Assessment of climatic suitability for the expansion of Solenopsis invicta Buren in Oklahoma using three general circulation models

Summary

This study assessed the climatic suitability for the expansion of Solenopsis invicta Buren (red imported fire ant) in Oklahoma under the present climate and with a doubling of atmospheric CO₂ using three general circulation models (GCMs) (GFDL R30, OSU, UKMO). Oklahoma was chosen as the geographical focus because it has a dense network of meteorological stations and lies on the edge of the current biogeographic range of S. invicta. Meteorological data were spatially referenced with model data in GIS to produce a series of images of selected suitability indicators: (1) mean annual precipitation >510 mm; (2) less than seven consecutive days with mean air temperature <1.1 C; and (3) mean winter air temperature >9.4 C. These indicator images were combined to produce suitability maps for the potential range of S. invicta. Under current climatic conditions, roughly three-quarters of Oklahoma is suitable for potential invasion by S. invicta. The GFDL R30, OSU, and UKMO show that the area suitable for colonization increases by approximately 26, 26, and 36%, respectively. In terms of actual land area, the increase with a warmer, wetter climate ranges from 35,300 km² to 47,600 km². The destructiveness of S. invicta on human livelihood necessitates a better understanding of the future expansion of the species for an uncertain future climate.