Denali National Park and Preserve - Ecology

Ecology

The Alaska Range is a mountainous expanse running through the entire park, strongly influencing the park's ecosystems. Vegetation in the park depends on the altitude. The treeline is at 2,500 feet (760 m), causing most of the park to be a vast expanse of tundra. In the lowland areas of the park, such as the western sections surrounding Wonder Lake, spruces and willows dominate the forest. Most trees and shrubs do not reach full size, due to unfavorable climate and thin soils. There are three types of forest in the park: from lowest to highest, they are low brush bog, bottomland spruce-poplar forest, upland spruce-hardwood forest. The forest grows in a mosaic, due to periodic fires.

In the tundra of the park, layers of topsoil collect on rotten fragmented rock moved by thousands of years of glacial activity. Mosses, ferns, grasses, and fungi grow on the topsoil. In areas of muskeg, tussocks form and may collect algae. The term 'muskeg' includes spongy waterlogged tussocks as well as deep pools of water covered by solid-looking moss. Wild blueberries and soap berries thrive in the tundra and provide the bears of Denali with the main part of their diet.

Over 450 species of flowering plants fill the park and can be viewed in bloom throughout summer. Images of goldenrod, fireweed, lupine, bluebell, and gentian filling the valleys of Denali are often used on postcards and in artwork.

Denali is home to a variety of Alaskan birds and mammals, including a healthy population of grizzly bears and black bears. Herds of caribou roam throughout the park. Dall sheep are often seen on mountainsides, and moose feed on the aquatic plants of the small lakes and swamps. Despite human impact on the area, Denali accommodates gray wolf dens, both historic and active. Smaller animals, such as hoary marmots, arctic ground squirrels, beavers, pikas, and snowshoe hares are seen in abundance. Foxes, martens, lynx, wolverines also inhabit the park, but are more rarely seen due to their elusive natures.

The park is also well known for its bird population. Many migratory species reside in the park during late spring and summer. Birdwatchers may find waxwings, Arctic Warblers, pine grosbeaks, and wheatears, as well as Ptarmigan and the majestic tundra swan. Predatory birds include a variety of hawks, owls, and the gyrfalcon, as well as the abundant but striking golden eagle.

Ten species of fish, including trout, salmon, and arctic grayling, share the waters of the park. Because many of the rivers and lakes of Denali are fed by glaciers, glacial silt and cold temperatures slow the metabolism of the fish, preventing them from reaching normal sizes. A single amphibious species, the wood frog, also lives among the lakes of the park.

Denali park rangers maintain a constant effort to keep the wildlife wild by limiting the interaction between humans and park animals. However, the number of wild bears necessitates their wearing collars to track movements. Feeding any animal is strictly forbidden, as it may cause adverse effects on the feeding habits of the creature. Visitors are encouraged to view animals from safe distances. Despite the large concentration of bears in the park, efforts by rangers to educate backpackers and visitors about preventive measures and BRFCs have greatly reduced the number of dangerous encounters. In August 2012 the park experienced its first ever fatal bear attack when a lone hiker apparently startled a large male grizzly while photographing it. Analysis of the scene and the hiker's camera strongly suggest he violated park regulations regarding backcountry bear encounters, which all permit holders are made aware of. Certain areas of the park are often closed due to uncommon wildlife activity, such as denning areas of wolves and bears or recent kill sites. These restricted areas may change throughout the year. Through the collective care of park staff and visitors, Denali has become a premier destination for wildlife viewing.