Ute ladies'-tresses (Spiranthes diluvialis) monitoring on the South Fork Snake River, Idaho: sixth year results

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Ute ladies'-tresses (Spiranthes diluvialis) was federally listed as Threatened in 1992 because of its small population sizes and geographic rarity, habitat loss and modification, and low reproduction rate. It is ranked as 'Imperiled' globally and 'Critically Imperiled' in Idaho (G2 and S1) by NatureServe, and as 'Threatened' by U.S. Fish and Wildlife Service (USFWS). Since 1997, the Idaho Natural Heritage Program, U.S. Bureau of Land Management (BLM), and U.S. Forest Service (USFS) have cooperatively inventoried the abundance of Ute ladies'-tresses element occurrences (EOs) on public lands along the South Fork of the Snake River, approximately 31km northeast of Idaho Falls, Idaho. In 2001, habitat monitoring transects were established at Ute ladies'-tresses EOs located on BLM and USFS lands, and many transects were re-sampled in 2002, 2003, 2005, 2007, and 2009. In 2009, 20 BLM and 4 USFS transects were re-sampled, and there were 220 Ute ladies'-tresses plants counted at those transects. A total of 3,117 Ute ladies'-tresses plants were counted at the 24 subpopulations. The primary disturbances to Ute ladies'-tresses were invasion by noxious and invasive weed species and shrub and tree encroachment. Disturbances to a lesser degree included competition by forbs, wildlife activity (native ungulate bedding, trails, and browsing), human-caused ground disturbance (roads, houses, excavation, and filling), and recreation (human trails and campsite impacts). Indications of cattle grazing impacts were identified at Warm Springs Bottom (transects 003A and 003B in EO 2), Annis Island (transects 006A, 006B, and 006C in EO 6), and Falls Campground (transect 004A in EO 4). Monitoring Ute ladies'-tresses along the South Fork of the Snake River provides information useful for managing the EOs and their habitat. Effectively managing Ute ladies'-tresses depends upon detecting and responding to disturbances and threats. In 2009, all transects were monitored, and should remain a priority so that there is meaningful, replicable count data, as well as habitat data, for both BLM and USFS managed lands. Continued responsive management by both the BLM and USFS is important to Ute ladies‟-tresses and its long-term persistence in Idaho.

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Reference Code: U10MIL01IDUS

Full Citation: Miller, J. J. 2010. 2009 Ute ladies'-tresses (Spiranthes diluvialis) monitoring on the South Fork Snake River, Idaho: sxth year results. Report prepared for Bureau of Land Management and USDA Forest Service. Idaho Department of Fish and Game, Boise, ID. 58 pp. plus appendices (CD).

Location: ELECTRONIC FILE BOTANY: PLANT SPECIES: {Spiranthes diluvialis}