Everyone has their limits: reproductive mode drives amphibian responses to land use in coastal areas

Abstract

Small wetlands are strongly bound to surrounding terrestrial habitats, so understanding their suitability after conversion to human land uses is critically important to produce an ecologically centred planning for amphibian species. Here, we explored how responses of amphibian assemblage to habitat conversion were influenced by reproductive modes in freshwater coastal wetlands in southern Brazil. We also assessed whether species from different biomes are affected in different ways by land conversion. Using data from tadpole assemblages in a transition zone between Atlantic Forest and Pampa, we tested the hypothesis that aquatic modes would be more affected by habitat conversion than are foam-nest species. Overall, quantitative data were influenced by the percentage of crop area, whereas assemblage structure derived from presence–absence data was associated with biome type. Species with aquatic egg-laying were influenced by the percentage of crop area, and many species were more abundant in ponds surrounded by up to 15% crop area in a 1000-m radius. However, foam-nest species were not influenced by any variable investigated (crops, planted pastures, urban areas and biome). This study has highlighted that agricultural conversion poses environmental filters to amphibian communities, selecting species according to some traits (adult reproductive strategies and tadpole plasticity).