Classification and sensitivity of taxonomic and functional diversity indices of anurans in the Andean coffee cultural landscape

Abstract

Taxonomical and functional facets of diversity are crucial to understanding the effects of landscape transformation on species assemblages, although there is a lack of consensus on the degree of congruence between diversity indices across land-uses. We evaluated the effect of natural and anthropogenic land cover types on anurans in the Andean region of Colombia. Changes between land cover types were detected but no effect of climatic season on the structure of anuran assemblages. Species with larger body sizes showed a greater affinity for anthropogenic land cover types. We analyzed the functional facet of diversity (based on diet and morphological traits) and discovered that the degree of congruence with taxonomic diversity metrics changed when comparing different land cover types. We evidenced a strong effect of the type of vegetation cover on the Hill numbers (from zero to third orders) for functional diversity but not for the other taxonomic diversity indices. Of all the diversity metrics evaluated, we found that Rao's quadratic entropy, functional dispersion, and average functional diversity were the most sensitive indices to land-use change. Surprisingly, the surrounding of houses, the land cover type with the greater degree of anthropogenic intervention had the higher values of functional diversity, suggesting broader types of specieś resource acquisition. These results suggest the importance of landscape mosaics in the conservation of different facets of anuran diversity. We also emphasize the importance of measuring anuran functional traits to understand more comprehensively the effects of landscape transformation at the assemblage level and to appropriately direct conservation and management actions.