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1.1L

Ecological site EX043B05C122

Loamy Bighorn Mountains Sub-alpine Zone

Home / Esd catalog / MLRA 043B / Ecological site EX043B05C122
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T 1-2 - Non-use (lack of use) or lack of fire allows Mountain big sagebrush to increase in crown cover and density, making the transition to the sagebrush/mixed grass state. Heavy, continuous season-long grazing and no fire will shift this state to the mixed shrubs/forbs community within state 2.
T 1-3 - Disturbance of the reference site will encourage the establishment of noxious weeds if a seed source is present. Heavy use, trailing or access roads/routes, as well as drought, season-long use, or impact of insects/disease can open the canopy to non-native/invader species.
R 2-1 - Grazing management and possibly brush management with prescribed fire or chemical control may be needed reduce the woody overstory and allow the grasses to recover.
T 2-3 - Once a site has transitioned to this state, the increased bare ground and weakened plant structure leaves the community vulnerable to encroachment or species creep by non-native species such as Kentucky bluegrass, dandelions, smooth brome, and in some instances conifers. Control of these species is difficult and complete eradication may not be possible.
T 4-5 - Planned disturbances, seeding, or development activities provides the open niche for invasive species to invade a location. Ground disturbance of a site will encourage weedy species, especially when introduced into the system on equipment.

State 1 submodel, plant communities

CP 2.1-2.2 - Drought, season-long use or other disturbances impact grass/grass-like cover and encourage forbs as well as woody species.
CP 2.2-2.1 - Targeted rest/deferred grazing or rotational grazing will help to manage the forb component and will encourage the grasses/grass-like species aiding in the shift back to the 2.1 community.
CP 3.1-3.2 - Non-native species seeds utilize the weakened condition of the encroached community to establish a foothold.
CP 3.1-3.3 - The mechanism driving woody encroachment provides the opportunity for invasive species establishment. Drought, human impact, or animal disturbance can exacerbate this transition.
CP 3.2-3.3 - The encroachment of non-native species provides the opportunity for more aggressive invasive species to take over a community. Drought, human or animal disturbance can exacerbate this transition.
CP 4.1-4.2 - Completion of a re-vegetation project with seeding, integrated pest management, and long-term prescribed grazing or other managed use of a landscape is needed to shift a disturbed community back to a representative or functional plant community.
CP 4.2-4.1 - If a reclaimed/restored site is not managed for the established community, the community will revert back or will fail to establish converting once again to the degraded community phase. Lack of management can include non-use, loss of natural disturbance regimes, or over-use by large herbivores or humans.