34.5 Thursday, Jan. 5 Predicting regional and global responses of ants to climate change DIAMOND, SE*; SORGER, DM; HULCR, J; PELINI, SL; SANDERS, NJ; ELLISON, AM; GOTELLI, NJ; DUNN, RR; North Carolina State Univ.; North Carolina State Univ.; North Carolina State Univ.; Harvard Forest; Univ. of Tennessee; Harvard Forest; Univ. of Vermont; North Carolina State Univ. firstname.lastname@example.org
Global climate change has already altered the conditions nearly every terrestrial organism on Earth faces. A key question becomes how the responses of organisms to such change are likely to vary across taxa and regions. We first develop models for physiological thermal tolerances in ants based on current and projected future climates. We found that tropical ants have lower warming tolerances, a metric of susceptibility to climate warming, than temperate ants despite greater increases in temperature at higher latitudes. Using climatic, ecological and phylogenetic data, we refine our predictions of which ants (across all regions) were most susceptible to climate warming. We found that ants living in the canopies of hot, tropical forest are the most at risk, globally, from climate warming. Unfortunately this is where many, perhaps most, ant and other species on Earth live. Secondly, we examine the potential for physiological thermal tolerances to predict the responses of many species of ants to experimental climatic warming in two large-scale experimental arrays, positioned at the northern and southern boundaries of temperate hardwood forests in eastern North America. We found that ants with higher thermal tolerances had greater maximal accumulation temperatures (temperature treatment weighted by ant density in the treatment) and thermal accumulation slopes (slope of the linear relationship between ant density and temperature treatment). This pattern held for the southern array, but not the northern array, supporting the findings of the global analysis showing ants inhabiting lower latitude environments to be more at risk from climate warming.