Ecosystem functions of tropical ants - comparing primary and secondary rainforest on two continents

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The present extinction rates are 100 to 1000 times higher than in prehistoric ages. The current loss in biodiversity is highest in tropical rainforests, which are logged and/or converted to plantations or secondary habitats. However, the ecosystem effects of species extinctions are still insufficiently understood. In particular, it is largely unknown whether the ecosystem effects of an extinct species can be buffered by others, or whether the loss of a species results in a cascade of linked extinctions. Ants are among the most abundant animal taxa in tropical rainforests and therefore have major impacts on the ecosystem. In this project, we will study the ecosystem effects (or ‘functions’) of ant communities in primary and secondary forests in South America and Southeast Asia. At each site, we will assess the ants’ performance in a set of ecosystem functions that are related to food consumption and the defense of food resources. We will use standardized experiments to assess these functions for the most abundant ant species in each habitat. The results will be used (1) to assess ecosystem functioning and functional redundancy of ant communities in primary and disturbed habitats, (2) to compare niche differentiation in ant communities of two ecologically similar, but geographically distant biogeographical regions, and (3) to evaluate trade-offs between specialization and functional performance among syntopic ant species. Our approach thus allows to directly quantify ecosystem functions and functional differentiation among ant species, and can be used for a variety of research questions.