ORCID Profile
0000-0002-6515-7864
Current Organisation
Murdoch University
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Macromolecular and Materials Chemistry | Synthesis of Materials |
Expanding Knowledge in the Chemical Sciences | Expanding Knowledge in Technology
Publisher: Copernicus GmbH
Date: 11-11-2022
DOI: 10.5194/ESSD-14-4811-2022
Abstract: Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2021, EFOS increased by 5.1 % relative to 2020, with fossil emissions at 10.1 ± 0.5 GtC yr−1 (9.9 ± 0.5 GtC yr−1 when the cement carbonation sink is included), and ELUC was 1.1 ± 0.7 GtC yr−1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 10.9 ± 0.8 GtC yr−1 (40.0 ± 2.9 GtCO2). Also, for 2021, GATM was 5.2 ± 0.2 GtC yr−1 (2.5 ± 0.1 ppm yr−1), SOCEAN was 2.9 ± 0.4 GtC yr−1, and SLAND was 3.5 ± 0.9 GtC yr−1, with a BIM of −0.6 GtC yr−1 (i.e. the total estimated sources were too low or sinks were too high). The global atmospheric CO2 concentration averaged over 2021 reached 414.71 ± 0.1 ppm. Preliminary data for 2022 suggest an increase in EFOS relative to 2021 of +1.0 % (0.1 % to 1.9 %) globally and atmospheric CO2 concentration reaching 417.2 ppm, more than 50 % above pre-industrial levels (around 278 ppm). Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959–2021, but discrepancies of up to 1 GtC yr−1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extratropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set. The data presented in this work are available at 0.18160/GCP-2022 (Friedlingstein et al., 2022b).
Publisher: Wiley
Date: 17-08-2006
DOI: 10.1111/J.1523-1739.2006.00530.X
Abstract: The U.S. Endangered Species Act (ESA) allows listing of subspecies and other groupings below the rank of species. This provides the U.S. Fish and Wildlife Service and the National Marine Fisheries Service with a means to target the most critical unit in need of conservation. Although roughly one-quarter of listed taxa are subspecies, these management agencies are hindered by uncertainties about taxonomic standards during listing or delisting activities. In a review of taxonomic publications and societies, we found few subspecies lists and none that stated standardized criteria for determining subspecific taxa. Lack of criteria is attributed to a centuries-old debate over species and subspecies concepts. Nevertheless, the critical need to resolve this debate for ESA listings led us to propose that minimal biological criteria to define disjunct subspecies (legally or taxonomically) should include the discreteness and significance criteria of distinct population segments (as defined under the ESA). Our subspecies criteria are in stark contrast to that proposed by supporters of the phylogenetic species concept and provide a clear distinction between species and subspecies. Efforts to eliminate or reduce ambiguity associated with subspecies-level classifications will assist with ESA listing decisions. Thus, we urge professional taxonomic societies to publish and periodically update peer-reviewed species and subspecies lists. This effort must be paralleled throughout the world for efficient taxonomic conservation to take place.
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/SR13339
Abstract: There is an increasing interest in eucalypt reforestation for a range of purposes in Australia, including pulp-wood production, carbon mitigation and catchment water management. The impacts of this reforestation on soil water repellency have not been examined despite eucalypts often being associated with water repellency and water repellency having impacts on water movement across and within soils. To investigate the role of eucalypt reforestation on water repellency, and interactions with soil properties, we examined 31 sites across the south-west of Western Australia with paired plots differing only in present land use (pasture v. plantation). The incidence and severity of water repellency increased in the 5–8 years following reforestation with Eucalyptus globulus. Despite this difference in water repellency, there were no differences in soil characteristics, including soil organic carbon content or composition, between pasture and plantation soils, suggesting induction by small amounts of hydrophobic compounds from the trees. The incidence of soil water repellency was generally greater on sandy-surfaced ( % clay content) soils however, for these soils 72% of the pasture sites and 31% of the plantation were not water repellent, and this was independent of measured soil properties. Computer modelling revealed marked differences in the layering and packing of waxes on kaolinite and quartz surfaces, indicating the importance of interfacial interactions in the development of soil water repellency. The implications of increased water repellency for the management of eucalyptus plantations are considered.
Publisher: Elsevier BV
Date: 03-2009
Publisher: Wiley
Date: 28-02-2013
DOI: 10.1111/REC.12012
Publisher: Wiley
Date: 16-08-2020
Publisher: Springer Science and Business Media LLC
Date: 08-2009
Publisher: Springer Science and Business Media LLC
Date: 28-06-2013
Publisher: Elsevier BV
Date: 12-2015
Publisher: Wiley
Date: 26-06-2012
Publisher: Springer Science and Business Media LLC
Date: 30-05-2015
Publisher: Wiley
Date: 10-04-2012
Publisher: Wiley
Date: 10-2015
DOI: 10.1890/14-1519.1
Abstract: State-and-transition models are increasingly used as a tool to inform management of post-disturbance succession and effective conservation of bio ersity in production landscapes. However, if they are to do this effectively, they need to represent faunal, as well as vegetation, succession. We assessed the congruence between vegetation and avian succession by s ling avian communities in each state of a state-and-transition model used to inform management of post-mining restoration in a production landscape in southwestern Australia. While avian communities differed significantly among states classified as on a desirable successional pathway, they did not differ between desirable and deviated states of the same post-mining age. Overall, we concluded there was poor congruence between vegetation and avian succession in this state-and-transition model. We identified four factors that likely contributed to this lack of congruence, which were that long-term monitoring of succession in restored mine pits was not used to update and improve models, states were not defined based on ecological processes and thresholds, states were not defined by criteria that were important in structuring the avian community, and states were not based on criteria that related to values in the reference community. We believe that consideration of these four factors in the development of state-and-transition models should improve their ability to accurately represent faunal, as well as vegetation, succession. Developing state-and-transition models that better incorporate patterns of faunal succession should improve the ability to manage post-disturbance succession across a range of ecosystems for bio ersity conservation.
Publisher: Springer Science and Business Media LLC
Date: 30-08-2018
DOI: 10.1038/S41598-018-31236-5
Abstract: Heat waves have profoundly impacted biota globally over the past decade, especially where their ecological impacts are rapid, erse, and broad-scale. Although usually considered in isolation for either terrestrial or marine ecosystems, heat waves can straddle ecosystems of both types at subcontinental scales, potentially impacting larger areas and taxonomic breadth than previously envisioned. Using climatic and multi-species demographic data collected in Western Australia, we show that a massive heat wave event straddling terrestrial and maritime ecosystems triggered abrupt, synchronous, and multi-trophic ecological disruptions, including mortality, demographic shifts and altered species distributions. Tree die-off and coral bleaching occurred concurrently in response to the heat wave, and were accompanied by terrestrial plant mortality, seagrass and kelp loss, population crash of an endangered terrestrial bird species, plummeting breeding success in marine penguins, and outbreaks of terrestrial wood-boring insects. These multiple taxa and trophic-level impacts spanned ,000 km 2 —comparable to the size of California—encompassing one terrestrial Global Bio ersity Hotspot and two marine World Heritage Areas. The subcontinental multi-taxa context documented here reveals that terrestrial and marine biotic responses to heat waves do not occur in isolation, implying that the extent of ecological vulnerability to projected increases in heat waves is underestimated.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 04-08-2006
Abstract: We reported that postfire logging 2 to 3 years after the 2002 Biscuit Fire was associated with significant mortality in natural conifer regeneration and elevated potential fire behavior in the short term as a result of increased surface fuel loads. We underscore the strength of our study design and statistical conclusions, provide additional details of the research setting and scope, and address comments pertinent to forest development and fire ecology.
Publisher: Elsevier BV
Date: 07-2018
Publisher: Elsevier BV
Date: 06-2010
Publisher: Wiley
Date: 05-07-2017
Publisher: Wiley
Date: 19-03-2019
DOI: 10.1111/GCB.14589
Abstract: Prolonged drought and intense heat-related events trigger sudden forest die-off events and have now been reported from all forested continents. Such die-offs are concerning given that drought and heatwave events are forecast to increase in severity and duration as climate change progresses. Quantifying consequences to carbon dynamics and storage from die-off events are critical for determining the current and future mitigation potential of forests. We took stand measurements five times over 2+ years from affected and unaffected plots across the Northern Jarrah Forest, southwestern Australia, following an acute drought/heatwave in 2011. We found a significant loss of live standing carbon (49.3 t ha
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/WF15119
Abstract: Removal of fire-killed trees (i.e. post-fire or salvage logging) is often conducted in part to reduce woody fuel loads and mitigate potential reburn effects. Studies of post-salvage fuel dynamics have primarily used chronosequence or modelling approaches, with associated limitations longitudinal studies tracking fuels over time have been rare. We res led a network of post-fire plots, comprising a range of logging intensities, 10 years after the 2002 Biscuit Fire (Oregon, USA). For surface woody fuels, which started from large treatment differences immediately following logging (stepwise increases with harvest intensity), we found converging trends among treatments at 10 years, with convergence nearly complete for fine fuels but not for coarse fuels. Fire-killed snags for the dominant species (Pseudotsuga menziesii) decayed while standing at a statistically significant rate (single-exponential k = 0.011), similar to or only slightly slower than down wood, suggesting that not all snag biomass will reach the forest floor. Live vegetation (largely resprouting sclerophyllous vegetation) is beginning to dominate surface fuel mass and continuity ( % cover) and likely moderates differences associated with woody fuels. Post-fire logging had little effect on live fuels or their change over time, suggesting high potential for stand-replacing early-seral fire regardless of post-fire harvest treatments.
Publisher: Wiley
Date: 25-04-2021
DOI: 10.1111/REC.13379
Abstract: Ecological resilience is widely acknowledged as a vital attribute of successful ecosystem restoration, with potential for restoration practice to contribute to this goal. Hence, defining common metrics of resilience to naturally occurring disturbances is essential for restoration planning, efforts, and monitoring. Here, we reviewed how plant community ecologists have measured resilience of restoration projects to disturbances and propose a framework to guide measurement of restoration projects to disturbance. We found 22 studies that investigated the impact of disturbances on restoration projects, from three continents and for three disturbance types. Over half of the studies were from Australia, with the dataset biased toward fire responses of restored, or partially restored, forest ecosystems. Native plant species richness, cover, and density were common response variables. Studies varied in restoration context, design, response variables, and statistical approaches, limiting generalizations. Nonetheless we have identified several response variables that offer potential as lagging indicators (e.g. species richness) and leading indicators (e.g. recruitment) of resilience in erse vegetation types exposed to a variety of disturbance regimes. We suggest a third set of variables, proxy measures of resilience (e.g. functional redundancy), to complement lagging and leading indicators. We conclude with a framework to guide decisions about when to use each of the three types of measures to assess resilience of restoration projects to disturbance, providing some clarity to decision‐making despite the uncertainty of changing disturbance regimes. Lastly, we invite researchers to understand the impact of disturbance on the resilience of restoration projects, rather than assume resilience.
Publisher: Public Library of Science (PLoS)
Date: 06-03-2013
Publisher: Canadian Science Publishing
Date: 04-2009
DOI: 10.1139/X09-016
Abstract: Large-scale wildfires (∼10 4 –10 6 ha) have the potential to eliminate seed sources over broad areas and thus may lead to qualitatively different regeneration dynamics than in small burns however, regeneration after such events has received little study in temperate forests. Following a 200 000 ha mixed-severity wildfire in Oregon, USA, we quantified (1) conifer and broadleaf regeneration in stand-replacement patches 2 and 4 years postfire and (2) the relative importance of isolation from seed sources (live trees) versus local site conditions in controlling regeneration. Patch-scale conifer regeneration density (72%–80% Douglas-fir ( Pseudotsuga menziesii (Mirb). Franco)) varied widely, from 127 to 6494 stems·ha –1 . Median densities were 1721 and 1603 stems·ha –1 2 and 4 years postfire, respectively, i.e., ∼12 times prefire overstory densities (134 stems·ha –1 ). Because of the complex burn mosaic, ∼58% of stand-replacement area was ≤200 m from a live-tree edge (seed source), and ∼81% was ≤400 m. Median conifer density exceeded 1000 stems·ha –1 out to a distance of 400 m from an edge before declining farther away. The strongest controls on regeneration were distance to live trees and soil parent material, with skeletal coarse-grained soils supporting lower densities (133 stems·ha –1 ) than fine-grained soils (729–1492 stems·ha –1 ). Other site factors (e.g., topography, broadleaf cover) had little association with conifer regeneration. The mixed-severity fire pattern strongly influenced the regeneration process by providing seed sources throughout much of the burned landscape.
Publisher: Wiley
Date: 05-2016
DOI: 10.1002/ECS2.1341
Publisher: Oxford University Press (OUP)
Date: 04-2013
Publisher: Wiley
Date: 12-02-2023
Abstract: Many degraded ecosystems need active restoration to conserve bio ersity and re‐establish ecosystem function, both highlighted targets of the UN Decade on Ecosystem Restoration and the proposed EU Nature restoration law. Soil translocation, where both plant propagules and their associated soil biota are co‐introduced, has increasingly been proposed as a powerful restoration technique for terrestrial ecosystems. However, a synthesis of the effectiveness of this method across ecosystems is lacking. To address how soil translocation affects restoration success, we performed a meta‐analysis synthesizing data from 46 field experiments and their respective reference ecosystems in 17 countries across four continents. In each experiment, vegetation composition was recorded in response to soil translocation treatments and the resultant vegetational changes ( ersity and composition) were quantified. We found that soil translocation leads to plant community development further away from the control and more towards the reference plant communities compared with treatments where only plant propagules were introduced. However, the variability of effect sizes among experiments was large, suggesting strong dependence of restoration success on restoration context. We found that restoration success was more likely on loamy soils and when translocation treatments were implemented over larger spatial areas ( m 2 ). Furthermore, we found that restoration success either consistently increased or decreased over time depending on the experiment. Not only is this congruent with positive feedbacks between plant and soil communities driving plant community development, but it also suggests that the composition of the translocated plant and soil communities, and initial starting conditions, are critical for long‐term restoration success. Synthesis and applications . Our analysis highlights soil translocation can be a successful restoration method across a broad range of ecosystems. However, its implementation needs to depend on a thorough evaluation of local conditions and the potential added value. Further refinement of soil translocation techniques is needed to increase success rates.
Publisher: Wiley
Date: 09-2014
Publisher: IOP Publishing
Date: 07-09-2018
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/WR18100
Abstract: Abstract ContextFeral pigs (Sus scrofa) are an increasing threat to agriculture and ecological communities globally. Although ground rooting is their most readily observable sign, feral pigs typically remain highly cryptic and their abundance and impacts are difficult to quantify. AimsThe aim of the present study was to evaluate the effect of current feral pig population management practices (trapping, baiting, no feral pig management) on feral pig abundance and digging impacts, using a BACI (before–after control–impact) experimental design at a landscape scale. MethodsA monitoring program was established to quantify both the abundance and digging impacts of feral pig populations within a temperate sclerophyll forest landscape using distance s ling. Transects were established across eight drinking water catchments where the whole catchment was the unit of replication for feral pig population management. Monitoring was carried out at 6-monthly intervals for 3 years, with no feral pig population management undertaken in the first year. In total, 367 feral pigs were trapped out of three catchments subject to trapping, and 26 were baited across two catchments subject to baiting with a commercial product (PIGOUT, Animal Control Technologies Australia, Melbourne, Vic., Australia). Three catchments were exempt from feral pig population management for the duration of this study. Key resultsFeral pig density within the overall study site was estimated as 1.127pigskm–2, resulting in 4580diggingskm–2year–1. There was no significant difference in feral pig density estimates observed among population management treatments or the treatment×year interaction term. An overall decrease in feral pig density across all catchments was attributed to extreme temperature and drought conditions experienced during the study. ConclusionsFeral pig populations demonstrate high resilience to current feral pig population management practices in the present study. The annual volume of soil disturbed by the numbers of feral pigs estimated across this study area is comparable to a commercial-scale resource extraction industry. We did not find significant differences in feral pig digging density among dominant vegetation types, but larger digs were associated with sw vegetation. ImplicationsCurrent levels of feral pig population management did not reduce pig densities across eight catchments in the northern jarrah forest therefore, more intensive population management is needed.
Publisher: Oxford University Press (OUP)
Date: 06-2012
Publisher: Elsevier BV
Date: 03-2016
Publisher: Wiley
Date: 04-2011
DOI: 10.1890/ES10-00184.1
Publisher: American Geophysical Union (AGU)
Date: 03-2016
DOI: 10.1002/2015JG003165
Publisher: Springer Science and Business Media LLC
Date: 19-02-2022
Publisher: University of Wisconsin Press
Date: 03-08-2017
DOI: 10.3368/ER.35.3.237
Publisher: MDPI AG
Date: 04-12-2017
DOI: 10.3390/ANI7120092
Abstract: Many healthy adult cats are euthanised annually in shelters, and novel approaches are required to reduce euthanasia rates. Waiving adoption fees is one such approach. However, concerns that less responsible owners will be attracted to free events persist among welfare groups. We evaluated evidence for differences in cat fate, health, and adherence to husbandry legislation via a case-study of a free adoption-drive for cats ≥1 year at a Western Australian shelter. Post-adoption outcomes were compared between free adopters and a control group of normal-fee adopters. The free adoption-drive rehomed 137 cats, increasing average weekly adoptions by 533%. First-time adopters were a significantly larger portion of the free cohort, as a result of mixed-media promotions. Both adopter groups selected cats of similar age sex and pelage. Post-adoption, both groups retained % cats, reporting near identical incidences of medical and behavioural problems. Adopters did not differ in legislative compliance regarding fitting collars, registering cats, or allowing cats to roam. The shelter reported satisfaction with the adoption-drive, because in addition to relieving crowding of healthy adults, adoption of full-fee kittens increased 381%. Overall, we found no evidence for adverse outcomes associated with free adoptions. Shelters should not be dissuaded from occasional free adoption-drives during overflow periods.
Publisher: Elsevier BV
Date: 10-2015
Publisher: Wiley
Date: 11-12-2008
Publisher: Wiley
Date: 26-07-2014
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/WF13006
Abstract: Fuel age is an imprecise surrogate for fire hazard in species-rich Mediterranean-type shrublands. We present an efficient method for aerial biomass and litter estimation of shrublands on sandy and calcareous substrates in south-western Australia that enables fuel accumulation patterns to be compared independently of vegetation age. For sites ranging 3–16 years since last fire, total available fuel loads were 2.7–7.6tha–1 for the sandplain and 2.6–8.14tha–1 for the calcareous shrublands. Despite calcareous shrublands having higher soil nutrient concentrations and winter rainfall, total available fuel loads were similar between community types over the range of fuel ages examined. Sandplain biomass was dominated by resprouters and calcareous sites, by non-sprouters. Topographic variation in fuel loads was observed among sandplain sites, with greater available biomass and litter on the deeper sands of dunes compared to swales. More rapid fuel accumulation at the youngest sites and more uniform canopy structure in the calcareous shrublands indicate that they have the potential to support fire at shorter intervals than the sandplain. For each community type, an allometric equation based on the relationship between average maximum plant height and total available fuel was derived that enables rapid estimation of fuel loads that is more accurate than using fuel age.
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/WF15028
Abstract: Forest die-offs associated with drought and heat have recently occurred across the globe, raising concern that associated changes in fuels and microclimate could link initial die-off disturbance to subsequent fire disturbance. Despite widespread concern, little empirical data exist. Following forest die-off in the Northern Jarrah Forest, south-western Australia, we quantified fuel dynamics and associated microclimate for die-off and control plots. Sixteen months post die-off, die-off plots had significantly increased 1-h fuels (11.8 vs 9.8 tonnes ha–1) but not larger fuel classes (10-h and 100-h fuels). Owing to stem mortality, die-off plots had significantly greater standing dead wood mass (100 vs 10 tonnes ha–1), visible sky (hemispherical images analysis: 31 vs 23%) and potential near-ground solar radiation input (measured as Direct Site Factor: 0.52 vs 0.34). Supplemental mid-summer microclimate measurements (temperature, relative humidity and wind speed) were combined with long-term climatic data and fuel load estimates to parameterise fire behaviour models. Fire spread rates were predicted to be 30% greater in die-off plots with relatively equal contributions from fuels and microclimate, highlighting need for operational consideration by fire managers. Our results underscore potential for drought-induced tree die-off to interact with subsequent fire under climate change.
Publisher: Proceedings of the National Academy of Sciences
Date: 06-03-2023
Abstract: Increasing fire severity and warmer, drier postfire conditions are making forests in the western United States (West) vulnerable to ecological transformation. Yet, the relative importance of and interactions between these drivers of forest change remain unresolved, particularly over upcoming decades. Here, we assess how the interactive impacts of changing climate and wildfire activity influenced conifer regeneration after 334 wildfires, using a dataset of postfire conifer regeneration from 10,230 field plots. Our findings highlight declining regeneration capacity across the West over the past four decades for the eight dominant conifer species studied. Postfire regeneration is sensitive to high-severity fire, which limits seed availability, and postfire climate, which influences seedling establishment. In the near-term, projected differences in recruitment probability between low- and high-severity fire scenarios were larger than projected climate change impacts for most species, suggesting that reductions in fire severity, and resultant impacts on seed availability, could partially offset expected climate-driven declines in postfire regeneration. Across 40 to 42% of the study area, we project postfire conifer regeneration to be likely following low-severity but not high-severity fire under future climate scenarios (2031 to 2050). However, increasingly warm, dry climate conditions are projected to eventually outweigh the influence of fire severity and seed availability. The percent of the study area considered unlikely to experience conifer regeneration, regardless of fire severity, increased from 5% in 1981 to 2000 to 26 to 31% by mid-century, highlighting a limited time window over which management actions that reduce fire severity may effectively support postfire conifer regeneration.
Publisher: Wiley
Date: 12-02-2015
DOI: 10.1111/AVSC.12162
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/WF11065
Abstract: Fuel age (time since last fire) is often used to approximate fire hazard and informs decisions on placement of shrubland management burns worldwide. However, uncertainty remains concerning the relative importance of fuel age and weather conditions as predictors of fire hazard and behaviour. Using data from 35 experimental burns across three types of shrublands in Western Australia, we evaluated importance of fuel age and fire weather on probability of fire propagation (hazard) and four metrics of fire behaviour (rate of spread, fireline intensity, residence time, surface temperature) under moderate to high fire danger weather conditions. We found significant support for a threshold effect of fuel age for fire propagation but limited evidence for an effect of fuel age or fire weather on rates of spread or fireline intensity, although surface heating and heating duration were significantly related to fuel age and shrubland type. Further analysis suggested that dead fuel mass and accumulation rate rather than live fuels were responsible for this relationship. Using BEHAVE, predicted spread rates and intensities were consistently lower than observed values, suggesting further refinement is needed in modelling shrubland fire behaviour. These data provide important insight into fire behaviour in globally significant, fire-adapted shrublands, informing fire management and relationships between fire frequency and fire intensity.
Publisher: Copernicus GmbH
Date: 26-04-2022
DOI: 10.5194/ESSD-14-1917-2022
Abstract: Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize datasets and methodology to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the first time, an approach is shown to reconcile the difference in our ELUC estimate with the one from national greenhouse gas inventories, supporting the assessment of collective countries' climate progress. For the year 2020, EFOS declined by 5.4 % relative to 2019, with fossil emissions at 9.5 ± 0.5 GtC yr−1 (9.3 ± 0.5 GtC yr−1 when the cement carbonation sink is included), and ELUC was 0.9 ± 0.7 GtC yr−1, for a total anthropogenic CO2 emission of 10.2 ± 0.8 GtC yr−1 (37.4 ± 2.9 GtCO2). Also, for 2020, GATM was 5.0 ± 0.2 GtC yr−1 (2.4 ± 0.1 ppm yr−1), SOCEAN was 3.0 ± 0.4 GtC yr−1, and SLAND was 2.9 ± 1 GtC yr−1, with a BIM of −0.8 GtC yr−1. The global atmospheric CO2 concentration averaged over 2020 reached 412.45 ± 0.1 ppm. Preliminary data for 2021 suggest a rebound in EFOS relative to 2020 of +4.8 % (4.2 % to 5.4 %) globally. Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959–2020, but discrepancies of up to 1 GtC yr−1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use changes emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extra-tropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and datasets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this dataset (Friedlingstein et al., 2020, 2019 Le Quéré et al., 2018b, a, 2016, 2015b, a, 2014, 2013). The data presented in this work are available at 0.18160/gcp-2021 (Friedlingstein et al., 2021).
Publisher: Wiley
Date: 23-04-2021
DOI: 10.1111/NPH.17348
Abstract: With climate change, heat waves are becoming increasingly frequent, intense and broader in spatial extent. However, while the lethal effects of heat waves on humans are well documented, the impacts on flora are less well understood, perhaps except for crops. We summarize recent findings related to heat wave impacts including: sublethal and lethal effects at leaf and plant scales, secondary ecosystem effects, and more complex impacts such as increased heat wave frequency across all seasons, and interactions with other disturbances. We propose generalizable practical trials to quantify the critical bounding conditions of vulnerability to heat waves. Collectively, plant vulnerabilities to heat waves appear to be underappreciated and understudied, particularly with respect to understanding heat wave driven plant die‐off and ecosystem tipping points.
Publisher: CSIRO Publishing
Date: 2013
DOI: 10.1071/WF12109
Abstract: Following severe wildfires, managing fire hazard by removing dead trees (post-fire logging) is an important issue globally. Data informing these management actions are relatively scarce, particularly how fuel loads differ by post-fire logging intensity within different environmental settings. In mixed-evergreen forests of Oregon, USA, we quantified fuel profiles 3–4 years after stand-replacement fire – assessing three post-fire logging intensities (0, 25–75, or % basal area cut) across two climatic settings (mesic coastal, drier interior). Stand-replacement fire consumed ~17% of aboveground biomass. Post-fire logging significantly reduced standing dead biomass, with high-intensity treatment leaving a greater proportion (28%) of felled biomass on site compared with moderate-intensity treatment (14%) because of less selective tree felling. A significant relationship between logging intensity and resulting surface fuels (per-hectare increase of 0.4–1.2Mg per square metre of basal area cut) indicated a broadly applicable predictive tool for management. Down wood cover increased by 3–5 times and became more spatially homogeneous after logging. Post-fire logging altered the fuel profile of early-seral stands (standing material removed or transferred, short-term increase in surface fuels, likely reduction in future large fuel accumulation), with moderate-intensity and unlogged treatments yielding surface fuel loads consistent with commonly prescribed levels, and high-intensity treatment resulting in greater potential need for follow-up fuel treatments.
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.TREE.2019.07.009
Abstract: Altered fire regimes resulting from climate change and human activity threaten many terrestrial ecosystems. However, we lack a holistic and detailed understanding of the effects of altering one key fire regime component - season of fire. Altered fire seasonality can strongly affect post-fire recovery of plant populations through interactions with plant phenology. We identify seven key mechanisms of fire seasonality effects under a conceptual demographic framework and review evidence for these. We reveal negative impacts of altered fire seasonality and identify research gaps for mechanisms and climate types for future analyses of fire seasonality effects within the identified demographic framework. This framework and these mechanisms can inform critical decisions for conservation, land management, and fire management policy development globally.
Publisher: Wiley
Date: 26-10-2023
DOI: 10.1111/AEC.13447
Publisher: Springer Science and Business Media LLC
Date: 16-09-2011
Publisher: Oxford University Press (OUP)
Date: 27-09-2010
Publisher: Wiley
Date: 11-08-2021
DOI: 10.1002/EAP.2411
Abstract: Unseasonal fire occurrence is increasing globally, driven by climate change and other human activity. Changed timing of fire can inhibit postfire seedling recruitment through interactions with plant phenology (the timing of key processes, e.g., flower initiation, seed production, dispersal, germination), and therefore threaten the persistence of many plant species. Although empirical evidence from winter‐rainfall ecosystems shows that optimal seedling recruitment is expected following summer and autumn (dry season) fires, we sought experimental evidence isolating the mechanisms of poor recruitment following unseasonal (wet season) fire. We implemented a seed‐sowing experiment using nine species native to fire‐prone, Mediterranean‐climate woodlands in southwestern Australia to emulate the timing of postfire recruitment and test key mechanisms of fire seasonality effects. For seeds sown during months when fire is unseasonal (i.e., August–September: end of the wet winter season), seedling recruitment was reduced by up to 99% relative to seeds sown during seasonal fire months (i.e., May–June: end of the dry summer season) because of varying seed persistence, seedling emergence, and seedling survival. We found that up to 70 times more seedlings emerged when seeds were sown during seasonal fire months compared to when seeds were sown during unseasonal fire months. The few seedlings that emerged from unseasonal sowings all died with the onset of the dry season. Of the seeds that failed to germinate from unseasonal sowings, only 2% survived exposure on the soil surface over the ensuing hot and dry summer. Our experimental results demonstrate the potential for unseasonal fire to inhibit seedling recruitment via impacts on pregermination seed persistence and seedling establishment. As ongoing climate change lengthens fire seasons (i.e., unseasonal wildfires become more common) and managed fires are implemented further outside historically typical fire seasons, postfire seedling recruitment may become more vulnerable to failure, causing shifts in plant community composition towards those with fewer species solely dependent on seeds for regeneration.
Publisher: Wiley
Date: 04-01-2023
DOI: 10.1002/EAP.2775
Abstract: The frequency and intensity of forest disturbances, such as drought and fire, are increasing globally, with an increased likelihood of multiple disturbance events occurring in short succession. Disturbances layered over one another may influence the likelihood or intensity of subsequent events (a linked disturbance) or impact response and recovery trajectories (a compound disturbance), with substantial implications for ecological spatiotemporal vulnerability. This study evaluates evidence for disturbance interactions of drought followed by wildfire in a resprouting eucalypt‐dominated forest (the Northern Jarrah Forest) in southwestern Australia. Sites were stratified by drought (high, low), from previous modeling and ground validation, and fire severity (high, moderate, unburnt), via remote sensing using the relative difference normalized burn ratio (RdNBR). Evidence of a linked disturbance was assessed via fine fuel consumption and fire severity. Compound disturbance effects were quantified at stand scale (canopy height, quadratic mean diameter, stem density) and stem scale (mortality). There was no evidence of prior drought influencing fine fuel consumption or fire severity and, hence, no evidence of a linked disturbance. However, compound disturbance effects were evident stands previously affected by drought experienced smaller shifts in canopy height, quadratic mean diameter, and stem density than stands without prior drought impact. At the stem scale, size and fire severity were the strongest determinants of stem survival. Proportional resprouting height was greater in high drought sites than in low drought sites ( p 0.01), meaning, structurally, the low drought stands decreased in height more than the high drought stands. Thus, a legacy of the drought was evident after the wildfire. Although these resprouting eucalypt forests have been regarded as particularly resilient, this study illustrates how multiple disturbances can overwhelm the larger tree component and promote an abundance of smaller stems. We suggest that this is early evidence of a structural destabilization of these forests under a more fire‐prone, hotter, and drier future climate.
Publisher: Wiley
Date: 29-12-2017
DOI: 10.1002/LDR.2866
Publisher: CSIRO Publishing
Date: 2023
DOI: 10.1071/BT22134
Publisher: Wiley
Date: 2023
DOI: 10.1111/AVSC.12713
Abstract: Responses of ecological restoration projects to disturbances are rarely explored, yet their capacity to withstand and recover from disturbance (resilience) is a critical measure of restoration success. In many plant communities, the soil seed bank (SSB) provides an important source of propagules for species persistence and community resilience to disturbance. Understanding how SSBs develop with time can inform restoration of resilient ecosystems. Here, in fire‐prone Banksia woodland restoration following sand mining, we ask: (a) how does the smoke‐responsive (dormancy broken by smoke) SSB develop over time (b) what plant‐trait and climate factors influence its development and (c) what do the data suggest for the resilience of these restored woodlands to fire? Ellenbrook, Swan Coastal Plain, Western Australia (latitude −31.76, longitude 115.95). We used smoke, a key germination cue associated with fire disturbance, to trigger germination of the SSB in Banksia woodland restoration. Using a chronosequence of nine ages between 3 and 26 years since initiation of restoration, we tested how the SSB develops using counts and richness of germinating native and invasive annuals, and native perennial obligate seeding and resprouting species. To understand the contribution of above‐ground restored vegetation to SSB development, we compared Sørensen's similarity of the smoke germinable SSB (smoked SSB) and untreated germinable SSB (control SSB) with above‐ground vegetation. Smoked SSB germinant density decreased with restoration age for both native and invasive annuals, but was stable for native perennials. Similarity between smoked SSB and above‐ground vegetation was higher for perennial obligate seeders than for resprouters and peaked for perennials at 23 years. Post‐fire regeneration potential of the SSB was evident across the chronosequence, with restoration age influencing the density of native annuals and overall composition of the SSB. The findings for perennial species suggest an increase in resilience to fire with restoration age.
Publisher: Springer Science and Business Media LLC
Date: 23-05-2022
DOI: 10.1007/S11258-022-01244-7
Abstract: Climate change projections predict that Mediterranean-type ecosystems (MTEs) are becoming hotter and drier and that fires will become more frequent and severe. While most plant species in these important bio ersity hotspots are adapted to hot, dry summers and recurrent fire, the Interval Squeeze framework suggests that reduced seed production (demographic shift), reduced seedling establishment after fire (post fire recruitment shift), and reduction in the time between successive fires (fire interval shift) will threaten fire killed species under climate change. One additional potential driver of accelerated species decline, however, has not been considered so far: the decrease in pollination success observed in many ecosystems worldwide has the potential to further reduce seed accumulation and thus population persistence also in these already threatened systems. Using the well-studied fire-killed and serotinous shrub species Banksia hookeriana as an ex le, we apply a new spatially implicit population simulation model to explore population dynamics under past (1988–2002) and current (2003–2017) climate conditions, deterministic and stochastic fire regimes, and alternative scenarios of pollination decline. Overall, model results suggest that while B. hookeriana populations were stable under past climate conditions, they will not continue to persist under current (and prospective future) climate. Negative effects of climatic changes and more frequent fires are reinforced by the measured decline in seed set leading to further reduction in the mean persistence time by 12–17%. These findings clearly indicate that declining pollination rates can be a critical factor that increases further the pressure on the persistence of fire-killed plants. Future research needs to investigate whether other fire-killed species are similarly threatened, and if local population extinction may be compensated by recolonization events, facilitating persistence in spatially structured meta-communities.
Publisher: Wiley
Date: 23-07-2020
Publisher: Wiley
Date: 09-02-2016
DOI: 10.1111/JVS.12378
Publisher: Oxford University Press (OUP)
Date: 11-2013
Publisher: Elsevier BV
Date: 10-2020
Publisher: Wiley
Date: 11-12-2019
Publisher: Oxford University Press (OUP)
Date: 09-05-2016
DOI: 10.1111/BOJ.12433
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.SCITOTENV.2015.04.002
Abstract: Postfire resprouting and recruitment from seed are key plant life-history traits that influence population dynamics, community composition and ecosystem function. Species can have one or both of these mechanisms. They confer resilience, which may determine community composition through differential species persistence after fire. To predict ecosystem level responses to changes in climate and fire conditions, we examined the proportions of these plant fire-adaptive traits among woody growth forms of 2880 taxa, in eight fire-prone ecosystems comprising ~87% of Australia's land area. Shrubs comprised 64% of the taxa. More tree (>84%) than shrub (~50%) taxa resprouted. Basal, epicormic and apical resprouting occurred in 71%, 22% and 3% of the taxa, respectively. Most rainforest taxa (91%) were basal resprouters. Many trees (59%) in frequently-burnt eucalypt forest and savanna resprouted epicormically. Although crown fire killed many mallee (62%) and heathland (48%) taxa, fire-cued seeding was common in these systems. Postfire seeding was uncommon in rainforest and in arid Acacia communities that burnt infrequently at low intensity. Resprouting was positively associated with ecosystem productivity, but resprouting type (e.g. basal or epicormic) was associated with local scale fire activity, especially fire frequency. Although rainforest trees can resprout they cannot recruit after intense fires and may decline under future fires. Semi-arid Acacia communities would be susceptible to increasing fire frequencies because they contain few postfire seeders. Ecosystems dominated by obligate seeders (mallee, heath) are also susceptible because predicted shorter inter-fire intervals will prevent seed bank accumulation. Savanna may be resilient to future fires because of the adaptive advantage of epicormic resprouting among the eucalypts. The substantial non-resprouting shrub component of shrublands may decline, but resilient Eucalyptus spp. will continue to dominate under future fire regimes. These patterns of resprouting and postfire seeding provide new insights to ecosystem assembly, resilience and vulnerability to changing fire regimes on this fire-prone continent.
Publisher: Wiley
Date: 06-2015
DOI: 10.1890/140231
Publisher: University of Notre Dame
Date: 2006
Publisher: CSIRO Publishing
Date: 2021
DOI: 10.1071/BT20089
Abstract: The rapid expansion of urban areas worldwide is leading to native habitat loss and ecosystem fragmentation and degradation. Although the study of urbanisation’s impact on bio ersity is gaining increasing interest globally, there is still a disconnect between research recommendations and urbanisation strategies. Expansion of the Perth metropolitan area on the Swan Coastal Plain in south-western Australia, one of the world’s thirty-six bio ersity hotspots, continues to affect the Banksia Woodlands (BWs) ecosystem, a federally listed Threatened Ecological Community (TEC). Here, we utilise the framework of a 1989 review of the state of knowledge of BWs ecology and conservation to examine scientific advances made in understanding the composition, processes and functions of BWs and BWs’ species over the last 30 years. We highlight key advances in our understanding of the ecological function and role of mechanisms in BWs that are critical to the management of this ecosystem. The most encouraging change since 1989 is the integration of research between historically disparate ecological disciplines. We outline remaining ecological knowledge gaps and identify key research priorities to improve conservation efforts for this TEC. We promote a holistic consideration of BWs with our review providing a comprehensive document that researchers, planners and managers may reference. To effectively conserve ecosystems threatened by urban expansion, a range of stakeholders must be involved in the development and implementation of best practices to conserve and maintain both bio ersity and human wellbeing.
Publisher: Springer Science and Business Media LLC
Date: 23-09-2022
DOI: 10.1186/S42408-022-00145-4
Abstract: Climate change is eroding forest resilience to disturbance directly through warming climate and indirectly through increasing disturbance activity. Forests characterized by stand-replacing fire regimes and dominated by serotinous species are at risk when the inter-fire period is insufficient for canopy seed bank development and climate conditions for recruitment in the post-fire growing season are unsuitable. Although both factors are critical to serotinous forest persistence, their relative importance for post-fire regeneration in serotinous forests remains poorly understood. To assess the relative effects of each factor, we established plots in severely burned knobcone pine ( Pinus attenuata Lemmon) forests in Oregon and California, USA, representing a range of past fire intervals (6 to 31+ years). Specifically, we evaluated effects of fire interval and pre-fire canopy seed bank (proxies for seed supply) and post-fire climate on three metrics of post-fire tree regeneration (seedling density, probability of self-replacement, percent population recovery). Seed supply consistently had the strongest effect on post-fire regeneration. Between 6- and 31-year fire intervals, post-fire seedling density increased from 1000 to 100,000 seedlings ha −1 , while probability of self-replacement increased from ~ 0 to ~ 100% and percent population recovery increased from 20 to 2000% of the pre-fire population, respectively. Similarly, increasing the canopy seed bank by two orders of magnitude increased seedling density and percent population recovery by two orders and one order of magnitude, respectively, and increased the probability of self-replacement by 50%. Greater post-fire climatic moisture deficit exacerbated the effect of seed supply an additional 4–6 years between fires was required under high moisture stress conditions to reach similar regeneration levels as under low moisture stress conditions. The overriding effect of seed supply—strongly driven by pre-fire stand age—on post-fire regeneration suggests that altered fire frequency (an indirect effect of climate change) will have a profound impact on serotinous forests. Although direct effects of hot and dry climate are lower in magnitude, they can alter forest recovery where seed supply nears a threshold. These findings reveal how fire interval and climate combine to determine changes in forest cover in the future, informing management and vulnerability mapping.
Start Date: 03-2013
End Date: 06-2017
Amount: $709,778.00
Funder: Australian Research Council
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