ORCID Profile
0000-0002-2543-680X
Current Organisation
UNSW
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Publisher: Copernicus GmbH
Date: 27-03-2022
DOI: 10.5194/EGUSPHERE-EGU22-3645
Abstract: & & & span& A recent global study showed that there was a large discrepancy between air temperature and soil temperature with variances of up to 10 degrees depending on ground cover and soil moisture. Vegetation cover increases soil moisture and decreases soil temperature, and vegetation types have shown significant differences in their impact on soil respiration. Australian vegetation has evolved closely with the soil biota and the influence of these organisms likely has a strong role in dictating vegetation type. Exploring the correlation of vegetation and soil microbes under climate change would have two-way benefits. Identifying microbes which improve soil functionality under climate change could improve revegetation strategies. Understanding how vegetation cover might buffer the impacts of climate change on soil functionality could enable targeted management for facilitating ecosystem resilience and resistance to climate change. & & /span& & &
Publisher: Springer Science and Business Media LLC
Date: 05-08-2021
DOI: 10.1038/S41598-021-95544-Z
Abstract: Platypuses ( Ornithorhynchus anatinus ) inhabit the permanent rivers and creeks of eastern Australia, from north Queensland to Tasmania, but are experiencing multiple and synergistic anthropogenic threats. Baseline information of health is vital for effective monitoring of populations but is currently sparse for mainland platypuses. Focusing on seven hematology and serum chemistry metrics as indicators of health and nutrition (packed cell volume (PCV), total protein (TP), albumin, globulin, urea, creatinine, and triglycerides), we investigated their variation across the species’ range and across seasons. We analyzed 249 unique s les collected from platypuses in three river catchments in New South Wales and Victoria. Health metrics significantly varied across the populations’ range, with platypuses from the most northerly catchment, having lower PCV, and concentrations of albumin and triglycerides and higher levels of globulin, potentially reflecting geographic variation or thermal stress. The Snowy River showed significant seasonal patterns which varied between the sexes and coincided with differential reproductive stressors. Male creatinine and triglyceride levels were significantly lower than females, suggesting that reproduction is energetically more taxing on males. Age specific differences were also found, with juvenile PCV and TP levels significantly lower than adults. Additionally, the commonly used body condition index (tail volume index) was only negatively correlated with urea, and triglyceride levels. A meta-analysis of available literature revealed a significant latitudinal relationship with PCV, TP, albumin, and triglycerides but this was confounded by variation in s ling times and restraint methods. We expand understanding of mainland platypuses, providing reference intervals for PCV and six blood chemistry, while highlighting the importance of considering seasonal variation, to guide future assessments of in idual and population condition.
Publisher: Springer International Publishing
Date: 2023
DOI: 10.1007/698_2023_966
Publisher: Copernicus GmbH
Date: 04-03-2021
DOI: 10.5194/EGUSPHERE-EGU21-16398
Abstract: & & Arid and semi-arid (from hereafter dryland) ecosystems cover 70% of Australia, with climate change set to increase this area through desertification. Increased temperatures and reduced water availability are compounded through agricultural overgrazing. This degradation and habitat loss has led to bio ersity loss which disrupts the biogeochemical cycles that maintain these environments, creating a negative feedback loop, and making restoration efforts largely unsuccessful. With soil microbes being important drivers in dryland systems, understanding how different stressors impact the soil biome is needed to improve conservation and restoration efforts and promote resilience and resistance to climate change. Particularly lacking is understanding of these interactions over time.& & & & Fowlers Gap Research Station is the only research station in the arid zone of Australia and was a working sheep station until 2019. Due to agricultural overgrazing the site is largely degraded however exclusion zones have been set up on the property ranging in time from 3 years to 40 years. These exclusion zones provide a powerful comparison for the impact of soil degradation on drylands. To investigate the impact of overgrazing on the soil bio ersity and ecosystem functions, we selected three of the exclusion zones paired with three degraded sites directly outside of the exclusion zone to assess their microbial composition and functional ersity, along with soil physicochemical properties. We aim to build 16S rRNA gene libraries and co-relate them with the soil chemical variables, to assess the impact of overgrazing on these microbial communities and the ecosystem functions they provide. This knowledge can be used to improve monitoring of conservation and restoration initiatives by providing environmental indicators for soil health over time.& &
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-13204
Abstract: & & The depletion and degradation of native plant communities is a major threat to the long-term health and functionality of many ecosystems worldwide. Some of the current challenges in mine rehabilitation programs are poor recruitment and establishment of native plants. Indigenous soil bacteria, including cyanobacteria from soil biocrusts, have shown promise as bio-fertilizers as they may promote germination and enhance seedling growth of native plants in reconstructed soil profiles. In this research, we assessed the potential of bioinoculants composed by locally sourced soil bacteria from the rhizosphere and cyanobacteria from biocrusts, to promote germination and growth of native arid plants from Western Australia and New South Wales (Australia). In idual cyanobacteria species (e.g. Leptolyngbya sp, Nostoc sp. and Microcoleus sp), a cyanobacteria mix of these three species, and enrichments of soil bacteria from the rhizosphere were considered as inoculum for seed bio-priming. Overall, our results showed that lower concentrations of cyanobacteria inoculants (1 g l& sup& -1& /sup& ) are more effective for promoting seedling growth than highly concentrated inoculum (5 g l& sup& -1& /sup& ). The effects of the cyanobacterial/bacterial inoculants were specific to each plant species. However, biopriming seeds with soil bacteria and the cyanobacteria mix resulted in three times larger roots in hummock grasses (e.g. Triodia epactia) compared to the control treatment. We also identified the bio-active components or metabolites produced by targeted cyanobacteria species through GC/MS analyses. Our results showed that some of the cyanobacterial inoculants produced substances chemically like plant hormones such as auxins, i.e. indole-3-acetic acid. The positive effects of the native soil bacteria and cyanobacteria inoculants on native plants could be related to their ability of promoting nutrient bioavailability, improving stress resistance, protection against other microbes, and production of substances that may act as hormones. The findings of this research can allow selecting the most effective bio-active inoculants for application in seed-based land rehabilitation programs.& &
No related grants have been discovered for Jana Stewart.