Ecology

Introduction to the Great Basin

This is my first week of work and it began with some background history about the region I will be working in, which is the Great Basin.

The Basin and Range province is 300,000 square miles. It is bordered by the Sierra Nevada and southern Cascade mountains to the west and the Wasatch mountains to the east.

It’s characterized by it’s geology, climate, and vegetation. The basins, mountains, and plateaus are at elevations of 1,300 to 10,000 ft. The region has an accordion shape with its high-low-high-low elevation patterns due to the faults that run north to south.

As the earth’s crust moved over time, it became stretched and thinned to the point where it became fractured by faults. This created normal faults and as the crust continued to move, the basin developed.

The common soil orders found in the area are mollisols, aridisols, and entisols. The mollisols are highly fertile, rich, and fairly rare. The aridisols are associated with grasslands, and contain salt, gypsum, and carbonites which impact plant growth. The entisols are young and undifferentiated.

The basins contain alluvium and playa lakebed deposits. The foothills and mountains contain volcanic rock (basalt, andesite, and rhyolite).

There are large seasonal and diurnal fluctuations in temperature and variable precipitation patterns. A co-worker said that he’s seen snow in every month of the year here and desert temperatures can reach the hundreds and drop back down to the thirties at night. Air masses west of the Sierras are more moist, but cool and lose moisture when they hit the Cascades.

Climate change has caused region-wide warming of 0.3-0.6 degrees Celsius in the past 100 years alone.

The lower elevation areas are composed of basins that are mesic/aridic and desert shrubland. The higher elevations are mountainous. The mountain ranges are separated by flat desert plains and basins.

The Great Basin is a sagebrush dominated, wildfire-adapted system. The species composition changes more dramatically with elevation and landscape position. Think basins, foothills, and mountains.

Pinyon-juniper is found at lower elevations and forested communities are at higher elevations. There are also displays of evolutionary isolation due to geologic forces, akin to a series of mountain islands in a desert sea valley, as valleys are barriers to movement.

70% of all North American mammals are found in this region. Our particular program focuses on vegetation and soil monitoring to use for managing sage-grouse habitat.

The Great Basin was inhabited for several thousands of years by the Shoshone, Ute, Goshute, Paiute, and Washoe. European colonization began in the 18th century by the Spaniards. There were 3 distinct cultural manifestations in this region, the Paleo-Indian, Archaic, and Fremont.

Public lands make up 70% (114 million acres) of the Great Basin, and a majority is grazing allotment.

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