Ute Ladies'-tresses (Spiranthes diluvialis) Monitoring, Inventory, and Surveys at Chester Wetlands, Idaho, 2003-2004

摘要

Ute ladies-tresses (Spiranthes diluvialis Sheviak) is a white-flowered orchid that has been considered a conservation concern in the western United States since its description in 1984. It was listed as a Threatened species under the Endangered Species Act in 1992 due to its rarity, small population sizes, and threats of loss or modification of riparian habitats. Ute ladies-tresses was discovered in 2002 at the Chester Wetlands segment of the Idaho Fish and Game Sand Creek Wildlife Management Area. In August and September 2003 and 2004, we conducted field surveys and inventory for Ute ladies-tresses at the Chester Wetlands. We established 6 permanent habitat monitoring transects and baseline habitat information was collected at 4 transects in 2003 and 2 transects in 2004. First year results indicate that invasive exotic and noxious weed species are widespread and pose a potentially threat to all 6 transects monitored. The Chester Wetlands population is significant for the species statewide conservation due to its large size, somewhat unusual habitat, and location outside the South Fork Snake River drainage (where all other known Ute ladies-tresses populations occur in Idaho). In addition, a large-scale wetland enhancement project planned for Chester Wetlands will directly affect occupied Ute ladies-tresses habitat. This report documents 2003 and 2004 survey, inventory, and baseline monitoring results and makes recommendations for monitoring and managing Ute ladies-tresses at Chester Wetlands.