Ecosystem Response and Reorganization in the Face of Global Change

Today I attended a lecture at the University of Tennessee Knoxville by Aimée Classen. Dr. Classen is currently a professor at The University of Tennessee Knoxville and received her PH.D. from Northern Arizona University. Her research interests include ecosystem ecology, global change, plant-herbivore interactions, microbial ecology, nutrient cycling, and ecogenomics. Today’s lecture was entitled ecosystem response and reorganization in the face of global change.  The lecture focused on how how abiotic and biotic environmental interactions affect how ecosystems respond and in some cases reorganize when faced with climate change. She spent the majority of her lecture discussing her experiment that revolves around the question: Do multiple climate change drivers interact to alter ecosystems response to global climate change? In order to answer this question Dr. Classen planted a complex ecosystem of seven species on an abandoned oil field. To test the effects of climate change the different sections of this ecosystem were exposed to varying levels of CO₂, temperatures, and participation. This experiment showed that the changing variables effected many things including individual plant function, plant distribution and abundance, plant community composition, and the overall ecosystem response.  The experiment showed that among the seven species festuca, a c3 grass, and lespedeza, a nitrogen fixing shrub, dominated the ecosystems based on net primary productivity and other factors. The experiment has concluded that in fact multiple climate change drivers do alter ecosystems. Dr. Classes has also concluded that while abiotic factors are important in determining future of ecosystems, biotic factors might be even more important.