Pathogen driven change in species-diverse woodlands of the Southwest Australian Floristic Region: A hybrid ecosystem in a Global Biodiversity Hotspot

摘要: Human-induced change in natural environments is occurring at unprecedented rates over ecologically brief periods of time. The consequences such disturbance has been documented both terrestrial and marine habitats with much focus on events as extreme weather (hurricanes, cyclones etc.), agriculture, altered fire regimes, weeds climate change. Pathogens are increasingly being recognised powerful agents change, though documentation limited often restricted to species-level changes. Inextricably linked the direct changes species composition indirect effects pathogens community structure ecosystem function. Traditional species-based studies looking pathogen-induced specific somewhat one-dimensional shifts richness, cover un-standardised diversity indices. This project was developed explore impact pathogen beyond using a structured comprehensive approach that integrates current ecological theories. PhD part larger ARC linkage titled 'Towards Landscape Conservation Culture - broadening spatio-temporal scope anticipate Australian forested ecosystems'. It aims questions regarding biodiversity management an integrated landscape-level conservation which looks individual species. because performance persistence dependent upon complexity relationships between different components range spatial scales species-level. Through integrating utilising theory frameworks, this thesis links concepts methods ecology link inadequate literature requires bridging through application testing field situations or novel research. practical integration Resilience Novel Ecosystem theory, forms basis provides alternate view shifts. suggests lead irreversible regime shift. will be used describe impacts criteria for determining if hybrid ecosystems results. I across provide account forest ecosystem. use introduction Phytophthora cinnamomi into Banksia attenuata woodlands case study. high rainfall zone Southwest Floristic Region highly susceptible P. infestation. These contain substantial suite pathogen-susceptible found low lying areas landscape prime position infestation by overland water flow. Due these factors obvious disease expression, were chosen investigation. Using resilience framework begin describing vegetation further enquiry plant functional traits. chronosequence expression replicated landscape, identify dominance associated stand variables (canopy cover, leaf litter basal area). also apply uni-variate multivariate indices community-level. continue trait deduced addition then determine resulted from demonstrates although have undergone shift identity (species dominance, beta diversity, variables, composition) some original features retained including diversity. For reasons, post-pathogen identifies equally speciose despite other Following infestation, unlikely return their previous state due site microclimate related variables.