State 1
Grassland

This state is dominated by grasses.

Community 1.1
Grassland

In the reference plant community, sand bluestem and big bluestem are the dominant grasses with sideoats grama, little bluestem, blue grama, and dropseeds occurring as sub-dominants. Other grasses that can occur in significant amounts include black grama and Indian ricegrass. This site will support a wide variety of woody species although they are a minor component of the reference plant community. At higher elevations, pinyon and juniper are favored, whereas yucca, fourwing saltbush, and sand sagebrush are more typical of lower elevations. Although forbs are usually a minor component, during years of abundant rainfall, their production may increase significantly. Continuous grazing pressure can cause a decrease in bluestems, sideoats grama, and Indian ricegrass, resulting in communities dominated by blue grama, with hairy grama and threeawns occurring as sub-dominants. Diagnosis: Grass and litter cover is typically uniform with few large (greater than 1 meter) bare areas present. Blue grama exhibits an upright, bunchgrass form. Grass species such as sand bluestem, big bluestem, little bluestem, sideoats grama, and sand dropseed, are present in significant amounts. Shrubs and trees are a scattered with a combined canopy cover of less than 10 percent. Evidence of erosion is minimal.

Forest understory. Other grasses that could appear on this site include: cane bluestem, mesa dropseed, threeawn spp., green sprangletop, bottlebrush squirreltail, mat muhly, plains lovegrass, purple lovegrass, bush muhly and tumble windmillgrass. Other shrubs that could appear on this site include: rabbitbrush, broom snakeweed, pinyon, Bigelow sagebrush, cacti spp. and catclaw acacia. Other forbs that could appear on this site include: larkspur, purple nightshade, salsify, curly dock, Indian paintbrush, scarlet globemallow, Rocky Mountain beeplant, threadleaf groundsel, wooly Indianwheat, tansymustard and Russian thistle.

State 2
Blue Grama-Sod

This state is characterized by abundant, sod-bound blue grama.

Community 2.1
Blue grama-Sod

Under continuous grazing pressure without adequate recovery periods, blue grama may form a less productive, low growing sod. Grass species such as big bluestem, sand bluestem, little bluestem, sideoats grama, and Indian ricegrass are present only in trace amounts or are absent. Threeawns, ring muhly, and buffalograss typically increase in representation. In some instances, broom snakeweed may be a major component in response to increased amounts of fall or early spring moisture. Diagnosis: Blue grama is the dominant grass. It exhibits a low-growing, sod-like growth form. Black grama, sideoats grama, and New Mexico feathergrass are either sparsely represented or absent. Transition to Blue Grama-Sod (1a) Continuous grazing without adequate recovery periods may cause this transition. Blue grama is resilient to grazing due to the location of its growing points at or near the soil surface and high ratio of vegetative shoots. When grazed or clipped close to the ground, it can spread laterally by tillers and form a less-productive, low-growing sod. Key indicators of approach to transition: Decrease in cover of black and sideoats grama Increase in cover of blue grama Transition back to Grassland (1b) Long term prescribed grazing may be successful in reversing the transition back to a Grassland state. The timeframe is affected by the presence/absence and the recruitment of key species such as bluestems, sideoats grama, and Indian ricegrass. Alternatively, chemical or mechanical treatment of the portion of the range dominated by blue grama may reduce competition for nutrients and available water. This may accelerate the change back to a more upright, bunchgrass form and increase production. Seeding may be necessary to reestablish desired key species where they are sparse or absent. Prescribed grazing will help to maintain proper forage utilization.

State 3
Pinyon/Juniper Encroached

This state contains considerable amounts of pinyon/juniper.

Community 3.1
Pinyon/Juniper Encroached

An increase in pinyon and/or juniper and decreased cover and production of grasses characterize this state. Blue grama is the dominant grass. Other species that are typically present in varying amounts include hairy grama, ring muhly, galleta, buffalograss, threeawns, and sand dropseed. Diagnosis: Pinyon/juniper is present in significant amounts. Blue grama is the dominant grass. Grass cover is variable ranging from fairly uniform to patchy with large bare areas present. Evidence of erosion such as elongated water flow patterns, pedestalling of plants, and rills may be common. Transition to Pinyon/Juniper Encroached (2, 3a) Loss of grass cover, the associated decreased competition by grasses, seed dispersal, and lack of fire are believed to facilitate the encroachment of piñon/juniper. Loss of herbaceous cover due to overgrazing and drought can provide competition-free areas for seedling establishment, and afford a competitive advantage to established woody species. Wildlife and livestock can act as dispersal agents for pinyon/juniper seed and increase the probability of invasion. Sites in close proximity to established pinyon/juniper woodlands are at greater risk of invasion. Historically, periodic fire may have helped to suppress pinyon/juniper by killing seedlings and some established trees, and by increasing the susceptibility in others to damage by insects, disease, and drought. Additionally, variation in precipitation patterns such as periods of mild wet winters may produce conditions favorable to the establishment and growth of woody species, initiating periods of increased recruitment and establishment. Key indicators of approach to transition: Increase in bare ground patch size Increase in amount of piñon/juniper seedlings Transition back to Grassland (3b) Brush control is necessary to reduce the competitive influence of pinyon/juniper and facilitate grass recovery. Prescribed fire may be useful in maintaining grass dominance, provided adequate fine fuels remain. Prescribed grazing will help ensure adequate rest following brush control and will assist in the establishment and maintenance of grass cover.