North America's Appalachian Mountains may be a safe haven from climate change, according to a new study by the Nature Conservancy, thanks to hardy ecosystems that can endure warmer, drier weather over time. If left intact, these habitats may become oases for people and wildlife pushed out of other areas, the researchers say.
The study covered 156 million acres from Virginia to Nova Scotia, looking for landscapes that are best-equipped to handle global warming. Places with diverse topography, geology and elevation scored highest — namely the highland forests of West Virginia, the coastal plains and oak-pine forests of Virginia and New Jersey, the river floodplains of New York, and the limestone flats of Maine and southeast Canada. According to Rodney Bartgis, director of the Nature Conservancy in West Virginia, this is because varied environments give plants and animals more opportunities to adapt.
"If you're a plant that lives on a low slope, and as the climate warms you have access to cool, north-facing slopes or higher elevations, you have more options for surviving into the future," Bartgis says in an interview with MNN. "Resiliency depends both on ecological complexity and permeability, or the ability of things to move within a given area." While much of the Eastern U.S. is now divided by roads, cities and farms, he adds, Appalachia still has vast wilderness areas that give it a leg up as temperatures rise: "The Appalachians really stand out because they are much more ecologically complex, and they do have a lot of remaining forest cover."
These forests aren't immune to wild weather, of course, as Hurricane Irene proved last year when it spurred deadly flooding in parts of New England. But they are more resilient overall, Bartgis says, especially if they're big. "In larger areas, it's less likely that any one event will drastically alter everything, whether it's a flood, a wildfire or a pest outbreak. So all the areas identified tend to be substantially large, tens of thousands of acres in most cases, especially in the Appalachians."
Yet despite their size, these landscapes may still be vulnerable to other threats such as invasive species, mountaintop-removal mining or even poorly placed wind turbines, potentially robbing entire eco-regions of their refuge from climate change. "To keep an area as resilient as possible, you need to minimize the other stressors," Bartgis says. And even in resilient habitats that stay intact, things could still turn out badly if too many people and wildlife immigrate from harder-hit areas. "There are going to be changes, and some of the changes are undesirable. So ultimately, you still want to limit how much climate change happens."
Some climate change is inevitable, given the amount of carbon dioxide now in the atmosphere and various effects already under way. So while global efforts to curb CO2 emissions drag on, this study simply identifies places worth saving as climate shelters, Bartgis explains. "If you're going to make specific investments in things like land restoration or energy development, these areas are good for long-term investments. They will still have functioning, healthy ecological systems."
The study was funded by the Doris Duke Charitable Foundation, the Northeast Association of Fish and Wildlife Agencies and the Nature Conservancy, and Bartgis says it's just the first in a series. "We're going to expand the study now into the Southeastern United States," he says, predicting similar patterns in the eastern Blue Ridge Mountains as in the central and northern Appalachians. Ultimately, he adds, the conservancy will extend the study "across the United States and elsewhere."