State 1
Reference: Saltbush / Mid-Stature Grasses

Saline Upland is a dynamic and complex concept that crossed soil textural breaks and includes a wide range of soil chemistry, that work together to create a salt-tolerant community. Field sampling cannot capture the full dynamic of the chemistry and the current lack of soil laboratory data prevents clear separation of specific characteristics. Composition and production for this state have been designed to incorporate the full range of possibilities.

Soils within the 5-9" precipitation zone, and with a wide range of alkali, saline, sodic and gypsum influences, are characterized by Gardner's saltbush dominated plant communities. These communities may also have birdfoot sagebrush, spiny hopsage, shadscale, four-wing saltbush, and in some locations greasewood; these woody species together will comprise approximately 50% of the production on the site. Soil texture will help determine what species are more apt to be on a specific site, although they do cross over. Sandy (coarse-loamy) soils support spiny hopsage and four-wing saltbush more often, where clayey (fine) soils support birdfoot sagebrush. Loamy (fine-loamy) soils tend to support for shadscale, but again many variations have been observed.

The grasses, comprising 40% of the plant community, are predominately Indian ricegrass, bottlebrush squirreltail and rhizomatous wheatgrasses. Needleandthread is incidental in this state. The forb component is minor with only 10% of the production from a few select forbs. A variety of biscuitroot/desert parsleys (Lomatiums), wild onion, milkvetches, and asters are found in this state.

Community 1.1
Reference: Saltbush / Bunchgrasses

Figure 9. Indian Ricegrass and wheatgrass dominated community with Gardner's Saltbush.

This is the Reference Plant Community for the Saline Upland ecological site. The community evolved with grazing by large herbivores and droughty saline and/or alkaline soils. This plant community can be found on areas that are properly managed with grazing and on areas receiving periods of rest. Potential vegetation is about 40% grasses or grass-like plants, 10% forbs, and 50% woody plants.

Gardner’s saltbush dominates this state. Other salt tolerant shrubs include bud sagebrush and birdfoot sagebrush. The major grasses include Indian ricegrass, bottlebrush squirreltail, and rhizomatous wheatgrasses. Other grasses occurring in this state include Sandberg bluegrass and needleandthread. 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 300 pounds per acre, but it can range from about 200 lbs./acre in unfavorable years to about 400 lbs./acre in above average years.

Resilience management. Rangeland Health Implications/Indicators: This state is fragile, but well adapted to the variable climatic conditions within the Wind River Basin. The diversity in plant species allows for high drought tolerance. This is a sustainable plant community, but is difficult to reestablish when degraded. Site/soil stability, watershed function, and biologic integrity are unique to this site and function at the best possible level. Higher extents of bare ground and the erosional tendencies of salt laden soils, leaves this site naturally vulnerable to sheet erosion and wind erosion.

Community 1.2
Saltbush / Rhizomatous Wheatgrass

Figure 12. Rhizomatous Wheatgrass and Squirreltail dominated community with Gardner's Saltbush.

Historically, this plant community evolved under grazing by large ungulates. Currently this plant community is found under moderate, season-long grazing by livestock. Gardner’s saltbush and rhizomatous wheatgrasses are the major components of this plant community. Cool-season grasses make up the majority of the understory with the balance made up of short warm-season grasses, annual cool-season grasses, and various forbs.

Dominant grasses include rhizomatous wheatgrasses, bottlebrush squirreltail, Sandberg bluegrass, and blue grama. Forbs commonly found in this plant community include smooth woodyaster, Cous biscuitroot, wild onion, and fernleaf biscuitroot. Plains prickly pear and winterfat can also occur.

When compared to the Reference Plant Community (1.1), birdfoot sagebrush and blue grama have increased. Plains prickly pear cactus will also increase, but occurs only in small patches. Indian ricegrass has decreased and may occur in only trace amounts within the patches of prickly pear. In addition, winterfat and shadscale may or may not have changed depending on the season of use by livestock.

The total annual production (air-dry weight) of this community is about 240 lbs/acre, but it can range from about 150 lbs./acre in unfavorable years to about 350 lbs./acre in above average years.

Resilience management. Rangeland Health Implications/Indicators: This plant community is relatively resistant to change. The herbaceous species present are well adapted to grazing; however, species composition can be altered through long-term severe grazing. Prolonged drought can also play an important role, exacerbating these conditions. The herbaceous component is mostly intact and plant vigor and replacement capabilities are sufficient. Water flow patterns and litter movement may occur, but are not extensive. Incidence of pedestalling is minimal. Soils are mostly stable and the surface shows minimal soil loss. The watershed is functioning and the biotic community is intact.

Pathway 1.1A
Community 1.1 to 1.2

Reference: Saltbush / Bunchgrasses

Saltbush / Rhizomatous Wheatgrass

Moderate Continuous Season-long Grazing, Drought - Gardner’s Saltbush has shown a tolerance or resilience under slight and moderate grazing pressures over a period of time, however the herbaceous component is susceptible, and is weakened under constant use. Indian Ricegrass is the main species that will decrease initially. As the pressure persists, vigor and density of Indian Ricegrass will decrease while Sandberg Bluegrass increases, and Bottlebrush Squirreltail will remain fairly stable. Production may not be altered depending on the precipitation for the year, but with continued stress the production will decrease as overall diversity and herbaceous cover is reduced.

Pathway 1.2A
Community 1.2 to 1.1

Saltbush / Rhizomatous Wheatgrass

Reference: Saltbush / Bunchgrasses

Prescribed Grazing or Long-term Prescribed Grazing - Given there is a viable seed source within distance, and appropriate rest and recovery time between grazing periods occurs, Indian Ricegrass and Bottlebrush Squirreltail can re-establish. The recovery process will take time and with the low precipitation rates and the tendency towards less than desirable seed establishment conditions, it may take several years (10-30 years). At this stage, seeding or other mechanical treatments are not suggested. Increased ground disturbance increases the potential risk of introducing invasive species. Considering the reduced vigor and diversity at this stage, the lower the risks taken the more apt the site is to recover.

State 2
Saltbush / Mixed Short Grasses

The Saltbush/Mixed Short Grasses State (State 2) is dominated by mid-stature bluegrasses and low-stature warm season grasses, reducing the resiliency of the community. Species diversity has been reduced. The state is stable with approximately 50% canopy cover by saltbush or salt tolerant shrubs. However, the production is reduced. Yet long term studies with exclosures across the Wind River and Bighorn Basin, have shown a significant fluctuation of annual production within these communities.

Community 2.1
Saltbush / Bluegrasses

Figure 15. Sandberg Bluegrass dominated community with Gardner's saltbush.

Currently, this community persists under moderate, season-long grazing by livestock and can be the result of prolonged drought conditions. This site appears to respond with extreme variation in annual production caused by wet, normal and dry growing seasons. This plant community is still dominated by short cool-season grasses, while short warm-season grasses and forbs account for the remaining composition of the understory. Continued drought or severe grazing places this community at-risk of shifting to a sod-forming, warm-season grass dominated plant community.

The dominant plants for this community are Gardner’s saltbush and Sandberg bluegrass, with lesser amount of blue grama. Incidental grass species include: prairie junegrass, western wheatgrass, bottlebrush squirreltail, and needleandthread. Forbs commonly found in this plant community include annual mustards, stickseeds, desert parsley/biscuitroot, milkvetches and asters. This site can still provide a diverse plant community, but lacks the structure for nesting cover and wildlife habitat.

When compared to the Reference Community, Sandberg bluegrass and blue grama have increased; and plains prickly pear has invaded. Indian ricegrass and bottlebrush squirreltail have decreased and may occur in trace amounts protected within the patches of plains prickly pear. Livestock grazing season of use and land treatment type may have limited or removed winterfat and shadscale from this community.

The total annual production (air-dry weight) of this community phase is about 200 pounds per acre, but it can range from about 75 lbs./acre in unfavorable years to about 300 lbs./acre in above average years.

Resilience management. Rangeland Health Implications/Indicators: 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 severe grazing. The herbaceous component is mostly intact and plant vigor and replacement capabilities are sufficient (plants are still producing seeds, and seedlings are present). Water flow patterns and litter movement may be occurring but only on steeper slopes. Incidence of pedestalling is minimal. Soils are mostly stable and the surface shows minimal soil loss. The watershed is functioning, and the biotic community is intact.

Community 2.2
Saltbush / Sod-formers

Figure 18. Blue grama dominated saltbush community in the WRB Core.

This plant community evolved under frequent and severe grazing on saline and/or sodic soils. Gardner’s saltbush, birdfoot sagebrush and blue grama are the dominant species of this plant community. A dense sod of blue grama can be common but mostly occurs in large mosaic patterns. Cool-season grasses have almost been eliminated and if still present can only be found within patches of plains prickly pear.

Blue grama will appear to be in a monoculture with Gardner’s saltbush; however, Sandberg bluegrass or prairie junegrass will be present in the interspaces of sod. Cactus often has increased. When compared with the Reference State (1), the annual production is lower for the Gardner’s saltbush and the perennial cool-season grasses.

Total average annual production is 150 lbs./acre, but it can range from 25 lbs./acre in unfavorable years to 200 lbs./acre in above average years.

Resilience management. Rangeland Health Implications/Indicators: This plant community is resistant to change; the established stand of blue grama is able to resist the impacts of continued frequent and severe grazing. The removal of grazing does not seem to affect the plant composition or structure of the plant community. The biotic integrity of this community is compromised and minimally functional; with moderate to low plant diversity. Since the biotic integrity of this plant community is not intact, it is vulnerable to noxious weeds such as Russian knapweed and halogeton. Plant vigor is weakened and replacement capabilities are limited due to the reduced number of cool-season grasses. This community is stable. However, the sod formed by blue grama is resistant to water infiltration, protecting the soil under the sod, while excessive off-site runoff may occur between sod-patches; resulting in rills or other more severe erosional issues on the adjoining sites. The watershed may or may not be functioning, as runoff may affect adjoining sites.

Pathway 2.1A
Community 2.1 to 2.2

Saltbush / Bluegrasses

Saltbush / Sod-formers

Frequent and Severe Utilization of cool season mid-grasses during the growing season, Drought - The low growing warm season grass, blue grama, is encouraged with high utilization of the cool-season mid-stature grasses. As severe grazing reduces Sandberg bluegrass and opens the canopy, blue grama, if present in the system, increases in density forming a sod-mat between Gardner’s saltbush plants. Drought will also open the canopy, encouraging blue grama to gain dominance in this community.

State 3
Saltbush / Bare Ground

A saltbush dominant site with bare ground is the most degraded native community for Saline Upland. As more soils data and vegetation data were analyzed, a trend shows many of the study locations with this community contained a higher percent clay. The determination if this state is produced by soil texture, management, or climatic conditions may not be conclusive, and require additional investigation. It is recognized that with continued grazing pressure and drought conditions, the productivity and sustainability of most perennial grasses will decrease leaving a shrub dominated state. In the absence of invasive species, this state can persist on the landscape.

Very long-term prescribed grazing and grazing land mechanical treatment (with seeding possibly) may be practices that can be used to bring this state near or similar to reference. Remnant populations of native perennial grasses will persist in pockets within the Gardner's Saltbush, but in some instances, seeding may be required to help re-establish herbaceous species to these sites. No research was located for large areas of re-vegetation, but limited success has occurred with seeding trials completed by BLM and University of Wyoming.

Community 3.1
Gardner Saltbush / Bare Ground

Figure 21. Saltbush dominated community, with minimal other vegetation on a Saline Upland WRB Core site.

This plant community can occur where sites are subjected to continuous year-long grazing and where soils are highly sodic. Gardner’s saltbush dominates this site and in some cases comprises almost 100% of the plant community. The interspaces between plants have expanded significantly leaving the amount of bare ground very high and the soil surface exposed to erosive elements.

Cool season grasses have been eliminated or greatly reduced. When compared to the Reference State (1), plant production is greatly diminished due to the excessive amount of bare ground. Sandberg bluegrass comprises a portion of the grass cover, but blue grama is prominent in the understory. Given, the wide range of productivity in bluegrasses depending on timing of precipitation and spring conditions, the following production range does not capture the extremely abnormal years.

The total annual production (air-dry weight) of this state averages 90 pounds per acre, but it can range from 50 lbs./acre in unfavorable years to 150 lbs./acre in above average years.

Resilience management. Rangeland Health Implications/Indicators: This plant community is resistant to change as the stand becomes more decadent. These areas are resistant to fire as no or minimal fine fuels are available and the bare ground between plants is increased. Continued frequent and severe grazing or the removal of grazing does not seem to affect the plant composition or structure of the plant community. Plant diversity is extremely low. The plant vigor is diminished and replacement capabilities are severely reduced due to the decrease in the amount of cool-season grasses. Plant litter is noticeably less when compared to the Reference plant communities (1.1 and 1.2). Noxious weeds such as Russian knapweed and halogeton are able to invade the large openings and can become dominate, forcing the transition to the invaded state. Soil erosion is accelerated because of increased bare ground. Water flow patterns and pedestalling are obvious. Infiltration is reduced and runoff is increased. Rill channels may be noticeable in the interspaces and gullies may establish where rills have concentrated down slope.

State 4
Invaded

The Saline Upland site has proven to be more tolerable or resistant to invasion by many of the invasive species threatening the rangelands today. However, there are a few species that still present issues as these lands are disturbed by development, continued drought, and shifts in use patterns. Many of these sites are at risk from local threats such as mustards, kochia, and field pennycress; as well as the national threats of halogeton, cheatgrass (downy brome), and a variety of knapweeds and thistles. The persistence, resistance and resilience of specific communities within this state will be discussed further below.

Community 4.1
Native Grasses / Invasives / Saltbush

Figure 24. Cheatgrass Enroachment on Saline Upland, Loamy sit

The Saltbush/Annuals (Invaders)/Perennial Grasses phase has maintained a representative sample of the native perennial grasses and forbs with the accompanying Gardner’s Saltbush composition. The invasive species are present and hold a significant (10% or greater) composition of the landscape, and are prominent on the site (referring to a more wide scale composition, not isolated patches on the landscape). Production of the desired perennial species of this site is generally reduced but the total production is maintained or elevated due to the production potential of many of the annual or invasive species.

Production of this community phase will vary depending on the invasive species. Site-specific evaluation will need to be completed to determine productivity and the growth curve that is best suited. The curve selected below is for a Cheatgrass influenced community.

Resilience management. Rangeland Health Implications/Indicators: This plant community is resistant to change. Plant diversity is moderate to poor. The plant vigor is diminished and replacement capabilities are limited due to the reduced composition of cool-season grasses. Plant litter is noticeably more when compared to reference communities due to the potential biomass produced by the invasive species (species dependent). Soil erosion is variable depending on the species of invasion and the associated litter accumulation. This variability also applies to water flow patterns and pedestalling. Infiltration is reduced and runoff is increased due to loss of perennial vegetation and root density.

Community 4.2
Invasives / Saltbush

Figure 26. Halogeton and Gardner Saltbush dominated community

This community phase is the at-risk community. As the native populations of perennial grasses and forbs become weakened, the site becomes invader driven, and is extremely difficult to improve. Gardner’s Saltbush is able to compete and maintain a strong community under a heavy infestation level. The canopy, although dwarfed, can serve as a protective niche in the system to help native grass species to persist. But the system has low resiliency.

Resilience management. Rangeland Health Implications/Indicators: This plant community is resistant to change. Plant diversity is poor. The plant vigor is diminished and replacement capabilities are limited due to the reduced component of cool-season grasses. Plant litter is noticeably more when compared to reference communities as a response to the potential biomass produced by invasive species (species dependent). Soil erosion is variable depending on the species of invasion and the associated litter accumulation. Variability of water flow, pedestalling, infiltration and runoff is determined by the invasive species inhabiting the community.

Community 4.3
Halogeton (Invaded)

Halogeton is a common weed found on a variety of soils and in a wide range of climates. It is aggressive and able to take advantage of disturbed and degraded soils, out-competing other species for limited resources. It is a common species found on alkaline soils, especially saline or sodic soils. It was thought to fill a niche until perennial natives could establish and begin to out compete for the limited moisture and nutrients. Studies completed by the University of Wyoming and partnering agencies have found that over time, Halogeton has been able to encroach into and force Gardner’s saltbush out of locations. Photo point and transect data has shown that Gardner’s Saltbush can fluctuate significantly with precipitation and extended periods of drought, and will recover with the return of adequate moisture events; but given time and continued pressure from Halogeton, the shrub component will eventually be reduced or eliminated. This was documented with grazed as well as ungrazed locations (unpublished study completed with established exclosures and photo points over time – presented at Wyoming Section Society for Range Management in Evanston, WY 2012).

Management solutions are still being evaluated, but it appears that grazing is not a factor affecting the movement of this species. As perennial grasses decrease and annual forbs begin to dominate a site, the niche for halogeton to take over increases. Although chemical control is an option, success and longevity of this type of treatment is being reviewed. It is not seen as a stable state that cannot be transitioned out of without significant inputs. However it is a community that is of significant management impacts and is a concern for livestock on the landscape, especially sheep operations.

Currently only small isolated areas of this site have been identified on the landscape and no production data has been collected at this time. Halogeton is known to exhibit a wide swing in productivity based on the time and timing of precipitation for the year.

Resilience management. This plant community is resistant to change. Plant diversity is poor, and vigor is diminished. Replacement capabilities are significantly reduced due to the loss of cool-season grasses. Soil erosion is generally reduced in response to the litter accumulation. However, the annual nature of this plant accentuates the water flow patterns. Infiltration is reduced and runoff is increased with the loss of perennial vegetation, root depth and density.

Pathway 4.1A
Community 4.1 to 4.2

Native Grasses / Invasives / Saltbush

Invasives / Saltbush

No Use, Severe or Frequent Grazing, Drought, Disturbance – After crossing the threshold into an invaded state, the community will continue to degrade if disturbances(or over-use) are repetitive or persist. Drought and non-use can leave soils dispersed, disturbed, and susceptible to further loss of perennial grasses. Once an invasive species has gained a niche within a community and is able to begin to propagate, the transition from the initial phase in this state to a more degraded phase may happen quickly, especially if there are multiple factors working to remove or weaken the perennial grasses.

Pathway 4.1B
Community 4.1 to 4.3

No Use, Severe and Frequent Grazing with Drought or major disturbance – As mentioned above, once a community has transitioned into an invaded state it is at-risk of deteriorating quickly. The severity of the disturbance will exacerbate the situation even more. In cases where the disturbance or use removes the native vegetation, including the saltbush, the site will become a monoculture of Halogeton or at least dominated by the invasive species that was introduced to the site.

Pathway 4.2A
Community 4.2 to 4.1

Invasives / Saltbush

Native Grasses / Invasives / Saltbush

Integrated Pest Management with Prescribed Grazing – The native grasses displaced by invasive species will persist in remnant populations within the crowns of the Saltbush or scattered in small pockets on the landscape. If a site is addressed in the preliminary stages of the phase transition, there is a higher likelihood that integrated pest management (weed control) and grazing management will encourage the perennial grasses to increase or persist on the landscape. But as the site continues to degrade or transition to an invasive dominated community, the ability to recover becomes more and more minimal. Halogeton maintains a more desirable community for grasses to persist. Where Cheatgrass and knapweeds tend to overpower and remove or inhibit the perennial grasses from the system, making recovery more difficult without major inputs.

Pathway 4.2B
Community 4.2 to 4.3

No Use, Severe or Frequent Grazing, Drought with Disturbance – Photo point studies of Halogeton infested communities over a period of years have shown that continued season or year-long grazing pressure, or in areas with extended drought and development disturbance, transitions to a Halogeton dominated community with only a few random annual weedy species in the interspaces. The photo point studies also showed that non-use (exclosures) allowed the transition to continue, and was expedited by drought.

State 5
Altered

Mining/energy development, borrow/gravel pits, farming/irrigation, and roads are only a few of the land uses that have had an impact on this site. Much of the land correlated as Saline Upland is deemed unfit or non-productive, and either no attempt was made to reclaim areas or reseeding attempts have failed. As this land recovers, is restored or reclaimed, or further disturbances occur, the site potential and stability is greatly affected. Historic attempts to improve productivity of these areas has altered the resilience and response to management/natural disturbance regimes. Specific references will be discussed below.

Community 5.1
Disturbed/Degraded Lands

Figure 29. Contour Furrows completed in the late 1960s by BLM

Degraded or disturbed lands are locations that have been impacted by human settlement and land use development. Wind River Basin was farmed during settlement periods; however, scarcity of water and drought impacts, caused many to abandon farming for other land uses. In more current times, advancement of irrigation techniques extended farm fields or created edges/corners that are difficult to farm and have low productivity of salt-affected areas. The expanded zone was then abandoned and left to natural processes or seeded to a generic seed mix.

Rangeland improvement trials were completed in the late 1940’s and early 1960’s by the Bureau of Land Management in conjunction with University of Wyoming. Trials included, water spreader dikes, contour furrowing and range seeding. These barren landscapes were contour furrowed and/or seeded with pre-dominantly crested wheatgrass (Agropyron Cristatum) and Russian wildrye (Psathyrostachys juncea). The objective was to create increased water holding capacity, improving vigor and production of Nuttall’s (Gardner’s) Saltbush, and enhance seed establishment. In 2015, a few of these locations were visited within the Wind River Basin to find varying degrees of persistence of seeded species. The most dominant was the crested wheatgrass and rhizomatous wheatgrasses. However, the furrows were still visible to the eye and the spreader dikes, although visible) were holding significant sediment loads. An exclosure comparison of this treatment exhibited significant persistence of seeded species and the presence of native species as well. Productivity of Gardner’s saltbush and Sandberg bluegrass was markedly higher than expected, within the exclosure compared to outside.

Because these areas were mechanically altered with lasting affects to hydrology, in conjunction with a seeding of an introduced species, even though introduced species did not persist in all locations, these locations are marked as disturbed lands to capture the altered functionality when compared to the reference functionality group. Given more time the furrows may completely disappear from view and the benefits of such furrows will be decreased, but the argument is made that these communities will not respond the same as an unaltered, native community. Similarly, with lands that were farmed/irrigated and then left to return to a natural state of vegetation will never respond the same as a reference community.

Persistence of an introduced, non-native species is a very indicative trait that will assist in identifying this community. These non-native species are not invasive, although they may be persistent and aggressive. Crested wheatgrass, Russian wildrye, rhizomatous wheatgrasses, Indian ricegrass, and big bluegrass are a few cultivar species that have been planted that have persisted on the landscape, altering the community. The act of seedbed preparation alone, without consideration of the original disturbance, can be seen as an alteration to the soil function. The restored/reclaimed lands community phase is very similar to this concept; however, in the term restored/reclaimed the inference is “to a native or natural state pre-disturbance”. With the use of introduced or improved cultivars, the site is not similar to pre-disturbance.

Productivity of these sites varies greatly dependent on the disturbance, age and successional stage of recovery, and if or what species were seeded. Due to the lack of current and comparative production data, no production estimate is provided. The growth curve will depend on the species seeded, or the succession completed. So no growth curve will be given.

Community 5.2
Reclaimed Lands

When restoring a site (returning disturbed lands to a former, original, normal or unimpaired condition) or reclaiming a site (restoring to a pre-determined level of productivity or usefulness similar to pre-disturbance) within the Wind River Basin, climate is the most limiting factor for success. However, the sodicity/salinity/alkalinity of the soil also causes further complication and limitation of available species. Research has been completed by Plant Material Centers (Bridger, MT) and Universities, improving the seedling establishment of Gardner’s Saltbush and developing newer cultivars of key species.

Review of disturbed areas, showed very limited or non-existent success in reclamation. Every site that was found had a high rate of annuals and only trace amounts of desired grasses and forbs. Saltbush establishment was found to be very low, but the rate of desired and planted was unknown.

Production and the growth curve factors are dependent on the seeding mixtures selected and the level of establishment achieved. As with the disturbed lands, these sites are highly vulnerable to erosion and invasion by annuals or other undesirable species.

Pathway 5.1A
Community 5.1 to 5.2

Grazing Land Mechanical Treatment and/or Rangeland Seeding with Prescribed Grazing – Degraded communities may be at various levels of succession or ground condition. To have the desired seedbed, most areas will require site preparation (disking, plowing, harrowing, etc.) to seed a large area. In some instances, contour furrow plantings similar to those completed in the 1960s by the BLM, may be a preferred practice. No matter whether the area has a grazing land mechanical treatment or is seeded to natives (or selected seed mix), once the seed has a chance to establish, prescribed grazing is necessary to maintain the established plant community.

Pathway 5.2A
Community 5.2 to 5.1

No Use, Drought, Disturbances, Severe and Frequent Grazing – After initiation of the reclamation process, establishment of seed mixture or recovery of vegetation is affected by land use and environmental factors. Further/continued disturbances or use before fully established will quickly degrade the community. Non-use for extended periods of time after establishment has led to some species becoming decadent, causing reduced vigor and potentially leading to die off.

Transition T1A
State 1 to 2

Drought, Frequent or Severe Grazing – Drought conditions over extended periods of time weaken plant species beyond their resiliency, forcing the community over the threshold into the next state. Drought with added stress of frequent severe grazing can expedite the process. Frequent severe grazing of key species causes the site to become dominated by less desirable herbaceous species. Any combination of these factors reduces or removes the key bunchgrasses (Indian ricegrass and bottlebrush squirreltail), and causes Sandberg bluegrass or blue grama to become dominant.

Constraints to recovery.The loss of seed source, lack of hydrology (dry climate, sporadic rainfall, and alteration to water infiltration and runoff by sod-formers), and salt-laden soils limit the ability for seedling establishment.

Transition T1B
State 1 to 3

Frequent and Severe Grazing, Severe Ground Disturbance, Drought - The combination of frequent and severe grazing and drought reduces the key bunchgrasses of this community. With no recovery time or rest, the forbs and grasses may become very sparse or may be removed from the community leaving a saltbush dominated site. Extended long periods of drought alone, or severe ground disturbance, reduces or inhibits resiliency of this community, including Gardner's saltbush.

Constraints to recovery.The development of a soil crust is prevalent in this soil, especially with the lack of herbaceous cover to protect from rain-drop impact. With the loss of grasses in this system, the crusting becomes a hindrance to seedling establishment. The loss of seed sources for the native key species also limits the ability for this community to recover.

Context dependence.The texture of soils within each community can influence the ability to recover. Heavier textured soils (higher clay content) will favor soil crusting or become "fluffy" easier as a response to the increased sodic or saline properties within the shales that many of the heavier textured soils are derived. Soils that are coarser or lighter textured (sandy and loamy textures) tend to have a lest prominent crust or soil cap, and tend to not become as loose or "fluffy" as the heavier textures do.

Restoration pathway R2A
State 2 to 1

Prescribed Grazing (Long-term), (possibly with seeding) – By reducing use and allowing native grasses to propogate with rest or deffered grazing rotations, the potential to recover increases, but is dependent on a seed source and climate. The time necessary to see a transition back to reference may extend past what is feasible. Once this State has crossed into a blue grama dominated community, the potential for recovery is completely lost. Native seed mixtures that have been proven to tolerate saline, sodic, or saline/sodic soils are not necessarily the key species for the Reference communities. Once a site is seeded (drilled or broadcast seeding), the response to management and climatic conditions may be altered, and the site will not function as a native (undisturbed) site, and would correlate as a reclaimed site (R3-5).

Transition T2A
State 2 to 3

Frequent and Severe Grazing, Severe Ground Disturbance, Drought – Further stress opens the transition from the Saltbush/Perennial grasses to a Saltbush/<a class="species-link" href="https://plants.usda.gov/core/profile?symbol=2BARE" target="_blank" title="Open in plants.usda.gov"><i>Bare Ground</i></a> dominated community (State 3). Reduced function of the perennial herbaceous species and decreased diversity weakens the resilience to changing conditions within the community. As grazing intensity remains high, drought is extensive, or if a source of ground disturbance occurs, the native perennial grasses can not maintain a foothold in the community forcing the community across the threshold to a Saltbush/<a class="species-link" href="https://plants.usda.gov/core/profile?symbol=2BARE" target="_blank" title="Open in plants.usda.gov"><i>Bare Ground</i></a> state.

Transition T2B
State 2 to 4

Non-Use, Ground Disturbance (with presence of seed source), Drought, Frequent or Severe Grazing – The vulnerability of transitioning from the Saltbush/Other Perennial Native Grasses state to an invaded state is increased as the canopy is opened with further disturbance, drought or grazing use. Non-use of a community opens the possibility of the soils becoming loose (fluffy), open to seedling establishment, but highly erosive.

Constraints to recovery.The inability to eradicate fully the invasive species (Cheatgrass and Halogeton) from a community is the limiting constraint to recover. Cost for initial treatment, and the need for continued treatment limit the economic feasibility of recovery as well.

Context dependence.The spatial extent of the infestation and the intended use of the land may alter the economic feasibility of treating a site-specific community.

Restoration pathway R3A
State 3 to 1

Prescribed Grazing (Long-term), (possibly with seeding) – By reducing use and allowing native grasses to recover with prescribed grazing, the potential to recover is dependent on a seed source and climate. However, the time required may not be feasible. If management is not maintained, this community may shift to State 2 before it will shift to Reference. Native seed mixtures that have been proven to tolerate saline, sodic, or saline/sodic soils are not necessarily the key species for the Reference communities. Once a site is seeded (drilled or broadcast seeding), the response to management and climatic conditions may be altered, and the site will not function as a native (undisturbed) site, and would correlate as a reclaimed site (R3-5).

Transition T3A
State 3 to 4

Non-Use, Ground Disturbance (with seed source present), Drought, Frequent or Severe Grazing – Once a community has transitioned to a saltbush dominated community, productivity and functionality of the site are at risk. If further disturbance (livestock, human or environmental disturbance) occurs, saltbush will begin to decrease and annuals and other less desirable species will begin to dominate. Hydrologic function will decrease and erosion hazard will increase as a community transitions into an invaded state.

Constraints to recovery.The lack of native key species and the harsh environment of the salt-laden soils reduces the ability for this site to recover. The difficulties of treating the non-native invaders also limits the recovery opportunities for these communities.

Context dependence.Spatial distribution of specific non-native/invasive species will determine what species may inhibit the community. Each species has a select influence and restriction to control that will need to be evaluated on a case by case basis.

Restoration pathway R3B
State 3 to 5

Grazing Land Mechanical Treatment or Rangeland Seeding with Prescribed Grazing - The large scale success of contour furrowing on the rangelands with a mixture of crested wheatgrass and other introduced/cultivated species has shown that this landscape can be restored to a functional state using improved varieties and selective grazing land mechanical treatments. Once established the site will need to be managed for the species selected to ensure proper use of the resource. Once the site is disturbed there is a risk of erosion until establishment of the seedlings can occur. Management of undesired species (noxious or invasive weed species) is an integral component of the reclamation process to ensure the community is restored to an acceptable condition.

Restoration pathway R4A
State 4 to 5

Integrated Pest Management, Grazing Land Mechanical Treatment, or Rangeland Seeding with Prescribed Grazing – Once invasive species such as cheatgrass, halogeton, or knapweeds are established, complete eradication is generally not a feasible option, limiting the ability to restore the community to a higher state. An invaded site, however, can be restored to a functional plant community through intensive or integrated pest management. Grazing land mechanical treatments to reduce existing invasive populations and to introduce forage species that are desirable and able to compete with the invasive species will provide limited grazing. When a community has been significantly invaded, losing all of the key forage species, re-seeding the site to a competitive species may be the only option. Establishment will be slow and the variety of available seed sources for saline/sodic/alkaline soil conditions is limited; however, small scale projects have been achieved with marginal success.

Transition T5A
State 5 to 4

Non-Use, Disturbance, Severe and Frequent Grazing, Drought with a seed source present – Loose soils as a result of non-use or the decrease in key species due to severe and frequent grazing, drought or disturbance opens the canopy and provides opportunity for invasive species to establish. Continued pressure, added disturbances, or introduction of undesirable species will weaken and trigger a shift from the degraded state to an Invaded state.

Constraints to recovery.The alternation to the soils and exiting herbaceous cover due to ground manipulation and disturbance shift the response of this site from natural conditions and will impact the ability to respond as an undisturbed site. Although this may be to a positive factor for the community and soils, it does shift the potential recovery to an altered state, not to a reference or native state.

Context dependence.This transition and these community will vary in appearance due to locality of specific seed sources (a wide variety of invasive or non-native species exists across this MLRA). The specific species that dominates this site will determine the response, recovery, and potential treatments required.