It long has been expected that as the climate warms, vegetation would react by moving. Both north in latitude, and up in elevation. Now new research confirms that "because of the combination of climate change and habitat loss, up to one-quarter of the total area of the National Park System is vulnerable to vegetation shifting up slope and northward."
Concern of a hotter climate making conditions unsuitable for some vegetation has led efforts at Joshua Tree National Park in California to obtain land higher in elevation that could support Joshua trees once lower elevations become too hot.
Now the research by University of Southampton scientist Felix Eigenbrod, National Park Service climate change scientist Patrick Gonzalez and colleagues concludes that habitat loss from the development of roads and other urbanization, agriculture, and deforestation makes park ecosystems more vulnerable to climate change.
“We already established that climate change and habitat loss affect national parks, but this scientific study links these negative effects and identifies just how much of the landscape is at risk,” Park Service Director Jonathan B. Jarvis said. “The good news is that the study also identified areas of biodiversity that are refuges and wellsprings for species.”
Between 10 percent to 28 percent of the world is located in potential refugia or less vulnerable areas, according to the report. Refugia are areas of biological diversity that support many species and represent potential priority areas for future conservation. However, currently, only between one and two percent of the world’s vegetated area is found in existing refugia and is protected by a national park or other protected area.
In the United States, up to one half of the National Park System is in potential refugia.
The research identified the full spectrum of vulnerability in national parks, which will help land managers prioritize adaptation measures they can take in response. Areas of refugia with low levels of vulnerability require less effort to conserve biodiversity, while areas of high vulnerability generally require expensive and intense management measures, such as invasive species removal and prescribed burning.
The scientists conducted spatial and statistical analyses of historical climate data, satellite data on current vegetation, and projections of potential vegetation under climate change.
Past academic field research in Yosemite National Park, California, Noatak National Preserve, Alaska, and other sites around the world has shown that climate change has already shifted vegetation at the biome level upslope and towards the Poles or the Equator.
The authors analyzed the vulnerability of ecosystems to climate change based on habitat intactness and vulnerability to shifts in biomes. Biomes are the highest level of ecological organization and include rain forests, woodlands, grasslands, temperate forest, alpine and tundra. A change in climate that can shift the location of a biome is a very substantial force. When a biome shifts, plants and wildlife that cannot adapt may shift or disappear locally. When a road, town, or clear-cutting then destroys parts of the natural habitat, the ecosystem becomes even more vulnerable.
The scientists produced global maps and a map of North America that outlines U.S. national parks and identifies the areas that have a very low, low, medium, high, or very high potential for vegetation shifts.
Research results identified potential refugia in some remote parks like Gates of the Arctic National Park and Preserve in Alaska, and Death Valley National Park in California. North Cascades and Mount Rainier national parks in Washington are among the parks in highly vulnerable areas.
Since 2009, the National Park Service Climate Change Response Program has been helping national parks use climate change science like this new research to adapt natural resource management to climate change.
Gonzalez, who has also served as an author for four reports of the Intergovernmental Panel on Climate Change said, “Our research indicates that the world protected areas system may currently be insufficient to guard against the combined impacts of climate change and habitat fragmentation. Still, we identify potential refugia that provide some hope for wild species.”