THE NORTH AMERICAN GREAT BASIN:
(All photos by P. Wigand - left to right):
1) Columbus Saltmarsh, 2) Carson Sink and the Stillwater Range, 3) Lower Pahranagat Lake and the Pahranagat Range, 4) the South Snake Range
Investigations into the ecological history
of the Intermountain West of North America.
or
What fossil pollen and ancient woodrat nests tell us
about past vegetation history and climate.
By Peter E. Wigand (in consultation with Liesl Wigand)
What environments are found in the Great Basin today?
Are they different from those that the first Americans encountered or
from those that were here when the Columbian Mammoth roamed the lake basins of the West?
What is a sagebrush steppe or a semi-arid woodland?
The Great Basin is a land of high valleys and north/south trending mountain ranges that lies between the Rocky Mountains on the east and
the Sierra Nevada Mountains on the west. Most of the region lies just below or just above a mile high. In just a few miles one can travel from
valley floors around 4,500 feet to mountain tops over 11,000 feet and higher. This diversity of topography has given rise to a mosaic of
habitats that provide both home and refuge to a great variety of plant species. The rain-shadow created by the Sierra Nevada is felt
throughout the area except on the tops of the highest mountain ranges. Influenced by Pacific storms in the winter and spring, monsoonal
rains in the middle to late summer, and occasional cold, Arctic outbreaks in the depths of winter a climate of great extremes has come to
characterize the region. This harsh climate has bred a very hardy vegetation type that can survive both its hot, dry summers and its cold, dry
winters. Great Basin vegetation runs the range from valley floor salt desert shrub communities to subalpine and alpine grasslands. Between
these two extremes lie semi-arid and subalpine, and occasionally, montañe woodlands all with a diverse and often beautiful understory filled
with wild flowers. In the wetter regions the shrub steppes are grassy, in the drier areas they are not. Marshes often fill the basins below the
tallest and wettest of the Basin mountain ranges. At low elevations native grasses and other plants have succumbed to invading cheat grass
and other Eurasian plant species that follow in the wake of cattle. At higher elevations native plants still stave-off the invader.
Web pages composed by Peter E. Wigand / e-mail to: pewigand@yahoo.com Last modified: March 3, 2006
