Eucalypt fire ecology
The presence of fire in the environment has undoubtedly favoured those species best able to resist, recover and regenerate after fire. Eucalypts now possess adaptive characteristics that help the individuals survive, and life cycle features that allow them to cope with particular fire regimes.
It has been suggested that eucalypt species are not just adapted to fires, but are actually fire promoting as a means of maintaining site occupancy. This idea arises because eucalypts appear to exhibit a number of features which increase the rate of spread and intensity of fire, whilst themselves displaying adaptive traits to wildfire. In the absence of human intervention, the natural regeneration and continued existence of eucalypts depends on the recurrence of fire.
The leaves of eucalypts, like most sclerophyll plants, are relatively flammable because of their high volatile oil content and their low nitrogen and inorganic matter levels, especially when dead. The dead leaves typically have a slow decomposition rate. The open canopy frequently associated with eucalypts allows the periodic drying out of fuels further inhibiting decomposition and their prolific branch and bark shedding characteristics results in high fuel loads. The spotting process associated with either loose stringybark or long ribbons of shedding bark accelerates the spread of fire in eucalypt forest.
The presence of eucalypts in a forest community increases the probability of extensive fires. For instance, it is principally the presence of eucalypts in mixed forests that increases the possibility of the community burning relative to rainforest with otherwise the same species composition.