Dr Shasta Henry1, Dr Peter McQuillan1, Dr Jamie Kirkpatrick1

1University Of Tasmania, Hobart, Australia

Biography:

Shasta is a passionate scientist and science communicator. She is committed to both the frontier of entomological science & to bringing that knowledge to the broader community by developing significant learning projects & inspiring presentations. She completed her PhD in invertebrate ecology at the University of Tasmania. That research focused on the impact of fire on insect communities, wilderness research techniques, and taxonomy. Shasta also has10 years of experience as a science communicator in entomology, ecology & general science literacy.

This presentation is my PhD thesis in synopsis, both published and unpublished portions.

Abstract:

Tasmanian coniferous heath and scrub are the most fire-sensitive ecosystem in Australia. They have been well studied and shown to require hundreds of years to recuperate from burning. With climate change altering fire regimes globally, including Tasmania’s palaeoendemic alpine ecosystems, I endeavoured to investigate the long-term succession of the invertebrate community associated with this habitat. +

My original data was collected over 12 months (in six continuous sampling periods) using three trapping techniques to extract flying and sessile invertebrates from 33 quadrats. Quadrats straddled a 52-year-old fire boundary, in sub-alpine central Tasmania. The burned half of the site contained highly floriferous regrown heath vegetation. The unburned half of the site was characterised by fire sensitive and palaeoendemic evergreen and deciduous plant species. The site was located on the Tarn Shelf, Mount Field National Park which is part of the Tasmanian Wilderness World Heritage Area.

This work revealed that long-lasting post fire habitat changes in fire-sensitive vegetation were translated into the community composition of both flying and sessile invertebrates. This is in contrast to many researchers who report vegetation, and invertebrates return to pre-fire conditions within decades. My data also showed that the regrown heath was not equivalent to unburned heath, 52 years post-burn, both in terms of vegetation resources, and in terms of habitat for specific invertebrates. I observed that most of the invertebrates collected showed a warm season activity peak; the few invertebrate taxa which were most abundant during colder seasons were palaeoendemic. I also observed a cohort of generalist invertebrates which have not historically been associated with Tasmanian palaeoendemic vegetation. Their high fidelity with the fire-sensitive ecosystem infers an extinction cascade which is not currently considered in the conservation and management of these threatened host plants.