Desert Shrublands and Playas - Mountains and Plains: The Ecology of Wyoming Landscapes - page 141

be occasional periods of high precipitation, but the dry
periods are likely to be longer than during the past cen-
tury, and more of the annual precipitation will come as
rain rather than snow. Big sagebrush in Wyoming and
the region will become less common if deep soil water
recharge is inadequate. Most likely, desert plants will
expand to occupy some land now dominated by sage-
brush. other changes in plant species composition will
occur as well. For example, already endangered species,
such as the greater sage-grouse, will lose some of their
habitat as big sagebrush declines, and cheatgrass will
become more common and will occupy a larger area,
very likely surviving the droughts (because it grows pri-
marily in late fall and early spring, when sufficient mois-
ture probably will be available). the increased biomass
of cheatgrass will probably increase fire frequency, caus-
ing further declines in big sagebrush. carrying capacity
for big game and livestock in the intermountain basins
will then decline.

Whether disturbed by excessive livestock grazing or
industrial developments, the restoration of desert eco-
systems is difficult. even under experimental conditions,
new seedlings typically do not survive, and the devel-
opment of new soil crusts takes 10 years or more. Soil
erosion occurs with less plant cover, leading to the for-
mation of desert pavement and coppice dunes. Warmer
temperatures will make reclamation even more difficult
and most likely will cause a decline in the amount of
soil organic matter, making the soils still more erodible
and a source of atmospheric carbon dioxide—thereby
negating attempts to sequester carbon in terrestrial
ecosystems. the desert shrublands of the twenty-first
century—and the way they are used—are likely to be
considerably different than during the twentieth cen-
tury, primarily because of mistaken assumptions about
livestock management in the late 1800s, the invasion of
cheatgrass shortly thereafter, and the climate changes
now under way.