NEPA--Environmental Assessment

Red Mountain Allotment
Yellow toadflax occurs in the vicinity of the substation along Mineral Creek. Treatment is ongoing
and eradication of this site is expected.
West Lime Allotment
Noxious weed treatment in this area has been concentrated along the roads. Yellow toadflax occurs
in isolated patches along the South Mineral and Clear Lake roads, with scatterings of Canada thistle
occurring at dispersed campsites along roads. Treatment will continue to occur for many years
before containment is expected.
Summary Of Noxious Weeds Conditions
Noxious weed will continue to be a problem in this landscape. Treatment will continue to be
concentrated along travel corridors and other areas accessible by spray equipment. Biological
control using insects will not be utilized over much of the landscape in that patches of sufficient size
and density due not exist to support the insects. However, as situations evolve where insects will be
appropriate that may be used. It is unlikely that noxious weeds will be eradicated, but instead,
managed to an acceptable level over time.
ENVIRONMENTAL CONSEQUENCES
This section focuses on the vegetation and soils of the alpine zone (the alpine major vegetation type)
within the project area, since this is the area most affected by sheep grazing. Vegetation and soils of
the other vegetation types of the project area display no effects or only minor adverse effects from
sheep grazing.
Alternative 1 –No Action
Under this alternative, livestock grazing would not occur so there would be no direct livestockinduced
effects to the vegetation and soils of the project area, including those of riparian areas and
wetlands. The existing plant communities would proceed along their current successional pathways,
which would bring about changes in their composition, structure, and function. As is the case for all
alternatives, natural disturbances including fire, disease, insects, and weather events are likely to
occur and change ecological conditions in the vegetation types of the project area.
The vegetation types of the project area would benefit from reduced livestock grazing intensity
(Holechek 1981, McNaughton 1983) since grazing and overgrazing by sheep, and sheep impacts
from trailing and bedgrounds would not occur. Grazing intensity is defined by Holechek et al. 1998
as the cumulative effects grazing animals have on rangelands during a particular time period. This
would allow native forage plants (particularly forbs) to increase their vigor and root reserves, which
would increase their chances for survival by increasing their ability to reproduce, compete, and
withstand drought, disease, fire, and grazing (Heitschmidt and Stuth 1993). An increase in the
abundance and vigor of plant species would increase the amount of ground cover (vegetation and
litter), which would likely increase infiltration, and decrease runoff and erosion.
This alternative would result in improved ecological conditions compared to current conditions,
since the sites where adverse effects from sheep trailing and sheep bedding are occurring would
likely improve. Also under this alternative, the desired conditions for BLM lands and Forest Service
lands would continue to be met.
Noxious weeds would continue to be present in the analysis area under this alternative. Permitted
livestock would no longer contribute to the spread of noxious weeds, but recreational stock, wildlife
and a wide variety of other sources would continue to spread noxious weeds. The spread of
populations would be more dependent upon treatment intensity than upon livestock grazing.
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