Flora
Glacier is part of a large preserved ecosystem collectively known as the "Crown of the Continent Ecosystem", all of which is primarily untouched wilderness of a pristine quality. Virtually all the plants and animals which existed at the time European explorers first entered the region are present in the park today.
A total of over 1,132 plant species have been identified parkwide. The predominantly coniferous forest is home to various species of trees such as the Engelmann spruce, Douglas fir, subalpine fir, limber pine and western larch, which is a deciduous conifer, producing cones but losing its needles each fall. cottonwood and aspen are the more common deciduous trees and are found at lower elevations, usually along lakes and streams. The timberline on the eastern side of the park is almost 800 feet (244 m) lower than on the western side of the Continental Divide, due to exposure to the colder winds and weather of the Great Plains. West of the Continental Divide, the forest receives more moisture and is more protected from the winter, resulting in a more densely populated forest with taller trees. Above the forested valleys and mountain slopes, alpine tundra conditions prevail, with grasses and small plants eking out an existence in a region that enjoys as little as three months without snow cover. Thirty species of plants are found only in the park and surrounding National Forests. Beargrass, a tall flowering plant, is commonly found near moisture sources, and is relatively widespread during July and August. Wildflowers such as monkeyflower, glacier lily, fireweed, balsamroot and Indian paintbrush are also common.
The forested sections fall into three major climatic zones. The west and northwest are dominated by spruce and fir and the southwest by redcedar and hemlock; the areas east of the Continental Divide are a combination of mixed pine, spruce, fir and prairie zones. The cedar-hemlock groves along the Lake McDonald valley are the easternmost examples of this Pacific climatic ecosystem.
Whitebark pine communities have been heavily damaged due to the effects of blister rust, a non native fungus. In Glacier and the surrounding region, 30% of the Whitebark pine trees have died and over 70% of the remaining trees are currently infected. The Whitebark pine provides a high fat pine cone seed, commonly known as the pine nut, that is a favorite food of red squirrels and Clark's Nutcracker. Both grizzlies and black bears are known to raid squirrel caches of the pine nuts, and it is one of the bears' favorite foods. Between 1930 and 1970, efforts to control the spread of blister rust were unsuccessful, and continued destruction of whitebark pines appears likely, with attendant negative impacts on dependent species.
Fauna
Virtually all the historically known plant and animal species, with the exception of the bison and woodland caribou, are present, providing biologists an intact ecosystem for plant and animal research. Two threatened species of mammals, the grizzly bear and the Canadian lynx, are found in the park. Although their numbers remain at historical levels, both are listed as threatened because in virtually every other region of the U.S. outside of Alaska, they are either extremely rare or absent from their historical range. On average, one or two bear attacks on humans occur each year; since the creation of the park in 1910, there have been a total of 10 bear-related deaths. The number of grizzlies and lynx in the park is not known for certain, but park biologists believed as of 2008 that there were just above 300 grizzlies in the park; a study commenced in 2001 hoped to determine the number of lynx. The exact population figures for grizzlies and the smaller black bear are not known but biologists are using a variety of methods to try to determine an accurate population range. Another study has indicated that the wolverine, another very rare mammal in the lower 48 states, continues to reside in the park. Other large mammals such as the mountain goat (the official park symbol), bighorn sheep, moose, elk, mule deer, white-tailed deer, coyote, and the rarely seen mountain lion, are either plentiful or common. Unlike in Yellowstone National Park, which commenced a wolf reintroduction program in the 1990s, it is believed that wolves recolonized the park naturally during the 1980s. Sixty-two species of mammals have been documented, including badger, river otter, porcupine, mink, marten, fisher, six species of bats and numerous other smaller mammals.
A total 260 species of birds have been recorded, with raptors such as the Bald Eagle, Golden Eagle, Peregrine Falcon, Osprey and several species of hawks residing year round. The Harlequin Duck is a colorful species of waterfowl found in the lakes and waterways. The Great Blue Heron, Tundra Swan, Canada Goose and American Wigeon are species of waterfowl more commonly encountered in the park. Great Horned Owl, Clark's Nutcracker, Steller's Jay, Pileated Woodpecker and Cedar Waxwing reside in the dense forests along the mountainsides, and in the higher altitudes, the Ptarmigan, Timberline Sparrow and Rosy Finch are the most likely to be seen. The Clark's Nutcracker is less plentiful than in past years due to the decline in the number of whitebark pines.
Because of the colder climate, ectothermic reptiles are all but absent, with two species of garter snakes and the western painted turtle being the only three reptile species proven to exist. Similarly, only six species of amphibians are documented, although those species exist in large numbers. After a forest fire in 2001, a few park roads were temporarily closed the following year to allow thousands of Western toads to migrate to other areas.
Glacier is also home to the endangered bull trout, which is illegal to possess and must be returned to the water if caught inadvertently. A total of 23 species of fish reside in park waters and native game fish species found in the lakes and streams include the cutthroat trout, northern pike, mountain whitefish, Kokanee salmon and grayling. Introduction in previous decades of lake trout and other non-native fish species has greatly impacted some native fish populations, especially the bull trout and west slope cutthroat trout.
Fire ecology
Forest fires were viewed for many decades as a threat to protected areas such as forests and parks. As a better understanding of fire ecology developed after the 1960s, forest fires were understood to be a natural part of the ecosystem. The earlier policies of suppression resulted in the accumulation of dead and decaying trees and plants which would normally have been reduced had fires been allowed to burn. Many species of plants and animals actually need wildfires to help replenish the soil with nutrients and to open up areas that allow grasses and smaller plants to thrive. Glacier National Park has a fire management plan which ensures that human-caused fires are generally suppressed as they always have been. In the case of natural fires, the fire is monitored and suppression is dependent on the size and threat a fire may pose to human safety and structures.
Increased population and the growth of suburban areas near parklands, has led to the development of what is known as Wildland Urban Interface Fire Management, in which the park cooperates with adjacent property owners in improving safety and fire awareness. This approach is common to many other protected areas. As part of this program, houses and structures near the park are designed to be more fire resistant. Dead and fallen trees are removed from near places of human habitation, reducing the available fuel load and the risk of a catastrophic fire, and advance warning systems are developed to help alert property owners and visitors about forest fire potentials during a given period of the year. Glacier National Park has an average of 14 fires with 5,000 acres (20 km2) burnt each year. In 2003, 136,000 acres (550 km2) burned in the park after a five year drought and a summer season of almost no precipitation. This was the most area transformed by fire since the creation of the park in 1910.
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