Climate change may create tipping points for populations, not just species

EurekAlert: 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.

…By looking at the performance of individual plants in particularly hot and cold years, they found that the compensatory effects across moderately cold to moderately warm years (lower survival balanced by more rapid growth) will not hold up with increased warming….

Sky Pilot (Polemonium eximium), at about 13,000', on Mount Abbot, shot by Will Beback, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported license