Equivalence of competitors in plant communities

Abstract

Argues that, in sessile plants at least, competitive interactions are not usually species-specific and that there exists a large degree of equivalence of the effect of species of similar growth form on the ability of any particular species to establish within a community. This null hypothesis of equivalence of competitive effects is based on 3 characteristics of plants: homogeneity of resource requirements among autotrophs; low encounter probabilities between individuals of any particular species pair; and the predominance of size asymmetries between competing individuals (eg. seedling-adult interactions). An experimental design to quantify competitive interactions among plant species under field conditions is presented. The competitive effect of one 'neighbor' species on one 'target' species is measured as the slope of a regression of performance of target individuals on biomass (or other measure of amount) of its immediate neighbors.-from Authors Show more