Herbivory can alter plant stoichiometry generating biogeochemical feedbacks that stabilize or drive transitions between ecosystem states. We report results after 23 years from a grazing experiment in Norway comparing five paired exclosures and grazed plots that were complemented with inclusion of five islands serving as a natural control. We tested the hypothesis that herbivory-driven shifts in plant dominance scale to alter e...

With the emerging field of community genetics, it is important to quantify the key mechanisms that link genetics and community structure. We studied cottonwoods in common gardens and in natural stands and examined the potential for plant chemistry to be a primary mechanism linking plant genetics and arthropod communities. If plant chemistry drives the relationship between plant genetics and arthropod community structure, then...

We tested the hypothesis that leaf modifying arthropod communities are correlated with cottonwood host plant genetic variation from local to regional scales. Although recent studies found that host plant genetic composition can structure local dependent herbivore communities, the abiotic environment is a stronger factor than the genetic effect at increasingly larger spatial scales. In contrast to these studies we found that de...

We define a genetic similarity rule that predicts how genetic variation in a dominant plant affects the structure of an arthropod community. This rule applies to hybridizing cottonwood species where plant genetic variation determines plant–animal interactions and structures a dependent community of leaf‐modifying arthropods. Because the associated arthropod community is expected to respond to important plant traits, we also te...

We argue that the genetic diversity of a dominant plant is important to the associated dependent community because dependent species such as herbivores are restricted to a subset of genotypes in the host‐plant population. For plants that function as habitat, we predicted that greater genetic diversity in the plant population would be associated with greater diversity in the dependent arthropod community. Using naturally hybrid...

While population genetic diversity has broad application in species conservation, no studies have examined the community‐level consequences of this diversity. We show that population genetic diversity (generated by interspecific hybridization) in a dominant riparian tree affects an arthropod community composed of 207 species. In an experimental garden, plant cross type structured the arthropod community of individual trees, an...

Fundamental links between genes and ecosystem processes have remained elusive, although they have the potential to place ecosystem sciences within a genetic and evolutionary framework. Utilizing common gardens with cottonwood trees of known genotype, we found that the concentration of condensed tannins is genetically based and is the best predictor of ecosystem‐level processes. Condensed tannin inputs from foliage explained 55...