Mountain Meadows and Snowglades - Mountains and Plains: The Ecology of Wyoming Landscapes - page 227

higher in the mountain meadows because of the variety
of plant communities that occur up and down moun-
tain slopes. 15 essentially, there is a wave of new plant
growth that the animals can follow, from the lowlands
in the spring to the high mountain meadows later in
the summer. Because of topographic diversity and dif-
ferent amounts of snow accumulation, a supply of green
forage almost always exists nearby.
Livestock managers have learned that the initiation
and duration of grazing is important to consider when
developing management plans. Ranchers prefer to rest
their low-elevation rangelands in the spring, when
plants there are actively growing and are most suscep-
tible to damage from grazing. consequently, they want
to move livestock onto the mountain meadows as soon
as possible. the trick is to move the animals at a time
when the soils are not so wet that damage from tram-
pling occurs. Moreover, just as in the lowlands, the
mountain plants are subject to stress if grazed exces-
sively in the early stages of their growth . 16
today, the grazing of mountain meadows is restricted
in many areas to a shorter summer period than in the
early 1900s. Fewer animals are permitted on federal
land, and often a shepherd must be employed to keep
the animals—especially sheep—from grazing specific
areas excessively. As a result, some ranchers now find
it uneconomical to move their livestock to the moun-
tains for such a short time, often midsummer to early
fall. Also, the amount of land area in meadows has
declined over the years in some areas, owing to fire sup-
pression and the subsequent expansion of trees. this
trend might be especially apparent in mountain ranges
that were subject to considerable burning or tree cut-
ting in the late 1800s and early 1900s. the best example
in Wyoming may be the Sierra Madre, where extensive
timber harvesting in conjunction with copper mining
created large areas of open rangeland. now much of this
area is again forested.
overall, mountain meadows are widely appreciated
for the benefits they provide in terms of livestock for-
age and water yield. As important, the edge between the
forest and meadow provides habitat for many birds and
mammals. trees have invaded some meadows, but only
rarely are forests converted to meadows after fire or tim-
ber harvesting. Shifts in the location of forest-meadow
boundaries may be an indication of climate change.

Fig. 13.7. At high elevations with strong winter winds, such
as in this area north of Medicine Bow Peak, parallel ribbons
of trees and snowglades sometimes develop. the trees are
predominantly engelmann spruce and subalpine fir. See fig.
10.13 for a photo of an aspen atoll, caused by the effects of
blowing snow at lower elevations. Photo by William K. Smith.

water-yield ecosystem, in which most of the snow accu-
mulates where there is comparatively little use of that
water by plants. not surprisingly, a common practice of
watershed hydrologists desiring to increase streamflow
is to create small openings in the forest, where snow
can accumulate in much the same way (see chapter 12).

Livestock Grazing on Mountain Meadows

Mountain meadows have long been an important com-
ponent of the summer range for elk and deer, and for a
century or more many ranchers have come to depend
on such meadows for supplemental livestock forage.
Using the meadows in this way during the summer pro-
vides a period of rest for rangelands in the valleys below.
the carrying capacity for both wildlife and livestock is