Effects of isolation on the colonisation of restored habitat patches by forest-dependent arthropods of soil and litter

1. A novel experimental approach was taken to investigate the effects of distance from rainforest remnants on the recolonisation patterns of ants and other soil and litter arthropods in 'restored' habitat patches within a pasture matrix. 2. Experimental habitat patches were created by adding a thick mulch of sterilised woodchips and leaves, and simulating shade using shadecloth, to create conditions similar to those that occur during rainforest restoration. These patches were deployed at five experimental sites in the Maleny plateau of subtropical eastern Australia. Artificial habitat patches were located at varying distances from a rainforest edge at each site, as well as within the rainforest. The experiment also included a test for efficacy of inoculation, which involved translocation of a small quantity of litter ( containing live arthropods) from rainforest habitat to isolated habitat patches. 3. The results showed that, after 9 months, there was little colonisation by rainforest-dependent taxa in any of the experimental plots beyond those closely adjacent to forest patches. Inoculation was unsuccessful in increasing the extent of arthropod establishment. 4. A number of explanations that potentially account for the observed results are suggested. An experimental approach provides an opportunity to test explicitly for factors considered important for the development of biota in restored habitat patches. There are, however, unavoidable limitations associated with the design of experiments that simulate small-scale analogues of restoration treatments. Avoiding these limitations may require controlled and replicated efforts in experimental restoration over larger areas, based on collaborations between researchers and practitioners.