Ecological drivers of eucalypt bark type distributions in south-east Australian forests and woodlands
Researchers and collaborators: PhD Candidate Kathryn Fuller, Prof Matthias Boer, Dr Rachel Nolan, Dr Mike Aspinwall (international)
Funding body: NSW Bushfire Risk Management Research Hub
Project Description: Fire is an important driver of tree species distributions in south-east Australia. Bark traits are known to correlate with fire severity and frequency, responding to fire as a selective pressure. Some eucalypt bark types are also known to significantly influence fire behaviour, via spotting and changes in fuel continuity. However, there is no comprehensive list of eucalypt species belonging to different bark types. In this study, we categorised eucalypts into twelve major bark type classes. We then used environmental covariates to identify the primary environmental drivers of bark type distributions in forests and woodlands of south-eastern Australian forests. We developed predictive models of bark type distributions and found that bark types were predictable at high levels of accuracy (up to 88% accuracy), with variables related to water stress and site productivity important to all bark type predictive models. Other important variables were rainfall seasonality, soil texture and fertility, and temperature at the driest time of year. Importantly, we found differing spatial patterns of all ten bark types, indicating divergent ecological strategies and possible differences in sensitivity to fire. This highlights the importance of bark type as an ecologically significant plant trait in eucalypts. The maps developed in the study can be used by management to identify locations with potentially hazardous bark fuels and by future researchers to further investigate bark type as a plant function trait.