State 1
Needleandthread/Prairie sandreed Plant Community

Community 1.1
Needleandthread/Prairie sandreed Plant Community

The interpretive plant community for this site is the Historic Climax Plant Community. This state evolved with grazing by large herbivores and periodic fires. The cyclical natural of the fire regime in this community prevented big sagebrush from being the dominant landscape. This plant community can be found on areas that are properly managed with grazing and/or prescribed burning, and on areas receiving occasional short periods of rest. The state is a mix of warm and cool season mid and tall grasses. Potential vegetation is about 70% grasses or grass-like plants, 10% forbs, and 20% woody plants. The major grasses include needleandthread, prairie sandreed, and Indian ricegrass. Other grasses occurring in the state include rhizomatous wheatgrasses, Sandberg bluegrass, blue grama and red threeawn. Fourwing saltbush, winterfat and silver and big sagebrush are conspicuous components of this state. A variety of forbs also occurs in this state and plant diversity is high (see Plant Composition Table). The total annual production (air-dry weight) of this state is about 500 pounds per acre, but it can range from about 350 lbs. /acre in unfavorable years to about 700 lbs. /acre in above average years. The state is stable and well adapted to the Northern Intermountain Desertic Basins climatic conditions. The diversity in plant species allows for high drought resistance. This is a sustainable plant community (site/soil stability, watershed function, and biologic integrity). Transitions or pathways leading to other plant communities are as follows: • Moderate, Continuous Season-Long grazing will convert the plant community to the Perennial Grass/Mixed Shrub Plant Community. Prolonged drought will exacerbate this transition.

State 2
Perennial Grass/Mixed Shrub Plant Community

Community 2.1
Perennial Grass/Mixed Shrub Plant Community

Historically, this plant community evolved under grazing by bison and a low fire frequency. Currently, this site normally is found under a moderate, season-long grazing regime and extended periods without fire is now common. Prolonged drought can also play an important role under these grazing regimes and will exacerbate these conditions. Shrubs such as silver and big sagebrushes, yucca, and green rabbitbrush, make up less than 25% of the total annual production. Mid and tall perennial grasses make up the majority of the understory with the balance made up of short, warm-season grasses, and miscellaneous forbs. The understory of grass and grass-like plants includes needleandthread, prairie sandreed, rhizomatous wheatgrasses, blue grama and red threeawn. Forbs commonly found in this plant community include scarlet globemallow, fringed sagewort, lemon scurfpea, sulfur buckwheat, sandwort, hairy goldaster, and phlox. The overstory of brush and understory of grass and forbs provide a diverse plant community. When compared to the Historic Climax Plant Community, Indian ricegrass, and winterfat have decreased. Indian ricegrass may occur in only trace amounts under the sagebrush canopy or within the patches of pricklypear. Blue grama, big and silver sagebrush, and yucca have increased. Plains pricklypear cactus will also have increased, but occurs only in small patches. The total annual production (air-dry weight) of this state is about 400 pounds per acre, but it can range from about 200 lbs. /acre in unfavorable years to about 525 lbs. /acre in above average years. This plant community is resistant to change. The herbaceous species present are well adapted to grazing; however, species composition can be altered through long-term overgrazing. The herbaceous component is mostly intact and plant vigor and replacement capabilities are sufficient. Incidence of pedestalling is minimal. Soils are mostly stable, but areas of wind-scouring and deposition are noticeable in small patches. The watershed is functioning and the biotic community is intact. Transitional pathways leading to other plant communities are as follows: • Prescribed grazing or possibly long-term prescribed grazing is needed to return this state to near Historic Climax Plant Community condition. • Frequent and severe grazing, will convert the plant community to the Blowout Dune/Mixed Shrub Plant Community.

State 3
Blowout Dune/Mixed Shrub Plant Community

Community 3.1
Blowout Dune/Mixed Shrub Plant Community

This plant community is the result of frequent and severe grazing and protection from fire. Bare sand and shrubs dominate this plant community, as the annual production of sagebrush, green rabbitbrush and yucca will exceed 25% of the total. Yucca can become a dominant plant on this site especially if browsing of the yucca during the bloom growth stage is removed. These shrub species are a significant component of the plant community and the preferred cool season grasses have been eliminated or greatly reduced. The dominant grasses are Sandberg bluegrass and blue grama. Weedy annual species such as cheatgrass, Russian thistle, kochia, and a variety of mustards may occupy the site if seed sources are available. Patches of pricklypear cactus can be noticeable. The interspaces between plants have expanded leaving the amount of bare ground more prevalent. Grass production as well as total production is significantly reduced. The total annual production (air-dry weight) of this state is about 150 pounds per acre, but it can range from about 100 lbs. /acre in unfavorable years to about 300 lbs. /acre in above average years. This plant community is relatively resistant to change. Continued frequent and severe grazing does not seem to affect the plant composition or structure of the plant community. These areas are more resistant to fire as less fine fuels are available and the bare ground between the shrub plants is increased. Plant diversity is poor. Production is reduced and plant vigor is diminished due to herbivore grazing and blowing sand, which can defoliate the vegetative parts of the grass plants. The soils are not protected from wind as erosion is accelerated and blowouts will increase. Pedestalling is pervasive and eolian deposits (dunes) form around the clumped vegetation. This situation is normally extensive. Transitions or pathways leading to other plant communities are as follows: • Deferment of use or very long-term grazing prescribed grazing, will convert this plant community to the Needleandthread/Yucca Plant Community. • Reseeding with mulch with brush management and prescribed grazing is necessary to return a protective vegetation cover to this state so as to convert this to near HCPC. The grazing prescription most commonly used is complete deferment during the growing season with limited use in the winter. This will provide as much plant litter cover as possible to protect the soil surface.

State 4
Needleandthread/Yucca Plant Community

Community 4.1
Needleandthread/Yucca Plant Community

This plant community can occur where the Blowout Dune/Mixed Shrub Plant Community is deferred from grazing or under very long term prescribed grazing practices. Shrubs and especially yucca remain a significant component of the plant community but grasses, especially needleandthread, have reestablished on the bare sands areas. Pricklypear cactus can also become established in dense patches. The shrub and yucca component is present but is mostly localized to the original areas occupied on the ridgeline of the dunes. The blowout areas and dune slopes are now mostly covered with needleandthread. Other important grasses are the rhizomatous wheatgrasses when present, threeawns, and Sandberg bluegrass. Patches of annuals such as cheatgrass and other weedy annual forbs such as halogeton, Russian thistle, and kochia, will persist on this site. Noxious weeds such as Russian knapweed may also remain if not treated. The interspaces between plants will have diminished in size. When compared with the HCPC or the Mixed Shrub/ Perennial Grass Plant Communities, the annual production is less. Most of the climax grasses are not present such as Indian ricegrass and prairie sandreed. The total annual production (air-dry weight) of this state is about 250 pounds per acre, but it can range from about 100 lbs. /acre in unfavorable years to about 325 lbs. /acre in above average years. This state is somewhat resistant to change under moderate grazing and the reestablishment of perennial mid and tall grasses is difficult in this situation. The biotic integrity of this state is minimally functional and plant diversity is moderate to low. Erosion has been diminished as the grassed areas are resistant to wind erosive processes. The remnant dune formations should not be confused with current wind erosion processes. Pedestalling is still apparent along the grassed edges, but is not progressing. Transitional pathways leading to other plant communities are as follows: • Reseeding with mulch with brush management and prescribed grazing is necessary to return a protective vegetation cover to this state so as to convert this to near HCPC. The grazing prescription most commonly used is complete deferment during the growing season with limited use in the winter. This will provide as much plant litter cover as possible to protect the soil surface. • Frequent and severe grazing will return the plant community to the Blowout Dune/Mixed Shrub Plant Community.