Use of Cross-Taxon Congruence for Hotspot Identification at a Regional Scale

Simone Fattorini,Roger L H Dennis,Laurence M Cook,Kimberly Patraw Van Niel

doi:10.1371/journal.pone.0040018

Abstract

One of the most debated problems in conservation biology is the use of indicator (surrogate) taxa to predict spatial patterns in other taxa. Cross-taxon congruence in species richness patterns is of paramount importance at regional scales to disclose areas of high conservation value that are significant in a broader biogeographical context but yet placed in the finer, more practical, political context of decision making. We analysed spatial patterns of diversity in six arthropod taxa from the Turkish fauna as a regional case study relevant to global conservation of the Mediterranean basin. Although we found high congruence in cross-taxon comparisons of species richness (0.241<r<0.645), hotspots of different groups show limited overlap, generally less than 50 per cent. The ability of a given taxon to capture diversity of other taxa was usually modest (on average, 50 percent of diversity of non-target taxa), limiting the use of hotspots for effective conservation of non-target groups. Nevertheless, our study demonstrates that a given group may partially stand in for another with similar ecological needs and biogeographical histories. We therefore advocate the use of multiple sets of taxa, chosen so as to be representative of animals with different ecological needs and biogeographical histories.

Highlights

A number of studies have tested biodiversity hotspot coincidence, i.e. whether the geographical patterns of species richness in one taxon act as a surrogate for those in other taxa [1,2,3,4,5,6]
It is of paramount importance to know if there is cross-taxon congruence, and if certain taxa can be used as surrogates for others, at a regional scale
In cross-taxon analyses, to measure the performance of priority sets based on indicator groups, we calculated the fraction of non-target species captured by hotspots of indicator taxa [4]

Summary

Introduction

A number of studies have tested biodiversity hotspot coincidence, i.e. whether the geographical patterns of species richness in one taxon act as a surrogate for those in other taxa [1,2,3,4,5,6]. We ask the following questions: (1) Do different taxa show congruent variation in diversity values across areas within a region (cross-taxon congruence)? It is important not to assess cross-taxon correlation in diversity metrics, and the extent to which the different taxa agree in their identification of hotspots.

Results

Conclusion