Understanding the factors that influence seedling establishment to improve the success of threatened species translocations in the Mediterranean-climate region of southwest Australia

[Truncated] Translocations have become a common management tool across the globe to establish or augment populations of threatened plant species to reduce the risk of extinction. Translocations often involve germinating seed ex-situ and planting seedlings into a specified site. As the translocation process is relatively costly and there is often limited seed availability, it is important to maximise seedling survival to increase the chances of establishing a self-sustaining population. Manipulating abiotic and biotic variables at a translocation site is one strategy used to improve seedling survival and further understand the ecology of threatened species. Southwest Australia is one of 34 global biodiversity hotspots with a high proportion of threatened plant species. Consequently, translocations have been implemented in this region by the Department of Parks and Wildlife over the last 20 years with varied degrees of success. My research focused on the Acacia and Banksia genera to build on the knowledge gained through past translocations and tests some novel ideas to explore the questions: (1) Is it possible to manipulate microhabitat “safe site” variables and plant seedlings with particular characteristics that together improve their growth and survival in a Mediterranean-climate? (2) Do plant physiological responses and microhabitat measurements help to explain seedling survival and growth? (3) Can we use data on natural seedling establishment and physiological responses to guide conservation of threatened species in a drying climate? My thesis incorporates research from both natural and translocation settings at three spatial scales.