Mechanistic resource competition theory applied to laboratory experiments with zooplankton

Abstract

There is a strong feeling that ecological thought today is hindered by the traditional, phenomenological Lotka-Volterra model. Recent publications have stressed the importance of considering the mechanisms underlying competitive interactions1,2. A mechanistic, resource-based approach to studying exploitative competition for limiting nutrients has been very successful in phytoplankton ecology3,4, where various nutrients are essential resources. Here I report results of laboratory1 experiments that show for the first time the applicability of this approach to the competition for substitutable resources in herbivorous zooplankton. The outcome of exploitative competition between the rotifers Brachionus rubens and B. calyciflorus for two species of food algae was predicted by a graphical model5 in 11 of 12 cases. These findings extend the applicability of the mechanistic consumer-resource approach to animal populations, and illustrate the phenomenon of food-niche separation. © 1988 Nature Publishing Group.