Impacts of the invasive pathogen Austropuccinia psidii (Myrtle rust) on Australian native communities

Despite ongoing research into the invasion of the fungal pathogen Austropuccinia psidii (myrtle rust) in Australia, few studies have attempted to examine the impacts it has on natural native communities at both the species- and community-level. This is surprising considering that it infects the Myrtaceae, one of the dominant plant families in Australia. Furthermore, the lack of a national program collating data on A. psidii spread, hosts and impacts makes restoration and conservation decision making challenging for natural resource managers. Therefore, the overarching aim of this thesis was to determine the impacts of the invasive pathogen Austropuccinia psidii on Australian native vegetation communities. Specifically, this thesis determines the geographic extent and impacts of A. psidii on Australian native vegetation communities from the outcomes of a survey distributed to researchers, land managers and government employees (Chapter 2); the susceptibility of 24 previously untested species/sub-species with a particular emphasis on endangered species (Chapter 3); the impacts of A. psidii on plant architecture, growth and biomass allocation of susceptible species after fire under controlled glasshouse conditions (Chapter 4); and finally the indirect and direct impacts of A. psidii on community species richness and abundance through a large scale field experiment (Chapter 5). Altogether, this suite of studies represents a significant contribution to our understanding of the A. psidii invasion in eastern Australian vegetation communities. The outcome of this contribution will hopefully be to inform and assist the successful conservation of one of the most iconic plant families in Australia as well as the communities that they define.