The widely held assumption that plants will have to migrate higher or become extinct in a warming world has been challenged today by a new study published in the journal Science, by Jonathan Greenberg, an assistant project scientist at the University of California, Davis, Center for Spatial Technologies and Remote Sensing.
Greenberg looked at data collected by the U.S. Forest Service since the 1930s through to 2000 and saw that, instead of migrating to higher elevations to maintain a constant temperature, many California plant species migrated downhill an average of 260 feet.
“While the climate warmed significantly in this period, there was also more precipitation. These wetter conditions are allowing plants to exist in warmer locations than they were previously capable of,” Greenberg said.
The previously held assumption that plants and animals would have to migrate to higher elevations or become extinct is based on the assumption that the sole driving factor is temperature. Greenberg, however, found that other factors such as precipitation are important and may in fact be more important than temperature in determining the habitable range for a species.
These findings are doubly important as many locations north of 45 degrees latitude have had an increased level of precipitation in the past century, and global climate models, on a whole, predict that that increased trend will continue well into the future.
Countries above 45 degrees include the northernmost United States, almost all of Canada and Russia, and most of Europe.
Needless to say, if species of animal and plant in those countries are liable to move downhill in search of stable habitable conditions, there are necessary steps to be taken to ensure the survival of these species.
“As we continue to improve our understanding of climate-change impacts on species, we will help land managers and policymakers to make more informed decisions on, for instance, conservation efforts for threatened and endangered species,” Greenberg said.