Responses of Australian Mammals to Disturbance: A Review.

Abstract

The Australian native mammal fauna has evolved in an environment where 'natural' or endogenous disturbance is ongoing and widespread, be it fire, flood, drought or cyclones. Since European settlement, however, the type, scale, frequency and intensity of disturbance has changed and added a new suite of exogenous impacts including introduced predators and herbivores, vegetation clearance, habitat fragmentation, altered fire regimes, grazing and timber harvesting. This has presented novel and significant adaptive challenges to native mammals over a compressed time-scale, resulting in major extinctions, population declines and disruption to community structure. In this paper we examine the ecology of Australian mammals in the context of these new disturbances, and compare the response patterns observed, and assess the processes operating. In general, Australian mammalian successional patterns are closely tied to vegetation regeneration, which is related to the degree of disruption. Disturbances such as predation do not fall within this pattern. Mammalian successional states vary between different disturbance types within an ecosystem, depending on the critical elements of vegetation structure and composition. Landscape and climatic factors also affect successional patterns and need to be further investigated.