Upland Gravelly Loam (Bonneville big sagebrush)

Description

This state includes the plant communities that were best adapted to the unique combination of factors associated with this ecological site prior to European settlement. It was in a natural dynamic equilibrium with the historic biotic, abiotic, climatic factors on its ecological site in North America at the time of European immigration and settlement. This dominant aspect of the plant community is Bonneville big sagebrush and bluebunch wheatgrass. The community is made up of 55 percent grasses, 25 percent forbs, and 20 percent shrubs on a dry weight base.

All of these scenarios are very interrelated and dependent on weather patterns and events as well as fire frequency and intensity. The fire frequency should be around 30 to 55 years. Any set of events that are strong enough to force the plant community out of this pattern can push it over a threshold and into another state.

Submodel

Description

This state includes the biotic communities that would become established on the ecological site if all successional sequences were completed without interferences by man under the present environmental conditions. Natural disturbances are inherent in its development. The Current Potential State (CPS) will include acclimatized, naturalized or invasive nonnative species. There is no known way to effectively remove these plants from the site once they have become established. The level of occurrence of these plants in the CPS is such that careful management can prevent their domination of the site. This site is irreversibly changed. Plant communities within the CPS state may be managed and used for various purposes by man without significant alteration in plant community composition or production. It includes all of the plant communities that exist in the RPC state with the inclusion of species that are non-native to this ESD. These non-native plants are not to be considered when considering plants for the rangeland health site evaluation.

The initial Plant List of Grasses and Forbs will be quite accurate in this community also. This community will likely have around 15 to 20 percent bare ground and surface rock fragments.

All of these scenarios are very interrelated and dependent on weather patterns and events as well as fire frequency and intensity. The fire frequency should be around 30 to 55 years. Any set of events that are strong enough to force the plant community out of this pattern can push it over a threshold and push it into another state.

Submodel

Description

This state has only two described plant communities but many variations of the represented ones are present. The lack of fire with a source of Utah Juniper and maybe a source of pinyon seed insight the move to this state. Movement from community phase to community phase can and often is accelerated by overgrazing. The dominant drivers of the plant community is Utah Juniper and cheatgrass. This state can persist for a long time until extreme conditions needed for a wildfire occur or some other management treatment is implemented.

Submodel

Description

This is the state that this plant community will move to when it is in an over-grazed or drought condition and then burned (wild or controlled) and not seeded. The dominant aspect of the plant community is cheatgrass, yellow rabbitbrush with a very small amount of Bonneville big sagebrush. The community will usually be made up of 70 percent cheatgrass, 10 percent forbs, and 20 percent yellow rabbitbrush with minor components of other shrubs.

Submodel

Description

This state exists when the site is cultivated or burned, and planted to introduced and, in some situations, native grasses and forbs.

Submodel