Interaction effects, pattern reversals, extended phenotypes, and community composition shifts

Here I examined three issues regarding how links within and among levels of organization influence the structure and function of biological systems. First, as the number of ecological factors operating in a system increases there is a high probability that biological patterns will shift and in many cases completely reverse due to interactions of those factors. Second, condensed tannins, a quantitative genetically based trait in cottonwoods, affects the patterns of herbivory by beavers, an ecosystem engineer. Thus, by connecting molecular processes and an ecosystem engineer, condensed tannins have multiple phenotypes: the phenotypic expression of condensed tannins in cottonwoods and an extended phenotype resulting from the engineering effects of beavers. Third, by examining how multiple factors operate together, the complex interactions of herbivores in two systems result in changes to trophic level interactions and arthropod community composition shifts. In combination, these results demonstrate how studies of biocomplexity can result in emergent outcomes and novel hypotheses.