AN ANALYSIS OF COMPETITIVE ABILITY IN THREE PERENNIAL GRASSES

Abstract

Competitive interactions between three perennial grasses of contrasted ecology were investigated using an experimental design which permitted measurement of the effects of paired species upon each other. Under productive conditions, each pairing resulted in the total elimination of one species and the order of competitive ability was Arrhenatherum elatius > Agrostis tenuis > Festuca ovina. Under conditions of severe nitrogen stress, the impact of competition upon yield was reduced but the order of competitive ability was unaffected. The results suggest (1) that competitive abilities above and below ground are interdependent and covariable and (2) that the ability to compete for mineral nutrients may be of relatively minor importance in the adaptive physiology of species colonizing very infertile soils. Copyright © 1976, Wiley Blackwell. All rights reserved