Resource competition among plants: from maximizing individuals to community structure

Evidence indicates that natural systems worldwide are threatened by increasing economic activity, suggesting a need for improved understanding of how ecosystems and economies interact. The model of plant community structure developed here is designed to be both biologically reasonable and adaptable to economic models. The model begins with individual plants maximizing their net intake of light energy in a competitive environment, and the individual's success determines whether the population of its species increases or decreases. This bridging model yields numerous testable predictions, and it provides a link between individual plant behavior and community structure. The driving force behind the dynamics of community structure is resource competition in which individual plants respond to a 'price' they pay when accessing light, while simultaneously the collective responses of all plants determine the price. Competition for light is well defined and determined by the value of the price. The parameters in the maximization problem that are species dependent determine what species can coexist. Water is added as another resource in the plant's maximization problem, which forces the plant to optimally allocate photosynthate to roots versus shoots. The maximization framework permits relatively easy integration with economic models. (C) 2002 Elsevier Science B.V. All rights reserved.