piled atop other stresses forest ecosystems now face. When all these stresses are combined, ecosystems are at greater risk. Because wilderness ecosystems are protected from a number of other stressors--such as fragmentation from logging and roads and motorized-recreation--wilderness should be more resilient to climate change than unprotected areas. • Second, because climate change has so clouded the future, including the future of our wildlands, the challenges themselves are unclear. So are the best responses. We will probably need to try a range of approaches to adaptation, including, possibly, such heavy-handed tactics as cultivation and assisted migration. But because we know so little about what will work, we will also need places where we do little or nothing. Wilderness is such a place and will continue to serve that vital role as we learn which approaches work best. Maintaining healthy, intact ecosystems is one of our best options for helping wildlands and the species that depend on them to adapt to climate change. An old biological adage says: “adapt, migrate or die.” But what if change is so swift that adaptation is impossible, or if there are no suitable remaining places into which to migrate (or if there are and populations can’t overcome human-created barriers to reach it)? As it writes new plans for the Nantahala and Pisgah, the Forest Service has a clear duty to very carefully and deliberately consider climate change in all of its management proposals. That will require at the outset that the agency gathers, analyzes and acts upon the best science available in making its decisions. Our job as citizens is to make sure that happens; they are our forests.
The Hemlock Woolly Adelgid The adelgid is a tiny insect, no bigger than the “e” in lethal, and of Asian origin. It turned up in our Pacific Northwest in
Hemlock infested with woolly aldelgids 14
North Carolina’s Mountain Treasures
Old-growth hemlock the 1920s and by the 1950s had made its way to the Eastern Seaboard, first detected here in a Virginia nursery. It gets its name from the trademark white “wooly” egg sacs it leaves on the branches of hemlocks. Though not particularly harmful to hemlocks in its native Asia, the adelgid arrived here to a system with no natural predators and no natural resistance. It is a lethal threat to the two species of hemlock we see in our Southern Appalachian forests: the eastern hemlock, (Tsuga canadensis) and the less-common Carolina hemlock (Tsuga caroliniana). The adelgid reached western North Carolina’s Nantahala and Pisgah National Forests in 2001 and some experts fear that today it infests half the hemlock forests in the Eastern U.S. The recital is a grim one. The National Park Service estimates that fully 80 percent of the hemlocks in Great Smoky Mountains National Park are already dead from the ravages of the insect and maybe as many as 90 percent have perished in Virginia’s Shenandoah National Park. It is difficult to overstate the significance of hemlock forests in our region. Eastern hemlocks grow on 19 million acres in forests from Georgia to Canada and are the predominant tree species on 2.3 million acres across their range. Those who have walked through a hemlock forest will know without being told the beauty and aesthetic value of this remarkable species. Among other things, the hemlock is the longest-lived tree in our forests, some reaching 800 years. The largest ever recorded soared 175 feet. It is amazingly shade tolerant, allowing new hemlocks to emerge in forest gaps to maintain hemlock stands. Foresters refer to the hemlock as a “keystone species,” one whose role in a system is disproportionately large compared to its abundance. Predictably, the disappearance of such a species is likely to result in the disappearance or diminution of many species associated with it. Hemlocks, the U.S. Forest Service’s Southern Research Station notes, play an important role in the ecology and hydrology