The maintenance of species richness in plant communities

Reviews theoretical ideas on processes affecting the stable coexistence of competitors and the maintenance of local diversity. Simple theory predicts that species richness can be no greater than the number of limiting resources, a prediction difficult to reconcile with the facts. The authors identify many restrictive assumptions of the simple theory (no spatial or temporal variation, equilibrium is attained, simple trophic structure, no limiting physical factors, no neighborhood effects, and simple life histories). They then explore the theoretical consequences for diversity of relaxing these assumptions. Some of these ideas are applied to understanding diversity patterns in nature, including the pervasive latitudinal gradient in species diversity. -from Editors