The U.S. Fish and Wildlife Service today published a final rule revising critical habitat for the federally threatened Peirsons milk-vetch. Approximately 12,105 acres within the Algodones Dunes in Imperial County, California, are included in the revised designation. Almost all of the land designated as critical habitat for the plant is managed by the Bureau of Land Management (BLM) as part of the Imperial Sand Dunes Recreation Area (ISDRA).
The original critical habitat designation completed in 2004 included about 21,863 acres of land. Todays revised final rule reduces the amount of critical habitat by 9,758 acres from the original 2004 designation.
An economic analysis was developed based on the areas included in the July 27, 2007, proposed rule to revise critical habitat for Peirsons milk-vetch which identified approximately 16,108 acres of land as proposed critical habitat.
The final economic analysis estimates that efficiency impacts could range from zero up to between $116 and $127 million over the next 20 years (undiscounted dollars). Approximately 93 percent - between $0 and $113 million - of the potential off-highway vehicle use welfare impacts attributable to critical habitat were projected to occur in proposed critical habitat Unit 2 which covered portions of the Gecko and Glamis Management Areas of the ISDRA.
In the revised final rule, all of Unit 2 is excluded from critical habitat designation, based on the disproportionate economic impacts.
Other factors that resulted in a smaller amount of land being designated as critical habitat include the use of a revised methodology to identify areas essential to the conservation of the plant, and refinements to mapping. The revised methodology used is based on extensive survey data collected by the BLM in 2005.
All of the areas included in the revised designation are occupied by Peirson's milk-vetch plants and/or its seed bank.
This revised final rule will become effective on March 17, 2008, and supercedes the 2004 critical habitat designation for Peirsons milk-vetch.
Copies of the revised final critical habitat rule, economic analysis and other information about Peirsons milk-vetch are available on the Internet at http://www.regulations.gov"> or http://www.fws.gov/carlsbad.
Peirsons milk-vetch is a perennial member of the legume family. It has a long tap root that can penetrate deep into the sand to reach moisture and functions as an anchor for the plant in shifting sands. The plant has delicate pale purple flowers and produces large fruits containing seeds. Plants may flower in their first year and produce between one and five fruits, while older plants produce significantly more fruits.
