Biotic
Communities of the Colorado Plateau
Mountain Wetlands
 |
|
Boulder Top subalpine lake on Utah's Aquarius Plateau. Photo © Ray Wheeler |
Interspersed among the region's high-elevation forests and mountain grasslands are marshes or cienegas and other similar aquatic environments. Though some areas have an abundance of surface water, such as the White Mountains of Arizona and a few of the high plateaus of Utah, in other areas such as the Kaibab Plateau surface water is limited by limestone or porous volcanic bedrock, despite adequate precipitation. Natural high-elevation wetlands on the plateau include Mormon and Stoneman Lakes along the Mogollon Rim in Arizona and the many subalpine lakes of the Boulder Top area of the Aquarius Plateau in southern Utah.
Common species living in areas of perennial or near-perennial surface water at middle and high elevations include cattail, bulrush, sedges, waterweed, spike rushes, quaking aspen, Colorado blue spruce, currants, shrubby cinquefoil, elderberry, and several types of willows. Pond weeds and manna grasses are common submergent plants. Principal waterfowl species include mallard, pintail, cinnamon teal, ruddy duck, and redhead. Taller emergent plants such as bulrush provide nesting sites for American bittern, yellow- and red-headed blackbirds, and marsh wren.
Beaver probably once played an important role in creating and maintaining mountain wetland areas. Tree cutting and dam building by beavers trap alluvial sediments, provide opportunities for new plant growth, and increase the diversity of wildlife habitats. The loss of beavers and their dams to overharvesting by early trappers probably degraded many if not most of these wetlands, contributing to arroyo-cutting and gullying of the landscape. As channels cut deeper water tables were lowered and surface sediments began to dry out; gradually, the vegetation becomes composed of plants tolerant of drier conditions.
Resources:
Almand, J., and W. Krohn. 1979. The position of the Bureau of Land Management on the protection and management of riparian ecosystems. Pages 259361 in R. Johnson and F. McCormick, technical coordinators. Strategies for protection and management of floodplain wetlands and other riparian ecosystems. Proceedings of the symposium, 1113 December 1978. U.S. Forest Service General Technical Report WO-12, Washington, D.C.
Brode, J. M. and Bury, R. B. 1984. The importance of riparian systems to amphibians and reptiles. Pp. 1035 In: Warner, R. E. and Hendrix, K. M., editors. California riparian systems: ecology, conservation, and productive management. University of California Press, Berkeley and Los Angeles.
Dahl, T. E. 1990. Wetland losses in the United States 1780's to mid-1980's. U.S. Fish and Wildlife Service, Washington, D.C., 13 pp.
Knopf, F. L. 1989. Riparian wildlife habitats: more, worth less, and under invasion. Pp. 20-22 In: Mutz, K., Cooper, D., Scott, M. and Miller, L., editors. Restoration, creation, and management of wetland and riparian ecosystems in the American West. Society of Wetland Scientists, Rocky Mountain Chapter, Boulder, CO.
Knopf, F. L. and Scott, M. L. 1990. Altered flows and created landscapes in the Platte River headwaters, 18401990. Pp. 47-70 In: Sweeney, J. M., editor. Management of dynamic ecosystems. North-central section, The Wildlife Society, West Lafayette, Ind.