COS 64-4 - Ecotypic variation in an arctic plant, Eriophorum vaginatum: A thirty-year experiment

Wednesday, August 10, 2011: 9:00 AM
16A, Austin Convention Center
Ned Fetcher, Institute for Environmental Science and Sustainability, Wilkes University, Wilkes-Barre, PA, James B. McGraw, Dept. of Biology, West Virginia University, Morgantown, WV, Cynthia C. Bennington, Dept. of Biology, Stetson University, DeLand, FL, Milan C. Vavrek, Dept. of Land Resources, Glenville State College, Glenville, WV, Sara Souther, Dept. of Botany, University of Wisconsin, Madison, WI, Zachariah K. Fowler, Biology, West Virginia University, Morgantown, WV and Gaius R. Shaver, Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA

In 1980-1982, we established a reciprocal transplant experiment with the tussock-forming sedge, Eriophorum vaginatum, at six sites; three locations north of the Brooks Range and three locations south of the Brooks Range in northern Alaska. In 2010 we recensused the gardens to test the hypothesis that populations from south of the Brooks Range would respond positively to warming conditions north of the Brooks Range in terms of tiller size as well as tussock survival and reproduction.  We also measured maximum assimilation rates (Amax), dark respiration (Rd), and chlorophyll fluorescence characteristics, dark-adapted Fv/Fm and light-adapted Fv’/Fm’.


There was a significant interaction between population origin and garden, because tiller size for plants from south of the Brooks Range responded more to the north-south climatic gradient than for plants from north of the Brooks Range.  Both tussock survival and reproduction (measured as number of flower culms) showed a significant home-team advantage whereby plants from a given site that were transplanted back into that site had higher survival and reproduction than plants from other sites. Amax also showed significant home-team advantage. No interaction was observed for Rd, Fv/Fm, and Fv’/Fm’. Rd measured at 15-17 C increased from south to north along the gradient. Fv/Fm decreased significantly from south to north, while Fv’/Fm’ increased.  Future projections of Arctic ecosystems will have to consider the role of ecotypic variation in conditioning the response of communities and ecosystems to climate change.

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