Dr Lisa Chandler1, Dr Kate Montgomery1, Dr Tom Mooney1, Dr David Beale2, Dr Andrew Bisset3, Dr Christine Chivas4, Dr Andrew Harford1
1Office of the Supervising Scientist, Department Of Climate Change, Energy The Environment And Water, Darwin , Australia, 2Department of Environment, Tourism, Science and Innovation, Brisbane, Australia, 3CSIRO, Hobart, Australia, 4School of Natural Sciences, Macquarie University, Sydney, Australia
Biography:
Lisa is a research scientist with the Office of the Supervising Scientist within the Department of Climate Change, Energy, the Environment and Water. She has more than 20 years’ experience in aquatic ecology research and monitoring across government and private sectors, with a particular focus on freshwater invertebrates. Her research has examined the responses of groundwater invertebrate and microbial communities to mine-derived stressors in seasonal sandy streams, and more broadly spans aquatic and groundwater ecology, ecotoxicology, macroinvertebrate taxonomy, and the use of biological indicators to assess disturbance and recovery. Her current work also applies DNA-based approaches to understand microbial and soil communities in environmental monitoring and rehabilitation contexts.
Abstract:
The rehabilitation of the Ranger uranium mine in northern Australia requires monitoring approaches capable of demonstrating whether key ecological processes are developing towards a self-sustaining state. While soil chemical and physical measurements provide context, they offer only indirect evidence of nutrient- cycling processes. Environmental DNA (eDNA) provides a scalable approach for characterising soil microbial communities, but its suitability for assessing ecosystem function remains uncertain.
This presentation describes a framework for evaluating eDNA-derived indicators of soil nutrient cycling using trial rehabilitated areas of Ranger and surrounding natural ecosystems in Kakadu National Park as test sites. Amplicon sequencing of bacterial, archaeal and fungal communities was assessed alongside metagenomic, metabolomic and soil physicochemical datasets to determine whether lower-cost eDNA approaches can provide sufficiently robust information for long-term monitoring. Rather than treating all molecular datasets as equivalent measures of function, the framework distinguishes community composition, inferred function, functional potential and complementary evidence of biochemical activity.
Reference-site datasets were used to characterise natural variability associated with season, soil depth and site conditions, and assess concordance among multiple lines of evidence. Rehabilitated and mine-impacted soils were then used to evaluate the applicability of these approaches under conditions relevant to rehabilitation monitoring. Preliminary findings indicate that integrating multiple omics datasets improves interpretation of nutrient-cycling processes while highlighting the need to account for natural spatial and temporal variability before differences are attributed to ecological condition.
The work provides a pathway for translating multi-omics investigations into practical, cost-effective eDNA indicators to support rehabilitation monitoring, closure planning and management decision-making.