Joint consequences of dispersal and niche overlap on local diversity and resource use

1. Several ecological theories predict that species coexist by exploiting different resource niches, and therefore, more diverse communities should have greater resource uptake. Supporting evidence, however, is equivocal. Species with similar competitive abilities are predicted to coexist with little niche differentiation, suggesting that communities containing more functionally redundant species may be more diverse but with little impact on resource use. Likewise, high rates of seed dispersal often increase diversity, but the effect of this diversity on resource uptake is unknown.