LINKING FLEXIBLE FOOD WEB STRUCTURE TO POPULATION STABILITY: A THEORETICAL CONSIDERATION ON ADAPTIVE, FOOD WEBS

This chapter describes a food web model that incorporates both population as well as adaptive dynamics to show how adaptive diet choice alters the previously held static view of the complexity-stability relationship. In the model discussed here, food web architectural properties such as connectance, link distribution, and interaction strength are not given a priori . Instead, they emerge as a consequence of foraging adaptation, which determines actual diets that are used from a given potential diet range. As adaptive foragers may not utilize all potential diets, some potential links may not be activated in a food web consisting of adaptive foragers. The connectance-stability relationship of adaptive food webs is different from static food webs in two ways: First, the relationship can be time-scale dependent, as the connectance of an adaptive food web depends on time scale. Second, the connectance-stability relationship can change depending on the factor that causes the inter-web variance of connectance, which is the potential connectance or adaptation level. The relationship cannot be determined without identifying the time scale of the connectance and the causal mechanism of the variance in the focal connectance. This implies a difficulty in detecting a consistent relationship between food web connectance and population stability. The dynamic food web models show that the adaptive nature of a predator's diet choice can have major impact on food web properties.