Food webs

Food webs are conceptual models of trophic interactions of organisms. Food webs can be simple or complex and sued for a variety of purposes. Food webs are typically more complex because more species are involved. As models they are limited in that they are static, don’t account for population fluctuations, competition, facilitation, mutualisms, etc. They can be used to better understand energy flows, if we know something about interaction strengths. Robert Paine studied an intertidal food web to study the effects removing the starfish from the ecosystem so see its effect on local diversity. The starfish is a top predator that promotes species diversity by preventing competitive exclusion by the mussels. This makes it an excellent example of a keystone predator.