Bear Valley Sandwort

Arenaria ursina

Description

Bear Valley sandwort, Arenaria ursina, a member of the pink family (Caryophyllaceae), is a low, tufted, perennial herb with stems from 2-6 in (5-15 cm) long. The leaves are opposite, 0.16-0.5 in (0.4-1 cm) long. The white, five-parted flowers are arranged in open cymes (clusters) 1.5-6 in (3.8-15 cm) high. The petals are 0.16-0.2 in (4-5 mm) long, the sepals are 0.16 in (4 mm) long in fruit. This species flowers from May to August. Bear Valley sandwort is distinguished from other members of the genus within its range by its glabrous (hairless), filiform (thread-like), nerveless leaves less than 0.08 in (2 mm) wide and its rounded, 0.12 to 0.16 in (3-4 mm) long sepals.

Habitat

Bear Valley sandwort occurs on pebble plain and dry slopes.

Distribution

Populations of Bear Valley sandwort are known from eight pebble plain complexes in the vicinity of Big Bear and Baldwin lakes. Most of the occurrences are on U. S. Forest Service land at elevations from 6,000-9,500 ft (1,829-2,896 m). Some occur on land owned by the California Department of Fish and Game, The Nature Conservancy, or private landowners. Bear Valley sandwort is threatened at six of the eight sites where it occurs.

Threats

This species is imperiled by a variety of activities that result in habitat modification, destruction, degradation, and fragmentation. These activities include urbanization, off-road vehicle activity, fuel-wood harvesting, mining activities, alteration of hydrological conditions, and vandalism. The Bear Valley sandwort is considered threatened at six of the eight sites where it occurs.

Conservation and Recovery

One of the eight critical habitats of the Bear Valley sandwort is owned by The Nature Conservancy, and is managed as an ecological reserve. Most of the other critical habitats are on federal land managed by U. S. Forest Service, and several others are on land owned by the California Department of Fish and Game, or by private landowners. The most important action needed to conserve the Bear Valley sandwort is to protect its pebble plains habitat. Only nine complexes of this habitat survive, totaling about 545 acres (220 hectares). About 514 acres (208 hectares) are administered by the Forest Service, while 32 acres (12 hectares) are on private land. The critical habitat on land administered by the Forest Service must be protected from threatening activities, especially intensive use by off-road vehicles on the pebble plains. This can be done by ensuring that these threatening activities are not permitted by the Management Plan for the Forest Service lands, or under the terms of residential and commercial leasing agreements. In addition, the Forest Service should allow no further development of commercial or residential facilities in areas containing the rare plant. Consideration should also be made of protecting the critical habitat on private land. This could be done by acquiring the land and establishing an ecological reserve, or by negotiating conservation easements. The populations of the Bear Valley sandwort should be monitored, and research undertaken into its biology and habitat needs.

Contacts

U.S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
(503) 231-6121
http://pacific.fws.gov/

U.S. Fish and Wildlife Service
Carlsbad Field Office
2730 Loker Avenue West
Carlsbad, California, 92008
Telephone: (760) 431-9440
Fax: (760) 431-9624

Reference

U.S. Fish and Wildlife Service. 14 September 1998. "Endangered and Threatened Wildlife and Plants: Final Rule To Determine Endangered or Threatened Status for Six Plants From the Mountains of Southern California." Federal Register 63 (177):49006-49022.