Food Web Architecture and its Effects on Consumer Resource Oscillations in Experimental Pond Ecosystems

This chapter evaluates how the behavior of one elemental "oscillator" in pond food webs is affected by different environmental conditions and by changes in food web architecture. The focus is on the interaction between limnetic zooplankton and edible algae. The ways in which the dynamics of this subsystem are altered by different environmental conditions involving nutrients and light and by the diversity of the grazer assemblage are also examined. One interesting and important additional perspective is that oscillators previously described in simple communities such as consumer-resource and cohort cycles were still observable in a more complex community, and they had the same basic characteristic periodicities, amplitudes, and phase relations. While the result still seems to be quite complex, it does provide evidence that these complex systems can be understood from an understanding of their component parts. The results indicated no evidence for substantially altered dynamics beyond those previously observed in the Daphnia algae food chain. This indicates that interactions of zooplankton and algae in complex systems still consist of the same basic elements, in this case consumer-resource cycles and cohort cycles.