Relative Species Abundance and Community Assembly
The degree to which communities are shaped by niche-based as opposed to neutral processes, which downplay the differences among species, is a topic of heated debate. However, neutral and niche-based assembly processes may both operate within a single community, in which case their importance may change according to the ecological similarity between species. On the one hand, ecologically similar species may exhibit the strongest competition and thus confer most strongly to niche-based community assembly. On the other hand, theoretical studies have suggested that ecologically similar species might actually exhibit neutral assembly processes (emergent neutrality). Our aim is to quantify the degree to which neutral or niche-based community assembly processes dominate by quantifying patterns of relative abundance between ecological similar species. Ecological similarity is defined both in terms of phylogenetic relatedness as well as functional similarity (e.g., similarity in body size, diet). We plan to quantify how the strength of neutral and niche-based community assembly processes change across environmental gradients and spatial scales.