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Major Land Resource Area or ecological site by name and/or ID.
General information
Draft. A draft ecological site description is either incomplete or has not undergone quality control and quality assurance review.
MLRA notes
Major Land Resource Area (MLRA): 022A–Sierra Nevada and Tehachapi Mountains
Major Land Resource Area 22A, Sierra Nevada Mountains, is located predominantly in California and a small section of western Nevada. The area lies completely within the Sierra Nevada Section of the Cascade-Sierra Mountains Province. The Sierra Nevada range has s gentle western slope, and a very abrupt eastern slope. The Sierra Nevada consists of hilly to steep mountains and occasional flatter mountain valleys. Elevation ranges between 1,500 and 9,000 ft. throughout most of the range, but peaks often exceed 12,000 ft. The highest point in the continental US occurs in this MLRA (Mount Whitney, 14,494 ft.). Most of the Sierra Nevada is dominated by granitic rock known as the Sierra Nevada Batholith. Additionally, glacial activity of the Pleistocene has played a major role in shaping Sierra Nevada features, including cirques, arêtes, and glacial deposits and moraines. Average annual precipitation ranges from 20 to 80 inches in most of the area, with increases along elevational and south-north gradients. Soil temperature regime ranges from mesic, frigid, and cryic. Due to the extreme elevational range found within this MLRA, Land Resource Units (LRUs) were designated to group the MLRA into similar land units.
LRU "B" Southern Sierra Subalpine
The Southern Sierra sublalpine LRU "B" occurs south of latitude 39 degrees north, and elevations are typically between 9,000 to 10,500 feet (2,743 to 3,200 m). MAAT ranges from 31 to 40 degrees F (-0.5 to 4.4 C), MAP ranges from 32 to 59 inches (813 to 1,499 mm), and the frost free season is 25 to 60 days. Forests are dominated by whitebark pine (Pinus albicaulis) and foxtail pine (Pinus balfouriana) near timberline, and a mix of Sierra lodgepole pine (Pinus contorta var. murrayana), whitebark pine, and/or mountain hemlock (Tsuga heterophylla) at the lower elevations. Threadleaf sedge (Carex filifolia) or purple mountainheath (Phyllodoce breweri) dominates the non-forested areas.
Ecological site concept
Site occurs on talus fields in the upper elevations of the subalpine zone. Soils are very deep, with a very high percentage of rock fragments composed of stones and boulders. Soil textures are loamy sands. There is very little vegetative cover, but Congdon’s sedge (Carex congdonii) is present.
Table 1. Dominant plant species
Tree Not specified
Shrub Not specified
Herbaceous (1) Carex congdonii