Tracy Feldman

Tracy Feldman

As Earth’s climate warms, species are expected to shift their geographical ranges away from the equator or to higher elevations. While scientists have documented such shifts for many plants and animals, the ranges of others seem stable.When species respond in different ways to the same amount of warming, it becomes more difficult for ecologists to predict future biological effects of climate change–and to plan for these effects.

In a study published this week in the journal Nature, University of Wyoming ecologist Daniel Doak and Duke University ecologist William Morris report on a long-term study of arctic and alpine plants.The results show why some species may be slow to shift their geographic ranges in the face of climate change, and why we might expect to see sudden shifts as warming continues.

“This study illustrates the critical need for long-term research to address our most pressing ecological challenges,” says Saran Twombly, program director in the National Science Foundation (NSF)’s Division of Environmental Biology, which funded the research.”Without the temporal and spatial scales employed here, we have little hope of understanding the complex ways in which organisms will respond to climate change.”

The plant species targeted by Morris and Doak range from populations in the high mountains of Colorado and New Mexico to species growing along the arctic coastline in far northern Alaska.These regions include habitats that have undergone substantial climate change, leading to the expectation, says Doak, that–especially at the southern edge of their range–populations of the plants should be collapsing.However, after studying the growth and survival of tens of thousands of individual plants over six years, the researchers show a more complex pattern of responses.