Lindeman's Contradiction and the Trophic Structure of Ecosystems

Abstract

R. L. Lindeman's empirically based generalizations that both progressive efficiencies and percent of energy lost due to respiration increase with trophic level appeared contradictory, because he linked trophic levels in series to form a simple trophic chain. This model equates the energy not respired by the populations aggregated to form a trophic level to the productivity of the populations assigned to the next trophic level. This is clearly not the case for Cedar Bog Lake and ecosystems generally, because of nonpredatory losses and energy gains from other than the previous step in the trophic chain, e.g., bacterivory, detritivory, and feeding on organisms at more than one trophic level. Network analyses of energy—flow models make possible an objective and unambiguous definition of trophic level that does not suffer this contradiction. Trophic guild is proposed as an alternative to trophic level when is meant is an aggregation of species with similar trophic resources.