ORCID Profile
0000-0003-2400-7453
Current Organisation
Western Sydney University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Terrestrial Ecology | Soil Biology | Ecology | Ecological Impacts of Climate Change | Ecological Applications | Horticultural Crop Protection (Pests, Diseases and Weeds) | Horticultural Production | Community Ecology
ANZSRC Socio-Economic Objective (SEO)
Ecosystem Adaptation to Climate Change | Sparseland, Permanent Grassland and Arid Zone Soils | Environmentally Sustainable Plant Production not elsewhere classified | Climate Variability (excl. Social Impacts) | Expanding Knowledge in the Biological Sciences |
Related Links
Publications
Antarctic nematode communities: observed and predicted responses to climate change
Publisher: Springer Science and Business Media LLC
Date: 27-04-2011
Global‐scale patterns of assemblage structure of soil nematodes in relation to climate and ecosystem properties
Publisher: Wiley
Date: 20-04-2014
DOI: 10.1111/GEB.12177
Mycorrhiza-induced mycocypins of Laccaria bicolor are potent protease inhibitors with nematotoxic and collembola antifeedant activity.
Publisher: Wiley
Date: 11-07-2022
Abstract: Fungivory of mycorrhizal hyphae has a significant impact on fungal fitness and, by extension, on nutrient transfer between fungi and host plants in natural ecosystems. Mycorrhizal fungi have therefore evolved an arsenal of chemical compounds that are hypothesized to protect the hyphal tissues from being eaten, such as the protease inhibitors mycocypins. The genome of the ectomycorrhizal fungus Laccaria bicolor has an unusually high number of mycocypin-encoding genes. We have characterized the evolution of this class of proteins, identified those induced by symbiosis with a host plant and characterized the biochemical properties of two upregulated L. bicolor mycocypins. More than half of L. bicolor mycocypin-encoding genes are differentially expressed during symbiosis or fruiting body formation. We show that two L. bicolor mycocypins that are strongly induced during symbiosis are cysteine protease inhibitors and exhibit similar but distinct localization in fungal tissues at different developmental stages and during interaction with a host plant. Moreover, we show that these L. bicolor mycocypins have toxic and feeding deterrent effect on nematodes and collembolans, respectively. Therefore, L. bicolor mycocypins may be part of a mechanism by which this species deters grazing by different members of the soil food web.
Integrated analysis of aboveground and belowground indicators support a comprehensive evaluation of ecosystem recovery
Publisher: Wiley
Date: 30-07-2023
DOI: 10.1111/REC.13987
Abstract: Analyses of erse aboveground and belowground indicators should underpin assessments of ecosystem recovery, yet monitoring many indicators is costly and their integration is challenging. Our objective was to combine indicators through a Bayesian hierarchical model to provide a comprehensive assessment of ecosystem status and identify a cost‐effective subset of indicators to provide an accurate estimate of ecosystem recovery. We assessed 59 aboveground–belowground indicators, classified into nine components of composition, structure, and function, to estimate the ecosystem status of restored rock spoils and reference forests in south‐eastern Australia. Overall ecosystem status, which integrates across ecosystem components and supporting indicators, was lower within restored forests but positively correlated with forest age. Reference forests had greater aboveground and belowground biotic structure, organic matter supply, and soil carbon stability, and trends were consistent among all of their supporting indicators. A subset of organic matter quality and nutrient cycling indicators were greater within restored forests, suggesting high ecosystem process rates, but that soil carbon may be more vulnerable to loss. Aboveground biotic structure was correlated with organic matter supply and quality, stability of soil carbon, the cycling of nutrients, and belowground biotic structure, providing evidence of aboveground–belowground coupling. A combination of four indicators representing belowground biotic structure, soil carbon stability, organic matter supply, and aboveground composition, provided a good estimate of ecosystem status at a third of the cost. Although ecosystem status can be monitored with a small set of indicators, a ersity of aboveground–belowground indicators provide a robust and comprehensive assessment of recovery.
The effect of weed cutting onLuronium natans
Publisher: Wiley
Date: 2006
DOI: 10.1002/AQC.755
Plant functional identity has predictable effects on nematode communities across successional stages
Publisher: Elsevier BV
Date: 11-2021
The role of microarthropods in emerging models of soil organic matter
Publisher: Elsevier BV
Date: 11-2016
The Enigma of Soil Animal Species Diversity Revisited: The Role of Small-Scale Heterogeneity
Publisher: Public Library of Science (PLoS)
Date: 13-07-2010
Responses of a desert nematode community to changes in water availability
Publisher: Wiley
Date: 03-2015
DOI: 10.1890/ES14-00319.1
Long‐term cattle grazing shifts the ecological state of forest soils
Publisher: Wiley
Date: 31-03-2022
DOI: 10.1002/ECE3.8786
Abstract: Cattle grazing profoundly affects abiotic and biotic characteristics of ecosystems. While most research has been performed on grasslands, the effect of large managed ungulates on forest ecosystems has largely been neglected. Compared to a baseline seminatural state, we investigated how long‐term cattle grazing of birch forest patches affected the abiotic state and the ecological community (microbes and invertebrates) of the soil subsystem. Grazing strongly modified the soil abiotic environment by increasing phosphorus content, pH, and bulk density, while reducing the C:N ratio. The reduced C:N ratio was strongly associated with a lower microbial biomass, mainly caused by a reduction of fungal biomass. This was linked to a decrease in fungivorous nematode abundance and the nematode channel index, indicating a relative uplift in the importance of the bacterial energy‐channel in the nematode assemblages. Cattle grazing highly modified invertebrate community composition producing distinct assemblages from the seminatural situation. Richness and abundance of microarthropods was consistently reduced by grazing (excepting collembolan richness) and grazing‐associated changes in soil pH, Olsen P, and reduced soil pore volume (bulk density) limiting niche space and refuge from physical disturbance. Anecic earthworm species predominated in grazed patches, but were absent from ungrazed forest, and may benefit from manure inputs, while their deep vertical burrowing behavior protects them from physical disturbance. Perturbation of birch forest habitat by long‐term ungulate grazing profoundly modified soil bio ersity, either directly through increased physical disturbance and manure input or indirectly by modifying soil abiotic conditions. Comparative analyses revealed the ecosystem engineering potential of large ungulate grazers in forest systems through major shifts in the composition and structure of microbial and invertebrate assemblages, including the potential for reduced energy flow through the fungal decomposition pathway. The precise consequences for species trophic interactions and bio ersity–ecosystem function relationships remain to be established, however.
Effect of temperature on survival of Australian entomopathogenic nematodes and their virulence against the Queensland fruit fly, Bactrocera tryoni
Publisher: Springer Science and Business Media LLC
Date: 11-2022
DOI: 10.1007/S10526-022-10166-2
Abstract: Entomopathogenic nematodes (EPNs) are commonly used biocontrol agents of insect pests, with a wide range of commercially available isolates targeting specific pests. New isolates are, however, required to improve pest control across a wider range of environmental conditions for target pests, including emerging threats. We assessed the effect of temperature on survival and virulence of 17 Australian isolates of five EPN species ( Heterorhabditis bacteriophora , Heterorhabditis indica , Heterorhabditis marelatus , Heterorhabditis zealandica and Steinernema feltiae ) against larvae and pupae of the Queensland fruit fly, Bactrocera tryoni . All isolates still infected and killed larvae after infective juveniles (IJ) had been kept without insect hosts at 15 °C, 25 °C or 30 °C for two weeks, indicating their potential to remain viable under field conditions. However, the mean LD 50 value ranged from 35 to 150 and was generally lower at 15 °C than at 25 °C and 30 °C. Similarly, after IJs had been kept at 25 °C for 1–3 weeks without insect hosts, all isolates infected B. tryoni larvae, with mean LD 50 values ranging from 25 to 144. Interestingly, 15 isolates infected and killed B. tryoni pupae after one week, with a mean LD 50 value between 130 and 209, but only two isolates after two weeks, with a mean LD 50 value between 229 to 209. No pupal mortality was seen after three weeks. In absence of hosts, EPNs survived longer at 15 °C and 25 °C than at 30 °C. Complete EPN mortality occurred after nine weeks at 30 °C, and after 18 weeks at 15 °C and 25 °C, except for some survival in one S. feltiae isolate (Sf.ECCS). Overall, six isolates of H. indica (Hi.HRN2, Hi.LMI2, Hi.QF6), H. bacteriophora (Hb.HIE), H. zealandica (Hz.NAR1) and S. feltiae (Sf.ECCS) performed best and need further testing as potential biocontrol agents against B. tryoni under semi-field and field conditions.
Allometric Estimates of Aboveground Biomass Using Cover and Height Are Improved by Increasing Specificity of Plant Functional Groups in Eastern Australian Rangelands
Publisher: Elsevier BV
Date: 05-2020
Nematodes in a polar desert reveal the relative role of biotic interactions in the coexistence of soil animals
Publisher: Springer Science and Business Media LLC
Date: 15-02-2019
DOI: 10.1038/S42003-018-0260-Y
Abstract: Abiotic factors are major determinants of soil animal distributions and their dominant role is pronounced in extreme ecosystems, with biotic interactions seemingly playing a minor role. We modelled co-occurrence and distribution of the three nematode species that dominate the soil food web of the McMurdo Dry Valleys (Antarctica). Abiotic factors, other biotic groups, and autocorrelation all contributed to structuring nematode species distributions. However, after removing their effects, we found that the presence of the most abundant nematode species greatly, and negatively, affected the probability of detecting one of the other two species. We observed similar patterns in relative abundances for two out of three pairs of species. Harsh abiotic conditions alone are insufficient to explain contemporary nematode distributions whereas the role of negative biotic interactions has been largely underestimated in soil. The future challenge is to understand how the effects of global change on biotic interactions will alter species coexistence.
Challenges, solutions and research priorities for sustainable rangelands
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/RJ20059
Abstract: Australia’s rangeland communities, industries, and environment are under increasing pressures from anthropogenic activities and global changes more broadly. We conducted a horizon scan to identify and prioritise key challenges facing Australian rangelands and their communities, and outline possible avenues to address these challenges, with a particular focus on research priorities. We surveyed participants of the Australian Rangeland Society 20th Biennial Conference, held in Canberra in September 2019, before the conference and in interactive workshops during the conference, in order to identify key challenges, potential solutions, and research priorities. The feedback was broadly grouped into six themes associated with supporting local communities, managing natural capital, climate variability and change, traditional knowledge, governance, and research and development. Each theme had several sub-themes and potential solutions to ensure positive, long-term outcomes for the rangelands. The survey responses made it clear that supporting ‘resilient and sustainable rangelands that provide cultural, societal, environmental and economic outcomes simultaneously’ is of great value to stakeholders. The synthesis of survey responses combined with expert knowledge highlighted that sustaining local communities in the long term will require that the inherent social, cultural and natural capital of rangelands are managed sustainably, particularly in light of current and projected variability in climate. Establishment of guidelines and approaches to address these challenges will benefit from: (i) an increased recognition of the value and contributions of traditional knowledge and practices (ii) development of better governance that is guided by and benefits local stakeholders and (iii) more funding to conduct and implement strong research and development activities, with research focused on addressing critical knowledge gaps as identified by the local stakeholders. This requires strong governance with legislation and policies that work for the rangelands. We provide a framework that indicates the key knowledge gaps and how innovations may be implemented and scaled out, up and deep to achieve the resilience of Australia’s rangelands. The same principles could be adapted to address challenges in rangelands on other continents, with similar beneficial outcomes.
Abundance and diversity of soil invertebrates in the Windmill Islands region, East Antarctica
Publisher: Springer Science and Business Media LLC
Date: 21-04-2015
A global database of soil nematode abundance and functional group composition
Publisher: Springer Science and Business Media LLC
Date: 26-03-2020
DOI: 10.1038/S41597-020-0437-3
Abstract: As the most abundant animals on earth, nematodes are a dominant component of the soil community. They play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition. This dataset includes 6,825 georeferenced soil s les from all continents and biomes. For geospatial mapping purposes these s les are aggregated into 1,933 unique 1-km pixels, each of which is linked to 73 global environmental covariate data layers. Altogether, this dataset can help to gain insight into the spatial distribution patterns of soil nematode abundance and community composition, and the environmental drivers shaping these patterns.
Cross-biome metagenomic analyses of soil microbial communities and their functional attributes
Publisher: Proceedings of the National Academy of Sciences
Date: 10-12-2012
Abstract: For centuries ecologists have studied how the ersity and functional traits of plant and animal communities vary across biomes. In contrast, we have only just begun exploring similar questions for soil microbial communities despite soil microbes being the dominant engines of biogeochemical cycles and a major pool of living biomass in terrestrial ecosystems. We used metagenomic sequencing to compare the composition and functional attributes of 16 soil microbial communities collected from cold deserts, hot deserts, forests, grasslands, and tundra. Those communities found in plant-free cold desert soils typically had the lowest levels of functional ersity ( ersity of protein-coding gene categories) and the lowest levels of phylogenetic and taxonomic ersity. Across all soils, functional beta ersity was strongly correlated with taxonomic and phylogenetic beta ersity the desert microbial communities were clearly distinct from the nondesert communities regardless of the metric used. The desert communities had higher relative abundances of genes associated with osmoregulation and dormancy, but lower relative abundances of genes associated with nutrient cycling and the catabolism of plant-derived organic compounds. Antibiotic resistance genes were consistently threefold less abundant in the desert soils than in the nondesert soils, suggesting that abiotic conditions, not competitive interactions, are more important in shaping the desert microbial communities. As the most comprehensive survey of soil taxonomic, phylogenetic, and functional ersity to date, this study demonstrates that metagenomic approaches can be used to build a predictive understanding of how microbial ersity and function vary across terrestrial biomes.
Impacts of eucalypt plantation management on soil faunal communities and nutrient bioavailability: trading function for dependence?
Publisher: Springer Science and Business Media LLC
Date: 22-03-2015
Naphthalene addition to soil surfaces: A feasible method to reduce soil micro-arthropods with negligible direct effects on soil C dynamics
Publisher: Elsevier BV
Date: 02-2014
Climate change-driven shifts in plant–soil feedbacks: a meta-analysis
Publisher: Springer Science and Business Media LLC
Date: 03-11-2022
DOI: 10.1186/S13717-022-00410-Z
Abstract: Climate change is expected to affect plant–soil feedbacks (PSFs, i.e., the effects of a plant on the growth of another plant or community grown in the same soil via changes in soil abiotic and biotic properties), influencing plant community dynamics and, through this, ecosystem functioning. However, our knowledge of the effects of climate changes on the magnitude and direction of PSFs remains limited, with considerable variability between studies. We quantified PSFs associated with common climate change factors, specifically drought and warming, and their corresponding ambient (control) conditions using a meta-analytical approach. We investigated whether drought and warming effects on PSFs were consistent across functional groups, life histories (annual versus perennial) and species origin (native versus non-native), planting (monoculture, mixed culture) and experimental (field, greenhouse/laboratory) conditions. PSFs were negative (a mechanism that encourage species co-existence) under drought and neutral under corresponding ambient conditions, whereas PSFs were negative under both ambient and elevated temperatures, with no apparent difference in effect size. The response to drought was largely driven by stronger negative PSFs in grasses, indicating that grasses are more likely to show stronger negative PSFs than other functional groups under drought. Moreover, non-native species showed negative drought-induced PSFs while native species showed neutral PSFs under drought. By contrast, we found the opposite in pattern in response to warming for native and non-native species. Perennial herbs displayed stronger drought-induced negative PSFs than annual herbs. Mixed species communities displayed more negative PSFs than monocultures, independent of climate treatment. Finally, warming and drought treatment PSF effect sizes were more negative in experiments performed in the field than under controlled conditions. We provide evidence that drought and warming can induce context-specific shifts in PSFs, which are dependent on plant functional groups, life history traits and experimental conditions. These shifts would be expected to have implications for plant community dynamics under projected climate change scenarios.
Climate change in the underworld: Impacts for soil-dwelling invertebrates
Publisher: Wiley
Date: 09-12-2016
The Soil Geochemistry in the Beardmore Glacier Region, Antarctica: Implications for Terrestrial Ecosystem History
Publisher: Springer Science and Business Media LLC
Date: 18-05-2016
DOI: 10.1038/SREP26189
Abstract: Although most models suggest continental Antarctica was covered by ice during the Last Glacial Maximum (LGM) it has been speculated that endemic species of soil invertebrates could have survived the Pleistocene at high elevation habitats protruding above the ice sheets. We analyzed a series of soil s les from different elevations at three locations along the Beardmore Glacier in the Transantarctic Mountains (in order of increasing elevation): Ebony Ridge (ER), Cloudmaker (CM), and Meyer Desert (MD). Geochemical analyses show the MD soils, which were exposed during the LGM, were the least weathered compared to lower elevations, and also had the highest total dissolved solids (TDS). MD soils are dominated by nitrate salts (NO 3 /Cl ratios ) that can be observed in SEM images. High δ 17 O and δ 18 O values of the nitrate indicate that its source is solely of atmospheric origin. It is suggested that nitrate concentrations in the soil may be utilized to determine a relative “wetting age” to better assess invertebrate habitat suitability. The highest elevation sites at MD have been exposed and accumulating salts for the longest times, and because of the salt accumulations, they were not suitable as invertebrate refugia during the LGM.
Susceptibility of Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), to entomopathogenic nematodes
Publisher: Elsevier BV
Date: 02-2014
Environmental harshness mediates the relationship between aboveground and belowground communities in Antarctica
Publisher: Elsevier BV
Date: 2022
Soil pore volume and the abundance of soil mites in two contrasting habitats
Publisher: Elsevier BV
Date: 06-2008
Altered precipitation impacts on above-and below-ground grassland invertebrates: Summer drought leads to outbreaks in spring
Publisher: Frontiers Media SA
Date: 06-10-2016
Extreme streams: flow intermittency as a control on diatom communities in meltwater streams in the McMurdo Dry Valleys, Antarctica1This article is derived from a special session entitled “A
Publisher: Canadian Science Publishing
Date: 08-2012
DOI: 10.1139/F2012-022
Abstract: In the McMurdo Dry Valleys of Antarctica, stream biota is limited by the brief availability of liquid water. The benthic microbial mats harbor diatoms that have adapted to hydrologic stresses, including numerous endemic species. We found a strong relationship between diatom community composition and flow intermittency in a data set including seven streams that spanned a gradient in flow intermittency. In particular, two genera represented by numerous endemic species in Dry Valley habitats, Hantzschia and Luticola , had high abundances in moderately and highly intermittent streams, respectively. The Shannon Index of ersity was greatest in streams with intermediate flow intermittency, with lower ersity in more stable streams resulting from lower evenness, and lower ersity in highly intermittent streams resulting from lower richness. These results indicate that multiple metrics of bio ersity may be useful in assessing the response of diatom communities to changing hydrologic regime. We propose that flow intermittency acts as a species filter that increases habitat heterogeneity in Dry Valley streams and may allow endemic species to persist. Future Antarctic warming may alter diatom community composition and habitats that act as refugia for desiccation-tolerant taxa.
Foraging in the Dark – Chemically Mediated Host Plant Location by Belowground Insect Herbivores
Publisher: Springer Science and Business Media LLC
Date: 22-04-2012
DOI: 10.1007/S10886-012-0106-X
Abstract: Root-feeding insects are key components in many terrestrial ecosystems. Like shoot-feeding insect herbivores, they exploit a range of chemical cues to locate host plants. Respiratory emissions of carbon dioxide (CO(2)) from the roots is widely reported as the main attractant, however, there is conflicting evidence about its exact role. CO(2) may act as a 'search trigger' causing insects to search more intensively for more host specific signals, or the plant may 'mask' CO(2) emissions with other root volatiles thus avoiding detection. At least 74 other compounds elicit behavioral responses in root-feeding insects, with the majority (>80 %) causing attraction. Low molecular weight compounds (e.g., alcohols, esters, and aldehydes) underpin attraction, whereas hydrocarbons tend to have repellent properties. A range of compounds act as phagostimulants (e.g., sugars) once insects feed on roots, whereas secondary metabolites often deter feeding. In contrast, some secondary metabolites usually regarded as plant defenses (e.g., dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA)), can be exploited by some root-feeding insects for host location. Insects share several host location cues with plant parasitic nematodes (CO(2), DIMBOA, glutamic acid), but some compounds (e.g., cucurbitacin A) repel nematodes while acting as phagostimulants to insects. Moreover, insect and nematode herbivory can induce exudation of compounds that may be mutually beneficial, suggesting potentially significant interactions between the two groups of herbivores. While a range of plant-derived chemicals can affect the behavior of root-feeding insects, little attempt has been made to exploit these in pest management, though this may become a more viable option with diminishing control options.
The influence of vegetation type, soil properties and precipitation on the composition of soil mite and microbial communities at the landscape scale
Publisher: Wiley
Date: 10-03-2010
Response of belowground communities to short-term phosphorus addition in a phosphorus-limited woodland
Publisher: Springer Science and Business Media LLC
Date: 12-03-2015
Belowground ecology of scarabs feeding on grass roots: Current knowledge and future directions for management in Australasia
Publisher: Frontiers Media SA
Date: 22-03-2016
Responses of nematode abundances to increased and reduced rainfall under field conditions: A meta‐analysis
Publisher: Wiley
Date: 2023
DOI: 10.1002/ECS2.4364
Abstract: Ecosystems are projected to experience altered precipitation patterns associated with climate change, with some areas becoming wetter and others drier. Both above‐ and belowground communities will be impacted by such rainfall changes, yet research has predominantly focused on the flora and fauna aboveground. Still, there is a growing body of literature for the effects of altered precipitation on soil fauna. Nematodes are erse and abundant in most soils, represent multiple trophic levels, and influence essential soil processes, making this group a good proxy for broader impacts on soil food webs. Hence, we assessed the effects of increased and reduced rainfall amount on total and trophic‐level abundances of nematodes using a meta‐analytical approach based on 46 independent observations from 37 field studies and tested whether effects differed among ecosystem types and with treatment duration ( year, short term year, long term). Overall, total and trophic group's abundances, except fungal feeders, were negatively impacted by reduced rainfall irrespectively of treatment duration. Increased rainfall had a positive effect on total abundances and plant parasitic nematodes, but only in longer term studies ( year). The impacts of altered rainfall were consistent across the ecosystems studied however, most studies focus on grasslands and deserts, making it difficult to draw broad generalizations. Reductions in rainfall are therefore likely to decrease soil nematode abundance, with less pronounced effects on fungal feeders. Increased rainfall, on the other hand, may favor plant parasites, likely due to increased plant productivity. Hence, projections of reduced rainfall will have significant negative impacts on nematode abundances, at least in grasslands and deserts, with cascading effects on soil processes.
DRI-Grass: A New Experimental Platform for Addressing Grassland Ecosystem Responses to Future Precipitation Scenarios in South-East Australia
Publisher: Frontiers Media SA
Date: 20-09-2016
Abstract: Climate models predict shifts in the amount, frequency and seasonality of rainfall. Given close links between grassland productivity and rainfall, such changes are likely to have profound effects on the functioning of grassland ecosystems and modify species interactions. Here, we introduce a unique, new experimental platform - DRI-Grass (
The fate of carbon in a mature forest under carbon dioxide enrichment
Publisher: Springer Science and Business Media LLC
Date: 08-04-2020
Coordination of hydraulic and morphological traits across dominant grasses in eastern Australia
Publisher: Wiley
Date: 10-02-2023
Abstract: Leaf hydraulic traits characterize plant drought tolerance and responses to climate change. Yet, plant hydraulics are biased towards northern hemisphere woody species. We collected rhizomes of several perennial grass species along a precipitation gradient in eastern Australia and grew them in an experimental pot study to investigate potential trade‐offs between drought tolerance and plant morphology. We measured the following leaf hydraulic traits: the leaf water potential (Ψ leaf ) at 50% and 88% loss of leaf hydraulic conductance (P50 Kleaf and P88 Kleaf ), the Ψ leaf at 50% loss of stomatal conductance (P50 gs ), leaf turgor loss point (TLP), leaf dry matter content (LDMC), leaf modulus of elasticity (ε), and the slope of the relationship between predawn and midday Ψ leaf . We also measured basal area, tiller density, seed head density, root collar diameter, plant height, and aboveground biomass of each in idual. As expected, grass species varied widely in leaf‐level drought tolerance, with loss of 88% hydraulic conductance occurring at a Ψ leaf ranging from −1.52 to −4.01 MPa. However, all but one species lost leaf turgor, and most reached P50 gs before this critical threshold. Taller more productive grass species tended to have drought vulnerable leaves characterized by low LDMC and less negative P88 Kleaf . Species with greater tiller production experienced stomatal closure and lost turgor at more negative Ψ leaf . Although our s le size was limited, we found no relationships between these species' traits and their climate of origin. Overall, we identified important hydraulic and morphological trade‐offs in Australian grasses that were surprisingly similar to those observed for woody plants: (1) xylem of taller species was less drought tolerant and (2) turgor loss occurs and stomatal closure begins before significant loss of K leaf . These data build upon a small yet growing field of grass hydraulics and may be informative of species responses to further drought intensification in Australia. Read the free Plain Language Summary for this article on the Journal blog.
Isolation and molecular characterization of five entomopathogenic nematode species and their bacterial symbionts from eastern Australia
Publisher: Springer Science and Business Media LLC
Date: 17-08-2022
Thawing permafrost alters nematode populations and soil habitat characteristics in an Antarctic polar desert ecosystem
Publisher: Elsevier BV
Date: 03-2012
Soil biodiversity and carbon cycling: a review and synthesis of studies examining diversity–function relationships
Publisher: Wiley
Date: 16-11-2010
Predictors of fine-scale spatial variation in soil mite and microbe community composition differ between biotic groups and habitats
Publisher: Elsevier BV
Date: 03-2012
Do eucalypt plantation management practices create understory reservoirs of scarab beetle pests in the soil?
Publisher: Elsevier BV
Date: 10-2013
Soil biodiversity and human health
Publisher: Springer Science and Business Media LLC
Date: 23-11-2015
DOI: 10.1038/NATURE15744
Abstract: Soil bio ersity is increasingly recognized as providing benefits to human health because it can suppress disease-causing soil organisms and provide clean air, water and food. Poor land-management practices and environmental change are, however, affecting belowground communities globally, and the resulting declines in soil bio ersity reduce and impair these benefits. Importantly, current research indicates that soil bio ersity can be maintained and partially restored if managed sustainably. Promoting the ecological complexity and robustness of soil bio ersity through improved management practices represents an underutilized resource with the ability to improve human health.
Impacts of altered precipitation regimes on soil communities and biogeochemistry in arid and semi‐arid ecosystems
Publisher: Wiley
Date: 05-12-2014
DOI: 10.1111/GCB.12789
Abstract: Altered precipitation patterns resulting from climate change will have particularly significant consequences in water-limited ecosystems, such as arid to semi-arid ecosystems, where discontinuous inputs of water control biological processes. Given that these ecosystems cover more than a third of Earth's terrestrial surface, it is important to understand how they respond to such alterations. Altered water availability may impact both aboveground and belowground communities and the interactions between these, with potential impacts on ecosystem functioning however, most studies to date have focused exclusively on vegetation responses to altered precipitation regimes. To synthesize our understanding of potential climate change impacts on dryland ecosystems, we present here a review of current literature that reports the effects of precipitation events and altered precipitation regimes on belowground biota and biogeochemical cycling. Increased precipitation generally increases microbial biomass and fungal:bacterial ratio. Few studies report responses to reduced precipitation but the effects likely counter those of increased precipitation. Altered precipitation regimes have also been found to alter microbial community composition but broader generalizations are difficult to make. Changes in event size and frequency influences invertebrate activity and density with cascading impacts on the soil food web, which will likely impact carbon and nutrient pools. The long-term implications for biogeochemical cycling are inconclusive but several studies suggest that increased aridity may cause decoupling of carbon and nutrient cycling. We propose a new conceptual framework that incorporates hierarchical biotic responses to in idual precipitation events more explicitly, including moderation of microbial activity and biomass by invertebrate grazing, and use this framework to make some predictions on impacts of altered precipitation regimes in terms of event size and frequency as well as mean annual precipitation. While our understanding of dryland ecosystems is improving, there is still a great need for longer term in situ manipulations of precipitation regime to test our model.
Plant functional traits affect competitive vigor of pasture grasses during drought and following recovery
Publisher: Wiley
Date: 07-2022
DOI: 10.1002/ECS2.4156
Abstract: Grassland biomass production is strongly linked with the timing and intensity of precipitation events. While the direct effects of precipitation patterns on grasses are well‐studied, less is known regarding plant–plant interactions during different phases of drought (i.e., dry down vs. recovery). Here, we examined how the intensity and timing of drought affected biomass production, traits related to growth rate and competitive vigor (specific leaf area [SLA], leaf dry matter content [LDMC], and height [HT]), and competitive effects in three common pasture grasses. Each species was grown alone (one in idual per 45‐L planter) or with competition (one in idual of each species per 45‐L planter) under three different drought types: (1) “short‐term” drought where water was withheld until the first species reached stomatal closure (2) “prolonged” drought where water was withheld until all three species reached stomatal closure and (3) “repeated” short‐term drought where water was withheld until the first species reached stomatal closure, plants were rewatered to capacity, and then, the drought was repeated. In all three drought types, replicates were assessed for biomass and traits pre‐ and post‐rewatering to represent the “resistance” and “recovery” phases of drought, respectively. Overall, we found (1) competitive interactions during phases of drought were primarily mediated by plant HT and LDMC, not SLA (2) the severity and frequency of drought were key factors in describing plant–plant interactions during phases of drought and (3) interspecific differences in traits and trait responses to drought phases were key in predicting plant–plant competition. Such shifts in competition interactions associated with interspecific trait responses to drought and during recovery from drought are likely to have significant effects on the productivity and composition of multispecies, grass‐dominated plant communities.
The importance of vegetative and sexual dispersal of Luronium natans
Publisher: Elsevier BV
Date: 02-2006
Soil Biodiversity and the Environment
Publisher: Annual Reviews
Date: 04-11-2015
DOI: 10.1146/ANNUREV-ENVIRON-102014-021257
Abstract: Soils represent a significant reservoir of biological ersity that underpins a broad range of key processes and moderate ecosystem service provision. Our understanding of the role that soil organisms play in ecosystems is still developing, but the increased investigation into bio ersity-ecosystem functioning relationships in soils over the past couple of decades has provided insights that have greatly enhanced our ability to sustainably manage soil bio ersity. In this review, we synthesize emerging knowledge of soil bio ersity as a natural resource that supports the functioning of terrestrial ecosystems and their delivery of ecosystem services. We explore how environmental changes alter soil bio ersity and how this in turn can affect ecosystem processes as well as resistance and resilience to environmental changes. We then discuss ways to include soil bio ersity in management strategies for sustainable production and bio ersity conservation. We conclude by highlighting key research challenges to further improve our knowledge of soil bio ersity and its management.
The future of soil invertebrate communities in polar regions: different climate change responses in the Arctic and Antarctic?
Publisher: Wiley
Date: 2013
DOI: 10.1111/ELE.12058
Abstract: The polar regions are experiencing rapid climate change with implications for terrestrial ecosystems. Here, despite limited knowledge, we make some early predictions on soil invertebrate community responses to predicted twenty-first century climate change. Geographic and environmental differences suggest that climate change responses will differ between the Arctic and Antarctic. We predict significant, but different, belowground community changes in both regions. This change will be driven mainly by vegetation type changes in the Arctic, while communities in Antarctica will respond to climate amelioration directly and indirectly through changes in microbial community composition and activity, and the development of, and/or changes in, plant communities. Climate amelioration is likely to allow a greater influx of non-native species into both the Arctic and Antarctic promoting landscape scale bio ersity change. Non-native competitive species could, however, have negative effects on local bio ersity particularly in the Arctic where the communities are already species rich. Species ranges will shift in both areas as the climate changes potentially posing a problem for endemic species in the Arctic where options for northward migration are limited. Greater soil biotic activity may move the Arctic towards a trajectory of being a substantial carbon source, while Antarctica could become a carbon sink.
Water track modification of soil ecosystems in the Lake Hoare basin, Taylor Valley, Antarctica
Publisher: Cambridge University Press (CUP)
Date: 10-07-2013
DOI: 10.1017/S095410201300045X
Abstract: Water tracks are zones of high soil moisture that route shallow groundwater down-slope, through the active layer and above the ice table. A water track in Taylor Valley, McMurdo Dry Valleys, was analysed for surface hydrogeological, geochemical, and biological characteristics in order to test the hypothesis that water tracks provide spatial structure to Antarctic soil ecosystems by changing the physical conditions in the soil environment within the water tracks from those outside the water tracks. The presence of the water track significantly affected the distribution of biotic and abiotic ecosystem parameters: increasing soil moisture, soil salinity, and soil organic matter within the water track relative to soils outside the water track, and reducing soil phosphate, soil pH, and the population of nematodes and other invertebrates in water track soils relative to off track soils. These results suggest that water tracks are distinct and extreme ecological zones in Taylor Valley that provide long-range (kilometre to multi- kilometre) structure to Antarctic hillslope ecosystems through physical control on soil moisture and solute content. Contrary to expectations, these high soil-moisture sites are not hotspots for faunal biological activity because high soil salinity makes them suitable habitats for only the most halo-tolerant organisms.
The effect of prolonged drought legacies on plant-soil feedbacks
Publisher: Wiley
Date: 11-2021
DOI: 10.1111/JVS.13100
Abstract: Climate change has been shown to cause shifts in plant–soil feedbacks (PSFs) that may affect plant community dynamics, but the effect of prolonged drought is uncertain. We asked whether prolonged drought legacies cause shifts in PSFs due to changes in plant–soil biotic interactions. Richmond, New South Wales, Australia. We collected soils from a five‐year field‐based rainfall manipulation experiment simulating ambient rainfall and drought (50% reduction) in a mesic temperate grassland. PSFs of twelve plant species representing four functional groups (C3 and C4 grasses, forbs, and legumes) were assessed when grown alone and in mixed cultures (one species from each of the four functional groups) under laboratory conditions following a standard PSF protocol in soils with ambient rainfall and drought legacies. All soils were sterilised and then re‐inoculated to create the respective treatments including a non‐inoculated control for biota‐mediated PSFs. PSFs varied considerably among species and functional types in both legacy treatments. Overall, C3 grasses displayed less negative and C4 grasses less positive PSFs in soils with a legacy of prolonged drought compared with soils with ambient rainfall legacies, while PSFs for forbs and legumes were not significantly different from zero in either rainfall treatment. However, PSFs differed between species within functional groups. For ex le, Plantago showed positive PSFs in soils with ambient rainfall legacies but negative PSFs in soils with drought legacies while the opposite was observed for Medicago . PSFs of the mixed communities showed a trend to shift from positive to neutral in soils with drought legacies, with significant differences in PSFs observed when comparing home vs sterile soils, suggesting that drought may destabilise plant communities. Our results provide evidence that prolonged drought legacies can modify plant community dynamics due to species‐specific changes in PSFs that persist after droughts are alleviated.
Prolonged drought causes negative plant-soil feedbacks in grassland species under field conditions
Publisher: Elsevier BV
Date: 09-2022
Dominant plants affect litter decomposition mainly through modifications of the soil microbial community
Publisher: Elsevier BV
Date: 10-2021
Polar lessons learned: long-term management based on shared threats in Arctic and Antarctic environments
Publisher: Wiley
Date: 08-2015
DOI: 10.1890/140315
Nematode communities of Byers Peninsula, Livingston Island, maritime Antarctica
Publisher: Cambridge University Press (CUP)
Date: 03-03-2011
DOI: 10.1017/S0954102011000174
Abstract: The nematode communities of Antarctica are considered simple. The few species present are well adapted to the harsh conditions and often endemic to Antarctica. Knowledge of Antarctic terrestrial ecosystems is increasing rapidly, but nematode communities remain to be explored in large parts of Antarctica. In soil s les collected at Byers Peninsula (Antarctic Specially Protected Area No. 126), Livingston Island we recorded 37 nematode taxa but s les showed great variation in richness and abundance. Nematode richness decreased with increasing soil pH, whereas total abundances, and the abundance of several trophic groups, were greatest at intermediate pH (around 6.5–7). Moreover, the community composition was mainly related to pH and less so to soil moisture. Trophic group, and total nematode, rotifer and tardigrade, abundances were generally positively correlated. Byers Peninsula is thus, by maritime Antarctic standards, a nematode bio ersity hotspot, and the presence of several previously unrecorded genera indicates that nematode species richness in maritime Antarctica is probably underestimated. Our results indicate that abiotic factors influence nematode communities with little evidence for biotic interactions. The unexplained heterogeneity in community composition is probably related to variation in microclimate, vegetation, topography and unmeasured soil properties, but may also be contributed to by biological processes.
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University Of Aberdeen
Location: United Kingdom of Great Britain and Northern Ireland
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Discovery Projects - Grant ID: DP150104199
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End Date: 04-2019
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Funder: Australian Research Council
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Amount: $421,500.00
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