Adapting to fire
Many plants in New South Wales have evolved in the presence of fire for thousands of years and have adapted to survive in a fiery environment.
Large sections of wet sclerophyll, rainforest and wetlands also exist in NSW. These plants have evolved in wetter or cooler areas and have not adapted to cope with successive fire events. It may take hundreds of years for some plant communities to fully recover from a fire.
The time between successive fire events determines a fire regime or frequency of fires for an area. When fires become more or less frequent, the fire regime changes.
Most plants in NSW have adapted to a specific fire regime. This means they are able to recover (reach maturity and produce viable seed) within the time between fires for that area’s fire regime.
The natural fire regime for an area may be altered through:
- successive prescribed burning or bushfire events, which increase the frequency of fire
- fire suppression and fire exclusion, which decrease the frequency of fire.
Plants that have adapted to an existing fire regime may die out and be replaced by plants that are better adapted to a new fire regime. The ecological consequences of high-frequency fires have been listed as a key threatening process under the Biodiversity Conservation Act. This has implications for the planning of hazard reduction burns.
Fire tolerant and intolerant plants
Many NSW plant species reshoot from buds on their stems or roots that enable them to recover rapidly after a fire event. Thick bark protects these buds from the damaging heat of fires.
Plants most vulnerable are those that can only regenerate from seed. These plants are usually killed by fire and regenerate from seeds stored on the plant or in the soil. If fires occur too frequently these species may not reach maturity to produce seed and will not persist.
Alternatively, infrequent fires can impact negatively on plants that rely on fire to regenerate. If fire is too infrequent, these species can grow old and die and their seeds rot in the soil before germinating.
We take these facts into account when we develop fire management strategies and park rehabilitation programs.