Does taxonomic diversity in indicator groups influence their effectiveness in identifying priority areas for species conservation?

Abstract

The identification of priority areas for biodiversity conservation is a cornerstone of systematic conservation planning. However, biodiversity, or even the distribution of all species, cannot be directly quantified, due to the inherent complexity of natural systems. Species indicator groups may serve as important tools for the identification of priority areas for conservation. Yet, it is unclear which factors make certain indicator groups perform better than others. In this study, using data on the Danish distribution of 847 species of plants, vertebrates and insects, we assessed whether the taxonomic diversity in species indicator groups influence their effectiveness in the identification of priority areas for species conservation. We tested whether indicator groups comprising a higher taxonomic diversity (i.e. indicator groups consisting of species from many different taxonomic groups) perform better than indicator groups comprising a lower taxonomic diversity. The performance of the indicator groups was evaluated on target groups, which, in terms of species composition, were independent of the indicator groups. Overall, we found that using taxonomically diverse indicator groups did not consistently increase the coverage of target species than when using less taxonomically diverse indicator groups. However, indicator groups chosen solely from one taxon were outperformed by taxonomically diverse groups. Second, we found that taxonomic diversity of the indicator did not influence the taxonomic diversity of the covered target species (in terms of number of represented families, orders, etc.) Thus, taxonomic diversity per se only had a marginal influence on the performance of indicator groups. Distributional characteristics, such as the proportion of species with narrow range sizes, had a larger impact on indicator performance. Our results suggest that it might be of minor importance to consider taxonomic diversity when acquiring species data for future conservation projects using indicator groups. © Journal compilation © 2008 The Zoological Society of London.