ORCID Profile
0000-0002-6518-239X
Current Organisations
CSIRO
,
CSIRO Land and Water
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Natural Resource Management | Environmental Rehabilitation (excl. Bioremediation) | Environmental Science and Management | Conservation and Biodiversity
Rehabilitation of Degraded Forest and Woodlands Environments | Rehabilitation of Degraded Mining Environments |
Publisher: Elsevier BV
Date: 08-2016
Publisher: Copernicus GmbH
Date: 11-06-2018
Abstract: Abstract. Ecosystem models commonly assume that key photosynthetic traits, such as carboxylation capacity measured at a standard temperature, are constant in time. The temperature responses of modelled photosynthetic or respiratory rates then depend entirely on enzyme kinetics. Optimality considerations, however, suggest this assumption may be incorrect. The “coordination hypothesis” (that Rubisco- and electron-transport-limited rates of photosynthesis are co-limiting under typical daytime conditions) predicts, instead, that carboxylation (Vcmax) capacity should acclimate so that it increases somewhat with growth temperature but less steeply than its instantaneous response, implying that Vcmax when normalized to a standard temperature (e.g. 25 ∘C) should decline with growth temperature. With additional assumptions, similar predictions can be made for electron-transport capacity (Jmax) and mitochondrial respiration in the dark (Rdark). To explore these hypotheses, photosynthetic measurements were carried out on woody species during the warm and the cool seasons in the semi-arid Great Western Woodlands, Australia, under broadly similar light environments. A consistent proportionality between Vcmax and Jmax was found across species. Vcmax, Jmax and Rdark increased with temperature in most species, but their values standardized to 25 ∘C declined. The ci:ca ratio increased slightly with temperature. The leaf N : P ratio was lower in the warm season. The slopes of the relationships between log-transformed Vcmax and Jmax and temperature were close to values predicted by the coordination hypothesis but shallower than those predicted by enzyme kinetics.
Publisher: Frontiers Media SA
Date: 23-06-2015
Publisher: Wiley
Date: 06-2013
DOI: 10.1890/12-0621.1
Abstract: Identifying the range of appropriate fire return intervals is crucial for ecosystem management in fire-prone environments. Plant vital attributes and changes in their associated trait values with time since fire are important indicators of suitable fire interval bounds to conserve bio ersity. However, using vital attributes to derive prescriptions for acceptable fire intervals remains challenging due to (1) uncertainty regarding how traits are best measured, (2) uncertainty in the acceptable ranges of trait values to avoid local extinctions, and (3) potential for variability among populations in the time taken postfire to reach trait threshold values. Using a time-since-fire gradient in contrasting mallee and mallee-heath vegetation types of southwestern Australia, we calculate, compare, and aggregate fire interval bound predictions from nine serotinous non-resprouters and seven serotinous resprouters across these three sources of uncertainty or variation. Relationships between time since fire and both trait measures reflecting minimum fire interval (mean number of closed fruit per plant or proportion of plants with closed fruit) were typically significant, had reasonable goodness of fit, and showed similar patterns of change with time since fire. Significant relationships reflecting maximum fire interval were less frequent but were more commonly detected using direct measures of mortality than using evidence for decline in reproductive potential. Of the two sources of uncertainty, trait value threshold selection caused more substantial differences in estimated interval bounds than trait measurement method. Variation between populations increased with greater estimated minimum interval length and, in some species, rendered interval estimates of limited practical value. On balance, we conclude that measures of vital attribute traits offer a transparent approach for estimating fire interval bounds at the plant community level, but selection of trait value thresholds is in need of stronger biological justification in their application. Further, variation between populations should be explicitly s led if fire interval estimates are to be applied across the landscape.
Publisher: Springer Science and Business Media LLC
Date: 1990
DOI: 10.1007/BF00937801
Publisher: Springer Science and Business Media LLC
Date: 18-06-2016
Publisher: Elsevier BV
Date: 08-2009
Publisher: Wiley
Date: 05-2014
DOI: 10.1111/MEC.12751
Abstract: Patterns of adaptive variation within plant species are best studied through common garden experiments, but these are costly and time-consuming, especially for trees that have long generation times. We explored whether genome-wide scanning technology combined with outlier marker detection could be used to detect adaptation to climate and provide an alternative to common garden experiments. As a case study, we s led nine provenances of the widespread forest tree species, Eucalyptus tricarpa, across an aridity gradient in southeastern Australia. Using a Bayesian analysis, we identified a suite of 94 putatively adaptive (outlying) sequence-tagged markers across the genome. Population-level allele frequencies of these outlier markers were strongly correlated with temperature and moisture availability at the site of origin, and with population differences in functional traits measured in two common gardens. Using the output from a canonical analysis of principal coordinates, we devised a metric that provides a holistic measure of genomic adaptation to aridity that could be used to guide assisted migration or genetic augmentation.
Publisher: CSIRO
Date: 2020
DOI: 10.25919/9TTS-F060
Publisher: Springer Science and Business Media LLC
Date: 20-06-2016
Publisher: The Royal Society
Date: 10-2019
Abstract: Revegetation plantings are a key management tool for ecological restoration. Revegetation success is usually measured using ecological traits, however, genetic ersity should also be considered as it can influence fitness, adaptive capacity and long-term viability of revegetation plantings and ecosystem functioning. Here we review the global literature comparing genetic ersity in revegetation plantings to natural stands. Findings from 48 studies suggest variable genetic outcomes of revegetation, with 46% demonstrating higher genetic ersity in revegetation than natural stands and 52% demonstrating lower ersity. Levels of genetic ersity were most strongly associated with the number of source sites used—where information was available, 69% of studies showing higher genetic ersity in revegetation reported using multiple provenances, compared with only 33% for those with lower ersity. However, with a few exceptions, it was unclear whether differences in genetic ersity between revegetation and natural stands were statistically significant. This reflected insufficient reporting of statistical error and metadata within the published studies, which limited conclusions about factors contributing to patterns. Nonetheless, our findings indicate that mixed seed sourcing can contribute to higher genetic ersity in revegetation. Finally, we emphasize the type of metadata needed to determine factors influencing genetic ersity in revegetation and inform restoration efforts.
Publisher: Springer Science and Business Media LLC
Date: 05-08-2015
Publisher: Oxford University Press (OUP)
Date: 02-2017
DOI: 10.1093/GBE/EVW290
Publisher: Springer Science and Business Media LLC
Date: 2016
DOI: 10.1038/NATURE16524
Abstract: How ecosystem productivity and species richness are interrelated is one of the most debated subjects in the history of ecology. Decades of intensive study have yet to discern the actual mechanisms behind observed global patterns. Here, by integrating the predictions from multiple theories into a single model and using data from 1,126 grassland plots spanning five continents, we detect the clear signals of numerous underlying mechanisms linking productivity and richness. We find that an integrative model has substantially higher explanatory power than traditional bivariate analyses. In addition, the specific results unveil several surprising findings that conflict with classical models. These include the isolation of a strong and consistent enhancement of productivity by richness, an effect in striking contrast with superficial data patterns. Also revealed is a consistent importance of competition across the full range of productivity values, in direct conflict with some (but not all) proposed models. The promotion of local richness by macroecological gradients in climatic favourability, generally seen as a competing hypothesis, is also found to be important in our analysis. The results demonstrate that an integrative modelling approach leads to a major advance in our ability to discern the underlying processes operating in ecological systems.
Publisher: Springer Science and Business Media LLC
Date: 16-02-2014
DOI: 10.1038/NATURE13014
Abstract: Studies of experimental grassland communities have demonstrated that plant ersity can stabilize productivity through species asynchrony, in which decreases in the biomass of some species are compensated for by increases in others. However, it remains unknown whether these findings are relevant to natural ecosystems, especially those for which species ersity is threatened by anthropogenic global change. Here we analyse ersity-stability relationships from 41 grasslands on five continents and examine how these relationships are affected by chronic fertilization, one of the strongest drivers of species loss globally. Unmanipulated communities with more species had greater species asynchrony, resulting in more stable biomass production, generalizing a result from bio ersity experiments to real-world grasslands. However, fertilization weakened the positive effect of ersity on stability. Contrary to expectations, this was not due to species loss after eutrophication but rather to an increase in the temporal variation of productivity in combination with a decrease in species asynchrony in erse communities. Our results demonstrate separate and synergistic effects of ersity and eutrophication on stability, emphasizing the need to understand how drivers of global change interactively affect the reliable provisioning of ecosystem services in real-world systems.
Publisher: Wiley
Date: 23-04-2018
DOI: 10.1111/AEC.12613
Publisher: CSIRO
Date: 2021
DOI: 10.25919/A9B7-9Y54
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.JENVMAN.2017.10.036
Abstract: The extent of roads and other forms of linear infrastructure is burgeoning worldwide, but their impacts are inadequately understood and thus poorly mitigated. Previous studies have identified many potential impacts, including alterations to the hydrological functions and soil processes upon which ecosystems depend. However, these impacts have seldom been quantified at a regional level, particularly in arid and semi-arid systems where the gap in knowledge is the greatest, and impacts potentially the most severe. To explore the effects of extensive track, road, and rail networks on surface hydrology at a regional level we assessed over 1000 km of linear infrastructure, including approx. 300 locations where ephemeral streams crossed linear infrastructure, in the largely intact landscapes of Australia's Great Western Woodlands. We found a high level of association between linear infrastructure and altered surface hydrology, with erosion and pooling 5 and 6 times as likely to occur on-road than off-road on average (1.06 erosional and 0.69 pooling features km
Publisher: CSIRO
Date: 2015
Publisher: Wiley
Date: 03-1992
Publisher: Copernicus GmbH
Date: 16-01-2018
Publisher: Wiley
Date: 12-1994
Publisher: Elsevier BV
Date: 02-2019
Publisher: Springer Science and Business Media LLC
Date: 08-02-2021
Publisher: Springer Science and Business Media LLC
Date: 06-2015
DOI: 10.1007/S00572-014-0587-2
Abstract: Arbuscular mycorrhizal fungi (AMF) are crucial to the functioning of the plant-soil system, but little is known about the spatial structuring of AMF communities across landscapes modified by agriculture. AMF community composition was characterized across four sites in the highly cleared south-western Australian wheatbelt that were originally dominated by forb-rich eucalypt woodlands. Environmentally induced spatial structuring in AMF composition was examined at four scales: the regional scale associated with location, the site scale associated with past management (benchmark woodlands with no agricultural management history, livestock grazing, recent revegetation), the patch scale associated with trees and canopy gaps, and the fine scale associated with the herbaceous plant species beneath which soils were sourced. Field-collected soils were cultured in trap pots then, AMF composition was determined by identifying spores and through ITS1 sequencing. Structuring was strongest at site scales, where composition was strongly related to prior management and associated changes in soil phosphorus. The two fields were dominated by the genera Funneliformis and Paraglomus, with little convergence back to woodland composition after revegetation. The two benchmark woodlands were characterized by Ambispora gerdemannii and taxa from Gigasporaceae. Their AMF communities were strongly structured at patch scales associated with trees and gaps, in turn most strongly related to soil N. By contrast, there were few patterns at fine scales related to different herbaceous plant species, or at regional scales associated with the 175 km distance between benchmark woodlands. Important areas for future investigation are to identify the circumstances in which recolonization by woodland AMF may be limited by fungal propagule availability, reduced plant ersity and/or altered chemistry in agricultural soils.
Publisher: Elsevier BV
Date: 08-2019
Publisher: CSIRO Publishing
Date: 2013
DOI: 10.1071/BT12212
Abstract: Establishing the time since fire in infrequently burnt, yet fire-prone, communities is a significant challenge. Until this can be resolved for -year timeframes, our capacity to understand important ecological processes, such as the periods required for development of habitat features, will remain limited. We characterised the relationship between observable tree growth rings, plant age and plant size in Eucalyptus salubris F.Muell. in the globally significant Great Western Woodlands in south-western Australia. In the context of recent concerns regarding high woodland fire occurrence, we then used this approach to estimate the age of long-unburnt E. salubris stands, and the age-class distribution of Eucalyptus woodlands across the region. Time since fire was strongly predicted by trunk growth rings and plant size predicted growth rings with reasonable accuracy. The best model estimating growth rings contained parameters for trunk diameter, plant height and plot location, although simple models including either trunk diameter or plant height were nearly as good. Using growth ring–size relationships to date long-unburnt stands represents a significant advance over the current approach based on satellite imagery, which substantially truncates post-fire age. However, there was significant uncertainty over the best model form for estimating the time since fire of stands last burnt over 200 years ago. The management implications of predicted age-class distributions were highly dependent on both the choice of what, if any, transformation was applied to growth rings, and the theoretical age-class distribution to which the actual age-class distribution was compared.
Publisher: Biodiversity Heritage Library
Date: 2003
DOI: 10.5962/P.254920
Publisher: Elsevier BV
Date: 12-2018
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 11-2014
DOI: 10.1016/J.TREE.2014.09.003
Abstract: Identifying the deleterious ecological effects of developments, such as roads, mining, and urban expansion, is essential for informing development decisions and identifying appropriate mitigation actions. However, there are many types of ecological impacts that slip 'under the radar' of conventional impact evaluations and undermine the potential for successful impact mitigation (including offsets). These 'enigmatic' impacts include those that are small but act cumulatively those outside of the area directly considered in the evaluation those not detectable with the methods, paradigms, or spatiotemporal scales used to detect them those facilitated, but not directly caused, by development and synergistic impact interactions. Here, we propose a framework for conceptualising enigmatic impacts and discuss ways to address them.
Publisher: Springer Science and Business Media LLC
Date: 09-03-2014
DOI: 10.1038/NATURE13144
Abstract: Human alterations to nutrient cycles and herbivore communities are affecting global bio ersity dramatically. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems. Here we use experimental data spanning a globally relevant range of conditions to test the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory. This experiment, replicated in 40 grasslands on 6 continents, demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant ersity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate. Nutrient addition consistently reduced local ersity through light limitation, and herbivory rescued ersity at sites where it alleviated light limitation. Thus, species loss from anthropogenic eutrophication can be ameliorated in grasslands where herbivory increases ground-level light.
Publisher: Wiley
Date: 08-2004
Publisher: Springer Science and Business Media LLC
Date: 07-04-2015
Publisher: Wiley
Date: 09-2018
DOI: 10.1111/EMR.12339
Publisher: CSIRO Publishing
Date: 1990
DOI: 10.1071/BT9900079
Abstract: Eucalyptus paliformis is restricted to a small, isolated plateau on the eastern escarpment of south-eastern Australia. Eucalyptus parvifolia populations are scattered discontinuously in a narrow band of nearby grazing land that has been substantially cleared over the last 100 years. Allozyme ersity was examined in six of the seven known populations of E. paliformis and in all the eight known populations of E. parvifolia to help assess the potential for the survival of these species under current conditions of management. Levels of genetic ersity in E. paliformis are comparable to levels in other eucalypts of restricted distribution and, in conjunction with its large population sizes, are likely to be adequate for its survival. The greatest threat to E. paliformis is its localised distribution, which renders it susceptible to extinction by disturbance. By contrast, the levels and distribution of ersity in E. parvifolia, and estimates of migration between populations, suggest that the high variability measured in this species may be a consequence of a once more continuous distribution. The recent dissection of its range through clearing is likely to lead to a decline in levels of genetic ersity in E. parvifolia, which, when combined with destruction of the habitat where it can best outcompete other eucalypts, suggests its survival is threatened.
Publisher: CSIRO
Date: 2021
DOI: 10.25919/DBRW-7S65
Publisher: Wiley
Date: 28-03-2011
Publisher: Public Library of Science (PLoS)
Date: 06-02-2013
Publisher: Public Library of Science (PLoS)
Date: 22-11-2019
Publisher: Proceedings of the National Academy of Sciences
Date: 17-08-2015
Abstract: Human activities have resulted in large increases in the availability of nutrients in terrestrial ecosystems worldwide. Although plant community responses to elevated nutrients have been well studied, soil microbial community responses remain poorly understood, despite their critical importance to ecosystem functioning. Using DNA-sequencing approaches, we assessed the response of soil microbial communities to experimentally added nitrogen and phosphorus at 25 grassland sites across the globe. Our results demonstrate that the composition of these communities shifts in consistent ways with elevated nutrient inputs and that there are corresponding shifts in the ecological attributes of the community members. This study represents an important step forward for understanding the connection between elevated nutrient inputs, shifts in soil microbial communities, and altered ecosystem functioning.
Publisher: Wiley
Date: 09-01-2016
DOI: 10.1111/JBI.12693
Publisher: Wiley
Date: 14-03-2014
DOI: 10.1111/GEB.12157
Publisher: Wiley
Date: 13-01-2014
DOI: 10.1111/PCE.12251
Abstract: Widespread species often occur across a range of climatic conditions, through a combination of local genetic adaptations and phenotypic plasticity. Species with greater phenotypic plasticity are likely to be better positioned to cope with rapid anthropogenic climate changes, while those displaying strong local adaptations might benefit from translocations to assist the movement of adaptive genes as the climate changes. Eucalyptus tricarpa occurs across a climatic gradient in south-eastern Australia, a region of increasing aridity, and we hypothesized that this species would display local adaptation to climate. We measured morphological and physiological traits reflecting climate responses in nine provenances from sites of 460 to 1040 mm annual rainfall, in their natural habitat and in common gardens near each end of the gradient. Local adaptation was evident in functional traits and differential growth rates in the common gardens. Some traits displayed complex combinations of plasticity and genetic ergence among provenances, including clinal variation in plasticity itself. Provenances from drier locations were more plastic in leaf thickness, whereas leaf size was more plastic in provenances from higher rainfall locations. Leaf density and stomatal physiology (as indicated by δ(13)C and δ(18)O) were highly and uniformly plastic. In addition to variation in mean trait values, genetic variation in trait plasticity may play a role in climate adaptation.
Publisher: Wiley
Date: 06-1992
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.SCITOTENV.2016.05.170
Abstract: Ecosystem monitoring networks aim to collect data on physical, chemical and biological systems and their interactions that shape the biosphere. Here we introduce the Australian SuperSite Network that, along with complementary facilities of Australia's Terrestrial Ecosystem Research Network (TERN), delivers field infrastructure and erse, ecosystem-related datasets for use by researchers, educators and policy makers. The SuperSite Network uses infrastructure replicated across research sites in different biomes, to allow comparisons across ecosystems and improve scalability of findings to regional, continental and global scales. This conforms with the approaches of other ecosystem monitoring networks such as Critical Zone Observatories, the U.S. National Ecological Observatory Network Analysis and Experimentation on Ecosystems, Europe Chinese Ecosystem Research Network International Long Term Ecological Research network and the United States Long Term Ecological Research Network. The Australian SuperSite Network currently involves 10 SuperSites across a erse range of biomes, including tropical rainforest, grassland and savanna wet and dry sclerophyll forest and woodland and semi-arid grassland, woodland and savanna. The focus of the SuperSite Network is on using vegetation, faunal and biophysical monitoring to develop a process-based understanding of ecosystem function and change in Australian biomes and to link this with data streams provided by the series of flux towers across the network. The Australian SuperSite Network is also intended to support a range of auxiliary researchers who contribute to the growing body of knowledge within and across the SuperSite Network, public outreach and education to promote environmental awareness and the role of ecosystem monitoring in the management of Australian environments.
Publisher: Springer Science and Business Media LLC
Date: 18-08-2011
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/RJ17069
Abstract: Principles underpinning the goals of nature conservation and ecological restoration have traditionally involved preventing ecological change or restoring ecosystems or populations towards preferred historical states. Under global climate change, it is increasingly recognised that this may no longer be achievable, but there has been limited debate regarding new principles that can help guide goal-setting for nature conservation and ecological restoration in dynamic environments. To stimulate such debate, we established a framework of human motivations implicit in historically focussed nature conservation approaches. We drew on this and a literature survey to propose a palette of five principles to guide goal-setting for nature conservation and ecological restoration in a changing climate. Our framework proposes three broad sets of human motivations relevant to nature conservation: (1) basic survival and material needs (akin to provisioning and regulating ecosystem services), (2) psychological and cultural needs such as a sense of place (reflecting cultural ecosystem services), and (3) the need to fulfil moral or ethical obligations (e.g. intergenerational and interspecies equity). Meeting basic needs for current and future generations is supported by a commonly proposed principle to optimise ecological processes and functions (Principle 1) which in turn is dependent on maintaining the ongoing evolutionary potential in the world’s biota (Principle 2). Beyond this, motivations relating to psychological, cultural and moral needs demand not only an emphasis on healthy ecosystem functioning, but on the character and ersity of the ecosystems and species that contribute to these functions. Our subsequent three principles, minimise native species losses (Principle 3), maintain the evolutionary character and biogeographic structuring of the biota (Principle 4), and maintain wild natural ecosystems (Principle 5) contribute to these further goals. Although these principles can sometimes be conflicting, we argue that by connecting directly with underlying motivations, this broader palette will help take us forward towards more effective nature conservation in a rapidly changing world.
Publisher: Wiley
Date: 09-2017
DOI: 10.1111/EMR.12275
Publisher: Wiley
Date: 22-03-2022
DOI: 10.1111/GCB.16141
Abstract: In 2020, the Australian and New Zealand flux research and monitoring network, OzFlux, celebrated its 20 th anniversary by reflecting on the lessons learned through two decades of ecosystem studies on global change biology. OzFlux is a network not only for ecosystem researchers, but also for those ‘next users’ of the knowledge, information and data that such networks provide. Here, we focus on eight lessons across topics of climate change and variability, disturbance and resilience, drought and heat stress and synergies with remote sensing and modelling. In distilling the key lessons learned, we also identify where further research is needed to fill knowledge gaps and improve the utility and relevance of the outputs from OzFlux. Extreme climate variability across Australia and New Zealand (droughts and flooding rains) provides a natural laboratory for a global understanding of ecosystems in this time of accelerating climate change. As evidence of worsening global fire risk emerges, the natural ability of these ecosystems to recover from disturbances, such as fire and cyclones, provides lessons on adaptation and resilience to disturbance. Drought and heatwaves are common occurrences across large parts of the region and can tip an ecosystem's carbon budget from a net CO 2 sink to a net CO 2 source. Despite such responses to stress, ecosystems at OzFlux sites show their resilience to climate variability by rapidly pivoting back to a strong carbon sink upon the return of favourable conditions. Located in under‐represented areas, OzFlux data have the potential for reducing uncertainties in global remote sensing products, and these data provide several opportunities to develop new theories and improve our ecosystem models. The accumulated impacts of these lessons over the last 20 years highlights the value of long‐term flux observations for natural and managed systems. A future vision for OzFlux includes ongoing and newly developed synergies with ecophysiologists, ecologists, geologists, remote sensors and modellers.
Publisher: Island Press/Center for Resource Economics
Date: 2016
Publisher: Frontiers Media SA
Date: 08-11-2022
Abstract: Selection on plant functional traits may occur through their direct effects on fitness (or a fitness component), or may be mediated by attributes of plant performance which have a direct impact on fitness. Understanding this link is particularly challenging for long-lived organisms, such as forest trees, where lifetime fitness assessments are rarely achievable, and performance features and fitness components are usually quantified from early-life history stages. Accordingly, we studied a cohort of trees from multiple populations of Eucalyptus pauciflora grown in a common-garden field trial established at the hot and dry end of the species distribution on the island of Tasmania, Australia. We related the within-population variation in leaf economic (leaf thickness, leaf area and leaf density) and hydraulic (stomatal density, stomatal length and vein density) traits, measured from two-year-old plants, to two-year growth performance (height and stem diameter) and to a fitness component (seven-year survival). When performance-trait relationships were modelled for all traits simultaneously, statistical support for direct effects on growth performance was only observed for leaf thickness and leaf density. Performance-based estimators of directional selection indicated that in iduals with reduced leaf thickness and increased leaf density were favoured. Survival-performance relationships were consistent with size-dependent mortality, with fitness-based selection gradients estimated for performance measures providing evidence for directional selection favouring in iduals with faster growth. There was no statistical support for an effect associated with the fitness-based quadratic selection gradient estimated for growth performance. Conditional on a performance measure, fitness-based directional selection gradients estimated for the leaf traits did not provide statistical support for direct effects of the focal traits on tree survival. This suggested that, under the environmental conditions of the trial site and time period covered in the current study, early-stage selection on the studied leaf traits may be mediated by their effects on growth performance, which in turn has a positive direct influence on later-age survival. We discuss the potential mechanistic basis of the direct effects of the focal leaf traits on tree growth, and the relevance of a putative causal pathway of trait effects on fitness through mediation by growth performance in the studied hot and dry environment.
Publisher: Wiley
Date: 06-1991
Publisher: Wiley
Date: 07-10-2017
DOI: 10.1111/MEC.14341
Abstract: Understanding whether populations can adapt in situ or whether interventions are required is of key importance for bio ersity management under climate change. Landscape genomics is becoming an increasingly important and powerful tool for rapid assessments of climate adaptation, especially in long‐lived species such as trees. We investigated climate adaptation in Eucalyptus microcarpa using the DA rTseq genomic approach. A combination of F ST outlier and environmental association analyses were performed using genomewide single nucleotide polymorphisms ( SNP s) from 26 populations spanning climate gradients in southeastern Australia. Eighty‐one SNP s were identified as putatively adaptive, based on significance in F ST outlier tests and significant associations with one or more climate variables related to temperature (70/81), aridity (37/81) or precipitation (35/81). Adaptive SNP s were located on all 11 chromosomes, with no particular region associated with in idual climate variables. Climate adaptation appeared to be characterized by subtle shifts in allele frequencies, with no consistent fixed differences identified. Based on these associations, we predict adaptation under projected changes in climate will include a suite of shifts in allele frequencies. Whether this can occur sufficiently rapidly through natural selection within populations, or would benefit from assisted gene migration, requires further evaluation. In some populations, the absence or predicted increases to near fixation of particular adaptive alleles hint at potential limits to adaptive capacity. Together, these results reinforce the importance of standing genetic variation at the geographic level for maintaining species’ evolutionary potential.
Publisher: Wiley
Date: 28-11-2015
DOI: 10.1111/ELE.12381
Abstract: Aboveground-belowground interactions exert critical controls on the composition and function of terrestrial ecosystems, yet the fundamental relationships between plant ersity and soil microbial ersity remain elusive. Theory predicts predominantly positive associations but tests within single sites have shown variable relationships, and associations between plant and microbial ersity across broad spatial scales remain largely unexplored. We compared the ersity of plant, bacterial, archaeal and fungal communities in one hundred and forty-five 1 m(2) plots across 25 temperate grassland sites from four continents. Across sites, the plant alpha ersity patterns were poorly related to those observed for any soil microbial group. However, plant beta ersity (compositional dissimilarity between sites) was significantly correlated with the beta ersity of bacterial and fungal communities, even after controlling for environmental factors. Thus, across a global range of temperate grasslands, plant ersity can predict patterns in the composition of soil microbial communities, but not patterns in alpha ersity.
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/BT11026
Abstract: Emerging ecological theory predicts that vegetation changes caused by introduction of livestock grazing may be irreversible after livestock are removed, especially in regions such as Australia that have a short evolutionary exposure to ungulate grazing. Despite this, fencing to exclude livestock grazing is the major tool used to restore vegetation in Australian agricultural landscapes. To characterise site-scale benefits and limitations of livestock exclusion for enhancing bio ersity in forb-rich York gum (Eucalyptus loxophleba Benth. subsp. loxophleba)–jam (Acacia acuminata Benth.) woodlands, we compared 29 fenced woodlands with 29 adjacent grazed woodlands and 11 little-grazed ‘benchmark’ woodlands in the Western Australian wheatbelt. We explored the following two hypotheses: (1) fencing to exclude livestock facilitates recovery of grazed woodlands towards benchmark conditions, and (2) without additional interventions after fencing, complete recovery of grazed woodlands to benchmark conditions is constrained by ecological or other limits. Our first hypothesis was supported for vegetation parameters, with fenced woodlands being more similar to benchmark woodlands in tree recruitment, exotic plant cover, native plant cover, native plant richness and plant species composition than were grazed woodlands. Further, exotic cover decreased and frequency of jam increased with time-since-fencing (2–22 years). However, we found no evidence that fencing led to decline in topsoil nutrient concentrations towards concentrations at benchmark sites. Our second hypothesis was also supported, with higher topsoil nutrient concentrations and exotic plant cover, and lower native plant richness in fenced than in benchmark woodlands, and different plant species composition between fenced and benchmark woodlands. Regression analyses suggested that recovery of native species richness is constrained by exotic species that persist after fencing, which in turn are more persistent at higher topsoil nutrient concentrations. We conclude that fencing to exclude livestock grazing can be valuable for bio ersity conservation. However, consistent with ecological theory, additional interventions are likely to be necessary to achieve some conservation goals or to promote recovery at nutrient-enriched sites.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 29-01-2016
Abstract: Fraser et al . (Reports, 17 July 2015, p. 302) report a unimodal relationship between productivity and species richness at regional and global scales, which they contrast with the results of Adler et al . (Reports, 23 September 2011, p. 1750). However, both data sets, when analyzed correctly, show clearly and consistently that productivity is a poor predictor of local species richness.
Publisher: Springer Science and Business Media LLC
Date: 22-05-2011
Publisher: Elsevier BV
Date: 12-2013
Publisher: American Association for the Advancement of Science (AAAS)
Date: 23-09-2011
Abstract: Standardized s ling from many sites worldwide was used to address an important ecological problem.
Publisher: Springer Science and Business Media LLC
Date: 07-04-2017
DOI: 10.1038/NCOMMS14790
Abstract: Microbial symbiosis is integral to plant growth and reproduction, but its contribution to global patterns of plant distribution is unknown. Legumes ( Fabaceae ) are a erse and widely distributed plant family largely dependent on symbiosis with nitrogen-fixing rhizobia, which are acquired from soil after germination. This dependency is predicted to limit establishment in new geographic areas, owing to a disruption of compatible host-symbiont associations. Here we compare non-native establishment patterns of symbiotic and non-symbiotic legumes across over 3,500 species, covering multiple independent gains and losses of rhizobial symbiosis. We find that symbiotic legume species have spread to fewer non-native regions compared to non-symbiotic legumes, providing strong support for the hypothesis that lack of suitable symbionts or environmental conditions required for effective nitrogen-fixation are driving these global introduction patterns. These results highlight the importance of mutualisms in predicting non-native species establishment and the potential impacts of microbial biogeography on global plant distributions.
Publisher: Copernicus GmbH
Date: 26-02-2019
Abstract: Abstract. Recent experimental evidence suggests that during heat extremes, wooded ecosystems may decouple photosynthesis and transpiration, reducing photosynthesis to near zero but increasing transpiration into the boundary layer. This feedback may act to d en, rather than lify, heat extremes in wooded ecosystems. We examined eddy covariance databases (OzFlux and FLUXNET2015) to identify whether there was field-based evidence to support these experimental findings. We focused on two types of heat extremes: (i) the 3 days leading up to a temperature extreme, defined as including a daily maximum temperature ∘C (similar to the widely used TXx metric), and (ii) heatwaves, defined as 3 or more consecutive days above 35 ∘C. When focusing on (i), we found some evidence of reduced photosynthesis and sustained or increased latent heat fluxes at seven Australian evergreen wooded flux sites. However, when considering the role of vapour pressure deficit and focusing on (ii), we were unable to conclusively disentangle the decoupling between photosynthesis and latent heat flux from the effect of increasing the vapour pressure deficit. Outside of Australia, the Tier-1 FLUXNET2015 database provided limited scope to tackle this issue as it does not s le sufficient high temperature events with which to probe the physiological response of trees to extreme heat. Thus, further work is required to determine whether this photosynthetic decoupling occurs widely, ideally by matching experimental species with those found at eddy covariance tower sites. Such measurements would allow this decoupling mechanism to be probed experimentally and at the ecosystem scale. Transpiration during heatwaves remains a key issue to resolve, as no land surface model includes a decoupling mechanism, and any potential d ening of the land–atmosphere lification is thus not included in climate model projections.
Publisher: No publisher found
Date: 2021
DOI: 10.25919%2F7ZF8-7073
Publisher: Copernicus GmbH
Date: 11-2016
Abstract: Abstract. As a result of climate change warmer temperatures are projected through the 21st century and are already increasing above modelled predictions. Apart from increases in the mean, warm/hot temperature extremes are expected to become more prevalent in the future, along with an increase in the frequency of droughts. It is crucial to better understand the response of terrestrial ecosystems to such temperature extremes for predicting land-surface feedbacks in a changing climate. While land-surface feedbacks in drought conditions and during heat waves have been reported from Europe and the US, direct observations of the impact of such extremes on the carbon and water cycles in Australia have been lacking. During the 2012/2013 summer, Australia experienced a record-breaking heat wave with an exceptional spatial extent that lasted for several weeks. In this study we synthesised eddy-covariance measurements from seven woodlands and one forest site across three biogeographic regions in southern Australia. These observations were combined with model results from BIOS2 (Haverd et al., 2013a, b) to investigate the effect of the summer heat wave on the carbon and water exchange of terrestrial ecosystems which are known for their resilience toward hot and dry conditions. We found that water-limited woodland and energy-limited forest ecosystems responded differently to the heat wave. During the most intense part of the heat wave, the woodlands experienced decreased latent heat flux (23 % of background value), increased Bowen ratio (154 %) and reduced carbon uptake (60 %). At the same time the forest ecosystem showed increased latent heat flux (151 %), reduced Bowen ratio (19 %) and increased carbon uptake (112 %). Higher temperatures caused increased ecosystem respiration at all sites (up to 139 %). During daytime all ecosystems remained carbon sinks, but carbon uptake was reduced in magnitude. The number of hours during which the ecosystem acted as a carbon sink was also reduced, which switched the woodlands into a carbon source on a daily average. Precipitation occurred after the first, most intense part of the heat wave, and the subsequent cooler temperatures in the temperate woodlands led to recovery of the carbon sink, decreased the Bowen ratio (65 %) and hence increased evaporative cooling. Gross primary productivity in the woodlands recovered quickly with precipitation and cooler temperatures but respiration remained high. While the forest proved relatively resilient to this short-term heat extreme the response of the woodlands is the first direct evidence that the carbon sinks of large areas of Australia may not be sustainable in a future climate with an increased number, intensity and duration of heat waves.
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/WF08200
Abstract: Managing fire regimes is increasingly recognised as important for bio ersity conservation in fragmented agricultural landscapes in fire-prone regions. In the global bio ersity hotspot of south-west Western Australia, chaining and burning is a novel technique for facilitating fire management. Vegetation is first dislodged using a chain, then after a period of curing, burnt. The effects on plant communities are largely unstudied, despite the potential consequences of combining two disturbance events. We hypothesised that outcomes would vary depending on plant functional types defined by disturbance response. We compared plant community composition and recruitment and resprouting of plant functional types in mallee-heath subject to chaining and burning, burning only and neither of these. The effects of chaining and burning did not differ from only burning at the community level. Importantly, however, we recorded 90% fewer recruits of serotinous, obligate seeders in chained and burnt compared with only burnt plots, and a 44% decrease in their species richness. By contrast, recruits of obligate seeding shrubs and fire-ephemeral herbs with persistent soil-stored seed banks increased by 166% in chained and burnt plots. Sprouters showed little difference. We conclude that chaining and burning is likely to significantly alter vegetation composition, and potentially poses a significant threat to serotinous, obligate seeders. These impacts require consideration in fire management planning.
Publisher: Wiley
Date: 31-08-2009
Publisher: Wiley
Date: 27-09-2019
DOI: 10.1002/EAP.1997
Abstract: In an era characterized by recurrent large wildfires in many parts of the globe, there is a critical need to understand how animal species respond to fires, the rates at which populations can recover, and the functional changes fires may cause. Using quantified changes in habitat parameters over a ~400-yr post-fire chronosequence in an obligate-seeding Australian eucalypt woodland, we build and test predictions of how birds, as in idual species and aggregated into functional groups according to their use of specific habitat resources, respond to time since fire. In idual bird species exhibited four generalized response types to time since fire: incline, decline, delayed, and bell. All significant relationships between bird functional group richness or abundance and time since fire were consistent with predictions based on known time-since-fire-associated changes in habitat features putatively important for these bird groups. Consequently, we argue that the bird community is responding to post-fire successional changes in habitat as per the habitat accommodation model, rather than to time since fire per se, and that our functional framework will be of value in predicting bird responses to future disturbances in this and other obligate-seeder forest and woodland ecosystems. Most bird species and functional groups that were affected by time since fire were associated with long-unburned woodlands. In the context of recent large, stand-replacement wildfires that have affected a substantial proportion of obligate-seeder eucalypt woodlands, and the multi-century timescales over which post-fire succession occurs, it would appear preferable from a bird conservation perspective if fires initiating loss of currently long-unburned woodlands were minimized. Once long-unburned woodlands are transformed by fire into recently burned woodlands, there is limited scope for alternative management interventions to accelerate the rate of habitat development after fire, or supplement the resources formerly provided to birds by long-unburned woodlands, with the limited exception of augmenting hollow availability for key hollow-nesting species.
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/RS16004
Abstract: Eucalypts are the cornerstone of ecological restoration efforts across the highly modified agricultural landscapes of southern Australia. ‘Local provenancing’ is the established strategy for sourcing germplasm for ecological restoration plantings, yet this approach gives little consideration to the persistence of these plantings under future climates. This paper provides a synopsis of recent and ongoing research that the authors are undertaking on climate adaptation in eucalypts, combining new genomic approaches with ecophysiological evidence from provenance trials. These studies explore how adaptive ersity is distributed within and among populations, whether populations are buffered against change through capacity for phenotypic plasticity, and how this informs provenancing strategies. Results to date suggest that eucalypts have some capacity to respond to future environmental instability through adaptive phenotypic plasticity or selection of putatively adaptive alleles. Despite this, growing evidence suggests that eucalypts will still be vulnerable to change. Provenancing strategies that exploit adaptations found in non-local provenances could thus confer greater climate-resilience in ecological restoration plantings, although they will also need to account for potential interactions between climate adaptations and other factors (e.g. cryptic evolutionary variation, non-climate-related adaptations, herbivory and elevated CO2).
Publisher: Wiley
Date: 16-10-2013
DOI: 10.1111/GCB.12370
Abstract: Invasions have increased the size of regional species pools, but are typically assumed to reduce native ersity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, native community ersity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant ersity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring species' relative abundance will more rapidly advance our understanding of invasions.
Publisher: Wiley
Date: 28-12-2011
Publisher: Wiley
Date: 12-2019
DOI: 10.1002/ECS2.2927
Publisher: Springer Science and Business Media LLC
Date: 03-01-2021
Publisher: Oxford University Press (OUP)
Date: 30-03-2017
Publisher: CSIRO Publishing
Date: 1990
DOI: 10.1071/SB9900047
Abstract: The utility of isozyme analysis in elucidating the relationship between Australian tree taxa is reviewed. Although little exploited to date, isozyme analysis is shown to be a rapid and relatively powerful method of examining relationships, if used at an appropriate taxonomic level. For Eucalyptus and Acacia, isozymes appear to be the most informative at the lower taxonomic levels. In Eucalyptus delegatensis and Casuarina cunninghamiana, isozyme data strongly support subspecies erected on the basis of morphological characteristics. In Acacia holoserocea, isozyme data predicted the existence of two subspecies, which prediction as later supported by morphological characters. An isozyme study of the phylogenetic relationships within the 'green ash' group of eucalypts yielded a phylogenetic hypothesi comparable to one derived from morphological characters, but also highlighted areas of discrepancy requiring further research. At the generic level, isozyme data for the Australian species of Litsea and Neolitsea successfully separated the two genera and allowed phylogenetic relationships within genera to be hypothesised. For the larger tree genera such as the Eucalyptus and Acacia, however, the utility of isozymes at the higher taxonomic levels is likely to be low, because of the difficulty in establishing homologies between taxa, or insufficient phylogenetic information when taxa being compared have few alleles in common.
Publisher: MDPI AG
Date: 14-07-2022
Abstract: With climate change impacting trees worldwide, enhancing adaptation capacity has become an important goal of provenance translocation strategies for forestry, ecological renovation, and bio ersity conservation. Given that not every species can be studied in detail, it is important to understand the extent to which climate adaptation patterns can be generalised across species, in terms of the selective agents and traits involved. We here compare patterns of genetic-based population (co)variation in leaf economic and hydraulic traits, climate–trait associations, and genomic differentiation of two widespread tree species (Eucalyptus pauciflora and E. ovata). We studied 2-year-old trees growing in a common-garden trial established with progeny from populations of both species, pair-s led from 22 localities across their overlapping native distribution in Tasmania, Australia. Despite originating from the same climatic gradients, the species differed in their levels of population variance and trait covariance, patterns of population variation within each species were uncorrelated, and the species had different climate–trait associations. Further, the pattern of genomic differentiation among populations was uncorrelated between species, and population differentiation in leaf traits was mostly uncorrelated with genomic differentiation. We discuss hypotheses to explain this decoupling of patterns and propose that the choice of seed provenances for climate-based plantings needs to account for multiple dimensions of climate change unless species-specific information is available.
Publisher: Springer Science and Business Media LLC
Date: 04-02-2019
DOI: 10.1038/S41559-018-0790-1
Abstract: Leaf traits are frequently measured in ecology to provide a 'common currency' for predicting how anthropogenic pressures impact ecosystem function. Here, we test whether leaf traits consistently respond to experimental treatments across 27 globally distributed grassland sites across 4 continents. We find that specific leaf area (leaf area per unit mass)-a commonly measured morphological trait inferring shifts between plant growth strategies-did not respond to up to four years of soil nutrient additions. Leaf nitrogen, phosphorus and potassium concentrations increased in response to the addition of each respective soil nutrient. We found few significant changes in leaf traits when vertebrate herbivores were excluded in the short-term. Leaf nitrogen and potassium concentrations were positively correlated with species turnover, suggesting that interspecific trait variation was a significant predictor of leaf nitrogen and potassium, but not of leaf phosphorus concentration. Climatic conditions and pretreatment soil nutrient levels also accounted for significant amounts of variation in the leaf traits measured. Overall, we find that leaf morphological traits, such as specific leaf area, are not appropriate indicators of plant response to anthropogenic perturbations in grasslands.
Publisher: Wiley
Date: 30-10-2018
Publisher: Elsevier BV
Date: 04-2015
Publisher: No publisher found
Date: 2021
DOI: 10.25919%2FA9B7-9Y54
Publisher: Wiley
Date: 15-01-2019
DOI: 10.1002/ECM.1333
Publisher: Wiley
Date: 09-2017
Publisher: Wiley
Date: 06-03-2013
Publisher: Springer Science and Business Media LLC
Date: 04-12-2017
DOI: 10.1038/S41559-017-0395-0
Abstract: Bio ersity is declining in many local communities while also becoming increasingly homogenized across space. Experiments show that local plant species loss reduces ecosystem functioning and services, but the role of spatial homogenization of community composition and the potential interaction between ersity at different scales in maintaining ecosystem functioning remains unclear, especially when many functions are considered (ecosystem multifunctionality). We present an analysis of eight ecosystem functions measured in 65 grasslands worldwide. We find that more erse grasslands-those with both species-rich local communities (α- ersity) and large compositional differences among localities (β- ersity)-had higher levels of multifunctionality. Moreover, α- and β- ersity synergistically affected multifunctionality, with higher levels of ersity at one scale lifying the contribution to ecological functions at the other scale. The identity of species influencing ecosystem functioning differed among functions and across local communities, explaining why more erse grasslands maintained greater functionality when more functions and localities were considered. These results were robust to variation in environmental drivers. Our findings reveal that plant ersity, at both local and landscape scales, contributes to the maintenance of multiple ecosystem services provided by grasslands. Preserving ecosystem functioning therefore requires conservation of bio ersity both within and among ecological communities.
Publisher: Copernicus GmbH
Date: 31-10-2016
Abstract: Abstract. OzFlux is the regional Australian and New Zealand flux tower network that aims to provide a continental-scale national research facility to monitor and assess trends, and improve predictions, of Australia's terrestrial biosphere and climate. This paper describes the evolution, design, and current status of OzFlux as well as provides an overview of data processing. We analyse measurements from all sites within the Australian portion of the OzFlux network and two sites from New Zealand. The response of the Australian biomes to climate was largely consistent with global studies except that Australian systems had a lower ecosystem water-use efficiency. Australian semi-arid/arid ecosystems are important because of their huge extent (70 %) and they have evolved with common moisture limitations. We also found that Australian ecosystems had a similar radiation-use efficiency per unit leaf area compared to global values that indicates a convergence toward a similar biochemical efficiency. The two New Zealand sites represented extremes in productivity for a moist temperate climate zone, with the grazed dairy farm site having the highest GPP of any OzFlux site (2620 gC m−2 yr−1) and the natural raised peat bog site having a very low GPP (820 gC m−2 yr−1). The paper discusses the utility of the flux data and the synergies between flux, remote sensing, and modelling. Lastly, the paper looks ahead at the future direction of the network and concludes that there has been a substantial contribution by OzFlux, and considerable opportunities remain to further advance our understanding of ecosystem response to disturbances, including drought, fire, land-use and land-cover change, land management, and climate change, which are relevant both nationally and internationally. It is suggested that a synergistic approach is required to address all of the spatial, ecological, human, and cultural challenges of managing the delicately balanced ecosystems in Australasia.
Publisher: Wiley
Date: 25-08-2016
DOI: 10.1111/AEC.12377
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.YMPEV.2019.03.016
Abstract: Plant taxa can be broadly ided based on the mechanisms enabling persistence through whole-crown disturbances, specifically whether in iduals resprout, populations reseed, or both or neither of these mechanisms are employed. At scales from species through to communities, the balance of disturbance-response types has major ramifications for ecological function and bio ersity conservation. In some lineages, morphologically identical populations except for differences in a disturbance-response trait (e.g. ± lignotuber) occur, offering the opportunity to apply genetic analyses to test whether trait state is representative of broader genetic distinctiveness, or alternatively, variation in response to local environmental conditions. In eucalypts, a globally-significant plant group, we apply dense taxon s ling and high-density, genome-wide markers to test monophyly and genetic ergence among pairs of essentially morphologically-identical taxa excepting lignotuber state. Taxa differing in lignotuber state formed discrete phylogenetic lineages. Obligate-seeders were monophyletic and strongly differentiated from each other and lignotuber-resprouters, but this was not the case for all lignotuber-resprouter taxa. One lignotuber state transition within our s le clade was supported, implying convergence of some non-lignotuber morphology characters. Greater evolutionary rate associated with the obligate-seeder disturbance-response strategy offers a plausible explanation for these genetic patterns. Lignotuber state is an important taxonomic character in eucalypts, with transitions in lignotuber state having contributed to the evolution of the exceptional ersity of eucalypts in south-western Australia. Differences in lignotuber state have evolved directionally with respect to environmental conditions.
Publisher: Elsevier BV
Date: 10-2014
Publisher: Wiley
Date: 18-03-2019
DOI: 10.1111/ELE.13258
Abstract: Soil stores approximately twice as much carbon as the atmosphere and fluctuations in the size of the soil carbon pool directly influence climate conditions. We used the Nutrient Network global change experiment to examine how anthropogenic nutrient enrichment might influence grassland soil carbon storage at a global scale. In isolation, enrichment of nitrogen and phosphorous had minimal impacts on soil carbon storage. However, when these nutrients were added in combination with potassium and micronutrients, soil carbon stocks changed considerably, with an average increase of 0.04 KgCm
Publisher: No publisher found
Date: 2018
Publisher: Wiley
Date: 29-05-2012
Publisher: Wiley
Date: 06-04-2018
Publisher: Elsevier BV
Date: 02-2019
Publisher: Frontiers Media SA
Date: 04-03-2022
Abstract: Anthropogenic climate change is increasing the frequency and intensity of heat waves, thereby threatening bio ersity, particularly in hot, arid regions. Although free-ranging endotherms can use behavioral thermoregulation to contend with heat, it remains unclear to what degree behavior can buffer organisms from unprecedented temperatures. Thermoregulatory behaviors that facilitate dry heat loss during moderate heat become maladaptive once environmental temperatures exceed body temperature. Additionally, the costs associated with behavioral thermoregulation may become untenable with greater heat exposure, and effective cooling may be dependent upon the availability of specific microhabitats. Only by understanding the interplay of these three elements (responses, costs and habitat) can we hope to accurately predict how heat waves will impact wild endotherms. We quantified the thermoregulatory behaviors and microhabitat use of a small passerine, the Jacky Winter ( Microeca fascinans ), in the mallee woodland of SE Australia. At this location, the annual number of days ≥ 42°C has doubled over the last 25 years. The birds’ broad repertoire of behavioral responses to heat was nuanced and responsive to environmental conditions, but was associated with reduced foraging effort and increased foraging costs, accounting for the loss of body condition that occurs at high temperatures. By measuring microsite surface temperatures, which varied by up to 35°C at air temperatures & 44°C, we found that leaf-litter coverage and tree size were positively correlated with thermal buffering. Large mallee eucalypts were critical to the birds’ response to very high temperatures, providing high perches that facilitated convective cooling, the coolest tree-base temperatures and the greatest prevalence of tree-base crevices or hollows that were used as refuges at air temperatures & 38°C. Tree-base hollows, found only in large mallees, were cooler than all other microsites, averaging 2°C cooler than air temperature. Despite the plasticity of the birds’ response to heat, 29% of our habituated study population died when air temperatures reached a record-breaking 49°C, demonstrating the limits of behavioral thermoregulation and the potential vulnerability of organisms to climate change.
Publisher: Wiley
Date: 31-10-2021
Abstract: Plant damage by invertebrate herbivores and pathogens influences the dynamics of grassland ecosystems, but anthropogenic changes in nitrogen and phosphorus availability can modify these relationships. Using a globally distributed experiment, we describe leaf damage on 153 plant taxa from 27 grasslands worldwide, under ambient conditions and with experimentally elevated nitrogen and phosphorus. Invertebrate damage significantly increased with nitrogen addition, especially in grasses and non‐leguminous forbs. Pathogen damage increased with nitrogen in grasses and legumes but not forbs. Effects of phosphorus were generally weaker. Damage was higher in grasslands with more precipitation, but climatic conditions did not change effects of nutrients on leaf damage. On average, invertebrate damage was relatively higher on legumes and pathogen damage was relatively higher on grasses. Community‐weighted mean damage reflected these functional group patterns, with no effects of N on community‐weighted pathogen damage (due to opposing responses of grasses and forbs) but stronger effects of N on community‐weighted invertebrate damage (due to consistent responses of grasses and forbs). Synthesis . As human‐induced inputs of nitrogen and phosphorus continue to increase, understanding their impacts on invertebrate and pathogen damage becomes increasingly important. Our results demonstrate that eutrophication frequently increases plant damage and that damage increases with precipitation across a wide array of grasslands. Invertebrate and pathogen damage in grasslands is likely to increase in the future, with potential consequences for plant, invertebrate and pathogen communities, as well as the transfer of energy and nutrients across trophic levels.
Publisher: Wiley
Date: 07-2022
DOI: 10.1002/ECE3.9058
Abstract: Ecological restoration of former agricultural land can improve soil conditions, recover native vegetation, and provide fauna habitat. However, restoration benefits are often associated with time lags, as many attributes, such as leaf litter and coarse woody debris, need time to accumulate. Here, we experimentally tested whether adding mulch and logs to restoration sites in semi‐arid Western Australia can accelerate restoration benefits. All sites had been cropped and then planted with native trees and shrubs (i.e., Eucalyptus , Melaleuca , and Acacia spp.) 10 years prior to our experiment, to re‐establish the original temperate eucalypt woodland vegetation community. We used a Multi‐site Before‐After‐Control‐Impact (MBACI) design to test the effects on 30 abiotic and biotic response variables over a period of 2 years. Of the 30 response variables, a significant effect was found for just four variables: volumetric water content, decomposition, native herbaceous species cover and species richness of disturbance specialist ants. Mulch addition had a positive effect on soil moisture when compared to controls but suppressed growth of native (but not exotic) herbaceous plants. On plots with log additions, decomposition rates decreased, and species richness of disturbance specialist ants increased. However, we found no effect on total species richness and abundance of other ant species groups. The benefit of mulch to soil moisture was offset by its disbenefit to native herbs in our study. Given time, logs may also provide habitat for ant species that prefer concealed habitats. Indeed, benefits to other soil biophysical properties, vegetation, and ant fauna may require longer time frames to be detected. Further research is needed to determine whether the type, quantity, and context of mulch and log additions may improve their utility for old field restoration and whether effects on native herbs are correlated with idiosyncratic climatic conditions.
Publisher: Resilience Alliance, Inc.
Date: 2011
Publisher: CSIRO Publishing
Date: 1990
DOI: 10.1071/SB9900275
Abstract: A new species of Eucalyptus, E. elaeophlioa, is described from the Nunniong Plateau in the far east of Victoria. It is classified in informal subgenus Symphyomyrtus, section Maidenaria and is sister species to E. imlayensis.
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/WF13096
Abstract: Understanding fire behaviour and vegetation flammability is important for predicting the consequences of fires. Visual assessments of fuel, such as those developed in Project Vesta, have been widely applied to facilitate rapid data acquisition to support fire behaviour models. However, the accuracy and potential wider application to other plant communities of Vesta visual fuel assessments has received limited attention. We conducted visual fuel assessments and detailed quantitative structural measurements in Eucalyptus salubris (gimlet) woodlands in the world’s largest extant Mediterranean-climate woodland. With one exception, there was moderate to strong correlation between visual assessments of cover in vegetation layers and quantitative measurements, indicating that visual assessments adequately capture changes in fuels. This suggests that the Vesta visual fuel assessment methodology may have wide application in Australian eucalypt forests and woodlands and perhaps in similar communities around the world. However, several issues limiting the wider application of Vesta visual fuel assessments were identified, mainly associated with differences in community ecology between non-resprouter dominated E. salubris woodlands and the epicormic resprouter-dominated dry forests where the method was developed. Patterns of change in fuels suggest that flammability in E. salubris woodlands peaks at intermediate times since fire, potentially providing opportunities for fire management interventions.
Publisher: CSIRO
Date: 2013
Publisher: Proceedings of the National Academy of Sciences
Date: 06-07-2021
Abstract: Predicting the effects of anthropogenic nutrient enrichment on plant communities is critical for managing implications for bio ersity and ecosystem services. Plant functional types that fix atmospheric nitrogen (e.g., legumes) may be at particular risk of nutrient-driven global decline, yet global-scale evidence is lacking. Using an experiment in 45 grasslands across six continents, we showed that legume cover, richness, and biomass declined substantially with nitrogen additions. Although legumes benefited from phosphorus, potassium, and other nutrients, these nutrients did not ameliorate nitrogen-induced legume decline. Given global trends in anthropogenic nutrient enrichment, our results indicate the potential for global decline in grassland legumes, with likely consequences for bio ersity, food webs, soil health, and genetic improvement of protein-rich plant species for food production.
Publisher: CSIRO Publishing
Date: 1996
DOI: 10.1071/BT9960057
Abstract: Grassy white box (Eucalyptus albens Benth.) woodlands once covered several million hectares of the wheat-sheep belt of south-eastern Australia. The pre-European floristic composition of these woodlands is little-known, as almost all of them were rapidly cleared for cropping or modified by livestock grazing. Woodland remnants were surveyed across NSW, to describe rangewide variation in the woodland flora, and to provide a basis for reserve design. As far as could be detected from current remnants, some of the major features of the original grassy white box woodland understorey appear to have been relatively constant across NSW: on a wide variety of soils and parent materials from southern to northern NSW, the dominant native grasses in little-disturbed sites were generally Themeda australis (R.Br.) Stapf andor Poa sieberiana Sprengel, and many of the subsidiary herbs and grasses occurred across this range. There were, however, several natural patterns of variation requiring consideration in conservation planning: about half of the subsidiary herb and grass species showed a relationship with latitude, probably relating to a climatic gradient the understorey became more shrubby, with a sparser and more varied grass component, on soils classed as being 'unsuitable for agriculture' and on basalt parent materials of the Inverell Plateau, Dichanthium sericeum (R.Br.) A.Camus may have been a more prominent component of the understorey. Natural floristic variation was overlain by patterns resulting from European disturbance, as indicated by floristic distinctions between sites of differing landuse. While these distinctions were partly related to poorer soil resource class in State Forests and Nature Reserves, grazing by livestock and tree clearing are likely to to have contributed to them. Reserves in ine whire box woodiands are presentiy few, and are not representative of the naturai variation. ~ o s t existing reserves occur on soils unsuited to agriculture, compared with the grazing or arable land of typical grassy woodland. Cemetery remnants, rail easements, Travelling Stock Reserves and roadsides provide the best opportunities for conservation on higher-quality soils. Remnant quality declined significantly in southern NSW, indicating a need for greater conservation effort in southern areas.
Publisher: Springer Science and Business Media LLC
Date: 19-05-2022
Publisher: Springer Science and Business Media LLC
Date: 23-08-2017
Publisher: Springer International Publishing
Date: 2015
Publisher: CSIRO
Date: 2010
Publisher: Elsevier BV
Date: 07-2015
Publisher: Wiley
Date: 12-1998
Publisher: CSIRO
Date: 2012
Publisher: American Association for the Advancement of Science (AAAS)
Date: 28-09-2022
Abstract: Deadwood is a large global carbon store with its store size partially determined by biotic decay. Microbial wood decay rates are known to respond to changing temperature and precipitation. Termites are also important decomposers in the tropics but are less well studied. An understanding of their climate sensitivities is needed to estimate climate change effects on wood carbon pools. Using data from 133 sites spanning six continents, we found that termite wood discovery and consumption were highly sensitive to temperature (with decay increasing .8 times per 10°C increase in temperature)—even more so than microbes. Termite decay effects were greatest in tropical seasonal forests, tropical savannas, and subtropical deserts. With tropicalization (i.e., warming shifts to tropical climates), termite wood decay will likely increase as termites access more of Earth’s surface.
Publisher: Springer Science and Business Media LLC
Date: 24-08-2016
DOI: 10.1038/NATURE19324
Publisher: Elsevier BV
Date: 02-2013
Publisher: Springer Science and Business Media LLC
Date: 18-06-2014
Publisher: No publisher found
Date: 2021
DOI: 10.25919%2FDBRW-7S65
Publisher: Royal Botanical Gardens and Domain Trust
Date: 27-04-2006
Publisher: CSIRO Climate Adaptation Flagship
Date: 2012
Publisher: Wiley
Date: 12-01-2009
Publisher: No publisher found
Date: 2014
Publisher: Wiley
Date: 10-06-2020
DOI: 10.1111/GCB.15146
Abstract: Microbial processing of aggregate‐unprotected organic matter inputs is key for soil fertility, long‐term ecosystem carbon and nutrient sequestration and sustainable agriculture. We investigated the effects of adding multiple nutrients (nitrogen, phosphorus and potassium plus nine essential macro‐ and micro‐nutrients) on decomposition and biochemical transformation of standard plant materials buried in 21 grasslands from four continents. Addition of multiple nutrients weakly but consistently increased decomposition and biochemical transformation of plant remains during the peak‐season, concurrent with changes in microbial exoenzymatic activity. Higher mean annual precipitation and lower mean annual temperature were the main climatic drivers of higher decomposition rates, while biochemical transformation of plant remains was negatively related to temperature of the wettest quarter. Nutrients enhanced decomposition most at cool, high rainfall sites, indicating that in a warmer and drier future fertilized grassland soils will have an even more limited potential for microbial processing of plant remains.
Publisher: Springer Science and Business Media LLC
Date: 17-03-2023
DOI: 10.1007/S11104-023-05962-3
Abstract: Degraded ecosystems can be maintained by abiotic and biotic legacies long after initial disturbances, preventing recovery. These legacies can include changes in arbuscular mycorrhizal fungi (AMF). To inform potential restoration pathways, we aimed to elucidate differences in AMF between intact and degraded ecosystems, their responses to modified soils, and interactions with invasive plants. We used a state-and-transition framework to characterise AMF communities, native and exotic plant cover, and soil physicochemical properties across little-modified reference states and degraded states, which were carbon (C) and nitrogen (N) -depleted, intermediate, and CN-enriched, in temperate eucalypt woodlands of south-eastern Australia. Most ground-layer states differed significantly in their AMF communities, with the CN-enriched states being most distinct. All states had unique taxa and characteristic indicator taxa, but intermediate and CN-enriched states harboured four-to-five times more indicator taxa than the reference state. Consistent with this, richness of AMF was higher in the intermediate and CN-enriched states than in reference states, driven by higher richness of Archaeosporaceae, Diversisporaceae, Glomeraceae, and Paraglomeraceae. Pathway analysis indicated that differences in AMF communities among states were strongly related to differences in native:exotic plant cover ratio, mediated by soil organic matter and nutrients. Our results indicate that ecosystem degradation is associated with both loss of AMF taxa and introduction of ‘weedy’ AMF, which in turn potentially contribute to maintenance of degraded ecosystems. We argue that our state-and-transition approach to characterising AMF communities improved our understanding of the different pathways of degradation, elucidating possible constraints to ecosystem recovery.
Publisher: Wiley
Date: 12-2001
Publisher: Wiley
Date: 25-11-2021
DOI: 10.1111/REC.13605
Abstract: Many old fields are undergoing ecological restoration aiming to return lost bio ersity and ecosystem functions. However, there is scant evidence that this outcome is achieved. Here we investigate the effects of tree planting following cessation of cropping on ant communities. Ants are a dominant faunal group, functionally important for ecosystem recovery and widely used as indicators of ecosystem restoration. Using a space‐for‐time approach, we surveyed eight fallow croplands, 10‐year‐old planted old fields, and reference woodlands in semi‐arid south‐western Australia. We tested the extent ant communities in planted old fields erged from those of fallow cropland and converged with those of reference woodlands, distinguishing areas under tree canopies and open patches to account for a direct tree effect. We analyzed ant community data at species, genus, and functional‐group levels. Ant species composition in planted old fields substantially converged from fallow croplands toward reference woodlands. Abundance and richness of genera in the tree‐associated functional group Subordinate C onotini was higher under trees than in open areas in planted old fields and reference woodlands. Unlike in reference woodlands, abundance and richness of Hot Climate Specialists was not higher in open areas than under trees in planted old fields, indicating that planted trees did not yet strongly impact the microclimate beneath them. Although old field restoration had positive effects on ant assemblages, full convergence to reference woodlands had not been achieved after 10 years. This was particularly evident for functional groups. Research on older plantings is needed to test if and when full convergence occurs.
Publisher: Wiley
Date: 31-03-2018
DOI: 10.1002/ECY.2175
Abstract: Plant stoichiometry, the relative concentration of elements, is a key regulator of ecosystem functioning and is also being altered by human activities. In this paper we sought to understand the global drivers of plant stoichiometry and compare the relative contribution of climatic vs. anthropogenic effects. We addressed this goal by measuring plant elemental (C, N, P and K) responses to eutrophication and vertebrate herbivore exclusion at eighteen sites on six continents. Across sites, climate and atmospheric N deposition emerged as strong predictors of plot-level tissue nutrients, mediated by biomass and plant chemistry. Within sites, fertilization increased total plant nutrient pools, but results were contingent on soil fertility and the proportion of grass biomass relative to other functional types. Total plant nutrient pools erged strongly in response to herbivore exclusion when fertilized responses were largest in ungrazed plots at low rainfall, whereas herbivore grazing d ened the plant community nutrient responses to fertilization. Our study highlights (1) the importance of climate in determining plant nutrient concentrations mediated through effects on plant biomass, (2) that eutrophication affects grassland nutrient pools via both soil and atmospheric pathways and (3) that interactions among soils, herbivores and eutrophication drive plant nutrient responses at small scales, especially at water-limited sites.
Publisher: Springer Science and Business Media LLC
Date: 29-10-2021
DOI: 10.1007/S10980-021-01313-8
Abstract: Understanding the variability and dynamics of ecosystems, as well as their responses to climate or land use change, is challenging for policy makers and natural resource managers. Virtual reality (VR) can be used to render virtual landscapes as immersive, visceral experiences and communicate ecosystem dynamics to users in an effective and engaging way. To illustrate the potential and believability of VR, a team of landscape ecologists and immersive visualisation researchers modelled a reference Australian Box Gum Grassy Woodland landscape, an endangered eucalypt woodland ecosystem that is difficult to observe in its pre-European colonisation form. We document considerations for designing the immersive virtual landscape, including the creation of animated three-dimensional (3D) plants that alternate between the seasons, and soundscapes that change through the course of a simulated day. We used a heuristic evaluation with experts to assess the potential of immersive VR landscape modeling. This cross disciplinary collaboration resulted in a VR experience that was evaluated in a series of meetings by 27 ecologists and managers in bio ersity conservation, many of whom were familiar with Box Gum Grassy Woodlands. 88% of participants stated that the simulation was believable and participants thought that virtual landscapes held great potential for education, public engagement and land management. Possible future directions include open-source libraries of ecological 3D models, and the visual simulation of historic landscapes and future climate change scenarios.
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.
Publisher: Public Library of Science (PLoS)
Date: 28-02-2017
Publisher: Wiley
Date: 06-2015
DOI: 10.1890/14-1902.1
Publisher: Springer Science and Business Media LLC
Date: 06-07-2015
Abstract: Terrestrial ecosystem productivity is widely accepted to be nutrient limited(1). Although nitrogen (N) is deemed a key determinant of aboveground net primary production (ANPP)(2,3), the prevalence of co-limitation by N and phosphorus (P) is increasingly recognized(4-8). However, the extent to which terrestrial productivity is co-limited by nutrients other than N and P has remained unclear. Here, we report results from a standardized factorial nutrient addition experiment, in which we added N, P and potassium (K) combined with a selection of micronutrients (K+μ), alone or in concert, to 42 grassland sites spanning five continents, and monitored ANPP. Nutrient availability limited productivity at 31 of the 42 grassland sites. And pairwise combinations of N, P, and K+μ co-limited ANPP at 29 of the sites. Nitrogen limitation peaked in cool, high latitude sites. Our findings highlight the importance of less studied nutrients, such as K and micronutrients, for grassland productivity, and point to significant variations in the type and degree of nutrient limitation. We suggest that multiple-nutrient constraints must be considered when assessing the ecosystem-scale consequences of nutrient enrichment.
Publisher: MDPI AG
Date: 03-09-2020
DOI: 10.3390/FIRE3030048
Abstract: Prior and Bowman added a new dimension to existing frameworks of post-fire responses of woody plants, by including the trait of colonisation ability (C) for those taxa which neither resprout (Rf−) nor produce seedlings (Sf−) after fire. Specifically, they recognised distinctions between: (i) post-fire obligate colonisers, being species that neither resprout nor produce seedlings from persistent seed banks post-fire but are able to colonise burnt areas through dispersal from unburnt populations, and (ii) fire-intolerant, which are unable to recover after fire by either resprouting, seeding or colonisation. We use data on temporal and spatial patterns of colonisation of Rf−Sf− mistletoes from a chronosequence study with an exceptionally long span of times since fire as a practical ex le of the delineation of post-fire obligate coloniser and fire-intolerant species. We propose that when a population of a species is burnt, if the species is unable to regularly colonise and reach reproductive maturity in burnt areas spatially distant from fire edges within plausible and regularly-occurring maximum fire-return intervals for the now-burnt community type, it would be classified as fire-intolerant. In our ex les, Lysiana meets the criteria for fire-intolerant in obligate-seeder eucalypt woodland, while Amyema is classed as a post-fire obligate coloniser.
Publisher: Public Library of Science (PLoS)
Date: 20-04-2012
Publisher: Wiley
Date: 07-2021
Abstract: Vegetation recovery in old fields towards mature reference states is often limited by abiotic and biotic thresholds resulting from agricultural land use legacies, as commonly highlighted using state and transition models. Old‐field restoration may include interventions (e.g. planting of vegetation) to overcome these thresholds and assist transition between states. However, our understanding of the effectiveness of these interventions is limited. Using a point‐intercept transect method, we surveyed nine sites, each comprising a triplet of fallow cropland, planted old field and woodland reference plots to reflect states of old‐field restoration, from the degraded state to the reference state. We compared ground cover attributes, and richness and cover of woody and herbaceous flora species, using ANOVA and multivariate analyses. We found that a decade after planting, cover of leaf litter and woody debris in planted old fields were significantly higher than in the fallow croplands however, woodland reference conditions were not achieved. Cover of logs was similar to the fallow cropland. Woody species cover and richness were similar in planted old fields and woodland reference plots, with planted old fields having more than 60% of the shrub species richness and cover, and similar tree species richness, to the woodland reference plot. In contrast, whilst herbaceous species contributed more than half the plant species richness in reference woodland plots, there were significantly fewer herbaceous species in the planted old fields, which were more similar to the fallow croplands. Cover of exotic annual forbs in planted old fields was about half that of fallow cropland, and exotic annual grass cover was similar to the reference woodland. Our results show that active restoration of old fields increased leaf litter, woody debris and cover and richness of trees and perennial shrubs. However, native herbaceous species richness, and to some extent cover, remained similar to the fallow cropland. To effect transitioning of the herbaceous layer to the woodland reference state, further intervention such as removal of exotics, followed by sowing or planting native herbaceous species, may be necessary.
Publisher: Wiley
Date: 27-04-2012
Publisher: CSIRO
Date: 2018
Publisher: Elsevier BV
Date: 11-2012
Publisher: CSIRO
Date: 2020
DOI: 10.25919/F61Q-1386
Publisher: American Association for the Advancement of Science (AAAS)
Date: 23-03-2012
Abstract: Pan et al . claim that our results actually support a strong linear positive relationship between productivity and richness, whereas Fridley et al . contend that the data support a strong humped relationship. These responses illustrate how preoccupation with bivariate patterns distracts from a deeper understanding of the multivariate mechanisms that control these important ecosystem properties.
Publisher: Department of Biodiversity, Conservation and Attractions
Date: 15-10-2019
DOI: 10.58828/NUY00927
Publisher: CSIRO
Date: 2021
DOI: 10.25919/7ZF8-7073
Publisher: Wiley
Date: 29-08-2016
DOI: 10.1111/JVS.12450
Publisher: Springer Science and Business Media LLC
Date: 15-07-0001
DOI: 10.1038/NCOMMS8710
Abstract: Exotic species dominate many communities however the functional significance of species’ biogeographic origin remains highly contentious. This debate is fuelled in part by the lack of globally replicated, systematic data assessing the relationship between species provenance, function and response to perturbations. We examined the abundance of native and exotic plant species at 64 grasslands in 13 countries, and at a subset of the sites we experimentally tested native and exotic species responses to two fundamental drivers of invasion, mineral nutrient supplies and vertebrate herbivory. Exotic species are six times more likely to dominate communities than native species. Furthermore, while experimental nutrient addition increases the cover and richness of exotic species, nutrients decrease native ersity and cover. Native and exotic species also differ in their response to vertebrate consumer exclusion. These results suggest that species origin has functional significance, and that eutrophication will lead to increased exotic dominance in grasslands.
Publisher: Elsevier BV
Date: 09-2010
Publisher: Wiley
Date: 02-2011
DOI: 10.1111/J.1461-0248.2010.01584.X
Abstract: Many ecosystems worldwide are dominated by introduced plant species, leading to loss of bio ersity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at 39 sites, within eight countries, revealed that species abundances were similar at native (home) and introduced (away) sites - grass species were generally abundant home and away, while forbs were low in abundance, but more abundant at home. Sites with six or more of these species had similar community abundance hierarchies, suggesting that suites of introduced species are assembling similarly on different continents. Overall, we found that substantial changes to populations are not necessarily a pre-condition for invasion success and that increases in species abundance are unusual. Instead, abundance at home predicts abundance away, a potentially useful additional criterion for biosecurity programmes.
Publisher: CSIRO
Date: 2010
Publisher: Wiley
Date: 09-2022
DOI: 10.1111/GCB.16346
Abstract: A globally relevant and standardized taxonomy and framework for consistently describing land cover change based on evidence is presented, which makes use of structured land cover taxonomies and is underpinned by the Driver-Pressure-State-Impact-Response (DPSIR) framework. The Global Change Taxonomy currently lists 246 classes based on the notation 'impact (pressure)', with this encompassing the consequence of observed change and associated reason(s), and uses scale-independent terms that factor in time. Evidence for different impacts is gathered through temporal comparison (e.g., days, decades apart) of land cover classes constructed and described from Environmental Descriptors (EDs state indicators) with pre-defined measurement units (e.g., m, %) or categories (e.g., species type). Evidence for pressures, whether abiotic, biotic or human-influenced, is similarly accumulated, but EDs often differ from those used to determine impacts. Each impact and pressure term is defined separately, allowing flexible combination into 'impact (pressure)' categories, and all are listed in an openly accessible glossary to ensure consistent use and common understanding. The taxonomy and framework are globally relevant and can reference EDs quantified on the ground, retrieved/classified remotely (from ground-based, airborne or spaceborne sensors) or predicted through modelling. By providing capacity to more consistently describe change processes-including land degradation, desertification and ecosystem restoration-the overall framework addresses a wide and erse range of local to international needs including those relevant to policy, socioeconomics and land management. Actions in response to impacts and pressures and monitoring towards targets are also supported to assist future planning, including impact mitigation actions.
Publisher: Wiley
Date: 25-02-2021
DOI: 10.1111/GCB.15539
Abstract: Globally, collapse of ecosystems—potentially irreversible change to ecosystem structure, composition and function—imperils bio ersity, human health and well‐being. We examine the current state and recent trajectories of 19 ecosystems, spanning 58° of latitude across 7.7 M km 2 , from Australia's coral reefs to terrestrial Antarctica. Pressures from global climate change and regional human impacts, occurring as chronic ‘presses’ and/or acute ‘pulses’, drive ecosystem collapse. Ecosystem responses to 5–17 pressures were categorised as four collapse profiles—abrupt, smooth, stepped and fluctuating. The manifestation of widespread ecosystem collapse is a stark warning of the necessity to take action. We present a three‐step assessment and management framework (3As Pathway Awareness , Anticipation and Action ) to aid strategic and effective mitigation to alleviate further degradation to help secure our future.
Publisher: CSIRO Publishing
Date: 1995
DOI: 10.1071/BT9950349
Abstract: Before European settlement, grassy white box woodlands were the dominant vegetation in the east of the wheat-sheep belt of south-eastern Australia. Tree clearing, cultivation and pasture improvement have led to fragmentation of this once relatively continuous ecosystem, leaving a series of remnants which themselves have been modified by livestock grazing. Little-modified remnants are extremely rare. We examined and compared the effects of fragmentation and disturbance on the understorey flora of woodland remnants, through a survey of remnants of varying size, grazing history and tree clearing. In accordance with fragmentation theory, species richness generally increased with remnant size, and, for little-grazed remnants, smaller remnants were more vulnerable to weed invasion. Similarly, tree clearing and grazing encouraged weed invasion and reduced native species richness. Evidence for increased total species richness at intermediate grazing levels, as predicted by the intermediate disturbance hypothesis, was equivocal. Remnant quality was more severely affected by grazing than by remnant size. All little-grazed remnants had lower exotic species abundance and similar or higher native species richness than grazed remnants, despite their extremely small sizes ( 6 ha). Further, small, littlegrazed remnants maintained the general character of the pre-European woodland understorey, while grazing caused changes to the dominant species. Although generally small, the little-grazed remnants are the best representatives of the pre-European woodland understorey, and should be central to any conservation plan for the woodlands. Selected larger remnants are needed to complement these, however, to increase the total area of woodland conserved, and, because most little-grazed remnants are cleared, to represent the ecosystem in its original structural form. For the maintenance of native plant ersity and composition in little-grazed remnants, it is critical that livestock grazing continues to be excluded. For grazed remnants, maintenance of a site in its current state would allow continuation of past management, while restoration to a pre-European condition would require management directed towards weed removal, and could take advantage of the difference noted in the predominant life-cycle of native (perennial) versus exotic (annual or biennial) species.
Publisher: Wiley
Date: 16-03-2021
Abstract: Restoration of old fields in agricultural landscapes has become increasingly important for conservation of species and their habitats owing to habitat destruction and rapid environmental change. Studies examining the outcomes of old field restoration predominantly focus on plant, and sometimes, vertebrate communities. Fewer studies have systematically investigated the effects of restoration efforts on soil properties or ground‐dwelling invertebrates and there is limited synthesis of these data. We conducted a global meta‐analysis of published studies to assess the effects of old field restoration on soil properties and soil invertebrate abundance and richness. We anticipated increased vegetation cover would improve soil properties towards reference condition and in turn, this would promote invertebrate abundance and richness. Studies were included if field sites had a history of cropping or livestock grazing. We identified 42 studies (1994–2019) from 16 countries that met our criteria. More studies assessed passive restoration methods than active planting, and native species were more commonly planted than exotic species. Results showed that restoration improved soil conditions with respect to total nitrogen, magnesium, soil carbon, bulk density and porosity when compared to controls however, conditions similar to those in reference ecosystems were generally not achieved, even 50+ years after restoration had been initiated. Moderator analyses showed few significant tends, however, bulk density improved with age, and in passively restored versus reference ecosystems. Outcomes for soil carbon and bulk density were most predominant in the top soil when compared to the degraded ecosystem. We detected no consistent trends for the effect of restoration on soil invertebrate richness and abundance compared to the control or reference ecosystems. Synthesis and applications . Our global meta‐analysis found strong evidence that old field restoration in agricultural landscapes had positive effects on soil condition but did not lead to full recovery when compared to a reference ecosystem. We detected few and idiosyncratic effects for invertebrates. Further research is needed to understand effects of restoration on soil invertebrate functional groups and to develop management interventions that accelerate the restoration of soil condition.
Publisher: Wiley
Date: 19-07-2013
Publisher: Wiley
Date: 14-10-2019
DOI: 10.1111/ELE.13389
Abstract: A pervasive challenge in microbial ecology is understanding the genetic level where ecological units can be differentiated. Ecological differentiation often occurs at fine genomic levels, yet it is unclear how to utilise ecological information to define ecotypes given the breadth of environmental variation among microbial taxa. Here, we present an analytical framework that infers clusters along genome-based microbial phylogenies according to shared environmental responses. The advantage of our approach is the ability to identify genomic clusters that best fit complex environmental information whilst characterising cluster niches through model predictions. We apply our method to determine climate-associated ecotypes in populations of nitrogen-fixing symbionts using whole genomes, explicitly s led to detect climate differentiation across a heterogeneous landscape. Although soil and plant host characteristics strongly influence distribution patterns of inferred ecotypes, our flexible statistical method enabled us to identify climate-associated genomic clusters using environmental data, providing solid support for ecological specialisation in soil symbionts.
Publisher: Wiley
Date: 21-07-2016
DOI: 10.1111/NPH.14084
Abstract: In order to contribute to evolutionary resilience and adaptive potential in highly modified landscapes, revegetated areas should ideally reflect levels of genetic ersity within and across natural stands. Landscape genomic analyses enable such ersity patterns to be characterized at genome and chromosomal levels. Landscape-wide patterns of genomic ersity were assessed in Eucalyptus microcarpa, a dominant tree species widely used in revegetation in Southeastern Australia. Trees from small and large patches within large remnants, small isolated remnants and revegetation sites were assessed across the now highly fragmented distribution of this species using the DArTseq genomic approach. Genomic ersity was similar within all three types of remnant patches analysed, although often significantly but only slightly lower in revegetation sites compared with natural remnants. Differences in ersity between stand types varied across chromosomes. Genomic differentiation was higher between small, isolated remnants, and among revegetated sites compared with natural stands. We conclude that small remnants and revegetated sites of our E. microcarpa s les largely but not completely capture patterns in genomic ersity across the landscape. Genomic approaches provide a powerful tool for assessing restoration efforts across the landscape.
Publisher: Wiley
Date: 2015
DOI: 10.1890/14-1902.1.SM
Publisher: CSIRO
Date: 2015
Publisher: Springer Science and Business Media LLC
Date: 22-03-2012
Publisher: Wiley
Date: 19-05-2017
DOI: 10.1002/ECE3.2995
Publisher: Wiley
Date: 29-03-2005
Publisher: Springer Science and Business Media LLC
Date: 03-03-2022
Location: Australia
Start Date: 11-2020
End Date: 12-2023
Amount: $439,000.00
Funder: Australian Research Council
View Funded Activity