Great Smoky Mountains National Park

Great Smoky Mountains National Park

Preserving the Smokies

The NPS plays a dual role at Great Smoky Mountains National Park: It preserves both the park's natural environment and the historic relics of the mountain settlers.

Smokier Smokies

As with all our national parks, Great Smoky Mountains National Park is no longer isolated from the outside world. Air pollution, coming from as far away as the Midwest, has decreased visibility by 60 percent over the past 50 years. In 1960, a visitor could see 22 miles from a park overlook. Now you can only see 12 miles. This is because sulfates and nitrogen oxide emissions from industries and urban centers are carried on air currents toward the park. Researchers believe that the emissions rise at night and, mixing with air, settle across the park's ridges. 

Ground-level ozone pollution produced by the reaction of nitrogen oxides (automobiles and factories are the main producers) with volatile organic compounds in the presence of sunlight, is one of the most serious air pollutants. Ozone concentrations measured in the park are among the highest in the eastern U.S. This type of pollution is a powerful respiratory irritant. During high ozone-pollution episodes, visitors (especially seniors and children) may wish to refrain from strenuous outdoor activities.

Acid rain results when sulfur and nitrogen by-products in the air combine with water vapor and return to the earth as weak acids. The acids damage sensitive plant foliage and affect the chemical balance of streams and soils. If an imbalance occurs, living things may fail to reproduce or may die. Air-quality monitoring data is on display at Sugarlands Visitor Center and the Oconaluftee Visitor Center.

Imperiled Firs & Hemlocks

Exotic, or nonnative, species can also threaten the native environment. In the case of the Fraser fir, it's a tiny insect called the balsam woolly adelgid. This native of Europe was inadvertently introduced to this country at the turn of the century. Adelgids drink the Fraser fir's sap, killing it within six to eight years after initial infestation. More than 70 percent of the mature Fraser firs in the park are dead, robbed of their lifeblood and poisoned by a toxin injected by the adelgid. 

The NPS is actively trying to save the park's last remnants of fir forest. In some more accessible areas, trees are sprayed with a natural fatty-acid soap, which is toxic to the adelgid but presents no harm to humans or the environment. The NPS also has collected seeds and is raising seedlings in other areas for continued protection.

The hemlock woolly adelgid (HWA) is a tiny insect native to Asia that attacks and kills hemlock trees within a three- to five-year period. Spreading by larger insects, on the feet of birds, by wind and infested landscape materials, the HWA feeds by sucking the sap from the base of the tree needles. The needles discolor and drop off, impairing new growth.

In an effort to combat this pest, the park's most aggressive control method is the release of tiny predator beetles which feed exclusively on the HWA. Methods of chemical treatments are also being employed but are only effective on a limited basis.

A "Save Our Hemlocks Action Team" of scientists, land managers and others was organized by the Southern Appalachian Man and the Biosphere (SAMAB). These experts are pooling their resources to survey and monitor impacts of the exotic pest, conduct outreach activities and look at other possible solutions—biological, chemical and cultural controls—to reduce the potential disaster comparable to that of the chestnut blight, which eliminated chestnut trees from the Southern Appalachian landscape and radically changed the composition of the southern forests. For more information, visit online at 

Saving Animals

In 1997, a pair of mated peregrine falcons nested with three chicks atop Peregrine Peak, on the south flank of Mount LeConte, for the first time since 1942. The birds returned to raise more chicks at the same location in succeeding years. This once-threatened species had disappeared from the eastern U.S. by the mid-1960s as a result of widespread pesticide use. Reintroduction efforts have included the release of 13 falcons in the park between 1984 and 1986.

River otters have taken up residence in the park after a 70-year absence. The animal was extinct in the park by the 1930s, mainly due to trapping and destruction of habitat. Between 1986 and 1994, 137 otters were released. 

Because of the results of decades of fisheries research and the success of the park's brook trout restoration efforts, visitors can now fish for brook trout, the only native trout species in the park.  In 1976, park management took steps to initiate brook trout restoration in selected streams, discontinued stocking non-native species such as rainbow and brown trout, and made it illegal to harvest brook trout.  Major population losses associated with fire, logging, and non-native fish introductions during the early 1900's reduced the original range of brook trout in the park by about 50 percent.   To date, brook trout have been successfully restored to 17 miles of streams and now inhabit about 140 miles of streams.