Temporal Dynamics of Species Richness and Composition in a Peri-Urban Tropical Frog Community in Central Brazil

Abstract

Analyzing the temporal dynamics of ecological communities can shed light on coexistence mechanisms and help understand how populations and communities will behave in the face of climate change. However, little is known about how frog communities respond to climate in urban ecosystems, especially in tropical countries. Here, we analyzed how frog species richness and abundance are influenced by weather variables both intra- and inter-annually. We surveyed a peri-urban area in central Brazil, monthly for 3 years. To test the effect of weather variables on species richness and abundance, we used Generalized Additive Mixed-effects Models. We assessed seasonality using circular statistics. We also tested for differences in temporal beta diversity within and among years by estimating species disappearance and temporal rank shift, in addition to a multivariate model-based method to test the effect of year on species composition. Finally, we tested how taxonomic and phylogenetic alpha diversity changed through time using a novel approach based on Hill numbers. We found that species richness varied little among years and was affected only by photoperiod, while species abundance was more variable both between and within years, being mostly affected by humidity, temperature, and photoperiod. Species composition varied little between years, mostly between the first and subsequent years. Conversely, beta diversity was highest within years. Only the effective number of species changed significantly through time. Our results help not only understand temporal mechanisms that allow species coexistence, but also allow to make inferences about the impact of urbanization on biodiversity in recently urbanized landscapes, showing that species composition in peri-urban sites remains unaltered in a mid-timescale, especially when climate conditions change little across years.