Bivariate Diagrams for Plant Competition Data: Modifications and Interpretation

Bivariate diagrams have not been widely accepted, mainly because the ecological interpretation of the diagrams has not been investigated. Pearce Gilliver (1968) developed methods to test the statistical significance of differences in total yield between mixtures, but did not investigate the ecological interpretation of the resulting diagrams. In this paper we propose several modifications of the basic method previously used, and consider ecological interpretations of the resulting bivariate diagrams