buffer at pH 8.0. The relative standard derivation at 1 mM of Ca(2+) and Mg(2+) were 3.9 and 3.7% (n=10), respectively. EGTA and 8-hydroxyquinoline were used as the masking agents for Ca(2+) and Mg(2+), respectively. Concentrations of Ca(2+) and Mg(2+) in natural waters were successfully determined by the proposed method.
Functional conservatism among Drosophila simulans flies experiencing different thermal regimes and mitochondrial DNA introgression
Publisher: Wiley
Date: 12-2010
DOI: 10.1002/JEZ.B.21389
Abstract: Drosophila simulans possesses three different mitochondrial haplotypes (siI, II and III) that are nonrandomly geographically sub ided with a 3% interhaplogroup variation. The aim of this study was to determine whether perturbation of mitochondrial metabolism and ROS management by temperature variation and mtDNA introgression would influence the development of aerobic capacity and the intensity of oxidative stress in D. simulans at different ages. Environmental temperature ergences during development had few impacts on metabolic capacities. Our data suggested strong functional conservatism of mitochondrial haplotypes between the D. simulans lines studied. This conservatism was expressed by the low ergences in either mitochondrial or ROS buffering enzyme activities, or even markers of ROS damage even after disruption of coevolved genomes. Disruption of coevolved mitochondrial and nuclear genomes through mtDNA introgression induced no clear ergence on metabolic phenotype at any state of development. Reduction of cytochrome c oxidase activity that was observed after introgression of one mitochondrial haplotype will require further investigation to delineate whether it is associated with any modification of mito-nuclear interactions.
Architectural plasticity in young Eucalyptus marginata on restored bauxite mines and adjacent natural forest in south-western Australia
Publisher: Oxford University Press (OUP)
Date: 24-06-2009
Abstract: The aboveground architecture of Eucalyptus marginata (Jarrah) was investigated in chronosequences of young trees (2.5, 5 and 10 m height) growing in a seasonally dry climate in a natural forest environment with intact soils, and on adjacent restored bauxite mine sites on soils with highly modified A and B horizons above an intact C horizon. Compared to forest trees, trees on restored sites were much younger and faster growing, with straighter, more clearly defined main stems and deeper, narrower crowns containing a greater number of branches that were longer, thinner and more vertically angled. Trees on restored sites also had a higher fraction of biomass in leaves than forest trees, as indicated by 20-25% thicker leaves, 30-70% greater leaf area, 10-30% greater leaf area to sapwood area ratios and 5-30% lesser branch Huber values. Differences in crown architecture and biomass distribution were consistent with putatively greater soil-water, nutrient and light availability on restored sites. Our results demonstrate that under the same climatic conditions, E. marginata displays a high degree of plasticity of aboveground architecture in response to the net effects of resource availability and soil environment. These differences in architecture are likely to have functional consequences in relation to tree hydraulics and growth that, on larger scales, is likely to affect the water and carbon balances of restored forest ecosystems. This study highlights substrate as a significant determinant of tree architecture in water-limited environments. It further suggests that the architecture of young trees on restored sites may need to change again if they are to survive likely longer-term changes in resource availability.
Differences in water use between mature and post-fire regrowth stands of subalpine Eucalyptus delegatensis R. Baker
Publisher: Elsevier BV
Date: 04-2012
Water availability and carbon isotope discrimination in conifers
Publisher: Springer Science and Business Media LLC
Date: 05-2001
Abstract: The stable C isotope composition (δ
Compound‐specific differences in 13C of soluble carbohydrates in leaves and phloem of 6‐month‐old Eucalyptus globulus (Labill)
Publisher: Wiley
Date: 22-06-2011
DOI: 10.1111/J.1365-3040.2011.02359.X
Abstract: Movement of photoassimilates from leaves to phloem is an important step for the flux of carbon through plants. Fractionation of carbon isotopes during this process may influence their abundance in heterotrophic tissues. We subjected Eucalyptus globulus to 20, 25 and 28 °C ambient growth temperatures and measured compound-specific δ(13)C of carbohydrates obtained from leaves and bled phloem sap. We compared δ(13)C of sucrose and raffinose obtained from leaf or phloem and of total leaf soluble carbon, with modelled values predicted by leaf gas exchange. Changes in δ(13)C of sucrose and raffinose obtained from either leaves or phloem sap were more tightly coupled to changes in c(i)/c(a) than was δ(13)C of leaf soluble carbon. At 25 and 28 °C, sucrose and raffinose were enriched in (13)C compared to leaf soluble carbon and predicted values - irrespective of tissue type. Phloem sucrose was depleted and raffinose enriched in (13)C compared to leaf extracts. Intermolecular and tissue-specific δ(13)C reveal that multiple systematic factors influence (13)C composition during export to phloem. Predicting sensitivity of these factors to changes in plant physiological status will improve our ability to infer plant function at a range of temporal and spatial scales.
The Kok effect in Vicia faba cannot be explained solely by changes in chloroplastic CO2 concentration
Publisher: Wiley
Date: 31-08-2017
DOI: 10.1111/NPH.14775
Abstract: The Kok effect – an abrupt decline in quantum yield ( QY ) of net CO 2 assimilation at low photosynthetic photon flux density ( PPFD ) – is widely used to estimate respiration in the light ( R ), which assumes the effect is caused by light suppression of R . A recent report suggested much of the Kok effect can be explained by declining chloroplastic CO 2 concentration ( c c ) at low PPFD . Several predictions arise from the hypothesis that the Kok effect is caused by declining c c , and we tested these predictions in Vicia faba . We measured CO 2 exchange at low PPFD , in 2% and 21% oxygen, in developing and mature leaves, which differed greatly in R in darkness. Our results contradicted each of the predictions based on the c c effect: QY exceeded the theoretical maximum value for photosynthetic CO 2 uptake QY was larger in 21% than 2% oxygen and the change in QY at the Kok effect breakpoint was unaffected by oxygen. Our results strongly suggest the Kok effect arises largely from a progressive decline in R with PPFD that includes both oxygen‐sensitive and ‐insensitive components. We suggest an improved Kok method that accounts for high c c at low PPFD .
Fertilizer impacts on the understorey of a regenerating Mountain Ash (Eucalyptus regnans F. Muell.) forest, Victoria
Publisher: Wiley
Date: 12-1996
Reduced metal ion concentrations in atherosclerotic plaques from subjects with Type 2 diabetes mellitus
Publisher: Elsevier BV
Date: 06-2012
DOI: 10.1016/J.ATHEROSCLEROSIS.2012.03.015
Abstract: Transition metal ions have been implicated in atherosclerosis. The goal of this study was to investigate whether metal ion levels were higher in people with diabetes, in view of their increased risk of aggravated atherosclerosis. Absolute concentrations of iron, copper, zinc and calcium, and products of protein and lipid oxidation were quantified in atherosclerotic lesions from subjects with (T2DM, n=27), without Type 2 diabetes (nonDM, n=22), or hyperglycaemia (HG, n=17). Iron (P<0.05), zinc (P<0.01) and calcium (P=0.01) were lower in T2DM compared to nonDM subjects. Copper levels were comparable. A strong correlation (r=0.618 P<0.001) between EPR-detectable and total iron in nonDM patients was not seen in T2DM. X-ray fluorescence microscopy revealed "hot spots" of iron in both T2DM and nonDM. Calcium and zinc co-localised and levels correlated strongly. F(2)-isoprostanes (P<0.05) and di-Tyr/Tyr ratio (P<0.025), oxidative damage markers were decreased in T2DM compared to nonDM, or HG. Advanced atherosclerotic lesions from T2DM subjects unexpectedly contained lower levels of transition metal ions, and protein and lipid oxidation products, compared to nonDM and HG. These data do not support the hypothesis that elevated metal ion levels may be a major causative factor in the aggravated atherosclerosis observed in T2DM patients.
Urban-wildland fires: How California and other regions of the US can learn from Australia
Publisher: IOP Publishing
Date: 2009
Comparison of four methods for measuring osmotic potential of tree leaves
Publisher: Wiley
Date: 28-04-2006
Sap flow measurements reveal influence of temperature and stand structure on water use of Eucalyptus regnans forests
Publisher: Elsevier BV
Date: 03-2019
Tree decline in southeastern Australia: Nitrate reductase activity and indications of unbalanced nutrition in Eucalyptus ovata (Labill.) and E. camphora (R.T. Baker) communities at Yellingbo, Victoria
Publisher: Springer Science and Business Media LLC
Date: 07-1994
DOI: 10.1007/BF00341475
Soil water nitrate and ammonium dynamics under a sewage effluent-irrigated eucalypt plantation
Publisher: Wiley
Date: 11-2007
DOI: 10.2134/JEQ2007.0175
Abstract: Managed forests and plantations are appropriate ecosystems for land-based treatment of effluent, but concerns remain regarding nutrient contamination of ground- and surface waters. Monthly NO3-N and NH4-N concentrations in soil water, accumulated soil N, and gross ammonification and nitrification rates were measured in the second year of a second rotation of an effluent irrigated Eucalyptus globulus plantation in southern Western Australia to investigate the separate and interactive effects of drip and sprinkler irrigation, effluent and water irrigation, irrigation rate, and harvest residues retention. Nitrate concentrations of soil water were greater under effluent irrigation than water irrigation but remained <15 mg L(-1) when irrigated at the normal rate (1.5-2.0 mm d(-1)), and there was little evidence of downward movement. In contrast, NH4-N concentrations of soil water at 30 and 100 cm were generally greater under effluent irrigation than water irrigation when irrigated at the normal rate because of direct effluent NH4-N input and indirect ammonification of soil organic N. Drip irrigation of effluent approximately doubled peak NO3-N and NH4-N concentrations in soil water. Harvest residue retention reduced concentrations of soil water NO3-N at 30 cm during active sprinkler irrigation, but after 1 yr of irrigation there was no significant difference in the amount of N stored in the soil system, although harvest residue retention did enhance the "nitrate flush" in the following spring. Gross mineralization rates without irrigation increased with harvest residue retention and further increased with water irrigation. Irrigation with effluent further increased gross nitrification to 3.1 mg N kg(-1) d(-1) when harvest residues were retained but had no effect on gross ammonification, which suggested the importance of heterotrophic nitrification. The downward movement of N under effluent irrigation was dominated by NH4-N rather than NO3-N. Improving the capacity of forest soils to store and transform N inputs through organic matter management must consider the dynamic equilibrium between N input, uptake, and immobilization according to soil C status, and the effect changing microbial processes and environmental conditions can have on this equilibrium.
Crops, Nitrogen, Water: Are Legumes Friend, Foe, or Misunderstood Ally?
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.TPLANTS.2018.02.009
Abstract: Biological nitrogen fixation (BNF) by crop legumes reduces demand for industrial nitrogen fixation (INF). Nonetheless, rates of BNF in agriculture remain low, with strong negative feedback to BNF from reactive soil nitrogen (N) and drought. We show that breeding for yield has resulted in strong relationships between photosynthesis and leaf N in non-leguminous crops, whereas grain legumes show strong relations between leaf N and water use efficiency (WUE). We contrast these understandings with other studies that draw attention to the water costs of grain legume crops, and their potential for polluting the biosphere with N. We propose that breeding grain legumes for reduced stomatal conductance can increase WUE without compromising production or BNF. Legume crops remain a better bet than relying on INF.
A validation, comparison and error analysis of two heat-pulse methods for measuring sap flow in Eucalyptus marginata saplings
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/FP04013
Abstract: We validated and compared two heat-pulse methods for measuring sap flow in potted Eucalyptus marginata Donn ex. Smith (jarrah) saplings. During daylight hours and under well-watered conditions, rates of sap flow (0.1–0.5 kg h–1) measured by the established compensation heat-pulse method (CHPM) and the newly developed heat-ratio method (HRM) were similar to rates measured with a weighing lysimeter, and most of the time there was no significant difference (P .001) between methods. The HRM accurately described sap flow at night when rates of flow were low ( 0.1 kg h–1) or near zero, but the CHPM was unable to measure low rates of sap flow due to its inability to distinguish heat-pulse velocities below a threshold velocity of 0.1 kg h–1 (3–4 cm h–1). The greatest potential for error in the calculation of daily sap flow was associated with the misalignment of temperature sensors, the estimation of sapwood area and the method used to acquire total sap flow from point measurements of sap velocity. A direct comparison of the two heat-pulse methods (applied synchronously) revealed that the HRM had a more convincing mechanism for correcting spacing errors and was more resistant to random fluctuation in measurements than the CHPM. While we view the HRM more favourably than the CHPM in some key areas, both methods are valid and useful, within their constraints, for measuring transpiration in jarrah and other woody species.
Short-term effects of biochar and salinity on soil greenhouse gas emissions from a semi-arid Australian soil after re-wetting
Publisher: Elsevier BV
Date: 12-2017
Phloem sap and leaf δ13C, carbohydrates, and amino acid concentrations in Eucalyptus globulus change systematically according to flooding and water deficit treatment
Publisher: Oxford University Press (OUP)
Date: 08-03-2010
DOI: 10.1093/JXB/ERQ045
Simple models for stomatal conductance derived from a process model: Cross-validation against sap flux data
Publisher: Wiley
Date: 04-05-2012
DOI: 10.1111/J.1365-3040.2012.02515.X
Abstract: Representation of stomatal physiology in models of plant-atmosphere gas exchange is minimal, and direct application of process-based models is limited by difficulty of parameter estimation. We derived simple models of stomatal conductance from a recent process-based model, and cross-validated them against measurements of sap flux (176-365 d in length) in 36 in idual trees of two age classes for two Eucalyptus species across seven sites in the mountains of southeastern Australia. The derived models - which are driven by irradiance and evaporative demand and have two to four parameters that represent sums and products of biophysical parameters in the process model - reproduced a median 83-89% of observed variance in half-hourly and diurnally averaged sap flux, and performed similarly whether fitted using a random s le of all data or using 1 month of data from spring or autumn. Our simple models are an advance in predicting plant water use because their parameters are transparently related to reduced processes and properties, enabling easy accommodation of improved knowledge about how those parameters respond to environmental change and differ among species.
Effects of phosphorus supply on growth and nitrogen fractions in xylem sap and foliage of Eucalyptus regnans (F.Muell.), E. nitens (Maiden) and E. globulus (Labill.) seedlings: implications for herbivory
Publisher: Springer Science and Business Media LLC
Date: 09-1995
DOI: 10.1007/BF00202496
Nitrogen Deposition Effects on Ecosystem Services and Interactions with other Pollutants and Climate Change
Publisher: Springer Netherlands
Date: 2014
Ecophysiology of ectomycorrhizal fungi associated with Pinus spp. in low rainfall areas of Western Australia
Publisher: Springer Science and Business Media LLC
Date: 2004
Dynamic light use and protection from excess light in upper canopy and coppice leaves of Nothofagus cunninghamii in an old growth, cool temperate rainforest in Victoria, Australia
Publisher: Wiley
Date: 09-12-2005
DOI: 10.1111/J.1469-8137.2004.01232.X
Abstract: Responses to simulated sunflecks were examined in upper canopy and coppice leaves of Nothofagus cunninghamii growing in an old-growth rainforest gully in Victoria, Australia. Shaded leaves were exposed to a sudden increase in irradiance from 20 to 1500 micromol m(-2) s(-1). Gas exchange and chlorophyll fluorescence were measured during a 10 min simulated sunfleck and, in the ensuing dark treatment, we examined the recovery of PS II efficiency and the conversion state of xanthophyll cycle pigments. Photosynthetic induction was rapid compared with tropical and northern hemisphere species. Stomatal conductance was relatively high in the shade and stomata did not directly control photosynthetic induction under these conditions. During simulated sunflecks, zeaxanthin was formed rapidly and photochemical efficiency was reduced. These processes were reversed within 30 min in coppice leaves, but this took longer in upper canopy leaves. Poor drought tolerance and achieving a positive carbon balance in a shaded canopy may be functionally related to high stomatal conductance in the shade in N. cunninghamii. The more persistent reduction in photochemical efficiency of upper canopy leaves, which means less efficient light use in subsequent shade periods, but stronger protection from high light, may be related to the generally higher irradiance and longer duration of sunflecks in the upper canopy, but potentially reduces carbon gain during shade periods by 30%.
Direct determination of phosphate in soil extracts by potentiometric flow injection using a cobalt wire electrode
Publisher: Elsevier BV
Date: 05-1998
Changes in gas exchange versus leaf solutes as a means to cope with summer drought in Eucalyptus marginata
Publisher: Springer Science and Business Media LLC
Date: 18-07-2007
DOI: 10.1007/S00442-007-0803-2
Abstract: Two of the ways in which plants cope with water deficits are stomatal closure and "osmotic adjustment". We sought to assess the contributions of these processes to maintenance of leaf hydration in field-grown, 7-year-old Eucalyptus marginata. Plants were exposed to their normal summer drought (controls) or supplied with additional water (irrigated). Irrigation increased photosynthesis by 30% in E. marginata. These increases in photosynthesis were related to an 80% increase in g (s). However, there was no difference in substomatal CO(2) concentrations between treatments, or in chloroplast CO(2) concentrations, as indicated by carbon isotope composition of leaf soluble sugars. This suggests that impaired mesophyll metabolism may partially explain slower rates of photosynthesis in plants exposed to their normal summer drought. There was no difference in concentrations of solutes or osmotic potential between non-irrigated and irrigated in iduals, perhaps because relative water content was the same in non-irrigated and irrigated plants due to stomatal sensitivity to water deficits. Irrespective of the absence of osmotic adjustment, analysis of leaf solutes gave a clear indication of the major groups of compounds responsible for maintaining cell osmotic potential. Soluble sugars were three times as abundant as amino acids. Proline, a putatively osmotically active amino acid, contributed less than 1% of total solutes. These patterns of solutes in E. marginata are consistent with a growing body of literature arguing a greater role for carbohydrates and cyclitols and lesser role for amino acids in maintaining osmotic potential. Our data suggest the primary mechanism by which E. marginata coped with drought was partial stomatal closure however, we cannot discount the possibility of osmotic adjustment under more severe water deficits.
Does season and grazing influence the δ13C and δ15N of C4 native grasses in semi-arid rangelands of the Pilbara region of NW Australia?
Publisher: Elsevier BV
Date: 2017
Plasticity of Leaf Respiratory and Photosynthetic Traits in Eucalyptus grandis and E. regnans Grown Under Variable Light and Nitrogen Availability
Publisher: Frontiers Media SA
Date: 06-02-2020
Water availability and branch length determine δ13C in foliage of Pinus pinaster
Publisher: Oxford University Press (OUP)
Date: 05-2000
DOI: 10.1093/TREEPHYS/20.10.637
Abstract: The stable carbon isotope composition (delta(13)C) of foliage integrates signals resulting from environmental and hydraulic constraints on water movement and photosynthesis. We used branch length as a simple predictor of hydraulic constraints to water fluxes and determined the response of delta(13)C to varying water availability. Foliage up to 6 years old was taken from Pinus pinaster Ait. trees growing at four sites differing in precipitation (P 414-984 mm year(-1)) and potential evaporation (ET 1091-1750 mm year(-1)). Branch length was the principal determinant of temporal trends in delta(13)C. The strong relationship between delta(13)C and branch length was a function of hydraulic conductance, which was negatively correlated with branch length (r(2) = 0.84). Variation in P and ET among sites was reflected in delta(13)C, which was negatively correlated with P/ET (r(2) = 0.66). However, this analysis was confounded by differences in branch length. If the effects of branch length on delta(13)C were first removed, then the 'residual' delta(13)C was more closely related to P/ET (r(2) = 0.99), highlighting the importance of accounting for variation in hydraulic constraints to water flux between sites and years. For plant species that exhibit considerable phenotypic plasticity in response to changes in environment (e.g., variation in leaf area, branch length and number, or stem form), the environmental effects on delta(13)C in foliage can only be reliably assessed if deconvoluted from hydraulic constraints.
Trade-offs between the persistence of foliage and productivity in two Pinus species
Publisher: Springer Science and Business Media LLC
Date: 15-09-2000
DOI: 10.1007/PL00008874
ROLE OF ACACIA SPP IN NUTRIENT BALANCE AND CYCLING IN REGENERATING EUCALYPTUS-REGNANS F-MUELL FORESTS .1. TEMPORAL CHANGES IN BIOMASS AND NUTRIENT CONTENT
Publisher: CSIRO Publishing
Date: 1984
DOI: 10.1071/BT9840205
Abstract: Following severe fire in high-rainfall Eucalyptus regnans forests, several Acacia species may germinate in large numbers. Large amounts of nitrogen, calcium, magnesium and potassium are immobilized in the Acacia biomass, much of which is returned to the soil after canopy closure. Within 3 years of a regeneration burn, 280 kg N ha-1 was in the above-ground Acacia biomass and litter layer. The relative abundance of nitrogen in Acacia spp. is a result of N fixation. The probable rate of N fixation appears significant in relation to losses of nitrogen associated with slash-burning. It is concluded that the Acacia spp. may be important in the secondary succession through nutrient conservation, replacement and redistribution.
What determines rates of photosynthesis per unit nitrogen in Eucalyptus seedlings?
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/FP04115
Abstract: Species originating from xeric sites are characterised by slower rates of photosynthesis per unit nitrogen (PNUE) than species from mesic sites, but we lack mechanistic explanations for these interspecific differences. We examined N allocation to Rubisco and chlorophyll, and photosynthetic characteristics in seedlings of nine Eucalyptus species grown in a fully sunlit glasshouse with an optimal supply of nutrients. Species were selected from mesic (1800 mm year–1 rainfall) through to semi-arid habitats (300 mm year–1). All species were characterised by allocation of a large proportion of N to Rubisco (32–48%) with high in vivo specific activity. Intercellular CO2 concentration (Ci) varied between 260 and 300 μmol mol–1, and thus, stomatal limitations were low in all species. This combination of traits resulted in a PNUE (172–335 μmol mol–1 s–1) that was higher than is commonly observed in tree species and which may be related to the rapid growth, water-spender strategy of Eucalyptus seedlings. There were significant differences in photosynthetic parameters and N allocation among species, but these were only weakly related to rainfall at the site of seed origin. There were correlations of Ci with PNUE but a sensitivity analysis suggested that interspecific variation in Ci explained at most 7% of variation in PNUE. Photosynthesis and PNUE were also rather insensitive to large interspecific differences in RuBP-limited rate of electron transport per unit N (Jmax / N), because photosynthesis was primarily limited by the maximum rate of carboxylation (Vcmax). PNUE was most sensitive to changes in N allocation to Rubisco and Vcmax / Rubisco.
Simultaneous analysis of amino and organic acids in extracts of plant leaves as tert-butyldimethylsilyl derivatives by capillary gas chromatography
Publisher: Elsevier BV
Date: 06-1998
Abstract: The simultaneous determination of amino and organic acids in plant tissue extracts using capillary gas chromatography is described. Plant leaves were extracted in 5% (w/v) perchloric acid and neutralized extracts were purified using C18 cartridges. The amino and organic acids in purified extracts were then converted to tert-butyldimethylsilyl (TBDMS) derivatives prior to separation and detection by capillary gas chromatography (GC) with flame ionization detection. Conditions required for optimal derivatization were investigated. Amino and organic acids were readily converted to their TBDMS derivatives using N-methyl-N-tert-butyldimethylsilyltrifluoroacetamide in dimethylformamide solvent 1:6 (v/v) with an average recovery of 90% and a reproducibility of about 5%. The characteristic [M-57] and [M-159] fragment ion of the TBDMS derivatives was confirmed using GC-MS. The proposed method was demonstrated by the determination of amino and organic acids in extracts of Acacia and Eucalyptus leaves, where detection limits were 1-20 ng.
Plant and soil P determine functional attributes of subalpine Australian plants
Publisher: Informa UK Limited
Date: 2018
Separation of amino acids in plant tissue extracts by capillary zone electrophoresis with indirect UV detection using aromatic carboxylates as background electrolytes
Publisher: Springer Science and Business Media LLC
Date: 02-2000
DOI: 10.1007/BF02490562
Global transpiration data from sap flow measurements: the SAPFLUXNET database
Publisher: Copernicus GmbH
Date: 14-06-2021
DOI: 10.5194/ESSD-13-2607-2021
Abstract: Abstract. Plant transpiration links physiological responses of vegetation to water supply and demand with hydrological, energy, and carbon budgets at the land–atmosphere interface. However, despite being the main land evaporative flux at the global scale, transpiration and its response to environmental drivers are currently not well constrained by observations. Here we introduce the first global compilation of whole-plant transpiration data from sap flow measurements (SAPFLUXNET, sapfluxnet.creaf.cat/, last access: 8 June 2021). We harmonized and quality-controlled in idual datasets supplied by contributors worldwide in a semi-automatic data workflow implemented in the R programming language. Datasets include sub-daily time series of sap flow and hydrometeorological drivers for one or more growing seasons, as well as metadata on the stand characteristics, plant attributes, and technical details of the measurements. SAPFLUXNET contains 202 globally distributed datasets with sap flow time series for 2714 plants, mostly trees, of 174 species. SAPFLUXNET has a broad bioclimatic coverage, with woodland/shrubland and temperate forest biomes especially well represented (80 % of the datasets). The measurements cover a wide variety of stand structural characteristics and plant sizes. The datasets encompass the period between 1995 and 2018, with 50 % of the datasets being at least 3 years long. Accompanying radiation and vapour pressure deficit data are available for most of the datasets, while on-site soil water content is available for 56 % of the datasets. Many datasets contain data for species that make up 90 % or more of the total stand basal area, allowing the estimation of stand transpiration in erse ecological settings. SAPFLUXNET adds to existing plant trait datasets, ecosystem flux networks, and remote sensing products to help increase our understanding of plant water use, plant responses to drought, and ecohydrological processes. SAPFLUXNET version 0.1.5 is freely available from the Zenodo repository (0.5281/zenodo.3971689 Poyatos et al., 2020a). The “sapfluxnetr” R package – designed to access, visualize, and process SAPFLUXNET data – is available from CRAN.
Short-term forecasting of water yield from forested catchments after bushfire: A case study from Southeast Australia
Publisher: MDPI AG
Date: 09-02-2015
DOI: 10.3390/W7020599
Chapter 14 Smoke from Wildfires and Prescribed Burning in Australia: Effects on Human Health and Ecosystems
Publisher: Elsevier
Date: 2008
A rapid and simple method for processing wood to crude cellulose for analysis of stable carbon isotopes in tree rings
Publisher: Oxford University Press (OUP)
Date: 10-1999
DOI: 10.1093/TREEPHYS/19.12.831
Abstract: For analysis of carbon isotope discrimination in wood, cellulose or holocellulose is often preferred to whole tissue because of the variability in isotopic composition of different wood components and the relative immobility of cellulose. Most currently used methods for the preparation of wood components for stable isotope analysis (e.g., the Jayme-Wise method) produce a residue of holocellulose. The Jayme-Wise method was initially developed to extract holocellulose from small (~1 g) s les of wood, and, despite subsequent modifications, the method requires specialized glassware, considerable time and entails the risk of s le loss. For carbon isotope analysis, we adapted an acid-catalyzed solvolytic method for preparing crude cellulose by treating wood meal with acidified di-glycol methyl ether (diglyme). The one-step process requires no special glassware, is complete within 24 hours and enables over 100 s les to be processed in a day. This method gives similar delta(13)C values to the Jayme-Wise method for wood of Eucalyptus globulus Labill., Pinus radiata D. Don and Pinus pinaster Ait. The relationship between delta(13)C of wood and crude cellulose is as strong as that observed between wood and alpha-cellulose and stronger than that observed between wood and holocellulose in other species. These relationships suggest that variation in delta(13)C of wood may result from hemicellulose and that analysis of stable carbon isotopes in crude cellulose is preferable. If the consistent -0.3 bias in the value of delta(13)C of cellulose resulting from residual lignin is corrected for, then the relationship between delta(13)C of wood and crude cellulose may be used to predict delta(13)C of cellulose from a small sub-s le. The method is well suited to species with low concentrations of extractives, but further testing is needed to assess its general applicability.
Connecting ecological science and management in forests for scientists, managers and pocket scientists
Publisher: Elsevier BV
Date: 02-2018
Loss of patch-scale heterogeneity on primary productivity and rainfall-use efficiency in Western Australia
Publisher: Elsevier BV
Date: 2003
Overestimated gains in water‐use efficiency by global forests
Publisher: Wiley
Date: 16-05-2022
DOI: 10.1111/GCB.16221
Abstract: Increases in terrestrial water‐use efficiency (WUE) have been reported in many studies, pointing to potential changes in physiological forcing of global carbon and hydrological cycles. However, gains in WUE are of uncertain magnitude over longer (i.e. years) periods of time largely owing to difficulties in accounting for structural and physiological acclimation. 13 C signatures (i.e. δ 13 C) of plant organic matter have long been used to estimate WUE at temporal scales ranging from days to centuries. Mesophyll conductance is a key uncertainty in estimated WUE owing to its influence on diffusion of CO 2 to sites of carboxylation. Here we apply new knowledge of mesophyll conductance to 464 δ 13 C chronologies in tree‐rings of 143 species spanning global biomes. Adjusted for mesophyll conductance, gains in WUE during the 20th century (0.15 ppm year −1 ) were considerably smaller than those estimated from conventional modelling (0.26 ppm year −1 ). Across the globe, mean sensitivity of WUE to atmospheric CO 2 was 0.15 ppm ppm −1 . Ratios of internal‐to‐atmospheric CO 2 (on a mole fraction basis c i / c a ) in leaves were mostly constant over time but differed among biomes and plant taxa—highlighting the significance of both plant structure and physiology. Together with synchronized responses in stomatal and mesophyll conductance, our results suggest that ratios of chloroplastic‐to‐atmospheric CO 2 ( c c / c a ) are constrained over time. We conclude that forest WUE may have not increased as much as previously suggested and that projections of future climate forcing via CO 2 fertilization may need to be adjusted accordingly.
Contrasts between Eucalyptus subgenera
Publisher: Wiley
Date: 10-2000
Indirect photometric detection of aliphatic acids separated by ion-exclusion chromatography using aromatic acidic eluents
Publisher: Elsevier BV
Date: 08-1998
ROLE OF ACACIA SPP IN NUTRIENT BALANCE AND CYCLING IN REGENERATING EUCALYPTUS-REGNANS F-MUELL FORESTS .2. FIELD STUDIES OF ACETYLENE-REDUCTION
Publisher: CSIRO Publishing
Date: 1984
DOI: 10.1071/BT9840217
Abstract: Rates of C2H2 reduction by nodules of Acacia dealbata growing in 2-year-old Eucalyptus regnans regeneration were determined at monthly intervals for 1 year under field conditions. Intact soil cores containing roots and nodules showed maximum values of 7.1 μmol h-1 g-1 fresh weight of nodules with a mean value of 4.4 μmol h-1 g-1 fresh weight. Nodule mass was clearly related to climatic conditions, being greatest when both temperature and moisture levels were favourable, and was probably depressed during the s ling period by the prevailing severe drought. From the measured rates of C2H2 reduction, estimated N2 fixation was 12-32 kg ha-1 year-1. Rates of N2 fixation as high as this confirm the role of acacias as fast-growing pioneer species important in maintaining the nitrogen pool of the forest ecosystem.
The knowns, known unknowns and unknowns of sequestration of soil organic carbon
Publisher: Elsevier BV
Date: 2013
Estimation of leaf area index in eucalypt forest using digital photography
Publisher: Elsevier BV
Date: 04-2007
Photosynthetic benefits of ultraviolet-A to Pimelea ligustrina, a woody shrub of sub-alpine Australia
Publisher: Springer Science and Business Media LLC
Date: 27-03-2013
DOI: 10.1007/S00442-013-2640-9
Abstract: The definition of photosynthetically active radiation (Q) as the visible waveband (λ 400-700 nm) is a core assumption of much of modern plant biology and global models of carbon and water fluxes. On the other hand, much research has focused on potential mutation and damage to leaves caused by ultraviolet (UV) radiation (280-400 nm), and anatomical and physiological adaptations that help avoid such damage. Even so, plant responses to UV-A are poorly described and, until now, photosynthetic utilization of UV-A has not been elucidated under full light conditions in the field. We found that the UV-A content of sunlight increased photosynthetic rates in situ by 12% in Pimelea ligustrina Labill., a common and indigenous woody shrub of alpine ecosystems of the Southern Hemisphere. Compared to companion shrubs, UV-A-induced photosynthesis in P. ligustrina resulted from reduced physical and chemical capacities to screen UV-A at the leaf surface (illustrated by a lack of cuticle and reduced phenol index) and the resulting ability of UV-A to excite chlorophyll (Chl) a directly, and via energy provided by the carotenoid lutein. A screening of 55 additional sub-alpine species showed that 47% of the plant taxa also display Chl a fluorescence under UV-A. If Chl a fluorescence indicates potential for photosynthetic gain, continued exclusion of UV-A from definitions of Q in this ecosystem could result in underestimates of measured and modeled rates of photosynthesis and miscalculation of potential for carbon sequestration. We suggest that carbon gain for alpine environs across the globe could be similarly underestimated given that UV-A radiation increases with altitude and that the frequently dominant herb and grass life-forms often transmit UV-A through the epidermis.
Growth and nutrient content of perennial grasslands following burning in semi-arid, sub-tropical Australia
Publisher: Springer Science and Business Media LLC
Date: 2003
Tracking the origins of the Kok effect, 70 years after its discovery The 18 th New Phytologist Workshop 'The Kok effect: beyond the artefact, emerging leaf mechanisms ( KOALA)' Angers, France, July 2016
Publisher: Wiley
Date: 20-03-2017
DOI: 10.1111/NPH.14527
Attack on all fronts: functional relationships between aerial and root parasitic plants and their woody hosts and consequences for ecosystems
Publisher: Oxford University Press (OUP)
Date: 2011
Abstract: This review discusses how understanding of functional relationships between parasitic plants and their woody hosts have benefited from a range of approaches to their study. Gross comparisons of nutrient content between infected and uninfected hosts, or parts of hosts, have been widely used to infer basic differences or similarities between hosts and parasites. Coupling of nutrient information with additional evidence of key processes such as transpiration, respiration and photosynthesis has helped elucidate host-parasite relationships and, in some cases, the anatomical nature of their connection and even the physiology of plants in general. For ex le, detailed analysis of xylem sap from hosts and parasites has increased our understanding of the spatial and temporal movement of solutes within plants. Tracer experiments using natural abundance or enriched application of stable isotopes ((15)N, (13)C, (18)O) have helped us to understand the extent and form of heterotrophy, including the effect of the parasite on growth and functioning of the host (and its converse) as well as environmental effects on the parasite. Nutritional studies of woody hosts and parasites have provided clues to the distribution of parasitic plants and their roles in ecosystems. This review also provides assessment of several corollaries to the host-parasite association.
Sensitivity of plants to changing atmospheric CO 2 concentration: from the geological past to the next century
Publisher: Wiley
Date: 25-01-2013
DOI: 10.1111/NPH.12104
Abstract: The rate of CO 2 assimilation by plants is directly influenced by the concentration of CO 2 in the atmosphere, c a . As an environmental variable, c a also has a unique global and historic significance. Although relatively stable and uniform in the short term, global c a has varied substantially on the timescale of thousands to millions of years, and currently is increasing at seemingly an unprecedented rate. This may exert profound impacts on both climate and plant function. Here we utilise extensive datasets and models to develop an integrated, multi‐scale assessment of the impact of changing c a on plant carbon dioxide uptake and water use. We find that, overall, the sensitivity of plants to rising or falling c a is qualitatively similar across all scales considered. It is characterised by an adaptive feedback response that tends to maintain 1 − c i / c a , the relative gradient for CO 2 diffusion into the leaf, relatively constant. This is achieved through predictable adjustments to stomatal anatomy and chloroplast biochemistry. Importantly, the long‐term response to changing c a can be described by simple equations rooted in the formulation of more commonly studied short‐term responses. Contents Summary 1077 I. Introduction 1078 II. Atmospheric CO 2 concentrations through time 1079 III. Plant sensitivity to CO 2 at geological timescales 1080 IV. Plant sensitivity to CO 2 over the last 200 yr 1081 V. Increased water‐use efficiency? 1084 VI. Simple formulation of stomatal conductance in land surface models for simulating long‐term CO 2 response 1087 VII. Conclusions 1088 Acknowledgements 1089 References 1089
Separation of rubisco in extracts of plant leaves by capillary electrophoresis with sieving polymers
Publisher: Informa UK Limited
Date: 2000
Noise-induced schooling of fish
Publisher: Springer Science and Business Media LLC
Date: 02-03-2020
The design of redox active thiol peroxidase mimics: Dihydrolipoic acid recognition correlates with cytotoxicity and prooxidant action
Publisher: Elsevier BV
Date: 03-2016
Targeted metabolite profiling provides a functional link among eucalypt taxonomy, physiology and evolution
Publisher: Elsevier BV
Date: 02-2006
DOI: 10.1016/J.PHYTOCHEM.2005.11.027
Abstract: Adaptation to aridity is considered a major factor in the evolution of the genus Eucalyptus. For the first time, targeted metabolite profiling has uncovered a quantitative yet discrete phytochemical link with eucalypt taxonomy. The distribution of cyclitols among Eucalyptus species, and a range of other Australian tree genera, support their proposed functions in plant tissues and provide putative links with the acclimation of trees to arid environments.
NUTRIENT CYCLING IN FORESTS
Publisher: Wiley
Date: 08-1993
DOI: 10.1111/J.1469-8137.1993.TB03847.X
Abstract: Studies of nutrient cycling in forests span more than 100 yr. In earlier years, most attention was given to the measurement of the pools of nutrients in plants and soil and of the return of nutrients from plant to soil in litterfall. The past 20 yr or so have seen a major concentration on the processes of nutrient cycling, with particular emphasis on those processes by which the supply of nutrients to the growing forest is sustained. In the more highly productive forests, up to 10 tonnes of litter of low nutritional quality is deposited annually on the forest floor. The decomposition of this litter, the mineralization of the nutrients it holds, and the uptake of nutrients by tree roots in the carbon‐rich environment which results are the themes of this review. Studies of decomposition of litter in forests have been dominated by the role of nitrogen as a limiting factor, a domination which reflects the preponderance of studies of temperate forests in the Northern Hemisphere. For many forests of the world growing on soils of considerable age, it seems more probable that growth and nutrient cycling are limited by phosphorus (or some other element). There is increasing evidence for a number of forests that phosphorus is immobilized in the first stages of decomposition to a significantly greater extent than is nitrogen. Advances in research will depend, as with studies of soil organic matter, in denning and developing analytical techniques for studying biologically active forms of potentially limiting nutrients, rather than total elemental concentrations. The availability of phosphorus in forests is sustained by phosphorus cycling. More than 50% of the total phosphorus in the surface soils is in organic forms and much of the more labile phosphorus is in the form of diesters. Phosphorus availability is determined by competition between biological and geochemical sinks, and it is clear that the sinks in the rhizosphere (plant roots, microorganisms, soil mineral and organic components) are extensively modified by active processes (e.g. production of exudates, nutrient storage in a variety of organic or polymeric forms and nutrient transport away from sites of uptake). There is abundant evidence that roots of many species exude compounds which have the ability to solubilize sources of phosphorus of otherwise low availability. The significance of root exudates (for ex le, phosphatases, organic acids) in the functioning of perennial ecosystems has yet to be quantified and there are conflicting reports as to the effects of simple organic acids on phosphorus availability. The distribution of phosphorus sinks and their relative competitiveness and their modification are topics of fundamental importance for future research. In contrast to the mineralization of phosphorus, our knowledge of transformations and availability of nitrogen in forest soils is well‐developed. Net nitrogen mineralization rates approximate rates of nitrogen return in litterfall but the contribution of nitrification is variable. Nitrification is not inhibited by the low pH of many forest soils and there is increasing evidence of nitrate immobilization by microorganisms and of increased ersity and better competitiveness for NH 4 + of nitrifying microorganisms than has previously been accepted. Variability in rates of nitrification is often interpreted as being due to allelopathy. Hypotheses invoking allelopathy are more or less untestable, and it seems likely that new techniques using 15 N in situ will lead to a more fundamental understanding of nitrogen transformations in forest soils. Recent studies in coniferous forest soils have highlighted the short ( 1 d) turnover time of NH 4 + . Finally, it seems that forest soils are resistant to major changes in patterns of nitrogen mineralization (and certainly, because of the large number of sinks, in patterns of phosphorus mineralization) following disturbance by natural events such as wind‐throw and fire, and by man‐made events such as logging and fertilizing. The long‐term disturbance by acid rain is a more complex matter since forest ecosystems are not adequate buffers for nitrate. Contents Summary 561 I. Introduction 562 II. Linking nutrient cycling to nutrient availability – Setting the themes 563 III. The nature of soil organic matter 566 IV. Tree roots and the availability of nutrients 566 V. The decomposition of forest litter 569 VI. Mineralization of organically‐bound nutrients 571 Acknowledgements 576 References 576
Nutrient balance in forests of northern Tasmania. 1. Atmospheric inputs and within-stand cycles
Publisher: Elsevier BV
Date: 11-1991
Soil Security: Solving the Global Soil Crisis
Publisher: Wiley
Date: 28-10-2013
Pyrogenic carbon: the influence of particle size and chemical composition on soil carbon release
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/WF13189
Abstract: In many countries, prescribed or planned burning is increasingly used as a management strategy to reduce the risk and negative effects of wildfires. As a by-product of this practice, ash, charcoal and partially charred material (referred to here as pyrogenic carbon, PC) is created. The amount and type of PC produced and fate of this form of carbon is uncertain. PC is often assumed to be resistant to chemical and microbial degradation and therefore potentially persistent in soils for hundreds or thousands of years. As a result, PC has been proposed as a sink for carbon and promoted for its storage potential in soil. We hypothesised that the differing components of PC would interact differently with soil processes and have varying potential for carbon storage. We analysed the chemical composition of PC produced by prescribed fire in a eucalypt forest and measured its effect on soil respiration. A laboratory incubation experiment showed that when PC of differing size fractions was added to soil, only the smallest size fraction ( mm ash) increased rates of soil respiration, whereas larger fractions (charcoal) had little effect. The carbon contained in charcoal was resistant to microbial degradation and had little effect on microbial processes such as respiration. In general, fires of greater intensity will produce greater proportional amounts of smaller size particles and will likely result in faster rates of respiration than fires of lesser intensity. Therefore, lower intensity fires may ultimately have a greater capacity for soil carbon sequestration than those of higher intensity.
Disproportionate CH4 Sink Strength from an Endemic, Sub-Alpine Australian Soil Microbial Community
Publisher: MDPI AG
Date: 15-03-2021
DOI: 10.3390/MICROORGANISMS9030606
Abstract: Soil-to-atmosphere methane (CH4) fluxes are dependent on opposing microbial processes of production and consumption. Here we use a soil–vegetation gradient in an Australian sub-alpine ecosystem to examine links between composition of soil microbial communities, and the fluxes of greenhouse gases they regulate. For each soil/vegetation type (forest, grassland, and bog), we measured carbon dioxide (CO2) and CH4 fluxes and their production/consumption at 5 cm intervals to a depth of 30 cm. All soils were sources of CO2, ranging from 49 to 93 mg CO2 m−2 h−1. Forest soils were strong net sinks for CH4, at rates of up to −413 µg CH4 m−2 h−1. Grassland soils varied, with some soils acting as sources and some as sinks, but overall averaged −97 µg CH4 m−2 h−1. Bog soils were net sources of CH4 (+340 µg CH4 m−2 h−1). Methanotrophs were dominated by USCα in forest and grassland soils, and Candidatus Methylomirabilis in the bog soils. Methylocystis were also detected at relatively low abundance in all soils. Our study suggests that there is a disproportionately large contribution of these ecosystems to the global soil CH4 sink, which highlights our dependence on soil ecosystem services in remote locations driven by unique populations of soil microbes. It is paramount to explore and understand these remote, hard-to-reach ecosystems to better understand biogeochemical cycles that underpin global sustainability.
Interactive effects of elevated CO 2 and drought on nocturnal water fluxes in Eucalyptus saligna
Publisher: Oxford University Press (OUP)
Date: 25-05-2011
Abstract: Nocturnal water flux has been observed in trees under a variety of environmental conditions and can be a significant contributor to diel canopy water flux. Elevated atmospheric CO(2) (elevated [CO(2)]) can have an important effect on day-time plant water fluxes, but it is not known whether it also affects nocturnal water fluxes. We examined the effects of elevated [CO(2)] on nocturnal water flux of field-grown Eucalyptus saligna trees using sap flux through the tree stem expressed on a sapwood area (J(s)) and leaf area (E(t)) basis. After 19 months growth under well-watered conditions, drought was imposed by withholding water for 5 months in the summer, ending with a rain event that restored soil moisture. Reductions in J(s) and E(t) were observed during the severe drought period in the dry treatment under elevated [CO(2)], but not during moderate- and post-drought periods. Elevated [CO(2)] affected night-time sap flux density which included the stem recharge period, called 'total night flux' (19:00 to 05:00, J(s,r)), but not during the post-recharge period, which primarily consisted of canopy transpiration (23:00 to 05:00, J(s,c)). Elevated [CO(2)] wet (EW) trees exhibited higher J(s,r) than ambient [CO(2)] wet trees (AW) indicating greater water flux in elevated [CO(2)] under well-watered conditions. However, under drought conditions, elevated [CO(2)] dry (ED) trees exhibited significantly lower J(s,r) than ambient [CO(2)] dry trees (AD), indicating less water flux during stem recharge under elevated [CO(2)]. J(s,c) did not differ between ambient and elevated [CO(2)]. Vapour pressure deficit (D) was clearly the major influence on night-time sap flux. D was positively correlated with J(s,r) and had its greatest impact on J(s,r) at high D in ambient [CO(2)]. Our results suggest that elevated [CO(2)] may reduce night-time water flux in E. saligna when soil water content is low and D is high. While elevated [CO(2)] affected J(s,r), it did not affect day-time water flux in wet soil, suggesting that the responses of J(s,r) to environmental factors cannot be directly inferred from day-time patterns. Changes in J(s,r) are likely to influence pre-dawn leaf water potential, and plant responses to water stress. Nocturnal fluxes are clearly important for predicting effects of climate change on forest physiology and hydrology.
Three physiological parameters capture variation in leaf respiration of Eucalyptus grandis , as elicited by short‐term changes in ambient temperature, and differing nitrogen supply
Publisher: Wiley
Date: 26-04-2018
DOI: 10.1111/PCE.13162
Abstract: We used instantaneous temperature responses of CO
Grand Challenges: Forests and Global Change
Publisher: Frontiers Media SA
Date: 10-07-2018
Different models provide equivalent predictive power for cross-biome response of leaf respiration to temperature
Publisher: Proceedings of the National Academy of Sciences
Date: 04-10-2016
Quantifying uncertainty from large-scale model predictions of forest carbon dynamics
Publisher: Wiley
Date: 04-07-2006
Effects of elevated atmospheric [CO2 ] on instantaneous transpiration efficiency at leaf and canopy scales in Eucalyptus saligna
Publisher: Wiley
Date: 19-09-2012
Salt tolerance in Eucalyptus spp.: Identity and response of putative osmolytes
Publisher: Wiley
Date: 16-03-2005
Anatomical and physiological regulation of post-fire carbon and water exchange in canopies of two resprouting Eucalyptus species
Publisher: Springer Science and Business Media LLC
Date: 10-08-2014
DOI: 10.1007/S00442-014-3032-5
Abstract: The great majority of Eucalyptus spp. are facultative resprouters, and they dominate the eucalypt forests of Australia. Despite this numeric and geographic dominance, there is a general lack of knowledge of their capacity for carbon capture and water loss during canopy reinstation. After a crown-removing fire, we measured leaf-level determinants of carbon and water flux in resprouting canopies of Eucalyptus es and E. radiata over the 3 years that followed. Leaf anatomy and physiology changed markedly during canopy reinstation, and leaves produced in the second year (2010) were distinct from those produced later. Leaves produced in 2010 were thicker (all measures of leaf anatomy), yet more porous (increased intercellular airspace), causing specific leaf area also to be greater. Indicators of heterotrophic activity, leaf respiration rate and light compensation point, were twofold greater in 2010, whereas all measures of photosynthetic capacity were greatest in leaves produced in 2011 and 2012. Whilst stomatal density, vein density and leaf hydraulic conductance all progressively decreased with time, neither leaf water status nor carbon isotope discrimination were affected. We conclude that canopy reinstation is primarily limited by pre-fire carbon stores, rather than by post-fire edaphic conditions (e.g., water availability), and thus argue that capacity for recovery is directly linked to pre-fire forest health.
Phosphorus sources and availability modify growth and distribution of root clusters and nodules of native Australian legumes
Publisher: Wiley
Date: 27-06-2002
Simultaneous determination by capillary gas chromatography of organic acids, sugars, and sugar alcohols in plant tissue extracts as their trimethylsilyl derivatives
Publisher: Elsevier BV
Date: 1999
Abstract: A capillary gas chromatographic (GC) method for the simultaneous determination of organic acids, sugars, and sugar alcohols extracted from plant tissues is described. Plant leaves were extracted in 5% (w/v) perchloric acid and neutralized extracts were purified using C18 cartridges. Organic acids, sugars, and sugar alcohols in purified extracts were converted to their trimethylsilyl (TMS)/TMS-oxime derivatives prior to separation and detection by capillary GC with flame ionization detection (FID). Derivatization procedures were investigated in detail and the compounds of interest were readily converted to their TMS/TMS-oxime derivatives using hexamethyldisiazane reagent in acetonitrile solvent (1:6 v/v) at 100 degreesC for 60 min. The derivatives were sufficiently volatile and stable. The FID response to derivatized compounds was generally linear in the concentration range 30-300 microg ml-1, with detection limits in the order of 3-76 ng. The proposed method was demonstrated for the determination of organic acids, sugars, and sugar alcohols in leaf extracts of two native Australian plants.
Photosynthesis-Rubisco relationships in foliage of Pinus sylvestris in response to nitrogen supply and the proposed role of Rubisco and amino acids as nitrogen stores
Publisher: Springer Science and Business Media LLC
Date: 14-02-2003
Productivity of an Australian mountain grassland is limited by temperature and dryness despite long growing seasons
Publisher: Elsevier BV
Date: 06-2018
Nitrogen fixation and metabolism by groundwater-dependent perennial plants in a hyperarid desert
Publisher: Springer Science and Business Media LLC
Date: 28-07-2004
DOI: 10.1007/S00442-004-1655-7
Abstract: The Central Asian Taklamakan desert is characterized by a hyperarid climate with less than 50 mm annual precipitation but a permanent shallow groundwater table. The perched groundwater (2-16 m) could present a reliable and constant source of nitrogen throughout the growing season and help overcome temporal nitrogen limitations that are common in arid environments. We investigated the importance of groundwater and nitrogen fixation in the nitrogen metabolism of desert plants by assessing the possible forms and availability of soil N and atmospheric N and the seasonal variation in concentration as well as isotopic composition of plant N. Water availability was experimentally modified in the desert foreland through simulated flooding to estimate the contribution of surface water and temporally increased soil moisture for nutrient uptake and plant-water relations. The natural vegetation of the Taklamakan desert is dominated by plants with high foliar nitrogen concentrations (2-3% DM) and leaf nitrate reductase activity (NRA) (0.2-1 micromol NO2- g(-1) FW h(-1)). There is little evidence that nitrogen is a limiting resource as all perennial plants exhibited fast rates of growth. The extremely dry soil conditions preclude all but minor contributions of soil N to total plant N so that groundwater is suggested as the dominant source of N with concentrations of 100 microM NO3-. Flood irrigation had little beneficial effect on nitrogen metabolism and growth, further confirming the dependence on groundwater. Nitrogen fixation was determined by the 15N natural abundance method and was a significant component of the N-requirement of the legume Alhagi, the average contribution of biologically fixed nitrogen in Alhagi was 54.8%. But nitrogen fixing plants had little ecological advantage owing to the more or less constant supply of N available from groundwater. From our data we conclude that the perennial species investigated have adapted to the environmental conditions through development of root systems that access groundwater to satisfy demands for both water and nutrients. This is an ecologically favourable strategy since only groundwater is a predictable and stable resource.
Is photosynthesis related to concentrations of nitrogen and Rubisco in leaves of Australian native plants?
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/PP98162
Abstract: The relationships among light-saturated photosynthesis and concentrations of nitrogen and ribulose-1,5- bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) in Australian native plants are poorly known, primarily due to the difficulty of extracting and analysing Rubisco from such species. Rubisco may be rapidly quantified in crude extracts of plant tissue by capillary electrophoresis (CE) however, the presence of phenolic compounds in many Australian native plants limits the use of these methods. The addition of insoluble polyvinylpolypyrrolidone (PVPP) during leaf extractions effectively removed phenols permitting quantitation of Rubisco. Relationships among maximum rates of photosynthesis and concentrations of nitrogen and Rubisco were then investigated in ten species native to Australia. Total nitrogen and the major pools of N in foliage varied greatly between species. Equally, within species N-partitioning was highly plastic, as affected by different concentrations and forms of N applied in sand culture (0.5 or 8 mM, nitrate or ammonium). In Hakea prostrata, for ex le, the proportion of total N present as soluble proteins varied between 43 and 71%, while the proportion of total N present as Rubisco N ranged between 9.4 and 30.0%, and the contribution of Rubisco to soluble proteins varied between 21 and 42%. The measured concentration of Rubisco varied between 40% and 600% of that estimated from enzyme kinetics and measured rates of photosynthesis. Generally there was a large ‘excess’ of Rubisco, and in only two cases was the measured concentration of Rubisco significantly less than predicted. Total N, soluble protein and Rubisco concentrations were poorly related to maximum rates of photosynthesis, while the relationship between photosynthesis and Rubisco was worse than that with N, primarily due to the plants’ variable over-investment in Rubisco.
Stable osmotica in Eucalyptus spathulata — responses to salt and water deficit stress
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/FP05027
Abstract: Salt and water deficit stress elicited contrasting responses in seedlings of Eucalyptus spathulata (Hook.). Under salt stress, seedlings reduced osmotic potential by accumulating large quantities of inorganic ions in leaf tissues. Sodium concentrations reached 350 mm on a leaf water basis and total cellular osmolality reached ∼2000 mm. Under water deficit stress, maximum sodium concentrations were around 50 mm in leaf water and seedlings reduced osmotic potential through increasing concentrations of a range of constitutive solutes up to a total cellular osmolality of ∼1200 mm. We postulate that measured concentrations of the cyclic polyol, quercitol, of up to 200 mm leaf water, are the likely means of balancing accumulation of inorganic ions. Under the common assumption of localisation of inorganic ions to the vacuole and organic balancing solutes to the cytoplasm, the concentrations of cyclitol, and other carbohydrates were more than sufficient to balance osmotic potential across the tonoplast membrane. Results confirm other recent studies that suggest a range of putative roles for cyclitols in tissues and these are discussed in the larger context of plant responses to salt and water deficit stress.
Contrasting physiological responses of six Eucalyptus species to water deficit
Publisher: Oxford University Press (OUP)
Date: 19-09-2007
DOI: 10.1093/AOB/MCM234
Photosynthetic capacity is negatively correlated with the concentration of leaf phenolic compounds across a range of different species
Publisher: Oxford University Press (OUP)
Date: 2012
Role of soil drying in nitrogen mineralization and microbial community function in semi-arid grasslands of north-west Australia
Publisher: Elsevier BV
Date: 07-2007
Legumes are different: Leaf nitrogen, photosynthesis, and water use efficiency
Publisher: Proceedings of the National Academy of Sciences
Date: 30-03-2016
Abstract: Leaf traits are used to drive models of global carbon fluxes and understand plant evolution. Many syntheses have highlighted relationships between plant leaf nitrogen and photosynthesis as evidence of a strong evolutionary drive to “intercept light and capture CO 2 .” Different from previous studies, we compiled a global dataset constrained to sites and studies where nitrogen-fixing plants (N 2 FP) and nonfixing species [other plants (OP)] could be directly compared. We show that photosynthesis is not related to leaf nitrogen for N 2 FP, irrespective of climate or growth form. N 2 FP have clear advantages in water use efficiency over OP. These findings contribute to a more complete explanation of global distributions of N 2 FP and can help improve models of global carbon and nitrogen cycles.
Production of pyrogenic carbon during planned fires in forests of East Gippsland, Victoria
Publisher: Elsevier BV
Date: 08-2016
Phosphorus availability and the growth, mineral composition and nutritive value of ephemeral forbs and associated perennials from the Pilbara, Western Australia
Publisher: CSIRO Publishing
Date: 1999
DOI: 10.1071/EA98133
Abstract: The effect of phosphorus fertiliser on plant growth and the quality of leaf tissues for herbivores were investigated in field and glasshouse experiments. In the field, the relative abundance of ephemeral forb species was strongly affected by the seasonal variation in rainfall. In winter, C3 ephemeral forbs were abundant, whilst in summer, C4 ephemeral grasses dominated. During the dry months, growth of all species was poor. After rain, grasses to which phosphorus had been added increased growth significantly. Nutrient concentrations in ephemeral forbs were significantly greater than those in perennial or ephemeral grasses. Phosphorus concentrations were low in perennial and ephemeral grasses and declined during the dry months. The nitrogen : phosphorus ratio of ephemeral forbs and perennial shrubs suggested a deficiency of phosphorus, whilst that of ephemeral grasses suggested a deficiency of nitrogen. A glasshouse experiment investigated the response to phosphorus of 2 common and abundant ephemeral forbs – Ptilotus macrocephalus which responded to all treatments up to a maximum rate of 200 kg P/ha, and Ptilotus exaltatus which increased in growth up to a maximum rate of 100 kg P/ha. In both species, the concentration of phosphorus increased significantly with phosphorus supply, while that of nitrogen did not vary significantly among phosphorus treatments. Generalisations about growth and nitrogen and phosphorus nutrition of native species based on more mesic plant communities are not readily applied in the arid and chronically phosphorus-poor Pilbara environment. Instead, plant life-cycle and life form play major roles in determining nitrogen or phosphorus limitations and plant responses to added nutrients.
What determines interspecific variation in relative growth rate of Eucalyptus seedlings?
Publisher: Springer Science and Business Media LLC
Date: 23-04-2005
DOI: 10.1007/S00442-005-0092-6
Abstract: The present study examines relative growth rate (RGR) and its determinants in seedlings of nine Eucalyptus species. Species were selected from mesic (1,800 mm a(-1) rainfall) through to semi-arid habitats (300 mm a(-1)), and thus, notionally vary in "stress" tolerance. Seedlings were grown in a glasshouse during early summer and received between 33 mol and 41 mol PAR m(-2) day(-1) . The mean RGR varied among species-from a minimum of 66 mg g(-1) day(-1) in E. hypochlamydea to a maximum of 106 mg g(-1) day(-1) in E. delegatensis. RGR was positively related to rainfall at the sites of seed collection. Neither specific leaf area (SLA) nor net assimilation rate was related to rainfall or RGR. While the absence of relationships with SLA and net assimilation rate contrasts with other studies and species, we cannot rule out the effects of s le size (n=9 species) and modest ranges in SLA and RGR. The ratio of leaf mass to total mass (LMR) varied from 0.49+/-0.07 g g(-1) in E. socialis to 0.74+/-0.04 g g(-1) in E. delegatensis and was strongly positively related with rainfall (r2=0.77). Interspecific differences in RGR were strongly related to LMR (positive relationship, r2=0.50) and the rate of dry matter production per mol of leaf nitrogen (positive relationship, r2=0.64). Hence, the slow RGR of low-rainfall species was functionally related to a lower growth rate per mol of leaf nitrogen than high-rainfall species. Furthermore, slow RGR of low-rainfall species was related to greater allocation to roots at the expense of leaves. Increasing allocation to roots versus leaves is likely an adaptation to soil and atmospheric water deficits, but one that comes at the expense of a slow RGR.
Relationships among microclimate, edaphic conditions, vegetation distribution and soil nitrogen dynamics on the Bogong High Plains, Australia
Publisher: Wiley
Date: 28-03-2011
Is the bark of shining gum (Eucalyptus nitens) a sun or a shade leaf?
Publisher: Springer Science and Business Media LLC
Date: 09-02-2005
Validation of canopy transpiration in a mixed-species foothill eucalypt forest using a soil-plant-atmosphere model
Publisher: Elsevier BV
Date: 06-2013
Estimates of rhizosphere priming effects are affected by soil disturbance
Publisher: Elsevier BV
Date: 03-2200
Steps towards a mechanistic understanding of respiratory temperature responses
Publisher: Wiley
Date: 12-01-2011
DOI: 10.1111/J.1469-8137.2010.03576.X
Abstract: Temperature crucially affects the speed of metabolic processes in poikilotherm organisms, including plants. The instantaneous temperature responses of O 2 ‐reduction and CO 2 ‐release can be approximated by Arrhenius kinetics, even though respiratory gas exchange of plants is the net effect of many constituent biochemical processes. Nonetheless, the classical Arrhenius equation must be modified to account for a dynamic response to measurement temperatures. We show that this dynamic response is readily explained by combining Arrhenius and Michaelis–Menten kinetics, as part of a fresh appraisal of metabolic interpretations of instantaneous temperature responses. In combination with recent experimental findings, we argue that control of mitochondrial electron flow is shared among cytochrome oxidase and alternative oxidase under in vivo conditions, and is continuously coordinated. In this way, upstream carbohydrate metabolism and downstream electron transport appear to be optimized according to the demand of ATP, TCA‐cycle intermediates and anabolic reducing power under differing metabolic states. We provide a link to the ‘Growth and Maintenance Paradigm’ of respiration and argue that respiratory temperature responses can be used as a tool to probe metabolic states of plant tissue, such that we can learn more about the mechanisms that govern longer‐term acclimatization responses of plant metabolism. Contents Summary 659 I. Introduction 660 II. Representation of the instantaneous temperature response of respiration 661 III. Temperature responses of mitochondrial oxygen reduction 662 IV. The temperature response of CO 2 respiration 671 V. Conclusion 673 Acknowledgements 673 References 674
Assessing the impact of large-scale water table modifications on riparian trees: A case study from Australia
Publisher: Wiley
Date: 08-2015
DOI: 10.1002/ECO.1531
PTR-MS analysis of reference and plant-emitted volatile organic compounds
Publisher: Elsevier BV
Date: 05-2007
Simultaneous determination of aliphatic and aromatic acids in plant tissue extracts by ion-exclusion chromatography
Publisher: Elsevier BV
Date: 04-1999
Nutrient balance in forests of northern Tasmania. 2. Alteration of nutrient availability and soil-water chemistry as a result of logging, slash-burning and fertilizer application
Publisher: Elsevier BV
Date: 11-1991
Introduction to the characteristics, impacts and management of forest fire in China
Publisher: Elsevier BV
Date: 11-2015
Radiation modifies the effect of water availability on the carbon isotope composition of beech (Fagus sylvatica)
Publisher: Wiley
Date: 06-2001
Nitrogen mineralization potential in rewetted soils from a semi-arid stream landscape, north-west Australia
Publisher: Elsevier BV
Date: 2009
Mapping spatial and temporal variation in tree water use with an elevation model and gridded temperature data
Publisher: Elsevier BV
Date: 2015
A functional transcriptomics analysis in the relict marsupial Dromiciops gliroides reveals adaptive regulation of protective functions during hibernation
Publisher: Wiley
Date: 11-2018
DOI: 10.1111/MEC.14876
Abstract: The small South American marsupial, Dromiciops gliroides, known as the missing link between the American and the Australian marsupials, is one of the few South American mammals known to hibernate. Expressing both daily torpor and seasonal hibernation, this species may provide crucial information about the mechanisms and the evolutionary origins of marsupial hibernation. Here, we compared torpid and active in iduals, applying high-throughput sequencing technologies (RNA-seq) to profile gene expression in three D. gliroides tissues and determine whether hibernation induces tissue-specific differential gene expression. We found 566 transcripts that were significantly up-regulated during hibernation (369 in brain, 147 in liver and 50 in skeletal muscle) and 339 that were down-regulated (225 in brain, 79 in liver and 35 in muscle). The proteins encoded by these differentially expressed genes orchestrate multiple metabolic changes during hibernation, such as inhibition of angiogenesis, prevention of muscle disuse atrophy, fuel switch from carbohydrate to lipid metabolism, protection against reactive oxygen species and repair of damaged DNA. According to the global enrichment analysis, brain cells seem to differentially regulate a complex array of biological functions (e.g., cold sensitivity, circadian perception, stress response), whereas liver and muscle cells prioritize fuel switch and heat production for rewarming. Interestingly, transcripts of thioredoxin-interacting protein (TXNIP), a potent antioxidant, were significantly over-expressed during torpor in all three tissues. These results suggest that marsupial hibernation is a controlled process where selected metabolic pathways show adaptive modulation that can help to maintain homeostasis and enhance cytoprotection in the hypometabolic state.
Emissions from prescribed fires in temperate forest in south-east Australia: implications for carbon accounting
Publisher: Copernicus GmbH
Date: 15-01-2015
Abstract: Abstract. We estimated emissions of carbon, as equivalent CO2 (CO2e), from planned fires in four sites in a south-eastern Australian forest. Emission estimates were calculated using measurements of fuel load and carbon content of different fuel types, before and after burning, and determination of fuel-specific emission factors. Median estimates of emissions for the four sites ranged from 20 to 139 Mg CO2e ha−1. Variability in estimates was a consequence of different burning efficiencies of each fuel type from the four sites. Higher emissions resulted from more fine fuel (twigs, decomposing matter, near-surface live and leaf litter) or coarse woody debris (CWD 25 mm diameter) being consumed. In order to assess the effect of declining information quantity and the inclusion of coarse woody debris when estimating emissions, Monte Carlo simulations were used to create seven scenarios where input parameters values were replaced by probability density functions. Calculation methods were (1) all measured data were constrained between measured maximum and minimum values for each variable (2) as in (1) except the proportion of carbon within a fuel type was constrained between 0 and 1 (3) as in (2) but losses of mass caused by fire were replaced with burning efficiency factors constrained between 0 and 1 and (4) emissions were calculated using default values in the Australian National Greenhouse Accounts (NGA), National Inventory Report 2011, as appropriate for our sites. Effects of including CWD in calculations were assessed for calculation Method 1, 2 and 3 but not for Method 4 as the NGA does not consider this fuel type. Simulations demonstrate that the probability of estimating true median emissions declines strongly as the amount of information available declines. Including CWD in scenarios increased uncertainty in calculations because CWD is the most variable contributor to fuel load. Inclusion of CWD in scenarios generally increased the amount of carbon lost. We discuss implications of these simulations and how emissions from prescribed burns in temperate Australian forests could be improved.
Harnessing forest ecological sciences in the service of stewardship and sustainability. A perspective from 'down-under'
Publisher: Elsevier BV
Date: 11-2008
Vegetation type determines heterotrophic respiration in subalpine Australian ecosystems
Publisher: Wiley
Date: 02-12-2009
Disentangling respiratory acclimation and adaptation to growth temperature by Eucalyptus
Publisher: Wiley
Date: 15-05-2012
DOI: 10.1111/J.1469-8137.2012.04155.X
Abstract: • Respiratory acclimation to growth temperature differs between species, but underlying mechanisms are poorly understood. In the present study, we tested the hypothesis that respiratory acclimation of CO(2) release is a consequence of growth regulation such that growth rates of young foliage of Eucalyptus spp. are similar at contrasting growth temperatures. Further, we tested whether such a response is affected by adaptation of Eucalyptus to different thermal environments via growth at different altitudes in the Australian Alps. • We employed calorimetric methods to relate rates of CO(2) release (mainly from substrate oxidation) and rates of O(2) reduction to conservation of energy. Temperature responses of these processes provided insight into mechanisms that control energy conservation and expenditure, and helped define 'instantaneous enthalpic growth capacity' (CapG). • CapG increased with altitude, but was counteracted by other factors in species adapted to highland habitats. The acclimation response was partly driven by changes in respiratory capacity (CapR(CO2)), and partly by more pronounced dynamic responses of CO(2) release (δ(R(CO2))) to measurement temperature. We observed enhanced temperature sensitivity of O(2) reduction (E(o)(R(O2))) at higher altitudes. • Adaptation to growth temperature included differences in respiration and growth capacities, but there was little evidence that Eucalyptus species vary in metabolic flexibility.
Tree roots: Conduits for deep recharge of soil water
Publisher: Springer Science and Business Media LLC
Date: 2001
Abstract: In previous work, we provided evidence from sap flow measurements that when root systems span soil layers of different moisture content, water is redistributed by roots in the direction of the difference in water potential. In addition to the phenomenon termed "hydraulic lift", where water is redistributed from depth to dry topsoil, the process of "hydraulic redistribution" includes downward transfer of water when the surface layers of soils with low permeability become wet after rainfall. In this paper, we support our previous findings with evidence from measurements of soil water and estimate the quantities of water transferred to depth following rain. Amounts of water stored at depth are not likely to be significant for drought avoidance by plants. However, downward transfer of water may be important to plant establishment and the reduction of waterlogging in certain soil types.
31P-NMR analysis of phosphorus compounds in extracts of surface soils from selected karri (Eucalyptus diversicolor F. Muell.) forests
Publisher: Elsevier BV
Date: 1989
Effect of N source on concentration of Rubisco in Eucalyptus diversicolor, as measured by capillary electrophoresis
Publisher: Wiley
Date: 09-2000
Treatment strategies, outcomes and prognostic factors in 291 patients with secondary CNS involvement by diffuse large B-cell lymphoma
Publisher: Elsevier BV
Date: 04-2018
Water stress impacts on respiratory rate, efficiency and substrates, in growing and mature foliage of Eucalyptus spp
Publisher: Springer Science and Business Media LLC
Date: 09-03-2006
DOI: 10.1007/S00425-006-0247-7
Abstract: In previous studies, water stress has induced variable and sometimes contradictory changes in respiration. We used isothermal calorimetry to measure the response of foliar respiration to water deficit in nine eucalypt genotypes. Specific growth rates (R(SG)) of shoots and leaves of variable age were measured independently, and the data were applied to both the growth-maintenance and enthalpy balance models. We calculated the oxidation state of respiratory substrate and the enthalpy change for the conversion of substrate carbon to biomass (DeltaH(B)). Moderate water stress reduced the R(SG) of shoots by 38% (P<0.01) and carbon conversion efficiency by 15% (P<0.05). The relationship between carbon conversion efficiency and R(SG) was not affected by water deficit for shoots, but was significantly altered for leaves. Water deficit increased maintenance respiration by about 23% (P<0.001). The growth coefficient of respiration was not significantly altered. However, changes in oxidation states of substrate and biomass suggest that the energy requirements of biosynthesis were increased under water stress. Our results confirm that carbohydrates are the major respiratory substrates in growing tissues, though mature leaves utilized a substantial component of more reduced substrate. Mature leaves had variable oxidation states for respiration substrate, which indicates a variable relationship between CO(2) evolution and ATP production. Measured DeltaH(B) in shoots and leaves were too small for reliable estimation of R(SG) by the enthalpy balance model. We also found significant effects of water stress on the oxidation state of substrate and DeltaH(B).
Respiratory quotients and Q10 of soil respiration in sub-alpine Australia reflect influences of vegetation types
Publisher: Elsevier BV
Date: 06-2011
Enhanced kinetic stability of [Pd2L4]4+ cages through ligand substitution
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6DT00133E
Abstract: [Pd 2 ( tripy ) 4 ] 4+ cage architectures (where tripy = 2,6-bis(pyridin-3-ylethynyl)pyridine) were made more kinetically robust in the presence of range of nucleophiles by the addition of amino groups in either the 2-( 2A-tripy ) or 3-( 3A-tripy ) positions of the tripy ligands' terminal pyridines, with the [Pd 2 ( 2A-tripy ) 4 ] 4+ cage proving the most stable.
The role of continental shelf width in determining freshwater phylogeographic patterns in south-eastern Australian pygmy perches (Teleostei: Percichthyidae)
Publisher: Wiley
Date: 11-02-2013
DOI: 10.1111/MEC.12204
Abstract: Biogeographic patterns displayed by obligate freshwater organisms are intimately related to the nature and extent of connectivity between suitable habitats. Two of the more significant barriers to freshwater connections are seawater and major drainage ides. South-eastern Australia provides a contrast between these barriers as it has discrete areas that are likely influenced to a greater or lesser extent by each barrier type. We use continental shelf width as a proxy for the potential degree of river coalescence during low sea levels. Our specific hypothesis is that the degree of phylogeographic ergence between coastal river basins should correspond to the continental shelf width of each region. This predicts that genetic ergences between river basins should be lowest in regions with a wider continental shelf and that regions with similar continental shelf width should have similar genetic ergences. Pygmy perches (Nannoperca australis and Nannoperca 'flindersi') in south-eastern Australia provide an ideal opportunity to test these biogeographic hypotheses. Phylogeographic patterns were examined based on range-wide s ling of 82 populations for cytochrome b and 23 polymorphic allozyme loci. Our results recovered only limited support for our continental shelf width hypothesis, although patterns within Bass clade were largely congruent with reconstructed low sea-level drainage patterns. In addition, we identified several instances of drainage ide crossings, typically associated with low elevational differences. Our results demonstrate high levels of genetic heterogeneity with important conservation implications, especially for declining populations in the Murray-Darling Basin and a highly restricted disjunct population in Ansons River, Tasmania.
NITROGEN MINERALIZATION AND NITRATE REDUCTION IN FORESTS
Publisher: Elsevier BV
Date: 1982
Soil Functional Responses to Excess Nitrogen Inputs at Global Scale
Publisher: Royal Swedish Academy of Sciences
Date: 12-2004
DOI: 10.1579/0044-7447-33.8.530
Abstract: There is little evidence that nitrogen (N) cycling in the highly weathered, low-phosphorus (P), acidic soils found in Southern Hemisphere continents will differ greatly from that in North America and Europe. Evidence from the 'south' shows: the similarity in forms and temporal patterns in losses of N from different land uses that the C:N ratios of the forest floor/litter layer from different continents are strongly predictive of a range of processes on a global scale that generalizations based on Northern Hemisphere experience of the impact of N additions to 'P-limited' ecosystems are likely to fail for southern ecosystems where anatomical and physiological adaptation of native plants to low-P soils makes questionable the concept of 'P-limitation' that the greatest threats in the 'south' are probably changes in land use that may greatly increase N inputs and turnover that localized increases in N inputs produce similar effects to those seen in the 'north'.
A test of how coupling of vegetation to the atmosphere and climate spatial variation affects water yield modelling in mountainous catchments
Publisher: Elsevier BV
Date: 06-2014
A novel mechanistic interpretation of instantaneous temperature responses of leaf net photosynthesis
Publisher: Springer Science and Business Media LLC
Date: 24-05-2016
DOI: 10.1007/S11120-016-0262-X
Abstract: Steady-state rates of leaf CO2 assimilation (A) in response to incubation temperature (T) are often symmetrical around an optimum temperature. A/T curves of C3 plants can thus be fitted to a modified Arrhenius equation, where the activation energy of A close to a low reference temperature is strongly correlated with the dynamic change of activation energy to increasing incubation temperature. We tested how [CO2] < current atmospheric levels and saturating light, or [CO2] at 800 µmol mol(-1) and variable light affect parameters that describe A/T curves, and how these parameters are related to known properties of temperature-dependent thylakoid electron transport. Variation of light intensity and substomatal [CO2] had no influence on the symmetry of A/T curves, but significantly affected their breadth. Thermodynamic and kinetic (physiological) factors responsible for (i) the curvature in Arrhenius plots and (ii) the correlation between parameters of a modified Arrhenius equation are discussed. We argue that the shape of A/T curves cannot satisfactorily be explained via classical concepts assuming temperature-dependent shifts between rate-limiting processes. Instead the present results indicate that any given A/T curve appears to reflect a distinct flux mode, set by the balance between linear and cyclic electron transport, and emerging from the anabolic demand for ATP relative to that for NADPH.
Nutrient distribution among metabolic fractions in 2 Atriplex spp.
Publisher: JSTOR
Date: 2000
DOI: 10.2307/4003396
Population and individual‐scale responses to patch size, isolation and quality in the hazel dormouse
Publisher: Wiley
Date: 09-2014
DOI: 10.1890/ES14-00115.1
Do variations on a model of landscape function assist in interpreting the growth response of vegetation to rainfall in arid environments?
Publisher: Elsevier BV
Date: 2002
Close-Range Vertical Photography for Measuring Cover Changes in Perennial Grasslands
Publisher: JSTOR
Date: 11-2000
DOI: 10.2307/4003159
Integrating two physiological approaches helps relate respiration to growth of Pinus radiata
Publisher: Wiley
Date: 06-11-2008
DOI: 10.1111/J.1469-8137.2008.02601.X
Abstract: Correlation methods originating in the growth and maintenance paradigm (GMP) are traditionally used to calculate a 'growth coefficient' (g) or the 'growth potential' (1/g) of entire plants. The enthalpy balance approach is usually applied to plant organs and relies on determination of both CO(2) release and O(2) reduction to provide a measure of instantaneous rates of enthalpic growth (R(SG)DeltaH(B)). Aspects of both the approaches to explore physiological mechanisms that govern enthalpic growth (variation in rates of CO(2) release versus rates of O(2) reduction) were combined. Respiration and growth rates of apical buds of Pinus radiata were affected strongly by canopy position, and moderately by branching order. A linear relation between enthalpic growth and CO(2) respiration explained 69% of the observed variation. Despite faster rates of growth, enthalpic growth potential (1/g(H)) was comparatively low in the upper canopy. Low enthalpic growth potential entailed comparatively low enthalpy conversion efficiency (eta(H), ratio of R(SG)DeltaH(B) to R(CO(2)) DeltaH(CO(2)) proportional to CO(2):O(2) and to carbon conversion efficiency epsilon) at large R(SG)DeltaH(B). Maximizing enthalpic growth requires a large capacity for O(2) reduction. Relations between R(SG)DeltaH(B) and eta(H) could be described by hyperbolae using two parameters. One parameter, P(1), is equivalent to enthalpic growth potential (1/g(H)).
Leaf day respiration: low CO2 flux but high significance for metabolism and carbon balance
Publisher: Wiley
Date: 02-10-2017
DOI: 10.1111/NPH.14816
Abstract: It has been 75 yr since leaf respiratory metabolism in the light (day respiration) was identified as a low‐flux metabolic pathway that accompanies photosynthesis. In principle, it provides carbon backbones for nitrogen assimilation and evolves CO 2 and thus impacts on plant carbon and nitrogen balances. However, for a long time, uncertainties have remained as to whether techniques used to measure day respiratory efflux were valid and whether day respiration responded to environmental gaseous conditions. In the past few years, significant advances have been made using carbon isotopes, ‘omics’ analyses and surveys of respiration rates in mesocosms or ecosystems. There is substantial evidence that day respiration should be viewed as a highly dynamic metabolic pathway that interacts with photosynthesis and photorespiration and responds to atmospheric CO 2 mole fraction. The view of leaf day respiration as a constant and/or negligible parameter of net carbon exchange is now outdated and it should now be regarded as a central actor of plant carbon‐use efficiency. Contents Summary 986 I. Introduction 987 II. Pioneering metabolic studies of day respiration with 14 C 987 III. Metabolic flux pattern of day respiration 988 IV. Significance of day respiration for leaf N assimilation 991 V. Significance of day respiration for leaf gas exchange 992 VI. Is day respiration influenced by CO 2 mole fraction? 995 VII. Significance of day respiration at the plant and ecosystem levels 997 VIII. Conclusions and perspectives 998 References 998
Internal conductance does not scale with photosynthetic capacity: Implications for carbon isotope discrimination and the economics of water and nitrogen use in photosynthesis
Publisher: Wiley
Date: 23-09-2006
DOI: 10.1111/J.1365-3040.2005.01412.X
Abstract: Central paradigms of ecophysiology are that there are recognizable and even explicit and predictable patterns among species, genera, and life forms in the economics of water and nitrogen use in photosynthesis and in carbon isotope discrimination (delta). However most previous examinations have implicitly assumed an infinite internal conductance (gi) and/or that internal conductance scales with the biochemical capacity for photosynthesis. Examination of published data for 54 species and a detailed examination for three well-characterized species--Eucalyptus globulus, Pseudotsuga menziesii and Phaseolus vulgaris--show these assumptions to be incorrect. The reduction in concentration of CO2 between the substomatal cavity (Ci) and the site of carbon fixation (Cc) varies greatly among species. Photosynthesis does not scale perfectly with gi and there is a general trend for plants with low gi to have a larger draw-down from Ci to Cc, further confounding efforts to scale photosynthesis and other attributes with gi. Variation in the gi-photosynthesis relationship contributes to variation in photosynthetic 'use' efficiency of N (PNUE) and water (WUE). Delta is an information-rich signal, but for many species only about two-thirds of this information relates to A/gs with the remaining one-third related to A/gi. Using data for three well-studied species we demonstrate that at common WUE, delta may vary by up to 3 per thousand. This is as large or larger than is commonly reported in many interspecific comparisons of delta, and adds to previous warnings about simplistic interpretations of WUE based on delta. A priority for future research should be elucidation of relationships between gi and gs and how these vary in response to environmental conditions (e.g. soil water, leaf-to-air vapour pressure deficit, temperature) and among species.
Plant species affect acid phosphatase, ergosterol and microbial P in a Jarrah (Eucalyptus marginata Donn ex Sm.) forest in south-western Australia
Publisher: Elsevier BV
Date: 11-2000
Evergreen trees do not maximize instantaneous photosynthesis
Publisher: Elsevier BV
Date: 06-2004
Availability of nitrogen and phosphorus in forest soils in northeastern Tasmania
Publisher: Springer Science and Business Media LLC
Date: 10-0009
DOI: 10.1007/BF00266481
A critical review of the science underpinning fire management in the high altitude ecosystems of south-eastern Australia
Publisher: Elsevier BV
Date: 04-2013
Dynamics of necromass in woody Australian ecosystems
Publisher: Wiley
Date: 08-2021
DOI: 10.1002/ECS2.3693
Abstract: Litterfall (LF) is the major contributor to aboveground necromass in ecosystems. Litter decomposition or litter decay (LD) then offsets deposition in LF, with the balance of LF and LD determining the standing litter (SL). SL together with fine and coarse woody debris (FWD, CWD) are the largest necromass pools. The interactions of LF, SL, and LD at continental scales reflect carbon and nutrient cycling and other ecosystem processes. We compiled data on leaf, twig ( .6 cm), and other material (mostly bark and reproductive tissue) for SL and LF for the fire‐prone Australian continent, where SL is also a major “fuel load” and important for fire spread and fire intensity. We extracted data from 498 published and unpublished works (1825 LF observations n SL = 3914 n LD = 629). We used Olson’s (mass‐balance) approach ( k ˜ LF/SL) to calculate LD for sites long undisturbed with both LF and SL data. We compiled LF and SL by component (leaves, twigs, other material) and metainformation such as s ling location, tree species, or time since fire from literature and/or scientists. Most data were available from warm‐seasonal (36% for SL) and cool‐wet (31%) climates, linking the locations of our data with a bio‐climate classification. Warm‐wet (20%) and hot‐seasonal (8%) climates followed, while other climate zones each contributed % of the data. Across all climatic zones, average SL (1100 g/m 2 ) was roughly twice that of LF (468 g·m −2 ·yr −1 ). SL was greatest in cold climates (2334 g/m 2 ), compared to warm‐wet (1168 g/m 2 ) and hot‐seasonal conditions (499 g/m 2 ). Important drivers of SL are LD (e.g., slow under cold conditions) and fire frequency. Olson’s k varied with type of decomposing material (“composition”). For ex le, across the continent, k ˜ 1.942 yr −1 for leaves but was 0.504 yr −1 for twigs. SL varied strongly in composition according to climate type (e.g., seasonal vs. wet climates). Robust models of necromass dynamics must distinguish between the litter components (such as leaves and twigs) and consider the complex and non‐linear effects of climate, stand structure, and stand history on litterfall and decomposition.
Mineral nutrition of sub-alpine Australian vegetation under nutrient deficiency depends on lifeform
Publisher: Elsevier BV
Date: 04-2019
Possible causes of slow growth of nitrate-supplied Pinus pinaster
Publisher: Canadian Science Publishing
Date: 04-2002
DOI: 10.1139/X01-225
Abstract: We investigated possible causes of slower growth of Pinus pinaster Ait. supplied with nitrate, as compared with ammonium or with ammonium nitrate mixtures. Six-month-old mycorrhizal seedlings of P. pinaster were grown in sand culture for 4 months at four concentrations of N (0.125, 0.5, 2.0, or 8.0 mM) as nitrate or ammonium or with an ammoniumnitrate mixture at 0.125 or 2.0 mM. After 4 months of nutrient addition, we measured light-saturated rates of photosynthesis (A max ), rates of ammonium and nitrate uptake, growth, macro- and micro-elements, and patterns of N allocation in needles. Dry mass was unaffected by N form at 0.125 or 0.5 mM N. In contrast, dry mass of seedlings supplied with ammonium or ammonium nitrate at 2.0 and 8.0 mM N, was approximately threefold greater than seedlings supplied with nitrate alone. Concentrations of N in foliage and A max were unaffected by the form or concentration of N supplied. Furthermore, concentrations of amino acid N were greater in seedlings supplied with nitrate, suggesting rates of uptake were not limiting growth. Foliage concentrations of zinc were low with nitrate supplied at a concentration of 0.5 mM or greater, and seedlings displayed symptoms typical of zinc deficiency when nitrate was supplied at 2.0 or 8.0 mM. Slower growth with nitrate could not be explained solely by either slower root uptake of nitrate N or lesser A max . Instead, aspects of N metabolism postuptake coupled with other factors such as nutrient deficiencies may limit growth with nitrate as the sole N source.
Quercitol plays a key role in stress tolerance of Eucalyptus leptophylla (F. Muell) in naturally occurring saline conditions
Publisher: Elsevier BV
Date: 03-2009
Relationships between empirical and nominal indices of landscape function in the arid shrubland of Western Australia
Publisher: Elsevier BV
Date: 2002
Nitrogen and phosphorus availability and the role of fire in heathlands at wilsons promontory
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/BT9940269
Abstract: Analyses of carbon, nitrogen and phosphorus in heathland soils at Wilsons Promontory and on Snake Island show that the effects of fire, including repeated fires, are confined to the surface 2 cm. The uppermost soil in long-unburnt heathlands is rich in these elements and usually has a smaller C:N ratio compared with the soil below. Indices of N and P availability (C:N ratios, concentrations of potentially mineralisable N and extractable inorganic P, phosphatase activity) are similar to those in highly productive eucalypt forests-a finding in conflict with past assessments of nutrient availability in heathlands. Phosphatase activity and concentrations of carbon, nitrogen and potentially mineralisable N were less in soils from repeatedly burnt heathlands than in soils from long unburnt heathlands whereas there was a greater concentration of extractable inorganic P in soils from repeatedly burnt heathlands. The balance between nitrogen input and loss is dependent on fire frequency and present-day management of heathland (and other native plant communities with low nutrient capitals) should recognise that over- or under-use of fire will significantly alter soil nutrient pools and availability and that these changes may alter community species composition and productivity.
Relating water use to morphology and environment of Nothofagus from the world's most southern forests
Publisher: Springer Science and Business Media LLC
Date: 12-09-2014
Temperature responses are a window to the physiology of dark respiration: Differences between CO2 release and O2 reduction shed light on energy conservation
Publisher: Wiley
Date: 27-03-2008
DOI: 10.1111/J.1365-3040.2008.01808.X
Abstract: We showed that temperature responses of dark respiration for foliage of Pinus radiata could be approximated by Arrhenius kinetics, whereby E(0) determines shape of the exponential response and denotes overall activation energy of respiratory metabolism. Reproducible and predictable deviation from strict Arrhenius kinetics depended on foliage age, and differed between R(CO2) and R(O2). Inhibition of oxygen reduction (R(O2)) by cyanide (inhibiting COX) or SHAM (inhibiting AOX) resulted in reproducible changes of the temperature sensitivity for R(O2), but did not affect R(CO2). Enthalpic growth--preservation of electrons in anabolic products--could be approximated with knowledge of four variables: activation energies (E(0)) for both R(CO2) and R(O2), and basal rates of respiration at a low reference temperature (R(REF)). Rates of enthalpic growth by P. radiata needles were large in spring due to differences between R(REF) of oxidative decarboxylation and that of oxygen reduction, while overall activation energies for the two processes were similar. Later during needle development, enthalpic growth was dependent on differences between E(0) for R(CO2) as compared with R(O2), and increased E(0)(R(O2)) indicated greater contributions of cytochrome oxidase to accompany the switch from carbohydrate sink to source. Temperature-dependent increments in stored energy can be calculated as the difference between R(CO2)DeltaH(CO2) and R(O2)DeltaH(O2).
Availability of organic and inorganic forms of phosphorus to lupins (Lupinus spp.)
Publisher: Springer Science and Business Media LLC
Date: 09-1992
DOI: 10.1007/BF00009546
Improving forest sampling strategies for assessment of fuel reduction burning
Publisher: Elsevier BV
Date: 05-2017
Stand water use status in relation to fire in a mixed species eucalypt forest
Publisher: Elsevier BV
Date: 09-2013
Disproportionate CH4 sink strength from an endemic, sub-alpine Australian soil microbial community
Publisher: Cold Spring Harbor Laboratory
Date: 08-11-2020
DOI: 10.1101/2020.11.08.373464
Abstract: Soil-to-atmosphere methane (CH 4 ) fluxes are dependent on opposing microbial processes of production and consumption. Here we use a soil-vegetation gradient in an Australian sub-alpine ecosystem to examine links between composition of soil microbial communities, and the fluxes of greenhouse gases they regulate. For each soil-vegetation type (forest, grassland, and bog), we measured carbon dioxide (CO 2 ) and CH 4 fluxes and their production/consumption at 5-cm intervals to a depth of 30 cm. All soils were sources of CO 2 , ranging from 49-93 mg CO 2 m -2 h -1 . Forest soils were strong net sinks for CH 4 at rates up to −413 µg CH 4 m -2 h -1 . Grassland soils varied with some soils acting as sources and some as sinks, but overall averaged −97 µg CH 4 m -2 h -1 . Bog soils were net sources of CH 4 (+340 µg CH 4 m -2 h -1 ). Methanotrophs were dominated by USCα in forest and grassland soils, and Candidatus Methylomirabilis sp. in the bog soils. Methylocystis were also detected at relatively low abundance. The potential disproportionately large contribution of these ecosystems to global CH 4 oxidation, and poorly understood microbial community regulating it, highlight our dependence on soil ecosystem services in remote locations can be driven by a unique population of soil microbes. (Identify the key aspects of originality and significance that place the work within the top 10% of current research in environmental microbiology) Novel methanotrophic bacteria have been discovered in recent years, but few studies have examined the total known ersity of methanotrophs together with the net flux of CH 4 from soils. We used an ecosystem with a vegetation-soil gradient in the sub-alpine regions of Australia (with extremely strong consumption of atmospheric CH 4 ) to examine microbial and abiotic drivers of CH 4 fluxes across this gradient. Recently characterized methanotrophs, either USCα in forest and grassland soils, or oxygenic Candidatus Methylomirabilis sp. in the bog soil were dominant. Methanotrophs belonging to the families Methylococcaceae and Methylocystaceae represented only a small minority of the methanotrophs in this ecosystem.
Assessment of ecological effects due to forest harvesting: Approaches and statistical issues
Publisher: Wiley
Date: 19-07-2004
Patterns of nitrogen mineralization in 23-year old pine forest following nitrogen fertilizing
Publisher: Elsevier BV
Date: 02-1984
Enhanced decomposition and nitrogen mineralization sustain rapid growth of Eucalyptus regnans after wildfire
Publisher: Wiley
Date: 06-10-2016
Lack of genetic variation in tree ring δ13C suggests a uniform, stomatally-driven response to drought stress across Pinus radiata genotypes
Publisher: Oxford University Press (OUP)
Date: 05-12-2009
Abstract: We assessed the variation in delta(13)C signatures of Pinus radiata D. Don stemwood taken from three genetic trials in southern Australia. We sought to determine the potential of using delta(13)C signatures as selection criteria for drought tolerance. Increment cores were taken from P. radiata and were used to determine the basal area increment and the delta(13)C signature of extracted cellulose. Both growth increment and cellulose delta(13)C were affected by water availability. Growth increment and delta(13)C were negatively correlated suggesting that growth was water-limited. While there was significant genetic variation in growth, there was no significant genetic variation in cellulose delta(13)C of tree rings. This suggests that different genotypes of P. radiata display significant differences in growth and yet respond similarly to drought stress. The delta(13)C response to drought stress was more due to changes in stomatal conductance than to the variation in photosynthetic capacity, and this may explain the lack of genetic variation in delta(13)C. The lack of genetic variation in cellulose delta(13)C of tree rings precludes its use as a selection criterion for drought tolerance among P. radiata genotypes.
Clonal variation in shoot respiration and tree growth of Eucalyptus hybrids
Publisher: Canadian Science Publishing
Date: 08-2007
DOI: 10.1139/X06-314
Abstract: Respiration rate and efficiency in growing tissues are major determinants of plant growth. We measured apical shoot respiration and tree growth in 3-year-old clones of Eucalyptus camaldulensis Dehnhardt × Eucalyptus grandis W. Hill ex Maid. and Eucalyptus camaldulensis × Eucalyptus globulus Labill. Respiration was measured by isothermal calorimetry and the oxidation state of newly formed biomass was determined by elemental analysis. We found that the enthalpy change due to conversion of carbon substrate to biomass was too small for determining specific growth rate by an enthalpy balance model of respiration and growth. Negative phenotypic correlations were significant between respiration rate and basal area, height, volume, and volume growth. Genetic correlations between respiration rate and tree size or growth were mostly significant and estimates ranged from –0.55 to –1.02. Repeatability of the clone means was around 0.80 for respiration rate, 0.71–0.91 for summer growth, and in excess of 0.80 for tree size traits. The intraclass correlation for clones (within families) was 0.33 for rate of CO 2 evolution and 0.45 for rate of metabolic heat evolution. Our results suggest considerable potential for altering respiration rate in breeding populations by selection, although the mechanisms linking respiration with growth require further investigation.
Rainfall drives variation in rates of change in intrinsic water use efficiency of tropical forests
Publisher: Springer Science and Business Media LLC
Date: 14-08-2019
DOI: 10.1038/S41467-019-11679-8
Abstract: Rates of change in intrinsic water use efficiency ( W ) of trees relative to those in atmospheric [CO 2 ] ( c a ) have been mostly assessed via short-term studies (e.g., leaf analysis, flux analysis) and/or step increases in c a (e.g., FACE studies). Here we use compiled data for abundances of carbon isotopes in tree stems to show that on decadal scales, rates of change ( dW/dc a ) vary with location and rainfall within the global tropics. For the period 1915–1995, and including corrections for mesophyll conductance and photorespiration, dW/dc a for drier tropical forests (receiving ~ 1000 mm rainfall) were at least twice that of the wettest (receiving ~ 4000 mm). The data also empirically confirm theorized roles of tropical forests in changes in atmospheric 13 C/ 12 C ratios (the 13 C Suess Effect). Further formal analysis of geographic variation in decade-to-century scale dW/dc a will be needed to refine current models that predict increases in carbon uptake by forests without hydrological cost.
Climate determines vascular traits in the ecologically diverse genus Eucalyptus
Publisher: Wiley
Date: 06-01-2016
DOI: 10.1111/ELE.12559
Abstract: Current theory presumes that natural selection on vascular traits is controlled by a trade-off between efficiency and safety of hydraulic architecture. Hence, traits linked to efficiency, such as vessel diameter, should show biogeographic patterns but critical tests of these predictions are rare, largely owing to confounding effects of environment, tree size and phylogeny. Using wood s led from a phylogenetically constrained set of 28 Eucalyptus species, collected from a wide gradient of aridity across Australia, we show that hydraulic architecture reflects adaptive radiation of this genus in response to variation in climate. With increasing aridity, vessel diameters narrow, their frequency increases with a distribution that becomes gradually positively skewed and sapwood density increases while the theoretical hydraulic conductivity declines. Differences in these hydraulic traits appear largely genotypic in origin rather than environmentally plastic. Data reported here reflect long-term adaptation of hydraulic architecture to water availability. Rapidly changing climates, on the other hand, present significant challenges to the ability of eucalypts to adapt their vasculature.
Characterisation of hydrogen isotope profiles in an agroforestry system: Implications for tracing water sources of trees
Publisher: Elsevier BV
Date: 08-2000
Nitrogen and phosphorus cycling in relation to stand age of Eucalypus regnans F. Muell. - II. N mineralization and nitrification
Publisher: Springer Science and Business Media LLC
Date: 05-1992
DOI: 10.1007/BF00010963
Site-specific responses to short-term environmental variation are reflected in leaf and phloem-sap carbon isotopic abundance of field grown Eucalyptus globulus
Publisher: Wiley
Date: 29-05-2012
DOI: 10.1111/J.1399-3054.2012.01638.X
Abstract: The carbon isotopic composition (δ(13) C) of plant material has been used extensively as an indirect measure of carbon fixation per volume of water used. More recently, the δ(13) C of phloem sap (δ(13) C(phl) ) has been used as a surrogate measure of short-term, canopy scale δ(13) C. Using a combination of δ(13) C physiological, structural and chemical indices from leaves and phloem sap of Eucalyptus globulus at sites of contrasting water availability, we sought to identify short-term, canopy scale resource limitations. Results illustrate that δ(13) C(phl) offers valid reflections of short-term, canopy scale values of leaf δ(13) C and tree water status. Under conditions limited by water, leaf and phloem sap photoassimilates differ in (13) C abundance of a magnitude large enough to significantly influence predictions of water use efficiency. This pattern was not detected among trees with adequate water supply indicating fractionation into heterotrophic tissues that may be sensitive to plant water status. Trees employed a range of physiological, biochemical and structural adaptations to acclimate to resource limitation that differed among sites providing a useful context upon which to interpret patterns in δ(13) C. Our results highlight that such easily characterized properties are ideal for use as minimally invasive tools to monitor growth and resilience of plants to variations in resource availability.
Nitrogen and phosphorus cycling in relation to stand age of Eucalyptus regnans F. Muell - III. Labile inorganic and organic P, phosphatase activity and P availability
Publisher: Springer Science and Business Media LLC
Date: 05-1992
DOI: 10.1007/BF00010964
Contrasting responses of crop legumes and cereals to nitrogen availability
Publisher: Wiley
Date: 27-11-2017
DOI: 10.1111/NPH.14918
Abstract: In nonagricultural systems, the relationship between intrinsic water-use efficiency (WUE
A standardization method to disentangle environmental information from axial trends of xylem anatomical traits
Publisher: Oxford University Press (OUP)
Date: 09-10-2018
Abstract: Anatomical traits such as xylem conduit diameter and vessel connectivity are fundamental characteristics of the hydraulic architecture of vascular plants. Stem xylem conduits are narrow at the stem apex, and this confers resistance to embolisms that might otherwise be induced by large, negative water potentials at the top of tall trees. Below the apex, conduits progressively widen and this characteristic minimizes effects of path length on total hydraulic resistance. While interconnections among xylem vessels have been noted for decades, their role(s) are not fully clarified. For ex le, we do not know if they allow water to bypass embolized vessels, or increase the risk of spread of embolisms, or how their arrangement varies within a tree. Here we demonstrate the benefit of removing the independent effect of stem length on assessment of effects of external (e.g., climatic) factors on such xylem traits. We measured the hydraulic diameter (Dh) and vessel conductivity index (VCI) along the stem of 21 shrubs/trees of similar height (1.19 < H < 5.45 m) belonging to seven Acacia species, across a wide aridity gradient in Australia. All trees showed similar scaling exponents of Dh (b = 0.33) and VCI (b = 0.53) vs axial distance from the apex (L), thus conforming with general patterns in woody plants. After de-trending for L, neither Dh (P = 0.21) nor VCI (P = 0.109) differed across the aridity gradient. We found that across a wide gradient of aridity, climate had no effect on xylem anatomy of Acacia spp, which was instead dictated by axial distances from stem apices. We argue that the use of standardization procedures to filter out intrinsic patterns of vascular traits is an essential step in assessing climate-driven modifications of xylem architecture.
Empirical and model-based estimates of spatial and temporal variations in net primary productivity in semi-arid grasslands of Northern China
Publisher: Public Library of Science (PLoS)
Date: 07-11-2017
AusTraits, a curated plant trait database for the Australian flora
Publisher: Springer Science and Business Media LLC
Date: 30-09-2021
DOI: 10.1038/S41597-021-01006-6
Abstract: We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field c aigns, published literature, taxonomic monographs, and in idual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised in idual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge.
Whole-tree chambers for elevated atmospheric CO2 experimentation and tree scale flux measurements in south-eastern Australia: The Hawkesbury Forest Experiment
Publisher: Elsevier BV
Date: 15-07-2010
2,6-Pyridinedicarboxylic acid as an eluent for UV and conductivity detection of inorganic anions, magnesium and calcium in water by ion chromatography
Publisher: Springer Science and Business Media LLC
Date: 05-0004
DOI: 10.1007/BF02467748
Elective surgery system strengthening: development, measurement, and validation of the surgical preparedness index across 1632 hospitals in 119 countries
Publisher: Elsevier BV
Date: 11-2022
The challenge of tree height in Eucalyptus regnans: When xylem tapering overcomes hydraulic resistance
Publisher: Wiley
Date: 21-05-2010
DOI: 10.1111/J.1469-8137.2010.03304.X
Abstract: *Recent research suggests that increasing conduit tapering progressively reduces hydraulic constraints caused by tree height. Here, we tested this hypothesis using the tallest hardwood species, Eucalyptus regnans. *Vertical profiles of conduit dimensions and vessel density were measured for three mature trees of height 47, 51 and 63 m. *Mean hydraulic diameter (Dh) increased rapidly from the tree apex to the point of crown insertion, with the greatest degree of tapering yet reported (b > 0.33). Conduit tapering was such that most of the total resistance was found close to the apex (82-93% within the first 1 m of stem) and the path length effect was reduced by a factor of 2000. Vessel density (VD) declined from the apex to the base of each tree, with scaling parameters being similar for all trees (a = 4.6 b = -0.5). *Eucalyptus regnans has evolved a novel xylem design that ensures a high hydraulic efficiency. This feature enables the species to grow quickly to heights of 50-60 m, beyond the maximum height of most other hardwood trees.
Nitrogen availability and weed invasion in a remnant native woodland in urban Melbourne
Publisher: Wiley
Date: 03-03-2006
Modern tools to tackle traditional concerns: Evaluation of site productivity and Pinus radiata management via δ13C- and δ18O-analysis of tree-rings
Publisher: Elsevier BV
Date: 12-2012
Response of a perennial grassland to nitrogen and phosphorus additions in sub-tropical, semi-arid Australia
Publisher: Elsevier BV
Date: 07-2001
Seasonal changes in carbohydrates, cyclitols, and water relations of 3 field grown Eucalyptus species from contrasting taxonomy on a common site
Publisher: Springer Science and Business Media LLC
Date: 2010
Can a growth model be used to describe forest carbon and water balance after fuel reduction burning in temperate forests?
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.SCITOTENV.2017.09.315
Abstract: Empirical evidence from Australia shows that fuel reduction burning significantly reduces the incidence and extent of unplanned fires. However, the integration of environmental values into fire management operations is not yet well-defined and requires further research and development. WAVES, a plant growth model that incorporates Soil-Vegetation-Atmosphere Transfer, was used to simulate the hydrological and ecological effects of three fuel management scenarios on a forest ecosystem. WAVES was applied using inputs from a set of forest plots for one year after three potential scenarios: (1) all litter removed, (2) all litter and 50% of the understorey removed, (3) all litter and understorey removed. Modelled outputs were compared with sites modelled with no-fuel reduction treatment (Unburnt). The key change between unburnt and fuel reduced forests was a significant increase in soil moisture after fire. Predictions of the recovery of aboveground carbon as plant biomass were driven by model structure and thus variability in available light and soil moisture at a local scale. Similarly, effects of fuel reduction burning on water processes were mainly due to changes in vegetation interception capacity (i.e. regrowth) and soil evaporation. Predicted effects of fuel reduction burning on total evapotranspiration (ET) - the major component of water balance - were marginal and not significant, even though a considerable proportion of ET had effectively been transferred from understorey to overstorey. In common with many plant growth models, outputs from WAVES are dictated by the assumption that overstorey trees continue to grow irrespective of their age or stage of maturity. Large areas of eucalypt forests and woodlands in SE Australia are well beyond their aggrading phase and are instead over-mature. The ability of these forests to rapidly respond to greater availability of water remains uncertain.
Capillary electrophoresis of the major anions and cations in leaf extracts of woody species
Publisher: Wiley
Date: 2004
DOI: 10.1002/PCA.801
Abstract: Capillary electrophoresis methods are described for the analysis of the major inorganic anions (nitrite, nitrate, chloride, sulphate, phosphate), organic acids (oxalate, malate, citrate, succinate) and inorganic cations (ammonium, potassium, sodium, calcium, magnesium) in leaf extracts. Analytical performance was validated for extracts from leaves of four sclerophyllous species: Eucalyptus globulus, E. cladocalyx, E. nitens and Pinus radiata. Inorganic anions and organic acids were analysed in a single run within 5 min using a background electrolyte of 2,6-pyridinedicarboxylic acid (20 mM) and cetyltrimethylammonium bromide (0.5 mM). Cations were analysed in a separate run also within 5 min using imidazole (10 mM) and 18-crown-6 (2 mM) as background electrolyte. Replicate injections were highly repeatable when the capillary was rinsed between runs with hydrochloric acid (0.25 M) and background electrolyte, but not when the acid rinse was omitted or replaced by a rinse with sodium hydroxide (0.25 M). Standard curves for all analytes were linear over the range of 0.05-1 mm. Standard curves constructed by serial dilution of a leaf extract were also highly linear, and this, combined with the excellent recovery of added solutes in a spike and recovery test, suggests quantification was unaffected by the complex matrix that is present in un-purified, hot water extracts of leaves. There were significant differences in concentrations of the major anions and cations between the species studied.
Phosphatase activity and phosphorus fractions in Karri (Eucalyptus diversicolor F. Muell.) forest soils
Publisher: Springer Science and Business Media LLC
Date: 11-1992
DOI: 10.1007/BF00346061
Cyclitols and carbohydrates in leaves and roots of 13 Eucalyptus species suggest contrasting physiological responses to water deficit
Publisher: Wiley
Date: 10-08-2006
DOI: 10.1111/J.1365-3040.2006.01577.X
Abstract: In many tree species, physiological adaptations to drought include the accumulation of osmotically active substances and/or the presence of particular compatible solutes, among them cyclitols. Recently, the cyclitol quercitol was identified in species of Eucalyptus, a erse genus whose speciation is probably driven by adaptation to water availability. We subjected seedlings of 13 Eucalyptus species from different ecosystems ('mesic' and 'xeric') and different sub-generic taxonomic groups to 10 weeks of water deficit (WD) treatment. Pre-dawn water potentials (psi(pdwn)) and relative water content (RWC) were determined in shoots, and total osmolality, soluble low-molecular-weight carbohydrates and cyclitols were measured in leaves and roots. Responses to water deficit followed two distinct patterns: Eucalyptus species from 'mesic' environments adjusted concentrations of sucrose (through increased levels of sucrose and decreases in RWC) in response to water deficit, whereas 'xeric' species increased concentrations of quercitol (through reductions in RWC). In root tissues, only species from xeric environments contained high levels of quercitol and mannitol, increasing under WD conditions. We suggest that the former (mesic) strategy may be beneficial to respond to short-lasting drought conditions, because sucrose is easily metabolized, whereas the latter (xeric) strategy may relate to an effective acclimation to longer-lasting drought. These physiological response groups are also related to taxonomic groups within the genus.
In situ studies of nitrogen mineralization and uptake in forest soils; some comments on methodology
Publisher: Elsevier BV
Date: 1989
Effects of mound-cultivation (bedding) on concentration and conservation of nutrients in a sandy podzol
Publisher: Elsevier BV
Date: 06-1985
Three parameters comprehensively describe the temperature response of respiratory oxygen reduction
Publisher: Wiley
Date: 27-03-2008
DOI: 10.1111/J.1365-3040.2008.01809.X
Abstract: Using an exponential model that relies on Arrhenius kinetics, we explored Type I, Type II and dynamic (e.g. declining Q(10) with increasing temperature) responses of respiration to temperature. Our Arrhenius model provides three parameters: R(REF) (the base of the exponential model, nmol g(-1) s(-1)), E(0) (the overall activation energy of oxygen reduction that dominates its temperature sensitivity, kJ mol(-1)) and delta (that describes dynamic responses of E(0) to measurement temperature, 10(3) K(2)). Two parameters, E(0) and delta, are tightly linked. Increases in overall activation energy at a reference temperature were inversely related to changes in delta. At an E(0) of ca. 45 kJ mol(-1), delta approached zero, and respiratory temperature response was strictly Arrhenius-like. Physiologically, these observations suggest that as contributions of AOX to combined oxygen reduction increase, E(0)(REF) decreases because of different temperature sensitivities for V(max), and delta increases because of different temperature sensitivities for K(1/2) of AOX and COX. The balance between COX and AOX activity helps regulate plant metabolism by adjusting the demand for ATP to that for reducing power and carbon skeleton intermediates. Our approach enables determination of respiratory capacity in vivo and opens a path to development of process-based models of plant respiration.
Spatial and temporal variations in phloem sap composition of plantation-grown Eucalyptus globulus
Publisher: Springer Science and Business Media LLC
Date: 07-12-1998
Abstract: Spontaneous bleeding of sugar-rich sap from cambial-deep incisions in the bark of trunks was demonstrated for Eucalyptus globulus and other eucalypts across a range of localities and seasonal conditions in south-west Australia. High levels of sucrose and raffinose (up to 31% w/v total sugars) were present in the exudates, and upward and downward gradients in exudate sugar concentrations were recorded between s les obtained at different heights up trunks of E. globulus. The data indicated a phloem origin for the exudates, with source:sink pressure gradients driving translocation. Concentration ratios of sugars to amino acids were consistently lower in exudate from upper (distal) than basal regions of trunks, suggesting preferential partitioning of nitrogen upwards towards the trunk apex. A comparison of phloem and xylem sap composition from one plantation over a season showed nitrate in xylem but not phloem and substantial amounts of sodium, and high concentrations of chloride and sulphate relative to phosphate in xylem and phloem. Phloem sap s led across a range of 29 contrasting plantations of E. globulus at peak stress (autumn) showed great inter-site variability in concentrations of amino acids, sulphur, sodium and certain trace elements and in C:N and Na:K ratios of sap. Carbon isotope ratios (δ
Retention behavior and simultaneous separation of carboxylic and aromatic acids using ion-exclusion chromatography
Publisher: Informa UK Limited
Date: 1999
Nitrate reductase activity and growth response of forest species to ammonium and nitrate sources of nitrogen
Publisher: Springer Science and Business Media LLC
Date: 10-1982
DOI: 10.1007/BF02183803
Water flux of Eucalyptus regnans: Defying summer drought and a record heatwave in 2009
Publisher: Springer Science and Business Media LLC
Date: 16-10-2013
DOI: 10.1007/S00442-012-2494-6
Abstract: Making predictions as to how heatwaves will affect forests in the future is a major challenge in ecosystem science, not the least because we have few documented ex les of how they respond now. We captured the effects of drought and a record-breaking heatwave on whole-tree water use (Q) in Eucalyptus regnans during the summer drought of 2008/2009 in southeastern Australia. While air temperatures steadily increased, average maximum sap flow (J Smax) declined with progression of the drought prior to the heatwave. In the period approaching the heatwave, Q during daytime (Q d) steadily declined, while nighttime Q (Q n) increased. This pattern was particularly pronounced during nights that followed hot days (>32 °C) where Q n was frequently 20-30 % of Q d. We found clear trends in the relation of Q d to Q n that point to the increasing importance of refilling depleted stem water stores following hot days. On the day the heatwave climaxed (7 February 2009), sap flow (J S) was dramatically low, and declined as weather conditions became increasingly arid (air temperature > 42 °C, vapor pressure deficit >7 kPa). Almost immediately after the heatwave passed J S resumed its common diurnal hysteresis, albeit at slightly slower rates. In the context of prognosticated effects of future climate, our data highlight that depletion and refill of stored water in E. regnans are likely important features for the tree to endure drought- and heat-related climatic extremes. We suggest that elucidating the peculiarity of capacitance and defining its threshold for keystone tree species, such as E. regnans, can add to our understanding of how climatic extremes may affect forests.
Woody legumes: A (re)view from the South
Publisher: Oxford University Press (OUP)
Date: 08-07-2010
Abstract: This review is focused on woody legumes from the southern continents. We highlight that the evolution of the Caesalpinioideae and Mimosoideae with old soils, with variable supplies of water and also with fire has produced a suite of advantageous physiological characteristics. These include good potential for nitrogen fixation and mechanisms for acquiring P. The latter includes the ability to form cluster roots and produce extracellular phosphatase enzymes. Further, many of the species in these subfamilies are known to synthesize in significant amounts osmotically compatible solutes, such as pinitol and other cyclitols olyols, that help them cope with even severe drought conditions. In many cases, these species regenerate prolifically after fire from seed. Such species and their beneficial characters can now be better exploited to help sequester carbon, provide key nutrients such as nitrogen and phosphorus for companion crops and other plants and provide feedstocks for a range of industries, including energy industries.
Emissions of isoprene, monoterpene and short-chained carbonyl compounds from Eucalyptus spp. in southern Australia
Publisher: Elsevier BV
Date: 06-2009
AusTraits – a curated plant trait database for the Australian flora
Publisher: Cold Spring Harbor Laboratory
Date: 07-01-2021
DOI: 10.1101/2021.01.04.425314
Abstract: We introduce the AusTraits database - a compilation of measurements of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 375 traits across 29230 taxa from field c aigns, published literature, taxonomic monographs, and in idual taxa descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological parameters (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised in idual-, species- and genus-level observations coupled to, where available, contextual information on site properties. This data descriptor provides information on version 2.1.0 of AusTraits which contains data for 937243 trait-by-taxa combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data to increase our collective understanding of the Australian flora.
Ecological effects of harvesting in Victoria’s native forests: Quantification of research outputs
Publisher: Informa UK Limited
Date: 2004
Insulation capacity of three bark types of temperate Eucalyptus species
Publisher: Elsevier BV
Date: 02-2014
Productivity, carbon isotope discrimination and leaf traits of trees of Eucalyptus globulus Labill. in relation to water availability
Publisher: Wiley
Date: 05-11-2004
Using amino‐nitrogen pools and fluxes to identify contributions of understory Acacia spp. to overstory Eucalyptus regnans and stand nitrogen uptake in temperate Australia
Publisher: Wiley
Date: 10-08-2009
DOI: 10.1111/J.1469-8137.2009.02909.X
Abstract: Amino acid concentration and composition in xylem and phloem sap and in plant tissues are good markers of plant performance and general plant nitrogen (N)-supply. Here, we tested if amino acid pools in Eucalyptus regnans, growing in southeastern Australia were increased by understory acacias in 70-yr-old stands, and if xylem N-transport of temperate Acacia spp. differs from their tropical counterparts. We analysed amino-N concentrations and composition in foliage, xylem and phloem. In a novel approach we coupled amino-N concentrations of xylem with long-term sap flow measurements to calculate total stand N-transport. Xylem N-transport of E. regnans is largely based on amino compounds of the glutamate group (more than 90%). By contrast, Acacia spp. transport mainly aspartate group amino acids in xylem (up to 80%). Amino compound ersity and concentration in tissues and xylem and phloem sap were universally greater in acacias compared to eucalypts. Acacias investigated here can be classified as 'amide transporters'. We conclude that N-status and growth potential of aging E. regnans forest is not enhanced by a contribution of N from understory acacias, and that xylem N-transport in temperate Acacia spp. differs from acacias located in the tropics.
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