Wildlife Habitat
By Jeffrey P. Repp, State rangeland management specialist, Natural Resources Conservation Service.
Wildlife use patterns and numbers in areas of rangeland have varied considerably over time. Before 1900, wildlife numbers were low. California bighorn sheep and Rocky Mountain elk were eliminated from their historic range in the park. Improved wildlife management since that time has resulted in an increase in wildlife populations and diversity. Although the rangeland in the park is not extensive, it provides high-quality habitat for grazing ungulates. The combination of forage in the meadows and fens and the proximity of hiding, calving, and thermal cover make the area especially favorable for mule deer and Rocky Mountain elk. Bighorn sheep may have made use of the alpine areas in the rim area and on Union Peak and Mount Scott.
Wildlife extensively use range and forest areas for food and cover. The park provides excellent forage for grazing in summer and fall. The alpine meadows surrounding the rim and on Union Peak support dominantly western needlegrass (Achnatherum occidentale ssp. Californicum) with Hall’s sedge (Carex halliana) and Brewer’s sedge (Carex Breweri). In some areas bottlebrush squirreltail (Elymus elymoides ssp. elymoides) is also present. These species all provide nutritive value for grazing ungulates from greenup in June or July through September or early in October. In winter and spring, the deep snow cover and very cold temperatures make grazing of these areas impractical. The forest areas interspersed with the alpine meadows provide hiding and thermal cover as well as transportation corridors for wildlife.
The subalpine fens and meadows also provide excellent-quality forage. The fens in the forest areas and along streams have significant amounts of water sedge (Carex aquatilis), bluejoint reedgrass (Calomagrostis canadensis), tufted hairgrass (Deschampsia caespitosa), and pullup muhly (Muhlenbergia filiformis) that provide 3,000 to 7,000 pounds of forage per acre per year. These areas receive light to moderate use by Rocky Mountain elk. In summer there is evidence of grazing in the fens at the head of National Creek and in the Sphagnum Bog area. The current number of grazing animals does not seem to have an adverse effect on plant community composition or structure, but the animals do play a role in removing vegetation, which affects the frequency of fires and the availability of nutrients.
The fens and riparian areas provide important and diverse habitat for wildlife. Perennial riparian areas either support shrubs or have the potential to support shrubs. Healthy riparian areas have vigorous, complex plant communities consisting of shrubs, forbs, grasses, and grasslike plants. They provide a buffer during periods of high water flow, provide a connection to the flood plain, and contribute to good instream aquatic habitat. The potential to improve riparian habitat is excellent if proper management is used. The period of time needed for riparian plants to recover is relatively short because of the perennial high water table or the shallow depth to the water table. In areas of severe channel alteration and degradation, longer periods of time and additional improvement practices are needed.
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