WASHINGTON (CN) - Tuesday, the U.S. Fish and Wildlife Service listed
the Webber's ivesia as threatened under the Endangered Species Act, with 2,170 acres of critical habitat
. The tiny yellow-flowered plant is a perennial and a member of the rose family. It is found only in the region between the Sierra Nevada Mountains in California and the Great Basin Desert in Nevada.
The current listing is part of a 2011 settlement agreement between the USFWS and the Center for Biological Diversity (CBD) that resulted in a five-year workplan to speed listings for hundreds of at-risk species across the nation. The CBD first petitioned for the listing status for the ivesia in 2004.
"Thanks to the Endangered Species Act, this rare desert rose and its unique habitat have a shot at survival," Ileene Anderson, a senior scientist at the CBD was quoted as saying in the group's press release in response to the listing.
The Webber's ivesia grows on mid-elevation flats or terraces in only five counties in the two states. These areas are characterized by clay soils that swell during spring rains then shrink and crack in summer. "The shrink-swell of the clay zone, which extends into the subsoil, favors perennials with deep taproots or annuals with shallow roots that can complete their life cycle before the surface soil dries out," the action noted.
"Webber's ivesia is threatened with extinction because of many factors, particularly the invasion of nonnative plant species and associated increases in the frequency and severity of wildfires throughout the species' limited range," Ted Koch, State Supervisor for the Nevada Fish and Wildlife Office was quoted as saying in the USFWS press release.
Nonnative, invasive plant species compete with, displace and degrade the plant communities in which the ivesia occurs, and they contribute fuels that increase the frequency of wildfires, the action said.
The ivesia is currently found on only 165 acres. Of the 17 historically known populations, one has been wiped out and the status of two more are unknown. The plants receive some conservation protections already because 69 percent of the occupied habitat is on Forest Service lands and 3 percent is on Bureau of Land Management lands.
The USFWS determined that the ivesia is not currently in danger of extinction throughout all of its range, the criteria for endangered status, because the populations are spread across northeastern California and northwestern Nevada, and are thought to provide sufficient redundancy and resiliency that the species is not at risk of immediate extinction, the action noted.
The final critical habitat designation of 2,170 acres is an increase of 159 acres over the amount of land in the original proposed rule
. The change is the result of new information received from the U.S. Forest Service that "better defined the physical or biological features along the boundaries of five proposed units, resulting in changes to the acreages for those units," the action said.
"The critical habitat being proposed to protect the plant will require federal agencies to consult with the Fish and Wildlife Service before funding or permitting projects that could harm the flower's habitat," the CBD said.
Most of the designated critical habitat, approximately 70 percent, is on federally managed land, 10 percent is on state land and only 20 percent is on private land, the USFWS said.
The final listing and the critical habitat designation are effective July 3.