Following reports of isolated tree deaths throughout Kosciuszko National Park in 2007-08, sub-alpine forests in the Australian Alps are now in widespread decline. This phenomenon, known as snow-gum dieback, is associated with infestation by native longicorn beetle larvae that mine the outer xylem and inner phloem of trees, disrupting hydraulic function and carbohydrate flow. Severe infestations lead to complete death of affected trees and stands. The loss of woody overstorey across Australia’s sub-alpine forests would have far-reaching direct and cascading impacts upon all attendant invertebrate and vertebrate populations including threatened species. The niche left by the death of the overstorey would also increase the risk presented by invasive species and have significant hydrologic impacts with far reaching economic consequences.

In this talk, Dr Matthew Brookhouse will outline the current state of knowledge on snow-gum dieback. The talk will focus upon description of the unmistakable symptoms that distinguish dieback and introduce the candidate insect species currently linked to the phenomenon. Drawing upon a phenomenological perspective of forest dieback, the talk will explore current hypotheses on the ultimate drivers of snow-gum dieback. Matthew will also discuss current research activities aimed at understanding both the history and current trajectory of snow-gum dieback.

The large area, and rugged and complex terrain currently affected by dieback means community engagement in ongoing research is essential. Matthew will outline the opportunities for citizen science and the contribution it can make to understanding dieback at a landscape level.

About the Speaker

Dr Matthew Brookhouse completed a BSc (Forestry) Honours at ANU in 1997 and returned to the ANU in 2003 after six years designing and implementing growth and yield studies, and forest inventory protocols in Victoria's commercial native forests.

After receiving his PhD (2008) and two postdoctoral research projects focussed on the use of forest structural complexity for landscape planning and dendrochronological reconstrcution of river flow in Victoria, he accepted a position as Lecturer in Ecological Modelling and Measurement at the Fenner School of Environment & Society. In 2012 Dr Brookhouse commenced a dual appointment between the Research School of Biology (Farquhar Lab) and Fenner School and conducted research aimed at understanding water use in regenerating mountain ash forests and [CO₂] responsiveness in commercial forest species.

In 2018 he was permanently appointed as a Senior Lecturer in the Fenner School and currently teaches first-year research methods, with a specific focus on helping students make the important connection between the theory of inferential statistics and their application.

Dr Brookhouse continues to explore the genotype-by-[CO₂] interactions in eucalypt species and has ongoing dendrochronological, and silvicultural research interests. He also leads the collaborative research efforts focussed on understanding wood-borer induced dieback of snow-gum woodland in the Australian Alps.