Rainfall seasonality drives the spatiotemporal patterns of dung beetles in Amazonian forests in the arc of deforestation

Abstract

The Amazon Rainforest is facing high rates of deforestation, leaving anthropogenically dominated landscapes across the Amazon. Understanding the biodiversity response to the effects of rainfall seasonality can provide important examples of how species may respond to drastic climate conditions in anthropogenic landscapes. Here, we sampled dung beetles across the same Amazon forest sites during the rainy and dry seasons to evaluate the effect of seasonality on biodiversity patterns. We found a significant space–time interaction for the whole set of forest sites indicating that the spatial structure of the species abundance data has changed significantly between seasons. Dung beetle abundance and species richness was higher in the rainy season when evaluating all species and separately for nesting behavior group. For presence-absence and abundance data of the whole assemblage, the mean differences between losses and gains over all forest sites was negative, indicating dominance of species and individuals-per-species losses across all forest sites. Eleven species (5 tunnellers, 4 rollers, and 2 dwellers) had significant decreases in abundances in the forest sites from the rainy to the dry season, whereas one roller species increased in abundance from the rainy to the dry season. Rainfall seasonality drives the temporal patterns of dung beetle diversity in the Amazonian forests in the study region in the arc of deforestation. Understanding species vulnerability to changes in climatic conditions could help to predict species distributions in an increased scenario of higher temperatures and longer drought periods during dry seasons in the near future.