Geoscience Reference
In-Depth Information
A
B
Figure 17-16.
Vegetation of the cottongrass mire. A. Tall cottongrass,
Eriophorum angustifolium
. The cottongrass is
scattered among
Carex limosa
(mud sedge) around the margin of the fen. B. Green moss growing on a microbump
just above water level. Photos by J.S. Aber.
Figure 17-17.
Central portion of beaver mire looking toward the northwest. Dead spruce trees to right side grew
on an old beaver dam. Location of soil-temperature data logger marked by asterisk (*). Photo by J.S. Aber from a
tree on the southeastern edge of the mire.
shadow exists. Average annual precipitation is
in the range 6-10 inches (
The Rio Grande drains the southern part of
the valley, entering from the west and exiting
southward through a gorge in volcanic rocks
along the Colorado-New Mexico border. The
northern portion of the San Luis Valley is a
closed depression, however, with no surface
outlet for drainage (Fig. 17-20). Surface runoff
from the Sangre de Cristos and San Juans soaks
15-25 cm) at most
reporting stations (High Plains Regional Climate
Center 2011). Nonetheless, water is abundant in
the San Luis Valley. Surface and ground water
are derived from spring snow melt and summer
monsoon thunderstorms in the adjacent
mountains.
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