Ecotypic Variation and the Response of Tundra Plants to Climate Change
Plants form the base of Arctic tundra food webs and are the determinants of terrestrial primary productivity in the Arctic. Given this central role, the response of tundra plants to climate change will have regional and global implications. This project examines the role of ecotypic differentiation, i.e., local adaptation of plants to the environment, in modulating and potentially limiting the response of a plant species to climate change. In 1980, a reciprocal transplant experiment was set up to examine ecotypic differentiation in the tussock-forming sedge Eriophorum vaginatum along a latitudinal gradient in northern Alaska.
Map of northern Alaska showing location of experimental gardens at Eagle Creek (EC), No Name Creek (NN), Coldfoot (CF), Toolik Lake (TL), Sagwon (SAG) and Prudhoe Bay (PB). The Continental Divide separates southern and northern ecotypes of Eriophorum vaginatum.
Tussock of Eriophorum vaginatum from Toolik Lake at the Eagle Creek garden showing early senescence in mid-August, 1982.
Are the original differences between populations of E. vaginatum from south and north of the Brooks Range maintained after 27 years?
Response of tiller size index (length of the longest leaf x no. of green leaves) for six populations of E. vaginatum in 1983, 1993, and 2010 to a latitudinal gradient in northern Alaska. The effect of environment is shown by mean values for each garden while the effect of genotype is shown by the lines showing the response of each population. These graphs show that the populations south of the Brooks Range (EC, NN, CF) are more responsive to the environmental gradient than populations on the North Slope (TL, SAG, PB) (Fetcher and Shaver 1990).
Kelli Cummings and Cynthia Bennington measuring tiller size index
July, 2010, on BP oil field at Prudhoe Bay. Students in the background
are measuring photosynthesis.