Doctoral Thesis
Drivers of post-fire responses and ecological resilience in restored Banksia woodlands
Doctor of Philosophy (PhD), Murdoch University
2024
Abstract
In a time of global biodiversity loss, ecological resilience — an ecosystem's ability to return to its prior state following a disturbance — is crucial for restoration success in disturbance-prone regions. Despite this, responses of restored plant communities to disturbances remain uncertain across most ecosystems.
My thesis explores the drivers of post-fire responses of restored Banksia woodlands in southwestern Australia and implications for their resilience. Measurements spanned from individual plants to the entire community. Using a chronosequence of sites aged between three and 27 years since restoration after mining, I investigated the effects of restoration age and environmental factors relating to climate at establishment and soil conditions on soil seedbank development, resprouting and plant community responses to fire. I used these findings to assess the resilience of these restored sites to fire.
Across all restoration ages, resprouting and seedling establishment occurred following fire, but the development of these attributes varied among plant functional groups and, in some cases, restoration age. Annual species dominated the seedbank of younger restoration ages, while perennials dominated older ages. Drivers of resprouting success varied among species, and restoration age, plant size and soil conditions (e.g., compaction) poorly explained resprouting success. In most restoration ages, obligate seeders diversity, rarefied richness and functional redundancy did not change following fire, but resprouters diversity declined in age 14 suggesting lower levels of resilience to fire in this age. Change in restored sites following fire often did not reflect that of reference (i.e., intact, unmined) Banksia woodlands, and restored and reference Banksia woodlands differed in perennial and annual species composition and dominance.
Overall, these data suggest mixed responses of resprouter species and altered perennial community composition in restored Banksia woodlands impede resilience to fire, so further consideration of perennial vegetation development in fire-prone restoration sites is warranted.
Details
- Title
- Drivers of post-fire responses and ecological resilience in restored Banksia woodlands
- Authors/Creators
- Ebony L Cowan
- Contributors
- Joe Fontaine (Supervisor) - Murdoch University, Centre for Terrestrial Ecosystem Science and SustainabilityRachel Standish (Supervisor) - Murdoch University, School of Environmental and Conservation SciencesBen Miller (Supervisor)
- Awarding Institution
- Murdoch University; Doctor of Philosophy (PhD)
- Identifiers
- 991005676070307891
- Murdoch Affiliation
- School of Environmental and Conservation Sciences
- Resource Type
- Doctoral Thesis
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