Kimberley tropical monsoon rainforests of western Australia: Perspectives on biological diversity

There are more than 1,500 patches of monsoon rainforest, totaling 7,000 hectares, scattered across 170,000 square km of the tropical Kimberley region of Western Australia. They are small, isolated and embedded within a mosaic of mostly flammable eucalypt savanna woodlands. The status and condition of Kimberley monsoon rainforest biodiversity are assessed based on geographically comprehensive survey data from a total of 100 sites and opportunistic collecting in many others. Monsoon rainforests are rich in species not found in the region's other vegetation communities. Most rainforests and their associated faunal assemblages are not currently reserved and many of the survey sites were found to be severely disturbed by fire and introduced feral cattle. The disturbance impact of fires, introduced animals and weeds is shown to apply generally across the three major forms of land tenure operating in the Kimberley; namely, Aboriginal land (including Indigenous Protected Areas), Crown land (including pastoral leasehold), and national parks and reserves. The implications of these disturbance factors on the conservation and management practices of monsoon rainforest patches in the region are considered. It is concluded that conservation of patches requires active fire and feral animal management. Equally, however, the long-term genetic viability of these small scattered patches and populations requires effective conservation at the landscape scale. Mounting evidence of the Kimberley as a historical and significant center of refugia warrants action from scientists, governments, conservation agencies, Indigenous landholders as well as local communities to protect and conserve its unique biota and the processes responsible for generating and sustaining it.