ECOSYSTEM FUNCTIONING AND DUNG BEETLES

Abstract

A major challenge of ecological research is to assess the functional consequences of species richness loss over time and space in global biodiversity hotspots, where extinctions are happening at an unprecedented rate. In this study we propose a conceptual model that incorporates body size as a critical aspect of community responses to environmental change. The model was tested in biodiversity–ecosystem function experiments performed over two years in the Yasuni National Park in the Ecuadorian Amazonian rain forest, one of the most speciose ecosystems on the planet. We set up a two-year exclosure removal experiment in which we manipulated access to resources by the whole community of dung beetles, depending on their size. Our results demonstrate, for the first time in an animal assemblage in a tropical ecosystem, that although species may appear functionally redundant under one set of environmental conditions, many species would be needed to maintain ecosystem functioning at multiple temporal and spatial scales.