Bears are active in Grand Teton
Black and grizzly bears are roaming throughout the park--near roads, trails and in backcountry areas. Hikers and backcountry users are advised to travel in groups of three or more, make noise and carry bear spray. Visitors must stay 100 yards from bears. More »
Growing only millimeters a year, some lichens are thought to be the oldest living things on Earth. Lichens are not single organisms, but rather a partnership, or mutualistic symbiosis, between fungi and algae or cyanobacteria. The fungus builds the body of the lichen while the alga or cyanobacteria live within this structure and are photosynthetic, producing energy and nutrients for both organisms. This partnership allows lichens to colonize harsh environments such as the alpine areas of Grand Teton National Park.
Acids secreted by lichens dissolve the surface of the substrate they grow on. This, along with their action of infiltrating and wedging apart pieces of rock, are the beginnings of soil formation. Lichens serve as food in times of stress for many organisms including bighorn sheep, elk, and humans. Many birds also use lichens for nest building.
Many lichen species are highly sensitive to air quality; therefore, they are vulnerable to habitat alteration and serve as useful bio-indicators. The presence or absence of lichens in an area is a good indication of the area's air quality. Lichens absorb air pollution and heavy metals from their surrounding environment. Analyzing the pollutants absorbed by lichens allows scientists to determine the amount and kinds of air pollutants and how far they have traveled.
Did You Know?
Did you know that the granite and gneiss composing the core of the Teton Range are some of the oldest rocks in North America, but the mountains are among the youngest in the world?