Wednesday, December 13, 2006

Old-field insect community diversity measures are strongly affected by temperature within a simultaneous CO2, temperature and soil moisture experiment

Shawn Villalpando, and Ray S. Williams, Appalachian State University, Biology, PO Box 32027, 572 Rivers Street, Department of Biology, Boone, NC

Atmospheric [CO2] is approximately 375 ppm and currently increasing, which is predicted to potentially alter global climate. Along with increasing [CO2], future climate change may include increased temperature and changes in moisture patterns, which represent alterations in resource availability for insects in terrestrial ecosystems. The Old-Field Community Climate and Atmospheric Manipulation experiment is examining a plant community exposed to three climate change factors at Oak Ridge National Laboratory, TN. This long-term project is examining an old-field plant community’s responses to elevated [CO2]/temperature and soil moisture. We characterized the insect community to examine how multiple climatic factors may affect insect community structure. We also collected leaves from four plant species for phytochemical analyses. Using a combination of sticky traps and vacuum sampling, we have identified 150 morphospecies, representing several feeding guilds. A dominant herbivore Order (Thysanoptera) significantly increased in abundance at high temperature. In addition, overall insect morphospecies Richness changed due to temperature. It also appears that the herbivore guild is able to overcome observed reductions in host plant quality (e.g. leaf N) due to increased [CO2].