Biogeochemistry and Trophic Ecology: A New Food Web Diagram

Abstract

The essence of food web models lies in the presence of a set of ecological components (species, trophospecies, etc.) together with a set of connections indicating which components interact (usually via consumption of one by the other) (e.g., Schoenly and Cohen (1991)). We refer to such depictions as trophic webs. There is an active search for patterns in trophic webs; nature has generated certain patterns of connections, but not others. At the same time, ecosystem-level investigation seeks to understand different sorts of connections among ecological components, i.e., mass and energy flux among biotic and abiotic pools. A typical diagram from ecosystem study would include a set of pools of mass or energy together with connections indicating flux between some but not others. We call such diagrams chemical webs. Clearly, there should be a resemblance between these two types of diagrams: A consumer-resource interaction is a transfer of mass. The flux of matter and the strength of an ecological effect between species should be correlated, but not perfectly. Unfortunately, there has been only scanty interchange between those studying trophic webs and those studying chemical webs. This is not just a modern problem. Hagen (1992) recently discussed how the unification of biogeochemistry with population ecology was a major goal of G. Evelyn Hutchinson, but one that he never accomplished.