1997-06-13_REPORT - M1981302 (11)

Home Browse Search

features have been dramatically altered since settlement of the west by Europeans. Ungulate populations have been driven from winter range by agricultural activities and urban development. Orchid habitat is now grazed by cows, sheep, or horses, and both timing and intensity are different, than grazing patterns of native ungulates. Stream processes have also been severely altered. Reservoirs, dams, and diversions have removed water from stream systems, completely dewatering some reaches, and changed their hydrographs (magnitude and timing of flow) . Streams have been channelized, streambanks rip-rapped, and floodplains converted for agriculture or urban development. The Ute ladies'-tresses continues to survive either where streams are still in a somewhat natural condition within a floodplain, or where conditions mimic naturally created and maintained habitat. For example, the orchid can be found along old gravel pits that have been restored as wetlands, in irrigated pastures, and below leaky diversion dams and irrigation canals. Urbanization is one of the primary threats to the orchid. Urbanization continues to expand along streams and within floodplains. Both undeveloped habitat and agricultural areas near where the orchid exists or where it could exist are being converted to urban and suburban land uses. This is limiting the distribution of habitats sufficient to support viable populations as well as restricting the range of the species. Colorado's Front Range and Utah's Wasatch Front are two of the fastest growing urban areas in the nation. The orchid has been extirpated from some areas along the Wasatch Front and the Front Range. For example, except for two small populations in wetlands near Utah Lake and the recently discovered population along Diamond Fork, all known historic populations of the orchid along the Wasatch Front are presumed extirpated, as are all but one (rediscovered in 1994) in the eastern Great Basin. Two of the four historic populations in Colorado are also extirpated (Coyner 1989, 1990; Jennings 1989, 1990, U.S. Fish and Wildlife Service 1991) . The conversion of potential habitat is occurring at a rapid, and increasing, pace. Increasing demand for water, both for agriculture and for municipal and industrial uses, is also a severe threat to the orchid. In Colorado and Utah, water developers are planning water projects on most of the remaining undammed streams or stream reaches. Water is managed to optimize urban and agricultural uses. Water law and precedent, and water development interests, make it difficult to retain or reinstitute instream flows, particularly flows that mimic or reflect natural hydrographs. Recreational uses of streams and riparian areas are increasing as nearby urban populations increase. Management of streams for introduced game fish by moderating stream dynamics to produce even rather than varying flows and low sediment loads may impede creation and maintenance of orchid habitat. Recreational uses within riparian areas can trample orchids, cause compaction resulting in changes in hydrology, and encourage proliferation of weedy species. Although it is possible in some cases to manage streams to accommodate both the orchid and recreational activities including game fishing, efforts to do so have not been seriously initiated to date. 11