subsection is a valley at the southern end of Lake Tahoe. It has
a cold subhumid climate. MLRA 22e.
Lithology and Stratigraphy. Quaternary glacial till,
outwash, lacustrine deposits, and alluvium dominate this subsection.
A small hill of Mesozoic granitic and Jurassic marine sedimentary rocks
sticks up through the Quaternary deposits.
Geomorphology. The main landforms are gently sloping
to moderately steep glacial moraines and nearly level to very gently sloping
outwash plain, lake plain, floodplain, and alluvial fans. The elevation
ranges from 6230 feet along the shore of Lake Tahoe up to about 7500 feet.
Fluvial and lacustrine erosion and deposition are the main geomorphic processes.
Soils. The soils are mostly Entic and Pachic Xerumbrepts
on till and Alfic Xeropsamments, Entic Xerumbrepts, and Aquic Cryumbrepts
on alluvial deposits. The soils are mostly well to somewhat poorly
drained with some poorly drained soils. Soil temperature regimes
are mostly frigid, but cryic in somewhat poorly drained soils.
Soil moisture regimes are mostly xeric, with some aquic.
Vegetation. The predominant natural plant communities
on well drained soils are Jeffrey pine series and White fir series, with
the latter increasing in dominance toward the west. Sedge meadow
communities and Willow thickets predominate in wet areas, with Lodgepole
pine series around the margins of wet areas. Aspen series occurs
in moist habitats.
Characteristic series by lifeform include:
Climate. The mean annual precipitation is about 20 to 30 inches;
most of it falls as snow. Mean annual temperature is about 40°
to 45° F. The mean freeze-free period is in the range from 50
to 75 days.
Grasslands: Ashy ryegrass series, Breaked sedge series, Idaho
fescue series, Montane meadow habitat, Needle-and-thread series, Rocky
Mountain sedge series.
Shrublands: Big sagebrush series, Bitterbrush series, Low sagebrush
series, Rubber rabbitbrush series.
Forests and woodlands: Aspen series, Jeffrey pine series, Lodgepole
pine series, White fir series.