Ecological stoichiometry and the spatial distributions and temporal dynamics of arthropods

Stoichiometry, the study of the balance of multiple elements in living systems, is increasingly recognized as an integrative axis within ecology and across biological disciplines. We seek to characterize a series of little-explored links between stoichiometry and the spatial distributions and temporal dynamics of arthropods. These issues lie at the interface of macroecology and macrophysiology. We focus on four arthropod groups where different stoichiometric mechanisms likely help determine species-level spatial distributions and/or temporal dynamics. These include three taxonomically defined groups (the Orthoptera [grasshoppers and crickets], the Lepidoptera [butterflies and moths], and the Hymenoptera [ants and bees]) plus one ecologically defined group (troglobites [obligate cave dwellers]). Mechanisms link an arthropod's stoichiometry with its capacities for growth, reproduction, and dispersal. We use these linkages as springboards for testing three hypotheses. First, focusing on orthopterans and lepidopterans, we will characterize how a species' stoichiometry is linked to its tendency to exhibit "outbreak" dynamics and what elements are most important. Second, focusing on hymenopterans and troglobites, we will test how an arthropod's stoichiometric content relates to the breadth of habitats it exploits. Lastly, focusing on orthopterans, hymenopterans, lepidopterans and other arthropods, we will test whether these same stoichiometric mechanisms imply that the elemental content of some species will predispose them to respond to global change via shifts in their geographic ranges. We will address these three issues by characterizing the "intersections" of several ecological databases. Our work will be primarily from an empirical, ecoinformatic perspective; however, we will complement these efforts with theoretical modeling of insect outbreak dynamics in stoichiometrically explicit population models.