Climate change leading to major vegetation shifts around the world

Sarah Yang in the UC Berkeley News: Vegetation around the world is on the move, and climate change is the culprit, according to a new analysis of global vegetation shifts led by a University of California, Berkeley, ecologist in collaboration with researchers from the U.S. Department of Agriculture Forest Service. In a paper published today in the journal Global Ecology and Biogeography, researchers present evidence that over the past century, vegetation has been gradually moving toward the poles and up mountain slopes, where temperatures are cooler, as well as toward the equator, where rainfall is greater.

Moreover, an estimated one-tenth to one-half of the land mass on Earth will be highly vulnerable to climate-related vegetation shifts by the end of this century, depending upon how effectively humans are able to curb greenhouse gas emissions, according to the study.

The results came from a meta-analysis of hundreds of field studies and a spatial analysis of observed 20th century climate and projected 21st century vegetation. The meta-analysis identified field studies that examined long-term vegetation shifts in which climate, rather than impacts from local human activity such as deforestation, was the dominant influence. The researchers found 15 cases of biome shifts since the 18th century that are attributable to changes in temperature and precipitation.

"This is the first global view of observed biome shifts due to climate change," said the study's lead author Patrick Gonzalez, a visiting scholar at the Center for Forestry at UC Berkeley's College of Natural Resources. "It's not just a case of one or two plant species moving to another area. To change the biome of an ecosystem, a whole suite of plants must change."

…Gonzalez said that because of limited resources, it may be prudent to focus on protecting areas of greater resilience to ecological changes so that they can serve as refuges for plants and animals. "It is also useful to identify places of higher vulnerability, because agencies will need to consider adaptation measures for vulnerable ecosystems," he said. "Some shifts in vegetation could increase fuel for wildfires, for example, so prescribed burning may be necessary to reduce the risk of catastrophic fires."…

Map of vulnerability by Patrick Gonzalez et al., from the UC Berkeley website