ORCID Profile
0000-0003-0189-1899
Current Organisations
The University of Auckland
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University of Chicago
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University of Sydney
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Publisher: Oxford University Press (OUP)
Date: 31-01-2014
DOI: 10.1093/AOB/MCT314
Publisher: Wiley
Date: 15-07-2013
DOI: 10.1111/AEC.12065
Publisher: Wiley
Date: 03-03-2021
DOI: 10.1002/WCC.704
Abstract: Bushfires in Australia in the “Black Summer” of 2019–2020 shocked the world. Research is allowing us to begin to appreciate the scale of the catastrophe for humans, other animals, and the environment. If we are to anticipate, mitigate, and prevent further catastrophes and to protect bio ersity as best we can, we must develop a comprehensive picture of the impacts of these recent bushfires, understand their causes, and trace where responsibility for their catastrophic impact on bio ersity falls. This opinion piece argues that doing so requires an analysis that combines legal, philosophical, and scientific lenses. Correlatively, a comprehensive response demands the rapid introduction of a range of scientific, legal, political, economic, and cultural changes, not simply to reduce fossil fuel emissions and better protect bio ersity, but to disable the ideological conditions that enable the existing policy framework. This article is categorized under: Climate, Ecology, and Conservation Conservation Strategies
Publisher: Wiley
Date: 22-02-2016
Publisher: The Royal Society
Date: 11-2017
DOI: 10.1098/RSOS.170384
Abstract: Climate change is predicted to place up to one in six species at risk of extinction in coming decades, but extinction probability is likely to be influenced further by biotic interactions such as predation. We use structural equation modelling to integrate results from remote camera trapping and long-term (17–22 years) regional-scale (8000 km 2 ) datasets on vegetation and small vertebrates (greater than 38 880 captures) to explore how biotic processes and two key abiotic drivers influence the structure of a erse assemblage of desert biota in central Australia. We use our models to predict how changes in rainfall and wildfire are likely to influence the cover and productivity of the dominant vegetation and the impacts of predators on their primary rodent prey over a 100-year timeframe. Our results show that, while vegetation cover may decline due to climate change, the strongest negative effect on prey populations in this desert system is top-down suppression from introduced predators.
Publisher: Wiley
Date: 25-02-2016
DOI: 10.1111/AEC.12334
Publisher: Wiley
Date: 05-08-2021
DOI: 10.1111/ELE.13858
Abstract: Genetic differentiation and phenotypic plasticity jointly shape intraspecific trait variation, but their roles differ among traits. In short‐lived plants, reproductive traits may be more genetically determined due to their impact on fitness, whereas vegetative traits may show higher plasticity to buffer short‐term perturbations. Combining a multi‐treatment greenhouse experiment with observational field data throughout the range of a widespread short‐lived herb, Plantago lanceolata , we (1) disentangled genetic and plastic responses of functional traits to a set of environmental drivers and (2) assessed how genetic differentiation and plasticity shape observational trait–environment relationships. Reproductive traits showed distinct genetic differentiation that largely determined observational patterns, but only when correcting traits for differences in biomass. Vegetative traits showed higher plasticity and opposite genetic and plastic responses, masking the genetic component underlying field‐observed trait variation. Our study suggests that genetic differentiation may be inferred from observational data only for the traits most closely related to fitness.
Publisher: Wiley
Date: 25-01-2010
Publisher: Wiley
Date: 10-1998
Publisher: Wiley
Date: 05-10-2016
DOI: 10.1111/AEC.12450
Publisher: Wiley
Date: 05-2016
DOI: 10.1002/ECS2.1343
Publisher: Springer Science and Business Media LLC
Date: 23-06-2016
DOI: 10.1007/S00442-016-3672-8
Abstract: Resources are seldom distributed equally across space, but many species exhibit spatially synchronous population dynamics. Such synchrony suggests the operation of large-scale external drivers, such as rainfall or wildfire, or the influence of oasis sites that provide water, shelter, or other resources. However, testing the generality of these factors is not easy, especially in variable environments. Using a long-term dataset (13-22 years) from a large (8000 km(2)) study region in arid Central Australia, we tested firstly for regional synchrony in annual rainfall and the dynamics of six reptile species across nine widely separated sites. For species that showed synchronous spatial dynamics, we then used multivariate follow a multivariate auto-regressive state-space (MARSS) models to predict that regional rainfall would be positively associated with their populations. For asynchronous species, we used MARSS models to explore four other possible population structures: (1) populations were asynchronous, (2) differed between oasis and non-oasis sites, (3) differed between burnt and unburnt sites, or (4) differed between three sub-regions with different rainfall gradients. Only one species showed evidence of spatial population synchrony and our results provide little evidence that rainfall synchronizes reptile populations. The oasis or the wildfire hypotheses were the best-fitting models for the other five species. Thus, our six study species appear generally to be structured in space into one or two populations across the study region. Our findings suggest that for arid-dwelling reptile populations, spatial and temporal dynamics are structured by abiotic events, but in idual responses to covariates at smaller spatial scales are complex and poorly understood.
Publisher: Wiley
Date: 23-12-2016
DOI: 10.1111/AEC.12324
Publisher: Springer Science and Business Media LLC
Date: 25-07-2022
DOI: 10.1038/S41559-022-01809-9
Abstract: Ecological models predict that the effects of mammalian herbivore exclusion on plant ersity depend on resource availability and plant exposure to ungulate grazing over evolutionary time. Using an experiment replicated in 57 grasslands on six continents, with contrasting evolutionary history of grazing, we tested how resources (mean annual precipitation and soil nutrients) determine herbivore exclusion effects on plant ersity, richness and evenness. Here we show that at sites with a long history of ungulate grazing, herbivore exclusion reduced plant ersity by reducing both richness and evenness and the responses of richness and ersity to herbivore exclusion decreased with mean annual precipitation. At sites with a short history of grazing, the effects of herbivore exclusion were not related to precipitation but differed for native and exotic plant richness. Thus, plant species' evolutionary history of grazing continues to shape the response of the world's grasslands to changing mammalian herbivory.
Publisher: Royal Zoological Society of New South Wales
Date: 10-08-2022
DOI: 10.7882/AZ.2022.033
Abstract: Australia’s 2019–20 mega-fires burnt 79% of the Greater Blue Mountains World Heritage Area, prompting an urgent need for rapid on-ground post-fire assessments of flora and fauna to aid in post-fire recovery. This project aimed to determine spatial patterns in populations and assemblages of vertebrates, vertebrate temporal activity, and the diet of the invasive Red Fox Vulpes vulpes, across burnt and unburnt sites. Using remote camera traps we surveyed 12 unburnt and 10 burnt sites approximately 12 months after the fires. We detected 41 species (11 mammals, 28 birds and 2 reptiles), with different species composition, but similar vertebrate species richness across both unburnt and burnt sites. The relative abundance of the Eastern Grey Kangaroo Macropus giganteus, Common Wombat Vombatus ursinus and Australian Magpie Gymnorhina tibicen was higher in burnt sites, while small mammals (& 500 g) had higher relative abundance at unburnt sites. There was no difference in the relative abundance of the Superb Lyrebird Menura novaehollandiae across burnt and unburnt sites, and although 11 species of bird were only detected at unburnt sites, the numbers were too low for reliable estimates of differences. Red Fox scat analysis (n=23) revealed that invertebrates and plant material were the dominant prey items in both burnt and unburnt sites, but medium-sized mammals increased in Red Fox diets in burnt sites, and reptiles were consumed disproportionately more by Red Foxes in burnt compared to unburnt sites. Although the short-term nature of this study and low scat s le size limited detailed insights, our rapid survey was an effective tool to gain preliminary data on species responses to the 2019–20 megafires in the Blue Mountains and contribute to a baseline for understanding species recovery.
Publisher: Wiley
Date: 07-01-2015
DOI: 10.1111/AEC.12207
Publisher: American Association for the Advancement of Science (AAAS)
Date: 25-11-2022
Abstract: Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem services remain uncertain because pervasive interactions between grazing pressure, climate, soil properties, and bio ersity may occur but have never been addressed simultaneously. Using a standardized survey at 98 sites across six continents, we show that interactions between grazing pressure, climate, soil, and bio ersity are critical to explain the delivery of fundamental ecosystem services across drylands worldwide. Increasing grazing pressure reduced ecosystem service delivery in warmer and species-poor drylands, whereas positive effects of grazing were observed in colder and species-rich areas. Considering interactions between grazing and local abiotic and biotic factors is key for understanding the fate of dryland ecosystems under climate change and increasing human pressure.
Publisher: Royal Zoological Society of New South Wales
Date: 12-2018
DOI: 10.7882/AZ.2018.030
Publisher: University of Chicago Press
Date: 10-2015
DOI: 10.1086/682336
Publisher: Wiley
Date: 10-07-2023
DOI: 10.1111/ECOG.06619
Abstract: Species interactions play a fundamental role in ecosystems. However, few ecological communities have complete data describing such interactions, which is an obstacle to understanding how ecosystems function and respond to perturbations. Because it is often impractical to collect empirical data for all interactions in a community, various methods have been developed to infer interactions. Machine learning is increasingly being used for making interaction predictions, with random forest being one of the most frequently used of these methods. However, performance of random forest in inferring predator‐prey interactions in terrestrial vertebrates and its sensitivity to training data quality remain untested. We examined predator–prey interactions in two erse, primarily terrestrial vertebrate classes: birds and mammals. Combining data from a global interaction dataset and a specific community (Simpson Desert, Australia), we tested how well random forest predicted predator–prey interactions for mammals and birds using species' ecomorphological and phylogenetic traits. We also tested how variation in training data quality – manipulated by removing records and switching interaction records to non‐interactions – affected model performance. We found that random forest could predict predator–prey interactions for birds and mammals using ecomorphological or phylogenetic traits, correctly predicting up to 88 and 67% of interactions and non‐interactions in the global and community‐specific datasets, respectively. These predictions were accurate even when there were no records in the training data for focal species. In contrast, false non‐interactions for focal predators in training data strongly degraded model performance. Our results demonstrate that random forest can identify predator–prey interactions for birds and mammals that have few or no interaction records. Furthermore, our study provides guidance on how to prepare training data to optimise machine learning classifiers for predicting species interactions, which could help ecologists 1) address knowledge gaps and explore network‐related questions in data‐poor situations, and 2) predict interactions for range‐expanding species.
Publisher: Oxford University Press (OUP)
Date: 16-08-2010
Publisher: Wiley
Date: 16-07-2019
Abstract: Productivity is a key driver of ecosystem structure and function, so long-term studies are critical to understanding ecosystems with high temporal variation in productivity. In some deserts, productivity, driven by moisture availability, varies immensely over time (rainfall) and space (landscape factors). At high productivity, species richness is expected to be driven in opposing directions by abundance (More In iduals Hypothesis - MIH) and competition. While studies investigating the impacts of spatial variation in productivity on community structure are common, the impacts of temporal variability on productivity are poorly understood. We tested how well rainfall predicted the activity, species numbers and assemblage composition of ants and if responses were moderated by landscape position. We also asked whether the number of species (richness per s ling unit and estimated species richness) responded directly to rainfall or was moderated by ant activity or competition from dominant ants. Over a 22-year period, when annual rainfall fluctuated between 79 mm and 570 mm, we s led ants using pitfall traps in paired dune and swale habitats in the Simpson Desert, Australia. We used climate records over this period to model changes in ant assemblages. Activity of dominant ants responded primarily to long-term rainfall, increasing exponentially, while subordinate ants responded to short-term weather and time. Consistent with the MIH, the number of ant species was best predicted by activity, particularly that of subordinate ants. Activity of dominant ants had a declining positive effect on numbers of species. Landscape position strongly predicted species composition, while long-term rainfall determined composition at genus level but not species level. Over time, species composition fluctuated, but several genera consistently increased in activity. Productivity moderators such as long-term rainfall and landscape position are key drivers of ant activity and composition in the study ecosystem, acting indirectly on numbers of species. Numbers of species were explained largely by ant activity, making a strong case for the MIH, but not competition. Longer periods of low rainfall may indirectly reduce species richness in desert ecosystems. However, a trend to increasing richness over time may indicate that conservation management can ameliorate this impact.
Publisher: Wiley
Date: 10-10-2007
Publisher: Informa UK Limited
Date: 04-1987
Publisher: Wiley
Date: 23-02-2012
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.SCITOTENV.2018.03.285
Abstract: An unprecedented rate of global environmental change is predicted for the next century. The response to this change by ecosystems around the world is highly uncertain. To address this uncertainty, it is critical to understand the potential drivers and mechanisms of change in order to develop more reliable predictions. Australia's Long Term Ecological Research Network (LTERN) has brought together some of the longest running (10-60years) continuous environmental monitoring programs in the southern hemisphere. Here, we compare climatic variables recorded at five LTERN plot network sites during their period of operation and place them into the context of long-term climatic trends. Then, using our unique Australian long-term datasets (total 117 survey years across four biomes), we synthesize results from a series of case studies to test two hypotheses: 1) extreme weather events for each plot network have increased over the last decade, and 2) trends in bio ersity will be associated with recent climate change, either directly or indirectly through climate-mediated disturbance (wildfire) responses. We examined the bio ersity responses to environmental change for evidence of non-linear behavior. In line with hypothesis 1), an increase in extreme climate events occurred within the last decade for each plot network. For hypothesis 2), climate, wildfire, or both were correlated with bio ersity responses at each plot network, but there was no evidence of non-linear change. However, the influence of climate or fire was context-specific. Bio ersity responded to recent climate change either directly or indirectly as a consequence of changes in fire regimes or climate-mediated fire responses. A national long-term monitoring framework allowed us to find contrasting species abundance or community responses to climate and disturbance across four of the major biomes of Australia, highlighting the need to establish and resource long-term monitoring programs across representative ecosystem types, which are likely to show context-specific responses.
Publisher: Elsevier BV
Date: 04-2011
Publisher: Wiley
Date: 09-11-2014
Publisher: Wiley
Date: 10-10-2007
Publisher: Wiley
Date: 11-12-2018
DOI: 10.1111/DDI.12858
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/RJ15039
Abstract: Removing cattle as a management tool to conserve bio ersity may not necessarily alter grazing impacts on vegetation if other introduced or native herbivores move in and replace the cattle after removal. This study investigated whether there was a difference in the abundance of native red kangaroos (Osphranter (Macropus) rufus) and introduced feral camels (Camelus dromedarius) on arid rangelands where cattle had been recently removed compared with where cattle remained. Activity was measured by clearing and weighing dung, and by counting animal sightings. Kangaroos were encountered more frequently in high quality habitat (gidgee woodland) where cattle had been recently removed. However, kangaroo dung in newly cattle-free areas comprised only ~1.5% of the weight of cattle dung in this habitat where cattle still grazed, indicating no grazing compensation by the native herbivore. Camels showed no clear preference for particular habitat types but used dune tops usually avoided by kangaroos and cattle. There was no indication of camels using habitats differently in areas where cattle were removed. Camel dung collected across all habitats comprised less than a tenth the weight of cattle dung, but almost five times as much as kangaroo dung. As cattle removal had occurred relatively recently, further monitoring is needed to determine its impact over longer periods, especially through low and high rainfall cycles. Methods to improve the monitoring of large herbivores in the presence and absence of livestock and to assess whether anticipated conservation goals are achieved are discussed.
Publisher: Public Library of Science (PLoS)
Date: 06-04-2017
Publisher: Proceedings of the National Academy of Sciences
Date: 07-02-2020
Abstract: When plants establish outside their native range, their ability to adapt to the new environment is influenced by both demography and dispersal. However, the relative importance of these two factors is poorly understood. To quantify the influence of demography and dispersal on patterns of genetic ersity underlying adaptation, we used data from a globally distributed demographic research network comprising 35 native and 18 nonnative populations of Plantago lanceolata . Species-specific simulation experiments showed that dispersal would dilute demographic influences on genetic ersity at local scales. Populations in the native European range had strong spatial genetic structure associated with geographic distance and precipitation seasonality. In contrast, nonnative populations had weaker spatial genetic structure that was not associated with environmental gradients but with higher within-population genetic ersity. Our findings show that dispersal caused by repeated, long-distance, human-mediated introductions has allowed invasive plant populations to overcome environmental constraints on genetic ersity, even without strong demographic changes. The impact of invasive plants may, therefore, increase with repeated introductions, highlighting the need to constrain future introductions of species even if they already exist in an area.
Publisher: Springer Science and Business Media LLC
Date: 11-02-2019
Publisher: Wiley
Date: 09-07-2020
DOI: 10.1111/BRV.12636
Publisher: Wiley
Date: 15-07-2013
DOI: 10.1111/AEC.12073
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: Wiley
Date: 04-2006
Publisher: Springer Science and Business Media LLC
Date: 30-08-2018
Publisher: Wiley
Date: 09-09-2014
DOI: 10.1111/AEC.12188
Publisher: Elsevier BV
Date: 09-2005
Publisher: California Digital Library (CDL)
Date: 28-11-2019
Publisher: CSIRO Publishing
Date: 2013
DOI: 10.1071/SB12016
Abstract: Molecular data have revealed many morphologically cryptic species. More surprising than lack of difference, however, is that morphological variation and complex patterns of overlapping features can mask cryptic species. We employ geometric morphometric methods (GMM) to explore patterns of variation within four liverwort species, three of which were previously attributed to Lejeunea tumida Mitt. Each species exhibited considerable variation within, and overlap among, species in size and shape, independent of degree of relatedness. Most variation was expressed within in iduals, suggesting that the observed breadth of variation was within the developmental capacity of single genotypes. Size and shape variation within, and consequently overlap among, in iduals resulted primarily from variance in growth of shoots. Inter-specific differences were sw ed by intra- and inter-in idual variation. We coupled GMM with multivariate methods for outlier removal, and simple averaging of in iduals to explore whether intra-in idual variation could be reconciled to maximise the inter-species difference, facilitating resolution of cryptic species despite extensive morphological continuity and overlap. Unfortunately, outlier removal did not achieve separation among species, because removing extremes failed to eliminate overlap resulting from within-species variation. In idual averaging was partially successful in extracting L. tumida as a discrete entity but did not segregate the remaining three species. Although the challenges for morphology-based identification of cryptic species are significant, GMM provide one of the best sets of methods for identifying and communicating any subtle morphological differences that may exist.
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/WF09131
Abstract: Prescribed burning is a commonly applied management tool, and there has been considerable debate over the efficacy of its application. We review data relating to the effectiveness of prescribed burning in Australia. Specifically, we address two questions: (1) to what extent can fuel reduction burning reduce the risk of loss of human life and economic assets posed from wildfires? (2) To what extent can prescribed burning be used to reduce the risk of bio ersity loss? Data suggest that prescribed burning can achieve a reduction in the extent of wildfires however, at such levels, the result is an overall increase in the total area of the landscape burnt. Simulation modelling indicates that fuel reduction has less influence than weather on the extent of unplanned fire. The need to incorporate ecological values into prescribed burning programmes is becoming increasingly important. Insufficient data are available to determine if existing programs have been successful. There are numerous factors that prevent the implementation of better prescribed burning practices most relate to a lack of clearly defined, measurable objectives. An adaptive risk management framework combined with enhanced partnerships between scientists and fire-management agencies is necessary to ensure that ecological and fuel reduction objectives are achieved.
Publisher: Springer Science and Business Media LLC
Date: 15-05-2015
Publisher: Wiley
Date: 15-06-2010
DOI: 10.1111/J.1461-0248.2010.01506.X
Abstract: Explaining variation in population growth rates is fundamental to predicting population dynamics and population responses to environmental change. In this study, we used matrix population models, which link birth, growth and survival to population growth rate, to examine how and why population growth rates vary within and among 50 terrestrial plant species. Population growth rates were more similar within species than among species with phylogeny having a minimal influence on among-species variation. Most population growth rates decreased over the observation period and were negatively autocorrelated between years that is, higher than average population growth rates tended to be followed by lower than average population growth rates. Population growth rates varied more through time than space this temporal variation was due mostly to variation in post-seedling survival and for a subset of species was partly explained by response to environmental factors, such as fire and herbivory. Stochastic population growth rates departed from mean matrix population growth rate for temporally autocorrelated environments. Our findings indicate that demographic data and models of closely related plant species cannot necessarily be used to make recommendations for conservation or control, and that post-seedling survival and the sequence of environmental conditions are critical for determining plant population growth rate.
Publisher: Wiley
Date: 31-10-2011
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: 02-2003
Publisher: Elsevier BV
Date: 12-2007
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/WF19087
Abstract: Assessing wildfire regimes and their environmental drivers is critical for effective land management and conservation. We used Landsat imagery to describe the wildfire regime of the north-eastern Simpson Desert (Australia) between 1972 and 2014, and to quantify the relationship between wildfire extent and rainfall. Wildfires occurred in 15 of the 42 years, but only 27% of the study region experienced multiple wildfires. A wildfire in 1975 burned 43% of the region and is the largest on record for the area. More recently, a large wildfire in 2011 reburned areas that had not burned since 1975 (47% of the 2011 wildfire), as well as new areas that had no record of wildfires (25% of the 2011 wildfire). The mean minimum wildfire return interval was 27 years, comparable with other spinifex-dominated grasslands, and the mean time since last wildfire was 21 years. Spinifex-dominated vegetation burned most frequently and over the largest area. Extreme annual rainfall events (& 93rd percentile) effectively predicted large wildfires occurring 2 years after those events. Extreme rainfall is predicted to increase in magnitude and frequency across central Australia, which could alter wildfire regimes and have unpredictable and far-reaching effects on ecosystems in the region’s arid landscapes.
Publisher: Oxford University Press (OUP)
Date: 14-12-2011
Publisher: Royal Zoological Society of New South Wales
Date: 2012
DOI: 10.7882/FS.2012.016
Publisher: Schweizerbart
Date: 11-2009
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: Wiley
Date: 21-02-2011
DOI: 10.1111/J.1461-0248.2011.01594.X
Abstract: A general understanding of biological invasions will provide insights into fundamental ecological and evolutionary problems and contribute to more efficient and effective prediction, prevention and control of invasions. We review recent papers that have proposed conceptual frameworks for invasion biology. These papers offer important advances and signal a maturation of the field, but a broad synthesis is still lacking. Conceptual frameworks for invasion do not require invocation of unique concepts, but rather should reflect the unifying principles of ecology and evolutionary biology. A conceptual framework should incorporate multicausality, include interactions between causal factors and account for lags between various stages. We emphasize the centrality of demography in invasions, and distinguish between explaining three of the most important characteristics by which we recognize invasions: rapid local population increase, monocultures or community dominance, and range expansion. As a contribution towards developing a conceptual synthesis of invasions based on these criteria, we outline a framework that explicitly incorporates consideration of the fundamental ecological and evolutionary processes involved. The development of a more inclusive and mechanistic conceptual framework for invasion should facilitate quantitative and testable evaluation of causal factors, and can potentially lead to a better understanding of the biology of invasions.
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/SB10047
Abstract: A phylogeny based on nrITS1 and trnL–F sequences resolves the Lejeunea tumida species group polyphyletic with in iduals belonging in two clades either side of the basal-most node within Lejeunea. It is impossible for the Lejeunea tumida species group to be more polyphyletic and still be attributed to the same genus under the existing generic classification. A simulation-based approach to testing the null hypothesis of group monophyly rejects this at the P 0.01 level of significance. Bayesian tests find very strong support for polyphyly, given the data. The monophyly of L. tumida s.s. + L. colensoana is fully supported however, although Lejeunea tumida s.s. is nested within L. colensoana, this position is not supported. Both L. oracola and L. rhigophila are resolved as monophyletic. Whereas there is moderate support for the monophyly of L. rhigophila, there is no support for the monophyly of L. oracola. Neither is the monophyly of L. oracola + L. rhigophila supported in Bayesian or parsimony analysis.
Publisher: Wiley
Date: 06-10-2021
DOI: 10.1111/ELE.13894
Abstract: Fertilisation experiments have demonstrated that nutrient availability is a key determinant of biomass production and carbon sequestration in grasslands. However, the influence of nutrients in explaining spatial variation in grassland biomass production has rarely been assessed. Using a global dataset comprising 72 sites on six continents, we investigated which of 16 soil factors that shape nutrient availability associate most strongly with variation in grassland aboveground biomass. Climate and N deposition were also considered. Based on theory‐driven structural equation modelling, we found that soil micronutrients (particularly Zn and Fe) were important predictors of biomass and, together with soil physicochemical properties and C:N, they explained more unique variation (32%) than climate and N deposition (24%). However, the association between micronutrients and biomass was absent in grasslands limited by NP. These results highlight soil properties as key predictors of global grassland biomass production and point to serial co‐limitation by NP and micronutrients.
Publisher: Wiley
Date: 11-08-2022
Abstract: Ecological forecasting provides a powerful set of methods for predicting short‐ and long‐term change in living systems. Forecasts are now widely produced, enabling proactive management for many applied ecological problems. However, despite numerous calls for an increased emphasis on prediction in ecology, the potential for forecasting to accelerate ecological theory development remains underrealized. Here, we provide a conceptual framework describing how ecological forecasts can energize and advance ecological theory. We emphasize the many opportunities for future progress in this area through increased forecast development, comparison and synthesis. Our framework describes how a forecasting approach can shed new light on existing ecological theories while also allowing researchers to address novel questions. Through rigorous and repeated testing of hypotheses, forecasting can help to refine theories and understand their generality across systems. Meanwhile, synthesizing across forecasts allows for the development of novel theory about the relative predictability of ecological variables across forecast horizons and scales. We envision a future where forecasting is integrated as part of the toolset used in fundamental ecology. By outlining the relevance of forecasting methods to ecological theory, we aim to decrease barriers to entry and broaden the community of researchers using forecasting for fundamental ecological insight.
Publisher: Springer Science and Business Media LLC
Date: 08-06-2014
DOI: 10.1007/S00442-014-2977-8
Abstract: Top predators are declining globally, in turn allowing populations of smaller predators, or mesopredators, to increase and potentially have negative effects on bio ersity. However, detection of interactions among sympatric predators can be complicated by fluctuations in the background availability of resources in the environment, which may modify both the numbers of predators and the strengths of their interactions. Here, we first present a conceptual framework that predicts how top-down and bottom-up interactions may regulate sympatric predator populations in environments that experience resource pulses. We then test it using 2 years of remote-camera trapping data to uncover spatial and temporal interactions between a top predator, the dingo Canis dingo, and the mesopredatory European red fox Vulpes vulpes and feral cat Felis catus, during population booms, declines and busts in numbers of their prey in a model desert system. We found that dingoes predictably suppress abundances of the mesopredators and that the effects are strongest during declines and busts in prey numbers. Given that resource pulses are usually driven by large yet infrequent rains, we conclude that top predators like the dingo provide net benefits to prey populations by suppressing mesopredators during prolonged bust periods when prey populations are low and potentially vulnerable.
Publisher: MDPI AG
Date: 15-11-2019
DOI: 10.20944/PREPRINTS201911.0178.V1
Abstract: Ecosystem surveillance monitoring is critical to managing natural resources and especially so under changing environments. Despite this importance, the design and implementation of monitoring programs across large temporal and spatial scales has been h ered by the lack of appropriately standardised methods and data streams. To address this gap, we outline a surveillance monitoring method based on permanent plots and voucher s les suited to rangeland environments around the world that is repeatable, cost-effective, appropriate for large-scale comparisons and adaptable to other global biomes. The method provides comprehensive data on vegetation composition and structure along with soil attributes relevant to plant growth, delivered as a combination of modules that can be targeted for different purposes or available resources. Plots are located in a stratified design across vegetation units, landforms and climates to enhance continental and global comparisons. Changes are investigated through revisits. Vegetation is measured to inform on composition, cover and structure. S les of vegetation and soils are collected and tracked by barcode labels and stored long-term for subsequent analysis. Technology is used to enhance the accuracy of field methods, including differential GPS r plot locations, instrument based Leaf Area Index (LAI) measures, and three dimensional photo-panoramas for advanced analysis. A key feature of the method is the use of electronic field data collection to enhance data delivery into a publicly-accessible database.Our method is pragmatic, whilst still providing consistent data, information and s les on key vegetation and soil attributes. The method is operational and has been applied at more than 704 field locations across the Australian rangelands as part of the Ecosystem Surveillance program of the Terrestrial Ecosystem Research Network (TERN). The methodology enables continental analyses, and has been tested in communities broadly representative of rangelands globally, with components being applicable to other biomes. Here we also recommend the consultative process and guiding principles that drove the development of this method as an approach for development of the method into other biomes. The consistent, standardised and objective method enables continental, and potentially global analyses than were not previously possible with disparate programs and datasets.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 14-07-2017
Publisher: Frontiers Media SA
Date: 08-2022
Publisher: Elsevier BV
Date: 11-2022
DOI: 10.1016/J.SCITOTENV.2022.157480
Abstract: Global climate change has altered precipitation patterns and disrupted the characteristics of drought and rainfall events. Climate projections confirm that more frequent, intense, and extreme droughts and rainfall events will continue. However, knowledge around how drought and wet events move dynamically through space and time is limited, especially in the southern hemisphere. Australia is the driest inhabited continent, renowned as the land of droughts and flooding rains, but recent climate-driven changes to the severity of wildfires and floods have garnered global attention. Here we used S-TRACK, a novel method for spatial drought tracking, to build pathways for past drought and wet events in Australia to examine their spatiotemporal dynamics. Characteristics such as duration, severity, and intensity were obtained from these pathways, and modified Mann-Kendall tests and Sen's slope were used to detect significant trends in characteristics over time. Drought conditions in southern Australia have intensified, particularly in the southwest of Australia and Tasmania, while the north of the country is experiencing longer, more severe, and more intense wet conditions. We also found that the location of drought and wet hotspots has clearly shifted in response to precipitation changes since the 1970's. Finally, pathways for the most extreme events show peak severity is reached in the middle to late stages of pathways, and that the largest drought and wet areas of a pathway have moved further west in recent times. The findings in this study provide the necessary knowledge to improve preparedness for extreme precipitation events as they become more common and to inform predictions for agricultural output or the extent of other climate events such as wildfires and flooding.
Publisher: Wiley
Date: 27-11-2013
DOI: 10.1111/AEC.12092
Publisher: Elsevier BV
Date: 09-2019
Publisher: Oxford University Press (OUP)
Date: 03-2008
Publisher: Public Library of Science (PLoS)
Date: 17-06-2013
Publisher: Wiley
Date: 27-03-2013
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2015
Publisher: Springer Science and Business Media LLC
Date: 21-01-2021
DOI: 10.1038/S41467-021-20997-9
Abstract: A Correction to this paper has been published: 0.1038/s41467-021-20997-9.
Publisher: Springer US
Date: 1997
Publisher: Cold Spring Harbor Laboratory
Date: 06-08-2021
DOI: 10.1101/2021.08.05.455258
Abstract: Software for realistically simulating complex population genomic processes is revolutionizing our understanding of evolutionary processes, and providing novel opportunities for integrating empirical data with simulations. However, the integration between simulation software and software designed for working with empirical data is currently not well developed. Here we present slimr, an R package designed to create a seamless link between standalone software SLiM 3.0, one of the most powerful population genomic simulation frameworks, and the R development environment, with its powerful data manipulation and analysis tools. We show how slimr facilitates smooth integration between genetic data, ecological data and simulation in a single environment. The package enables pipelines that begin with data reading, cleaning, and manipulation, proceed to constructing empirically-based parameters and initial conditions for simulations, then to running numerical simulations, and finally to retrieving simulation results in a format suitable for comparisons with empirical data – aided by advanced analysis and visualization tools provided by R. We demonstrate the use of slimr with an ex le from our own work on the landscape population genomics of desert mammals, highlighting the advantage of having a single integrated tool for both data analysis and simulation. slimr makes the powerful simulation ability of SliM 3.0 directly accessible to R users, allowing integrated simulation projects that incorporate empirical data without the need to switch between software environments. This should provide more opportunities for evolutionary biologists and ecologists to use realistic simulations to better understand the interplay between ecological and evolutionary processes.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 10-08-2017
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: The University of Sydney Library
Date: 30-08-2021
DOI: 10.30722/IJISME.29.03.005
Abstract: In the last decade, the Australian higher education sector has ch ioned the inclusion of cultural competence (CC) as a key graduate quality. Diverse disciplinary learning and teaching approaches requiring careful consideration about how best to achieve the end goal of supporting graduates on their in idual, life-long pathways to engage with CC. Science can be viewed as an inflexible and immovable discipline. This perception seems particularly prevalent with respect to scientists acknowledging epistemes outside of a western cultural frame. It follows that eliciting curriculum reform with respect to CC broadly, and Aboriginal and Torres Strait Islander perspectives more specifically, was perceived to be a significant challenge. Through interviews with eleven non-Indigenous academics across the Faculty of Science at the University of Sydney, we uncovered several strategies for including multiple knowledges in science, with academics traversing these new horizons by building on the work of and collaborating with Indigenous Elders and academics to create enriched learning spaces. Alongside these strategies are staff reflections on their CC journey, which indicate that this endeavour entails necessary and vital discomforts that ultimately enable transformation. This process while guided by CC, led to experiences of cultural humility and a conviction in the role of cultural accountability.
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/WF08093
Abstract: Implementing appropriate fire regimes has become an increasingly important objective for bio ersity conservation programs. Here, we used Landsat imagery from 1972 to 2003 to describe the recent fire history and current wildfire regime of the north-eastern Simpson Desert, Australia, within each of the region’s seven main vegetation classes. We then explored the relationship between antecedent rainfall and El Niño–Southern Oscillation with wildfire area. Wildfires were recorded in 11 years between 1972 and 2003, each differing in size. In 1975, the largest wildfire was recorded, burning 55% (4561 km2) of the study region. Smaller fires in the intervening years burnt areas that had mostly escaped the 1975 fire, until 2002, when 31% (2544 km2) of the study region burnt again. Wildfires burnt disproportionally more spinifex (Triodia basedowii) than any other vegetation class. A total of 49% of the study area has burnt once since 1972 and 20% has burnt twice. Less than 1% has burnt three times and 36% has remained unaffected by wildfire since 1972. The mean minimum fire return interval was 26 years. Two years of cumulative rainfall before a fire event, rainfall during the year of a fire event, and the mean Southern Oscillation Index from June to November in the year before a fire event could together be used to successfully predict wildfire area. We use these findings to describe the current fire regime.
Publisher: Springer Science and Business Media LLC
Date: 23-07-2018
DOI: 10.1038/S41559-018-0608-1
Abstract: Inadequate information on the geographical distribution of bio ersity h ers decision-making for conservation. Major efforts are underway to fill knowledge gaps, but there are increasing concerns that publishing the locations of species is dangerous, particularly for species at risk of exploitation. While we recognize that well-informed control of location data for highly sensitive taxa is necessary to avoid risks, such as poaching or habitat disturbance by recreational visitors, we argue that ignoring the benefits of sharing bio ersity data could unnecessarily obstruct conservation efforts for species and locations with low risks of exploitation. We provide a decision tree protocol for scientists that systematically considers both the risks of exploitation and potential benefits of increased conservation activities. Our protocol helps scientists assess the impacts of publishing bio ersity data and aims to enhance conservation opportunities, promote community engagement and reduce duplication of survey efforts.
Publisher: Cold Spring Harbor Laboratory
Date: 05-09-2022
DOI: 10.1101/2022.09.02.506446
Abstract: Species interactions play a fundamental role in ecosystems. However, few ecological communities have complete data describing such interactions, which is an obstacle to understanding how ecosystems function and respond to perturbations. Because it is often impractical to collect empirical data for all interactions in a community, various methods have been developed to infer interactions. Machine learning is increasingly being used for making interaction predictions, with random forest being one of the most frequently used of these methods. However, performance of random forest in inferring predator-prey interactions in terrestrial vertebrates and its sensitivity to training data quality remain untested. We examined predator-prey interactions in two erse, primarily terrestrial vertebrate classes: birds and mammals. Combining data from a global interaction dataset and a specific community (Simpson Desert, Australia), we tested how well random forest predicted predator-prey interactions for mammals and birds using species’ ecomorphological and phylogenetic traits. We also tested how variation in training data quality—manipulated by removing records and switching interaction records to non-interactions—affected model performance. We found that random forest could predict predator-prey interactions for birds and mammals using ecomorphological or phylogenetic traits, correctly predicting up to 88% and 67% of interactions and non-interactions in the global and community-specific datasets, respectively. These predictions were accurate even when there were no records in the training data for focal species. In contrast, false non-interactions for focal predators in training data strongly degraded model performance. Our results demonstrate that random forest can identify predator-prey interactions for birds and mammals that have few or no interaction records. Furthermore, our study provides guidance on how to prepare training data to optimise machine-learning classifiers for predicting species interactions, which could help ecologists ( i ) address knowledge gaps and explore network-related questions in data-poor situations, and ( ii ) predict interactions for range-expanding species.
Publisher: Wiley
Date: 02-2008
DOI: 10.3732/AJB.95.2.146
Abstract: Up to 22% of plant species are the result of breeding among species-hybridization-directly conflicting with the prediction that hybrids, compared to parental species, are intermediate in character and of low fitness and little consequence. Few studies, however, have compared the fitness of hybrids and parental species under field conditions. This study evaluates components of fitness in the field for naturally occurring hybrids of the shrub Kunzea, relative to the parental speciesKunzea rupestris. Hybrid plants did not differ from the parental species in the level of effective pollination. Thus, we found no support for Grant's model (Evolution: International Journal of Organic Evolution3: 82-97) of reduced fitness of hybrids via reduced pollination level (the intermediate hypothesis). Hybrids displayed variable fitness across the measured fitness components. Seed set levels for hybrids were structured among populations, suggesting genetic structuring for this fitness component at this scale. The response of hybrids to fire (a major selective force in the study system) was partly consistent with a resource trade-off model. Hybrids were large robust plants but most did not resprout after fire. Hence, the fitness of hybrids was complex. We developed a model for relative fitness to estimate fitness for species and hybrids with complex life histories.
Publisher: Springer Science and Business Media LLC
Date: 23-10-2020
DOI: 10.1038/S41467-020-19252-4
Abstract: Eutrophication is a widespread environmental change that usually reduces the stabilizing effect of plant ersity on productivity in local communities. Whether this effect is scale dependent remains to be elucidated. Here, we determine the relationship between plant ersity and temporal stability of productivity for 243 plant communities from 42 grasslands across the globe and quantify the effect of chronic fertilization on these relationships. Unfertilized local communities with more plant species exhibit greater asynchronous dynamics among species in response to natural environmental fluctuations, resulting in greater local stability (alpha stability). Moreover, neighborhood communities that have greater spatial variation in plant species composition within sites (higher beta ersity) have greater spatial asynchrony of productivity among communities, resulting in greater stability at the larger scale (gamma stability). Importantly, fertilization consistently weakens the contribution of plant ersity to both of these stabilizing mechanisms, thus diminishing the positive effect of bio ersity on stability at differing spatial scales. Our findings suggest that preserving grassland functional stability requires conservation of plant ersity within and among ecological communities.
Publisher: Wiley
Date: 21-03-2013
DOI: 10.1111/AEC.12033
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/BT04148
Abstract: In fire-prone vegetation many plants bear thick woody fruits that retains seeds and insulate these seeds from heat. However, in the same vegetation, some plants retain seeds in thin indehiscent fruits that offer little protection from heat. The function of these thin indehiscent fruits is unknown. We investigated two closely related Kunzea species that occur together in fire-prone vegetation, namely eucalypt woodland. We also studied naturally occurring hybrids of these two species. K. rupestris bears indehiscent thin-walled fruit, whereas K. capitata bears fruit that dehisce to release seed on maturity. Hybrid fruits partly dehisce but retain seed. Studies of seed viability, dormancy and germination demonstrate a distinct combination of these traits for both species. Hybrid seed also has a unique combination of these traits, having some characteristics of both species. The indehiscent capsules impart dormancy to retained seed. However, K. capitata seed, which is not retained in fruit, also displays dormancy. In K. capitata, dormancy is associated with a water-impermeable seed coat. Surprisingly, seed retained in indehiscent capsules was found to have lower viability when exposed to heat than seed that had been released from capsules and exposed to heat.
Publisher: Wiley
Date: 24-10-2022
DOI: 10.1111/ELE.14126
Abstract: Global change drivers, such as anthropogenic nutrient inputs, are increasing globally. Nutrient deposition simultaneously alters plant bio ersity, species composition and ecosystem processes like aboveground biomass production. These changes are underpinned by species extinction, colonisation and shifting relative abundance. Here, we use the Price equation to quantify and link the contributions of species that are lost, gained or that persist to change in aboveground biomass in 59 experimental grassland sites. Under ambient (control) conditions, compositional and biomass turnover was high, and losses (i.e. local extinctions) were balanced by gains (i.e. colonisation). Under fertilisation, the decline in species richness resulted from increased species loss and decreases in species gained. Biomass increase under fertilisation resulted mostly from species that persist and to a lesser extent from species gained. Drivers of ecological change can interact relatively independently with ersity, composition and ecosystem processes and functions such as aboveground biomass due to the in idual contributions of species lost, gained or persisting.
Publisher: Frontiers Media SA
Date: 16-06-2020
Publisher: Wiley
Date: 21-09-2012
DOI: 10.1002/ECE3.377
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/BT02001
Abstract: Within the Apiaceae, subtle variation in reproductive characters such as dichogamy, pollinator specificity and umbel density may cause cryptic specialisation and be responsible for the ersity of life histories and gender expression in the family. To address the paucity of information for Australian species we investigated the reproductive ecology of the native perennial herb, Trachymene incisa Rudge subsp. incisa. T. incisa exhibits protandry within flowers and umbels however, an overlap of 3 days in male and female phases among umbels of consecutive orders permits geitonogamous pollination. There are 72 ± 2.0 (n = 74) white flowers per umbel and nectar is presented during the male and female phases. Apis mellifera appears to be the main diurnal pollinator. The pollen : ovule ratio is 1902 : 1, indicating that T. incisa is a facultatively xenogamous species. The long phase of pollen presentation and the low natural seed set of about 45% implies that many flowers are functioning as pollen donors only. Controlled pollination experiments showed that self-pollen led to lower seed set than cross, open and supplemental applications. Early and late-produced cohorts differed in days to emergence but not in seed mass or final percentage emergence.
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/BT20036
Abstract: The drivers and rate of vegetation change across spatial gradients can give critical insights into the compositional and structural change we can expect under climate change. Spatial ecotones are of particular interest as they represent heterogeneity in the patterning of vegetation that may reflect how temporal environmental change will manifest in more abrupt step changes in plant composition and/or structure. Another dimension of interest is the degree to which survey methodology impacts the detectability of thresholds in vegetation. We surveyed a Mediterranean to arid zone gradient in South Australia with nested and non-nested transect designs and related the observed vegetation change to soil, landscape and climate to determine the strongest environmental associations. Ordination, principal components analysis (PCA) and threshold indicator taxa analysis (TITAN) were used to detect potential ecotones associated with environmental thresholds. Results from the two transects were compared with test the effects of survey method and spatial s ling on pattern detection. Ordinations and regressions for both transects indicated vegetation changed linearly along the environmental gradient. Species richness and total cover increased with rainfall. Species turnover was very high, with low nestedness, indicating high susceptibility to environmental change. Climate is the major driver of broad-scale vegetation change on our gradient and at this scale vegetation trends are detectable with a range of survey methodologies. TITAN identification of a threshold within the shorter, nested transect (but not the longer transect which extended into the arid zone) indicated that survey methodology influences ecotone detectability, and that although smaller-scale vegetation disjunctions may be present, change spanning the entire mesic to arid zone is largely monotonic.
Publisher: Wiley
Date: 09-2021
DOI: 10.1111/CONL.12758
Publisher: Wiley
Date: 04-2003
Publisher: Wiley
Date: 29-08-2016
DOI: 10.1111/JVS.12450
Publisher: The Royal Society
Date: 09-2022
Abstract: Under the Ecosystem Exploitation Hypothesis ecosystem productivity predicts trophic complexity, but it is unclear if spatial and temporal drivers of productivity have similar impacts. Long-term studies are necessary to capture temporal impacts on trophic structure in variable ecosystems such as deserts. We s led ants and measured plant resources in the Simpson Desert, central Australia over a 22-year period, during which rainfall varied 10-fold. We s led dune swales (higher nutrient) and crests (lower nutrient) to account for spatial variation in productivity. We asked how temporal and spatial variation in productivity affects the abundance of ant trophic guilds. Precipitation increased vegetation cover, with the difference more pronounced on dune crests seeding and flowering also increased with precipitation. Generalist activity increased over time, irrespective of productivity. Predators were more active in more productive (swale) habitat, i.e. spatial impacts of productivity were greatest at the highest trophic level. By contrast, herbivores (seed harvesters and sugar feeders) increased with long-term rainfall seed harvesters also increased as seeding increased. Temporal impacts of productivity were therefore greatest for low trophic levels. Whether productivity variation leads to top-down or bottom-up structured ecosystems thus depends on the scale and dimension (spatial or temporal) of productivity.
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: Wiley
Date: 27-05-2015
DOI: 10.1111/AEC.12265
Publisher: American Society of Plant Taxonomists
Date: 12-2009
Publisher: Royal Zoological Society of New South Wales
Date: 12-2018
DOI: 10.7882/AZ.2018.016
Publisher: Royal Zoological Society of New South Wales
Date: 12-2018
DOI: 10.7882/AZ.2018.018
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/SB10037
Abstract: Plants attributed to Lejeunea tumida comprise a heterogeneous aggregate of four morphologically distinct species, each circumscribed by subtle yet significant differences in perianth morphology, oil bodies, lobule morphology and lobe ornamentation. Size and shape also have utility in delimiting species, despite morphological overlap. We employ geometric morphometric methods to quantify and communicate diagnostic differences in lobule shape. Two new species, Lejeunea oracola M.A.M.Renner and Lejeunea rhigophila M.A.M.Renner are described, and a previously described species of Taxilejeunea reinstated as a new combination, Lejeunea colensoana (Steph.) M.A.M.Renner. Descriptions and illustrations of these three species and Lejeunea tumida Mitt. are presented. All four species occur in New Zealand. Although L. tumida has been reported for New South Wales, Victoria, and Tasmania, the identities of Australian plants comprising these records are largely unresolved, and require further investigation.
Publisher: MDPI AG
Date: 15-09-2020
DOI: 10.3390/D12090355
Abstract: (1) Diffuse competition affects per capita rates of population increase among species that exploit similar resources, and thus can be an important structuring force in ecological communities. Diffuse competition has traditionally been studied within taxonomically similar groups, although distantly related intraguild species are likely also to compete to some degree. (2) We assessed diffuse competition between mammalian and reptilian predators at sites in central Australia over 24 years. Specifically, we investigated the effect of dasyurid marsupial abundance on the diet breadth of three groups of lizards (nocturnal dietary generalists, diurnal dietary generalists and dietary specialists). (3) Nocturnal generalist lizards had progressively narrower diets as dasyurid abundance increased. The diet breadth of diurnal generalist lizards was unaffected by overall dasyurid abundance, but was restricted by that of the largest dasyurid species (Dasycercus blythi). Ant- and termite-specialist lizards were unaffected by dasyurid abundance. (4) Diffuse competition, mediated by interference, between dasyurids and nocturnal generalist lizards appears to have strong effects on these lizards, and is the first such between-class interaction to be described. Diffuse interactions may be widespread in natural communities, and merit further investigation among other disparate taxon groups that occur in the same ecological guilds.
Publisher: Wiley
Date: 19-05-2017
DOI: 10.1002/ECE3.2995
No related grants have been discovered for Glenda Wardle.