Ecosystem resilience and nature conservation

Ecosystem resilience

Fire is a natural and vital process for many of Victoria’s ecosystems. Many plants rely on fire to reproduce. However, inappropriate fire regimes and particularly multiple severe fires in close succession can have detrimental impacts on the resilience of natural ecosystems.

In the context of bushfire management, ecosystem resilience is an ecosystem’s capacity to absorb natural and management-imposed disturbance but still retain its basic structure – in terms of species abundance and composition – function and identity over space and time.

Victoria currently monitors ecosystem resilience using 2 key metrics:

• Tolerable Fire Interval (TFI) – which measures how well vegetation is likely to regenerate after fire, with regard its reproductive maturity, and
• Growth Stage Structure (GSS) – which provides information on the diversity of ages of forests and other vegetation types, which are important for providing habitats for different plants and animals.

It is desirable to minimise the total area burnt (by bushfires and/or planned burning) while vegetation is below reproductive maturity or in early growth stages. Sometimes planned burning in areas below minimum TFI is undertaken where there is an important need to reduce bushfire risk. Planned burning may also be applied is areas below minimum TFI and/or in early growth stages where there is a need to reintroduce fire back into a bushfire affected area to create a diversity of growth stages (e.g. a large bushfire scar such as those in Gippsland following the 2019-20 Black Summer fires) and/or there is a net benefit to ecological resilience by using low-intensity planned fire to seek to reduce the impact of large high-severity bushfires.

Table 15: Percentage (%) of total public land estate in Growth stage structures by FFMVic, Victoria, 2022–23 to 2024–25

Table 16: Percentage (%) of total public land estate under min, over max and within Tolerable Fire Interval by FFMVic, Victoria, 2022–23 to 2024–25

Ecological burns have a primary objective to improve the health of our ecosystems and reduce the intensity and potential destructive impacts of bushfires on our native flora and fauna.

Table 17: Ecological burns delivered by FFMVic, Victoria, 2022-23 to 2024–25