Climatic warming is shifting where species occur, disrupting interactions among them, and altering how ecosystems work. In collaboration with scientists from Vermont, Massachusetts, and North Carolina, the proposed research uses an experimental temperature manipulation at field sites in North Carolina and Massachusetts to examine the impact of temperature on ant communities and their influence on the rest of the ecosystem. Many plants in eastern forests rely on ants to disperse their seeds, but it is unknown how changes in climate might affect how, or whether, ants disperse seeds. In some cases, warmer temperatures might increase seed dispersal by ants, but in others, it might totally shut down seed dispersal because some important ant species go locally extinct and are replaced by species that do not disperse seeds. This study will examine the potential for warming to indirectly affect plant community composition through changes in seed dispersal mutualisms. Additionally, this research will seek to determine traits indicative of species that respond strongly to climate change. Results of this research will provide a better understanding of the often complex and idiosyncratic responses of biodiversity to warming.
There is little doubt that changes in temperature are causing species to move outside of their historic ranges and are affecting interactions among species. Understanding the mechanisms driving these shifts, and predicting the consequences, will enhance our ability to plan for and mitigate the effects of warming on ecosystems. This project will educate and prepare students for future careers in science by involving undergraduate researchers from diverse backgrounds and geographic regions on all aspects of conducting environmental research. The warming project also has a strong public outreach component, which is key to informing the general public on this important issue.
We examined the potential effects of climatic warming on eastern deciduous forest ant communities and the ecosystem processes they mediate. Using an experimental temperature manipulation, we found warming to alter overall rates of foraging, as well as species-specific rates. The relative effects of temperature on foraging rates were predictable based on the thermal tolerance of the species. We also examined the potential for these altered levels of foraging to cause shifts in rates of ant-mediated seed dispersal, providing an indirect mechanisms via which climatic warming may alter the plant community. Despite the observed shifts in ant activity, however, I did not find rates of seed dispersal to vary across temperature treatments.These results suggest that climate change is likely to affect ant communities by altering foraging behavior variably across species, but this may not have consequences for the plant community as a result of shifts in rates of seed dispersal. This research has resulted in two manuscripts, one of which has been published in Ecology and Evolution, an open access journal, and the other which is under review at this time. We have also utilized this reserach to educate grade school children on ant ecology and the potential impacts of climatic warming.
