The interactions betwen members of an ecological community play an important role in stabilizing those communities as climate changes, a new study suggests. Eric Post, a professor of biology at Penn State University recently published the results of a 10-year study of an arctic community that shows the effects of climate change on large, plant-eating mammals.
In his study, Dr. Post placed warming chambers at a study site near Kangerlussuaq, Greenland. The warming chambers simulated climate change by creating a local greenhouse effect. The site was then divided into smaller areas, some of which were left open to grazing by caribou and muskoxen while others areas were closed off to large herbivores so as to prohibit grazing. In this manner, Dr. Post was able to create two environments, one in which vegetation and herbivores continued to coexist despite the simulated warming, and the other in which herbivores were absent during the simulated warming period.
The study revealed that the grazed and ungrazed areas of vegetation differed greatly in their response to the simulated warming. Where herbivores were not allowed to graze, shrubs suh as willow and birch took over the plant community. Where herbivores were allowed to graze, the composition and diversity of plants in the community remained quite stable.
Adult male caribou in Greenland. Photo © Eric Post / Penn State University.