EAGER-NEON: 20 Year Dynamics of North American Ant Communities: Evaluating the Role of Climate and Biogeochemistry on Ecological Change

University Of Oklahoma Norman Campus, Norman OK

Investigators

Abstract

Ants are one of the most abundant insects on Earth. Ants churn the soil, scavenge the dead, suppress (and sometimes propagate) pests, and are themselves some of our most pernicious pests. Ants are ectotherms (i.e., cold-blooded), which means that the health and activity of an ant colony depends in part on the weather. Climate, in turn, is weather observed over time, and abundance evidence shows that climate is changing. This research addresses a key task in ecology by exploring how changing climate across the U.S. will impact the health and activity of ants and, by extension, how shifts in ant species may impact the many species that ants influence. The research tackles a widespread problem: that to document ecological change one must first have detailed historical records of the way ecosystems once were. Such records are rare. This research fills that knowledge gap by revisiting 34 ant communities from across the United States that were first sampled approximately 20 years ago. At the time, those ant studies represented the best global snapshot of the abundance and diversity of this important insect group. This second, high-resolution snapshot will generate an unprecedented 34, 20-year trajectories of ant communities. When matched to the latest climate trends and ecological theory, the work will paint one of the first pictures of how ecological communities are changing nation-wide. These data will allow ecologists to refine the predictions of how animals respond to climate change, and will jump-start such efforts by the nascent National Ecological Observatory Network. This research resamples 34 ant transects of 30 m2 plots from across North America that were originally sampled in 1994-95. The sites include or are matched to those of the nascent NEON network. The resulting 20-year trajectories of ant abundance and diversity will be used to tests three theories: Thermal Adaptation (the dominant model of thermal ecology which posits that thermal tolerance tracks climate means and variability); Biogeochemical Competence (a new hypothesis that links biogeochemistry to tissue concentrations of phosphorus (P), with P-rich tissue enhancing thermal tolerance); and Species Energy Theory (a dominant model of macroecology that builds mechanistic links between climate, abundance, and diversity). It tests these hypotheses at the population scale (i.e., do populations of species vary predictably in their thermal tolerance and dynamics?), across species (how does the mean species performance vary?), and summed across whole communities (what is the net change in the activity and abundance of ants in an ecosystem?). These samples will be calibrated with NEON by-catch of ground beetle pitfall traps to couple historical with future community trajectories.