Tuesday, August 4, 2009 - 3:25 PM

SYMP 7-6: Ecosystem consequences of genetic-based, plant feedbacks

Jennifer A. Schweitzer and Joseph K. Bailey. University of Tennessee, Knoxville

Background/Question/Methods Research that connects terrestrial ecosystem processes to plant genetic mechanisms has recently gained significant ground, yet actual studies that span the levels of organization from genes to ecosystems are much more rare.  Here we synthesize the data to date from six plant systems and habitat types that have addressed the hypothesis that plant genetic diversity or plant genotypic diversity can impact ecosystem processes - from energy flow in trophic interactions, rates of primary productivity to cycles of water and nutrients.  These studies have utilized a wide range of plant genetic factors to address this hypothesis including genetic introgression, provenance variation or genotypic variation and diversity in common gardens.

Results/Conclusions The data to date suggest that intra-specific genetic factors can explain significant variation in ecosystem processes.  Plant genetic factors can vary in their magnitude of effect on ecosystem processes, but in Populus can explain up to 45% of net primary productivity, 65% of the variation in nitrogen cycling and 60% of total belowground carbon storage.  These data suggest that links between plant genetics and ecosystem processes occur across systems and that evolutionary processes that act on functional plant traits (or a combination of traits) may allow these extended phenotypes to change in response.  While the specific plant trait(s) associated with the ecosystem processes vary across these studies, these data support previous research demonstrating the importance of both plant population genetic variation and genotypic variation for ecosystem processes, which has both applied and evolutionary implications.