Marshy

Description

On soils having a mesic soil temperature regime, Baltic rush and Nebraska sedge are subordinate to Western Wheatgrass and are aggregated in colonies only in wetter depressions. Orange arnica, silverweed and small bedstraw are typical forbs of more mesic sites. On the drier precipitation range of this site Nevada bluegrass, Beardless wildrye (creeping wildrye), western yarrow and rose pussytoes are subordinate to tufted hairgrass. If the condition of this site deteriorates as a result of overgrazing, Western wheatgrass decreases and becomes co-dominant with other grasses, sedges and forbs. Baltic rush, sedges or reedgrass become more dominant, with large colonies of arnica, and silverweed occurring on the more mesic sites.

With overgrazing on soils having a mesic soil temperature regime, Nebraska sedge is capable of becoming dominant. On the drier precipitation range of this site, prairie junegrass and oatgrass along with yarrow, aster, cinquefoil and buttercups increase. With lowering of the water table Kentucky bluegrass can become naturalized and become co-dominant with mat muhly. Severe stream entrenchment may change the stand composition to upland species such as big sagebrush, grey rabbitbrush and annual weeds. Foxtail barley, squirreltail, lupine, dock and thistle are likely to invade.

This site is used for livestock grazing and wildlife habitat. The historic climax vegetation is rush, sedge, western wheatgrass, bluejoint. Dynamics of the site revolve around available moisture and drainage and deposits of alluvial material and scouring when the intermittent stream moves the channel. These events add or subtract soil and nutrients from the site. They also change the hydrology either adding water, ponding longer or the site drys out resulting in species shifts. The shallow water almost year round makes this a highly productive and resilient site. Most of the communities in this site are in the reference state. A major long term shift in hydrology is needed to change states.

Submodel

Description

The current potential state is similar in structure and function to the reference state, however invasive and non-natives species are present in all community phases. The current potential state is generally dominated by perennial grasses. Kentucky bluegrass can become a dominant in this plant community. The current potential state is less resilient than the reference state due to the presence of non-native/invasive species in the plant community. Annual herbaceous weedy plants have increased, but occur in small patches. Invasive species present can include knapweeds, Canada thistle, and curly dock.

Submodel

Description

This state results from seeding introduced perennial grasses. Some of the potential grass found may include the following: meadow foxtail, orchardgrass, meadow barley, timothy and smooth brome. Native perennial grasses, forbs and shrubs may be included in the seed mix. This state behave similar community dynamics to the current potential state community. Other vegetation treatments may be necessary to get to this state, they include mowing, disking, prescribed burning and other techniques which manipulate the plant community. The seeded state could persist for long periods of time with proper management. Native grasses and forbs may reestablish over time from nearby seed sources.

Submodel