A study is now in progress to identify and categorize every living creature within the park's boundaries. It is estimated that between 40,000 and 70,000 multicellular species exist in the park. The project is expected to take 10 to 15 years to complete. Also, to assist in monitoring and classifying the unique inventory of rare plants, animals, and ecosystems in the park, the GSMNP, in cooperation with The Nature Conservancy, became the first park in the nation to set up a National Heritage Data Center.
Establishment of the park saved more than 100,000 acres of old-growth forest, including some of the largest stands in the eastern United States. The areas scarred by lumbering operations have regenerated, and much of the damage done to various flora and fauna species has been reversed. Because the GSMNP is so biologically diverse, the United Nations Educational, Scientific, and Cultural Organization (UNESCO) designated it as an International Biosphere Reserve in 1976.
Today the park is home to some 1,600 flowering plants, 130 kinds of trees (including the largest known examples of 15 species), 300 mosses and liverworts, 1,800 fungi, 50 ferns and fern allies, and 230 lichens.
The GSMNP is well known for its diverse wildflower displays beginning in early spring and continuing through the fall. With up to 100 inches of annual rainfall (depending on location), ideal conditions are created for many species.
An even greater variety of plant life stems from the varied ecosystems within the park. Generally, the higher elevations are wetter and cooler, but as the altitude decreases, factors like the direction and shape of a slope become increasingly important. Although the elevation may change very little, the flora dramatically changes as you move through the folds of moist valleys and dry ridges. The more convex the ridge slope, the drier the conditions. When you consider the changes in elevation and the variety in topography found here, you begin to understand the reason for the diversity within the plant community of the GSMNP.
Over the years more than 300 species of non-native plants have invaded or been introduced into the Smokies. Many are ornamental flowers, such as daffodils (Narcissus sp.), that decorate open areas around old homesteads and cause no problems. Other species are detrimental and are considered serious threats to native flora by park officials.
Plants high on the list of detrimental species are kudzu (Pueraria lobata), Oriental bittersweet (Celastrus orbiculatus), mimosa (Albizzia julibrissin), princess trees (Paulownia tomentosa), and wisteria (Wisteria frutescens), while Japanese honeysuckle (Lonicera japonica) and privet (Ligustrum vulgare) are also problematic.
Non-native insects and diseases have caused much of the past and continuing damage to park trees. The first to heavily impact both the forest and, indirectly, the wildlife population was the Chinese chestnut blight that arrived in the 1930s and eliminated the American chestnut (Castanea dentata).
Until the blight occurred, the chestnut was the most common canopy tree in the park, and its prolific and consistent mast was a main food source for many animals and birds. Since the blight, more problems have surfaced.
Dutch elm disease, a well-known fungus, is transmitted to the American elm (Ulmus americana), slippery elm (U. ruba), and winged elm (U. alata) in the park by the elm bark beetle (Scolytus multistriatus). Since the late 1980s, hundreds of elms have died from the disease, mostly in the Little River drainage.
Butternut canker is believed to have been introduced into the U.S. about 30 years ago, but it went unnoticed in the park until the late 1980s when butternut (Juglans cinera) populations began plummeting. So far, no solutions to the problem have been discovered.
American holly (Ilex opace) trees have suffered defoliation and mortality in the park during the past decade, but no single agent has yet been identified as the cause of the problem.
American beech (Fragus grandifolia) trees have suffered a decline in the park, and in 1993 it was confirmed that the beech bark scale insect from Europe and the Nectaria fungus together cause beech bark disease. Large areas of New England have lost entire populations of beech trees, and park officials see the insect as a threat in the Smokies.
Dogwood anthracnose (Discula destructiva) was first found in Washington State in 1977, and shortly afterward it was found in the New York City area. It was found in Maryland in 1983 and in north Georgia in late 1987. It can kill all dogwoods (Cornus sp.) in large populations in just a few years. It has destroyed many trees in the park, where, ecologically, the flowering dogwood (C. florida) plays an important role. Its foliage, twigs, and fruit are higher in calcium than any other forest species, which makes it a prime soil builder. Migratory birds depend on its high protein fruit in the autumn, and the leaves and twigs are preferred by all herbivores, from deer to invertebrates.
During the past half-century, the balsam woolly adelgid, an insect from Europe, has devastated the once-magnificent stands of Fraser fir (Abies fraseri) in the park. The park contains 74 percent of all of the spruce-fir forest in the Southeast, and 91 percent of the mature trees in the park are dead. A related species, the hemlock woolly adelgid, is approaching the Smokies from the north and is capable of decimating stands of Eastern hemlock (Tsuga canadensis) trees. There is a ray of hope in the discovery of some small groups of mature Fraser fir found growing at high elevations. It is possible that some of these trees have a genetic resistance to the pests.
The European mountain ash sawfly (Cimbex americana) was first introduced to North America in Canada, and it has since spread throughout eastern U.S. forest regions. It defoliates American mountain ash (Sorbus americana) where it grows at high elevations along the crest of the Smokies.
The gypsy moth (Lymantria dispar) defoliates oak, maple (Acer sp.), beech, birch (Betula sp.), and other deciduous trees and poses a threat to the park. It has already done severe damage to forests to the North, and in eastern Tennessee, western North Carolina, and northern Georgia. Park officials are carefully monitoring the spread of this exotic and its presence in the park.