Species richness covariance in higher taxa: empirical tests of the biodiversity indicator concept

The distribution of much of the world's biodiversity is poorly known. It is suggested that the species richness of certain indicator taxa may reflect that of other, poorly studied taxa, making the mapping of individual taxa uneccessary and providing a guide to conservationists. In this paper we examine this proposition at a spatial scale relevant to practical conservation. We show that the relationship between the species richnesses of certain higher taxa in Britain is spatially highly variable and unpredictable. Britain may not be representative of other areas of the world but our results indicate that considerable further analysis is required before indicator taxa can be recruited as a reliable short cut to conservation planning.