Sagebrush - Mountains and Plains: The Ecology of Wyoming Landscapes - page 122

Fig. 7.11. the growth of grasses and
forbs increases greatly after big sage-
brush is reduced by burning, as in this
area northwest of Rock Springs. the
vegetation on the left provides more
forage for livestock but is less favorable
for sage-grouse. Burning sagebrush can
favor the establishment of cheatgrass
and other invasive plants (see fig. 7.13).

For herbaceous plants in the sagebrush ecosystem,
susceptibility to fire-caused mortality seems to depend
on the amount of fuel that has accumulated above the
root crowns, the depth of the latent buds below the soil
surface, and the stage of growth at the time of burn-
ing. Some research suggests that western wheatgrass
vigor and production increase with spring burning but
decline with fall burning, and that burning at any time
reduces the productivity of needle-and-thread grass. 66
Repeated burning in consecutive years can cause a
shift from a community dominated by both cool- and
warm-season species to one dominated primarily by
warm-season species, which are generally more fire
tolerant. this shift in dominance can be significant to
land managers if early-season production is viewed as

a critical resource, whether for livestock or big game.
Burning sagebrush may be useful, but it should be done
only in the context of management plans and after
careful consideration of the undesirable changes that
could result, including the spread of invasive plants and
undesirable effects on sagebrush obligate animals, such
as sage-grouse. 67

Cheatgrass

though problematic for some sagebrush-dependent
animals, prescribed fire simulates a natural distur-
bance to which many native plant species are adapted.
older shrubs are removed and herbaceous production
increases. Unfortunately, invasive plants also may ben-