Biogeographical concordance and efficiency of taxon indicators for establishing conservation priority in a tropical rainforest biota

Prioritizing areas for conservation requires the use of surrogates for asse ssing overall patterns of biodiversity. Effective surrogates will reflect g eneral biogeographical patterns and the evolutionary processes that have gi ven rise to these and their efficiency is likely to lie influenced by sever al factors, including the spatial scale of species turnover and the overall congruence of the biogeographical history. We examine patterns of surrogac y for insects, snails, one family of plants and vertebrates from rainforest s of northeast Queensland, an area characterized by high endemicity and an underlying history of climate-induced vicariance. Nearly all taxa provided some level of prediction of the conservation values For others. However, de spite an overall correlation of the patterns of species richness and comple mentarity, the efficiency of surrogacy was highly asymmetric.. snails and i nsects were strong predictors of conservation priorities for vertebrates, b ut not vice versa. These results confirm predictions that taxon surrogates can be effective in highly diverse tropical systems where there is a strong history of vicariant biogeography, but also indicate that correlated patte rns for species richness and/or complementarity do not guarantee that one t axon will be efficient as a surrogate for another. In our case, the highly diverse and narrowly distributed invertebrates were more efficient as predi ctors than the less diverse and more broadly distributed vertebrates.