Tadpole species richness within lentic and lotic microhabitats: an interactive influence of environmental and spatial factors

Abstract

Anurans inhabiting lentic and lotic water bodies show distinct responses to environmental and spatial variables due to dispersal by adults and microhabitat selection by tadpoles, which creates a hierarchical structure in these metacommunities. Aiming to understand the influence of tadpole microhabitat selection and adult dispersal on species richness distribution, we tested the influence of microhabitat environmental variables and habitat spatial variables on tadpole richness in lentic and lotic water bodies located in the Atlantic Rainforest. We sampled tadpoles in 99 lentic microhabitats and 288 lotic microhabitats for seven months. We performed a Hierarchical Partitioning Analysis to test the influence of environmental and spatial variables. The percentage of aquatic vegetation within microhabitats and the main spatial gradient (dbMEM1) affected species richness in lentic water bodies. Sand percentage, aquatic vegetation, and depth in the microhabitat and small-scale spatial gradient (dbMEM4) affected species richness in lotic water bodies. Spatial processes indicate an influence of adult dispersal limitation in search of reproductive habitats. The influence of microhabitat variables was mostly related to the amount of aquatic vegetation, indicating the influence of environmental processes on the larval phase of anuran life cycle. In conclusion, both environmental and spatial processes are driving the species richness in microhabitats inside lentic and lotic water bodies in the Atlantic Rainforest.