Experimental burning changes the quality of fallen timber as habitat for vertebrate and invertebrate fauna: implications for fire management

Abstract

Context: Fallen timber is a key habitat feature in forests and woodlands for vertebrate and invertebrate fauna, and is either consumed or left partially burnt after the passage of fire. This impact on habitat quality assumes significance because increasing areas of land are subject to frequent hazard-reduction burning and wildfire in eastern Australia. Aims: We test here whether partially burnt or charred fallen timber is employed as habitat to the same extent as unburnt fallen timber. Methods: Vertebrate and invertebrate abundance beneath burnt and unburnt fence posts was monitored for 13 months in unburnt forest and forest burnt by a wildfire. Key results: Both vertebrate and invertebrate fauna made significantly less use of charred refuges. In most taxa, twice as many animals occurred under unburnt as under burnt artificial timber refuges, ant nests being the exception. Fauna made greater use of experimental refuges in burnt forest. Key conclusions: Partially burnt fallen-timber refuges, where the log surface is left charred, are inferior habitat for fauna. Habitat quality in burnt forest may be enhanced by introducing fallen timber. Implications: The study highlights an ecological consequence of fire for habitat quality, whether through wildfire or hazard-reduction burning, which should be considered in fire management.