Fire and Mammalian Secondary Succession in an Australian Coastal Heath

Abstract

A species—rich small—mammal community on 7 ha of diverse coastal heath in Myall Lakes National Park, New South Wales, Australia, was studied for 7 mo before the area burned in a wildfire (August 1974) and has subsequently been monitored for 5 yr since the fire. Species regularly trapped were the dasyurids Antechinus stuartii and Sminthopsis murina, the peramelid Isoodon macrourus, and the native murids Pseudomys novaehollandiae and P. gradcilicaudatus, together with the introduced Mus musculus. Pseudomys species, M. musculus, and S. murina reached greater abundance on early seral stages, while the abundance there of both Rattus fuscipes and R. lutreolus was much reduced. Species reach peak abundance in an orderly replacement sequence exhibiting a mammalian secondary succession. A habitat accommodation model is proposed with species entering the succession and reaching peak abundance as externally controlled changes in the vegetation fulfil the habitat requirements of each species. Species leave the succession or are greatly reduced in abundance when these local physical conditions move out of the optimal range for the species. This study shows that a major perturbation of a small—mammal community can produce a variety of responses among species, suggesting that regeneration time may represent a resource axis subdivided by community members in this secondary succession. The rapid recovery illustrated by the total number of individuals, as a measure of community response, support the suggestion that fire and fire frequency have been major factors in producing a fire—adapted, species—rich small—mammal community on this heathland.