Impacts of climate change on freshwater macroinvertebrates and conservation prioritisation
thesisposted on 2022-03-28, 01:28 authored by Alex Bush
My thesis focuses on issues of monitoring and conserving aquatic macroinvertebrate biodiversity under climate change within Australia. Initially the research examines how existing bio-monitoring datasets from New South Wales could be analysed to draw conclusions about broad-scale trends in diversity and how these trends may affect vulnerability of assemblages in the future. The focus is then directed towards dragonflies and whether they have potential as biological indicators of climate change and surrogacy among macroinvertebrate families. The results show climatically sensitive habitats can be identified from biological trends using relatively coarse biomonitoring data, that turnover of dragonflies is highly sensitive to climatic factors, but that they also relatively poor surrogates for other macroinvertebrates. The distribution of suitable habitat for most dragonflies in Australia was then modelled under current and future climate conditions. The likely vulnerability of each species was assessed according to criteria of exposure, sensitivity and the importance of dispersal capacity. The distribution of dragonfly diversity was then analysed for Australia as a whole, including evolutionary as well as species diversity. A large number of species were found to be potentially vulnerable to the effects of climate change and the associated shifts in distribution could significantly modify the patterns of diversity in Australia. Finally, the modelled distribution of dragonflies was used to test the performance of proactive approaches to systematic conservation in eastern Australian rivers, and the effect of emphasising connectivity in reserve selection. Anticipating the effects of climate change can offer significant gains in efficiency, and connectivity that allows movement across catchment boundaries improves representation of dragonflies within reserve systems under climate change. Overall, the predicted impacts of climate change are likely to be conservative estimates and emphasise the urgent need for action to improve adaptation to climate change in freshwater ecosystems.