AbstractsBiology & Animal Science

Although the importance of fire management for biodiversity conservation is increasingly being recognised, little is known about the relationship between fire regimes and plant diversity in Australia’s temperate grassy woodland ecosystems. This project sought to address this gap in the woodlands of Western Sydney’s Cumberland Plain. Aspects of vegetation dynamics were investigated through six studies, mostly in shale-based Cumberland Plain Woodland (CPW) remnants. Results indicate that fire frequency profoundly affects both vegetation composition and structure. The influence of fire cycles was most readily apparent in the shrub layer. Findings from the six studies were synthesized into a state and transition model which allows exploration of management actions. Interfire intervals between 4 and 12 years are predicted to maintain Themeda woodland with both Bursaria thickets and open areas, and obligate seeder shrubs. Variable intervals across time and space within these thresholds should maintain much of the landscape at fuel levels compatible with property protection; fuel loads in CPW peak well below those in woodlands on sandstone. Low fire frequency remnants dominated by Bursaria retain many conservation values, but are likely to support lower abundances of obligate seeder shrubs and open patch herbs, and to be more weed-prone, than remnants burnt once or twice a decade. Experimentation with one or two short interfire intervals may be appropriate in long unburnt CPW. Doctor of Philosophy (PhD)