Bimodality for plant sizes and spatial pattern in cohorts: The role of competition and site conditions

The well-known size bimodality in cohorts of plants is revisited with metho ds emphasizing generic modeling. A link between bimodality and interface gr owth in nonequilibrium statistical physics is emphasized: the development o f bimodality is understood as a phase transition like interface roughening. A specific model is proposed, inspired by gap models. It is used to illust rate generic results, to understand the end point of mean field approximati on and aggregation of variables, and to discuss the role of site and compet ition for the development of a social hierarchy within a forest stand, in a wider ecological context. (C) 2001 Academic Press.