Idea paper: Elucidation of the long-term properties of food webs based on the intraspecific genetic diversity of hub species populations

Abstract

Organisms interact across time and space; collectively, these interactions constitute webs that drive energy and material cycles. Classical ecological studies have tested the hypothesis that complex food webs are less stable in closed systems and have thus focused mainly on internal, local drivers of interspecific interactions in food webs. Recently, theories relating to food webs and ecosystems have been expanded to larger spatial scales through the concept of metacommunities (i.e., metawebs and metaecosystems), whose properties are driven by climatic conditions. However, these concepts have been limited to short-term phenomena observable on ecological time scales, while long-term historical processes have rarely been considered. In addition, the components of food webs have not been considered as determinants of food web persistence, even though species' persistence is determined by factors other than interspecific interactions within local food webs. Here, I emphasized the potential utility of intraspecific genetic diversity of hub species as a metric for evaluating the long-term persistence of local food webs. I also proposed a method for calculating this new metric, expressed as the sum of all metaweb level centrality and intraspecific genetic diversity values for each species. Furthermore, I discussed hypothetical patterns in food web properties as determined from both food web structure and intraspecific genetic structure along geographical and climatic gradients; these patterns have yet to be verified empirically. Finally, I summarized recent developments in molecular methods for collecting genetic data, which may support the empirical study of the concepts presented here.