State 1
Historic Climax Plant Community

Community 1.1
Historic Climax Plant Community

State Containing Historic Climax Plant Grassland State: The historic plant community is dominated by alkali sacaton with western wheatgrass occurring as the sub-dominant. Other important grasses that typically appear on this site include blue grama, galleta, vine mesquite, spike muhly, and bottlebrush squirreltail. Fourwing saltbush is the dominant shrub. Rabbitbrush, broom snakeweed, and spineless horsebrush may also be sparsely scattered across the site. Continuous heavy grazing will cause a decrease in western wheatgrass and vine mesquite. A community dominated by alkali sacaton with blue grama or galleta as the sub-dominant may result. If the site continues to decline, blue grama may eventually dominate. Diagnosis: Grass cover is uniform with few large bare areas present. Shrubs are scattered with canopy cover averaging six percent or less. Evidence of erosion, including pedestalling of grasses, rills and gullies is infrequent.

State 2
Dry Grassland

Community 2.1
Dry Grassland

Additional States: Dry Grassland: This site is characterized by decreased available soil moisture. Typically galleta or blue grama is the dominant grass species. Alkali sacaton if present is generally found in clumps or tussocks with interconnected bare areas between plants, or in patches on wetter low spots. Diagnosis: Grass cover is variable ranging from relatively uniform to patchy with large interconnected bare areas present. Blue grama or galleta is the dominant grass species. Rills, gullies, or obstructions to overland flow are present. Transition to Dry Grassland (1a): Soil drying due to blocked or redirected flow of run-on water, loss of grass cover, or gullying are thought to initiate this transition. Water retention or diversion structures, sediment deposition, or roads may block or divert water that would naturally flow onto the site. Roads or trails may concentrate water during high flow periods and facilitate gully formation. Loss of adequate grass cover due to overgrazing can decrease infiltration, increase flow rates, and initiate gullying. Key indicators of approach to transition: * Reduction in western wheatgrass and alkali sacaton cover * Increase in size and frequency of bare patches. * Increase in cover of blue grama, galleta, ring muhly and mat muhly. * The formation of trails, gullies or other features that disrupts natural overland flow Transition back to Grassland (1b) The natural hydrology of the site must be restored. Erosion control structures, shaping or filling gullies, culverts, turnouts, or moving or re-routing obstructions may be necessary to restore natural run-on flow patterns. Prescribed grazing will help restore and maintain adequate grass cover.

State 3
Shrub-Dominated

Community 3.1
Shrub-Dominated

Shrub-Dominated: This state is characterized by the predominance of shrubs, especially rabbitbrush. Spineless horsebrush and broom snakeweed may also increase in representation. Blue grama, galleta, and alkali sacaton are typically the dominant grass species, however, alkali sacaton may be sparse if the transition to this state was from the Dry Grassland. Diagnosis: Rabbitbrush is found at increased densities relative to the Grassland state. Grass cover is patchy with large bare areas present. Evidence of erosion including pedestalling of plants, elongated water flow patterns, and litter dams is common. Rills or gullies may be present. Transition to Shrub-Dominated (2, 3a) Loss of grass cover and resulting decreased competition by grasses is believed to Initiate this transition. The loss of grass cover may be due to a change in hydrology, overgrazing, or other disturbance such as fire. Rabbitbrush is believed to increase under heavy grazing pressure4 and after 1-3 years following fire5. Key indicators of approach to transition: * Change in composition or distribution of grass cover. * Increase in size and frequency of bare patches. * Increase in amount of shrub seedlings. Transition back to Grassland (3b) Brush control is necessary to initiate the transition back to the grassland state. Chemical control has been shown to be effective in controlling rabbitbrush. 1, 3 Prescribed grazing will help ensure adequate deferment period following brush control and will assist in the establishment and aintenance of grass cover. In addition the natural hydrology of the site must be restored if the transition pathway was from Dry Grassland to Shrub-Dominated (2). See Transition Back to Grassland (1b).

State 4
Bare State

Community 4.1
Bare State

Bare State: Extensive areas of bare ground characterize this site. Surface soils in most bare areas are sealed over with physical crusts. Herbaceous cover consists mainly of annuals. If perennial grasses are present they occur only in isolated patches. Diagnosis: Annuals are the dominant herbaceous vegetation. Extensive interconnected bare areas are common with scattered or no grass plants. Evidence of erosion such as rills and gullies are present. Transition to Bare State (4) The continued loss of remaining grass cover due to overgrazing or soil drying may cause this transition. The subsequent sealing of the soil surface by physical crusts can inhibit grass reestablishment.2 Additionally, heavy use by livestock during periods when the soils are saturated can cause trampling damage and soil compaction. Soil compaction decreases infiltration limiting grass reestablishment. Transition back to Grassland (5) The hydrology of the site must be restored first (see 1b). Seeding may be necessary to reestablish bottomland grasses. Prescribed grazing will help restore and maintain adequate grass cover, and facilitate recovery of compacted soils. The degree to which this site is capable of recovery depends on the restoration of hydrology, the extent of degradation to soil resources, and adequate rainfall necessary to establish grasses.