Although Pleistocene tundra in the Smokies is a rather speculative notion, it seems certain that spruce-fir forest existed below today’s 1,400-meter (4,600-foot) limit. This supposition is supported by the fact that fossil pollen and other fragments of spruce and fir have been found in several lowland bog deposits of the South.
During the last Ice Age the Southern Appalachian spruce-fir forests and their animals must have been a richer version of the plant-animal community that exists in this zone today, for at the peak of the ice advance northern plants and animals probably could migrate along a continuous avenue of this boreal forest in the Appalachians. Bones from cave deposits at Natural Chimneys in Virginia’s Shenandoah Valley indicate that such northern animals as porcupines, snowshoe hares, pine martens, fishers, spruce grouse, and gray jays, as well as the now extinct longnosed peccary and giant beaver, roamed that area 10,000 to 15,000 years ago. The still existing species mentioned above now live farther north in the forests of New England and Canada. If such animals could live during the late Pleistocene at 450 meters (1,500 feet) in Virginia, many and perhaps all of them might well have lived at higher elevations in the Smokies. In the case of porcupines, archeological records from nearby regions in fact support this idea.
After the retreat of the last ice sheet a warm, dry period set in and caused the development of grasslands as far east as Ohio. To what extent this change in climate may have affected the Smokies is not known. But it may have been responsible for the development of the beech gaps: as the spruce-fir forests were forced ever higher, beeches and yellow birches followed in their wake. The once continuous band of spruce-fir forest through the Southern Appalachians would then have been broken into patches as it migrated to higher elevations—and disappeared entirely on the lower mountains. Today such forest is restricted in the Southern Appalachians to the highest parts of eastern West Virginia, southwestern Virginia, western North Carolina, and areas in and just north of the Great Smokies. During the warmer, drier period following glaciation, boreal forest must have been even smaller in extent.
Another consequence of warming was the northward migration of plants and animals into territory vacated by the ice sheet (north of the Ohio River and Long Island). The result today in northeastern United States is a broad patchwork of forest types, each type dominated by a few species, as in beech-maple or beech-birch-white pine forests. This stands in contrast to the diversity of the cove forests from which the migrants extended. Cove forests still harbor individuals of all these species.
What happens next? Has the Pleistocene epoch really ended or are we merely between glaciers, awaiting the next invasion of ice? For the Smokies the question implies others: Will the forest zones move up or down the mountainsides? How will this affect animal life?
While terrestrial life in the mountains flourished during the continent’s climatic swings, aquatic life fared equally well. Within Great Smoky Mountains National Park live some 70 species of fish. Contrast this with the number in Shenandoah National Park in the Blue Ridge of Virginia, which has only about 25 species. Why so many in the Smokies? The answer parallels the situation for plants and terrestrial animals: diversity of environments and plenty of time. All the streams of the Smokies lie within the Tennessee River drainage, which is part of the Mississippi River drainage. The Tennessee River has more species of fish than any other river in North America, because of its many environments (lowland, plateau, and mountain); the vastness of the Mississippi drainage; its existence for many millions of years; and its Pleistocene history. During glacial periods many species of fish were forced southward by ice and cold glacial water. The Tennessee River system offered them a refuge just as Southern Appalachian coves offered a refuge for plants. Even the Mississippi itself was a less favorable haven because it received most of the meltwater. In the headwaters of the Tennessee, the streams of the Smokies thus benefit from their contact with an ancient, relatively undisturbed river system. Within the park, stream environments range from cold and fast to comparatively cool and slow, with large, deep pools.
While most of the present plant and animal species of the Smokies have ranges that extend far beyond these mountains, and while many of these have spread here from other areas of origin, a few are restricted solely to the Smokies. This suggests that they may have evolved here. One such plant is Rugel’s groundsel, a member of the Composite family that grows to about 28 centimeters (11 inches) high and bears large, cylindrical clusters of tiny golden flowers. This plant, abundant in the park’s spruce-fir forests, has not been found outside the Smokies. This suggests that it evolved in the Southern Appalachians and that after the last glacial period, when connection with other sections of spruce-fir forest was broken, it persisted or survived only in the Smokies. By comparison, the Fraser fir, though most abundant in the Smokies, also occurs north to southwestern Virginia on the highest mountains, indicating that it evolved at some earlier, colder time when spruce-fir forest was more nearly continuous. The red-cheeked salamander, a striking creature, is probably the sole vertebrate found exclusively in the Smokies. Many other species of salamanders, however, are restricted to parts of the southern end of the Appalachians and probably evolved there, where the cool, wet climate and diverse topography provide ideal conditions for this group of animals. How many other species of plants and animals evolved in the region and subsequently spread far beyond this point of origin we can only conjecture.
Natural History Sampler
These eight pages sample the abundant life of the Smokies, from flowering plants and shrubs to birds, mammals, reptiles, and amphibians.
Species are shown for various reasons. You may want to identify the common species you see in the wild. Other species are uncommon and you are not likely to see them. Still others are uncommonly beautiful, and we don’t want you to miss seeing at least their pictures.
Information, drawings, and photographs of bears and wild boars are found in the [Bears, Boars and Acorns chapter].
Jack-in-the-pulpit
Scarlet painted-cup
Painted trillium
Coreopsis
Turk’s-cap lily
Bird’s-foot violet
Pink lady’s-slipper
Orange hawkweed
Passion-flower
Fringe-tree
Flame azalea
Mountain silverbell
Dog-hobble
Redbud
Witch-hobble
Umbrella magnolia
Catawba rhododendron
Yellow-poplar
Flowering dogwood
Fire cherry
Mountain laurel
Barred owl
Wild turkey
Common flicker
Cardinal
Yellow warbler
Tufted titmouse
Spotted skunk
Cottontail rabbit
Deermouse
Whitetail deer
Bobcat
Opossum
Fence lizard
Leopard frog
Midland mud salamander
Ringneck snake
Gray treefrog
Marbled salamander
Timber rattlesnake
Pine snake
Red-cheeked salamander
Copperhead
American toad
Spotted salamander
