Dr Lynne Forster1

1University Of Tasmania

Biography:

Dr Lynne Forster is an entomologist at TIA, University of Tasmania where she is a researcher, does teaching and works on the taxonomy of insects and spiders. Her work examines pollinators, parasitoids and biocontrol of pests, including conservation planting in agricultural production. She has researched insect interactions and ecological, chemical and genetic relationships of invertebrates across landscapes in changing environments. Some recent work examined recovery of beetles from disturbances such as fragmentation, fire and extreme weather events.

Abstract:

The persistence of an ecosystem and its biodiversity depends upon the ability of organisms to resist and adapt to disturbance or recover from it. Alternatively, an ecosystem may not recover its former structure and function and may shift to an alternative stable state.

It is increasingly difficult to predict the recovery trajectory of an ecosystem under the impact of altered disturbance regimes such as increased frequencies of drought, wildfire and extreme weather events driven by climate change. Yet, understanding how organisms respond to disturbance is essential for appropriate management of natural resources and conservation under a changing climate.

This presentation examines how threats to biodiversity were generated by altered disturbance regimes; how biodiversity responses were unexpected and counterintuitive; and how we might monitor these threats. Tasmania’s fire-adapted wet eucalypt forests and adjacent montane areas are the ecosystems in which distributions of beetles were used as a measure of the impact of these threats on dispersal processes.

A suite of multivariate analyses to test alternative hypotheses revealed unexpected insights into beetle responses and vulnerability to disturbance. Landscapes with less than 20% mature-forest cover, fire frequencies less than 100 years and ecotones that switch from being permeable to barriers during extremely hot weather events, emerged from the results as candidate early warning signals that dispersal processes disturbed by fragmentation, wildfire and extreme weather events, could initiate alternative trajectories of recovery in ecosystems. The implications of these findings for modelling distributions of species under future climate scenarios and for conservation are discussed.