Mojave River Valley Museum
Ecological Sections: Sierra Nevada - (MAP)
This subsection is the higher part of a granitic pluton and surrounding
rocks in the vicinity of Bucks Lake. It has a temperate to cold,
humid climate. MLRAs 22c and 22d.
Lithology and Stratigraphy. Mesozoic granitic rocks
predominate in this subsection. Also, there are Paleozoic marine
sedimentary and metavolcanic rocks. Quaternary alluvium and glacial
till are present, but not extensive.
Geomorphology. This subsection is on a gently sloping
to moderately steep plateau that is bisected by the North Fork of the Feather
River. The North Fork has cut across the plateau and runs in the
bottom of a very steep sided canyon, about 2000 to 4000 feet below the
plateau surface. Higher parts of the plateau and the northern edge
of it were glaciated during the Pleistocene. The elevation ranges
from about 2000 feet along Feather River up to 7176 feet on Bald Eagle
Hill. Fluvial erosion and, in the Feather River canyon, mass
wasting are the main geomorphic processes.
Soils. The soils on granitic rocks are mostly Dystric,
Lithic, and shallow Typic Xeropsamments and Typic and Dystric Xerochrepts.
On other kinds of rocks they are mostly Dystric Xerochrepts; Andic Xerumbrepts;
Lithic Ultic and Ultic Haploxerolls; and Ultic Haploxeralfs. The
soils are well drained. Soil temperature regimes are frigid on the
plateau and mostly mesic in the canyon of the Feather River. Soil
moisture regimes are mostly xeric.
Vegetation. The predominant natural plant communities
are Mixed conifer series and White fir series. Jeffrey pine series
is common in glacially eroded, or scoured, terrain. There is some
Red fir series at higher elevations. Huckleberry oak series occurs
on very stony colluvium, or talus. Wet areas with Sedge meadow communities
and Mountain alder series or Lodgepole pine series are common, but not
Characteristic series by lifeform include:
Climate. The mean annual precipitation is about 60 to 90 inches.
Much of the precipitation is snow; it is mostly snow on the high plateau.
Mean annual temperature is about 40° to 55° F. The mean freeze-free
period is about 50 to 150 days.
Grasslands: Ashy ryegrass series, Green fescue series, Idaho
fescue series, Montane meadow habitat, Nebraska sedge series, Needle-and-thread
series, Rocky Mountain sedge series.
Shrublands: Bush chinquapin series, Deerbrush series, Greenleaf
manzanita series, Huckleberry oak series, , Mountain whitethorn series,
Tobacco brush series, Wedgeleaf ceanothus series.
Forests and woodlands: Douglas-fir series, Douglas-fir - Ponderosa
pine series, Douglas-fir - tanoak series, Incense-cedar series, Jeffrey
pine series, Lodgepine pine series, Mixed conifer series, Red fir series,
Western white pine series, White fir series.
Surface Water. Runoff is rapid from most of the area.
Most of the runoff flows to the North Fork of the Feather River or its
tributaries. There are some small lakes, or ponds, in the glaciated
terrain, and a large reservoir (Bucks Lake).