is the weak interaction effect robust to environmental forcing?
Vasseur, David*,1, Fox, Jeremy1, 1 University of Calgary, Calgary, AB ABSTRACT- Since Robert Mays demonstration that food web models are far less stable than their natural counterparts, researchers have identified a number of mechanisms which have the potential to stabilize food web dynamics. Included in this list is the weak interaction effect, whereby weak trophic interactions create conditions facilitating negative covariance between species with similar roles in the food web (e.g. they share prey and/or predators), thereby enhancing the stability of the entire food web. Although weak trophic interactions have been shown to exist, published accounts of negative covariance among species are rather sparse; temporal synchrony (positive covariance), even across widely varying taxa, appears to be far more prevalent. Given that all species within a food web experience the same set of environmental conditions, the intrinsic tendency for weak interactions to generate negative covariance may
