Doctoral Thesis
Factors affecting establishment through to persistence of threatened plant translocations in south-western Australia
Doctor of Philosophy (PhD), Murdoch University
2023
Abstract
Translocations are used to conserve threatened plants, with the aim to establish viable populations with adequate levels of genetic diversity. Yet limited understanding of how to define and measure success has impeded its effectiveness as a conservation tool.
I used field-based studies and a glasshouse experiment to identify factors contributing to success of threatened plant translocations in southwestern Australia. A broad study of 76 translocations highlighted the impact of herbivory on translocation establishment and the need to account for seasonal water availability. My study of 16-year-old Acacia cochlocarpa subsp. cochlocarpa translocations showed they were demographically comparable to the wild source population indicating success. One of these populations recovered from prescribed fire indicating resilience to a common disturbance across the region. I found that levels of genetic diversity, an important indicator of resilience and evolutionary potential, were comparable to or greater than source populations of another translocated species, Lambertia orbifolia. However, high levels of inbreeding at two of these translocated populations suggests this diversity may decline over time. Finally, I considered what seed sourcing strategies were likely to be more effective in founding genetically diverse and persistent populations. Different strategies were effective for the two subspecies of L. orbifolia, with a single seed source suitable for one subspecies whereas admixture more appropriate for the second subspecies. Lastly, my study of the annual daisy Schoenia filifolia suggested genetic or demographic rescue of a small declining population, or admixture to establish a new population, were likely to be equally effective translocation strategies.
My findings suggest that future translocations will benefit from irrigation and herbivore exclusion, and that seed sourcing strategies underpinned by knowledge of genetic diversity and genetic structure, information about regeneration niche requirements and the appropriate application of disturbance regimes, especially in relation to fire, are likely to further improve translocation outcomes.
Details
- Title
- Factors affecting establishment through to persistence of threatened plant translocations in south-western Australia
- Authors/Creators
- Leonie T Monks
- Contributors
- Rachel Standish (Supervisor) - Murdoch University, School of Environmental and Conservation SciencesDavid Coates (Supervisor)
- Awarding Institution
- Murdoch University; Doctor of Philosophy (PhD)
- Identifiers
- 991005680462607891
- Murdoch Affiliation
- College of Environmental and Life Sciences; School of Environmental and Conservation Sciences
- Resource Type
- Doctoral Thesis
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