El Paper de la competència en les comunitats vegetals mediterrànies

Abstract

This paper reviews studies about the effect of competition on the structure of plant communities in mediterranean regions to determine the mechanisms of plant competition and the limitations of these studies. The review also addresses the coexistence mechanisms that decrease competition among species in these regions. Most studies are based on the patterns of species structure and abundance. However, during the last decade have appeared some publications on experimental studies that analyze the interaction of competition with the biotic and abiotic environment. According to these studies, competition for water and soil nutrients is more important than competition for light. Fire may diminish competition among individuals and among species, although during the early stages of regeneration, competition favors the largest individuals. Niche differentiation with regard to phenology, morphology of the root system and diversity of the responses to summer water stress may explain why species may compete for some limiting resources and coexist at the mature stages of community development. Differences in the requirements for regeneration and reproduction, and also the heterogeneity of the microenvironment, may explain why competition is less important at the early stages of community development.