Research
Ecotypic variation and functional genetic responses of an ecologically dominant grass under natural and reduced precipitation: genes to ecosystem response
Loretta Johnson, Sara Baer (SIU) Baer Lab Web Page, Karen Garrett, Eduard Ahkunov, Ted Morgan, and Paul St Amand
Learn more about the Center for Ecology at Southern Illinois University, Carbondale at http://www.ecology.siu.edu/
Andropogon gerardii (big bluestem) is the ecologically dominant grass of the Great Plains. It occurs across a sharp precipitation gradient from 400 mm/yr in western Kansas to >1200 mm/yr in eastern Illinois.
Goal: Provide an integrative and mechanistic understanding (spanning from genetics to plant physiology to ecosystem function) of the response of Andropogon gerardii to natural and experimentally reduced precipitation.
Objectives: Test whether ecotypes are locally or broadly adapted to climate, identify the extent of genetic diversity and functional genetic variation accounting for these putatively drought adapted phenotypes, and whether functional genetic variation scales to influence ecosystem processes.
Approach and Experimental Design
Common garden of reciprocally transplanted single and multiple source genotypes of A. gerardii established under ambient and reduced rainfall across the precipitation gradient (western KS (Hays), Konza, Belleville,Illinois)
Characterize phenotypes and functional genetic variation using cDNA-AFLP and microarrays, quantify ecosystem consequences of genotypic diversity
Significance and Conservation Implications:
- How will different ecotypes respond to future precipitation changes?
- How can this research inform land managers about how to restore tall grass prairie and to re-assemble CRP prairies?
- Which ecotypes to plant where in the face of climate change?
- Will planting multiple genotypes buffer the system against change?
