State 1
Native Perennial Grasses/Sagebrush

Figure 7. Clayey Overflow reference community two years post fire.

This state evolved with moderate grazing pressure from wildlife (large ungulates such as elk and deer). As areas were settled sheep were the prominent domestic grazers on these landscapes, but have since shifted to mainly cattle with only a few bands of sheep still utilizing these summer pastures. Fire had a role in this system. Although not frequent, these fires helped to manage the health and cover of the woody vegetation in these communities.

Characteristics and indicators. A dominance of native perennial tall and mid-stature cool-season grasses, both bunchgrasses and rhizomatous, is a key indicator of this state, with a healthy cover of mountain big sagebrush, silver sagebrush and rubber rabbitbrush. Snowberry is common as well with a mixture of forbs. Basin wildrye is the key species for the Reference Community. Once basin wildrye begins to decline and mountain big sagebrush becomes the dominant component in this community the state is beginning to transition.

Resilience management. This state is relatively resilient, with species adapted to the fluctuating climatic conditions of the upper foothills. Once the herbaceous understory is compromised and the woody cover begins to increase, the resistance to change is lowered and the State is at-risk.

Community 1.1
Slender Wheatgrass/Wildrye/Needlegrasses

This plant community is the interpretive plant community for this site and is considered to be the Reference Plant Community. This state evolved with grazing by large herbivores, additional overflow moisture, 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 potential vegetation is about 75% grasses or grass-like plants, 15% forbs, and 10% woody plants. Cool season tall and mid-grasses dominate this state. The major grasses include slender wheatgrass and other rhizomatous wheatgrasses, columbia and letterman's needlegrass, and basin wildrye. Other grasses occurring in this state include idaho fescue, spike fescue, mountain brome, prairie junegrass, and Cusick's bluegrass and Canby bluegrasses. Mountain big sagebrush, silver sagebrush, rubber rabbitbrush, and snowberry are conspicuous elements of this state and occur in a mosaic pattern. 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 2,000 lbs./acre, but it can range from about 1250 lbs./acre in unfavorable years to about 2,500 lbs./acre in above average years.

Resilience management. This plant community is stable and well adapted to the Upper Foothills climatic conditions. The diversity in plant species allows for the highly variable climate of the Upper Foothills. This is a sustainable plant community (site/soil stability, watershed function, and biologic integrity).

Community 1.2
Perennial Grasses/Sagebrush

Historically, this plant community evolved under grazing and a low fire frequency. Currently, it is found under moderate, season-long grazing by livestock and will be exacerbated by wildlife use and prolonged drought conditions. In addition, the fire regime for this site has been modified and extended periods without fire is now common. This plant community is still dominated by cool-season grasses, rhizomatous wheatgrasses, Idaoh fescue, and miscellaneous forbs account for the balance of the understory. Mountain big sagebrush is now a conspicuous part of the overall production and accounts for the majority of the overstory. The dominant grasses include rhizomatous wheatgrasses, Idaho fescue, letterman's needlegrass, and bluegrasses. Grasses and grass-like species of secondary importance include prairie junegrass, needleleaf and threadleaf sedge. Forbs commonly found in this plant community include lupine, scarlet paintbrush, little larkspur, hawksbeard, and phlox. Mountain big sagebrush along with possibly silver sagebrush and rubber rabbitbrush can make up to 20% of the annual production. The overstory of shrubs and understory of grass and forbs provide a diverse plant community. When compared to the Reference Plant Community, big sagebrush and rhizomatous wheatgrasses have increased. Basin wildrye and Columbia needlegrass have decreased and may occur in only trace amounts under the woody canopy. Total production has decreased, but the increase of shrubs has offset some of this loss. The total annual production (air-dry weight) of this state is about 1750 pounds per acre, but it can range from about 1250 lbs./acre in unfavorable years to about 2750 lbs./acre in above average years.

Resilience management. This plant community is resistant to change. The herbaceous species present are 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. 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 minimum soil loss. The watershed is functioning and the biotic community is intact.

Pathway CP1.1-1.2
Community 1.1 to 1.2

Timing of grazing, Dought, Climatic shifts – Location of this LRU places this site where historically, the area was grazed in combination with the US Forest Service summer grazing allotments. Areas tend to be utilized hardest in late spring and early fall as the cattle are preparing to move up and to return from the higher elevation grazing lands. The repetitive season-long use of sensitive species, specifically wildrye and needlegrasss, would have slowly removed these species from the system. Long periods of drought and shifts in spring melt have weakened and impacted the productivity and vigor of most species, leaving a hostile climate for native species to establish. Although the species of herbivory and timing has changed with the installation of more grazing management, pressure from large ungulates, namely elk, have had an impact on the foothills as they follow the available feed sources.

Pathway CP1.2-1.1
Community 1.2 to 1.1

Prescribed grazing will assist with the recovery of this plant community to Reference. The probability of this occurring is high especially if rotation with short deferred is implemented as part of the prescribed method of use. Allowance for natural fire patterns to occur will aid in sagebrush health, but does add to the complexity of grazing management. Upland wildlife habitat management is also key to allow the rest needed for this site to recover.

State 2
Sagebrush/Idaho Fescue

Continuous grazing pressure and lack of fire in this system allows the shrub cover to dominate the community while the herbaceous understory is reduced. Herbivory pressure is a combination of wildlife use as well as the historical season-long use by sheep and cattle. Increased predation pressures, shifts in climate, and increased human activity are a few of the reasons that have been listed for the cause of increased elk herds and deer use on the upper foothills zone for longer periods of time, or more frequent use. This increased use with continued frequent and severe use by cattle have compromised this system.

Characteristics and indicators. The dominant cover in this State is mountain big sagebrush with limited herbaceous understory. The forb component has shifted to lower stature forbs and has increased in composition, while the grass and grass-like cover has declined in stature, percent cover, and composition. The major grass cover is Idaho fescue, bluegrasses, and rhizomatous wheatgrasses.

Resilience management. The increased bare ground and reduced vigor of the herbaceous component of this State, puts the community at high risk of transitioning to a further degraded state. The increased woody cover elevates the risk of and changes the behavior of fire in the system.

Community 2.1
Sagebrush/Idaho Fescue

Figure 11. Sagebrush dominated Clayey Overflow ecological site.

This plant community is the result of frequent and severe (continuous season-long) grazing and protection from fire. This improper grazing has negatively affected the tall and some of the mid perennial grasses. Most of the preferred cool season grasses have been reduced or removed from the community. Shrubs, specifically mountain big sagebrush and rubber rabbitbrush, account for up to about one-third of the total production of this plant community. The dominant grasses are rhizomatous wheatgrasses, prairie junegrass, Sandberg bluegrass, threadleaf sedge, and blue grama. Weedy annual species such as cheatgrass may occur in patches if a seed source is available. Cactus and sageworts often increase. The interspaces between plants have expanded leaving the amount of bare ground more prevalent. As compared with the HCPC or the Perennial Grass/Big Sagebrush Plant Communities, the annual production is less, but the increase in shrub and rhizomatous wheatgrass production compensates for some of the loss of the tall and mid perennial production. The total annual production (air-dry weight) of this state is about 1750 pounds per acre, but it can range from about 1200 lbs./acre in unfavorable years to about 3000 lbs./acre in above average years. These figures are estimates based on a low number of ocular inventories and will change with further data collection.

Resilience management. This plant community is relatively resistant to change as the stand becomes more decadent, although continued improper grazing can eventually lead to the reduction in the Idaho fescue and rhizomatous wheatgrasses and increase the dominance of shrubs. These areas may actually become more resistant to fire as less fine fuels are available and the bare ground between the sagebrush plants is increased. Plant diversity is moderate. The plant vigor is diminished and replacement capabilities are limited due to the reduced number of cool-season grasses. Plant litter is noticeably less when compared to the Reference. Soil erosion is accelerated because of increased bare ground. Water flow patterns and pedestalling are forming. Infiltration is reduced and runoff is increased. Rill channels may be noticeable in the interspaces and gullies may be establishing where rills have concentrated down slope.

State 3
Invaded

Any disturbance provides an opportunity for aggressive species, such as many of our introduced invaders, to establish in a community. Catastrophic events or natural climatic events (drought, wildfire, etc) can be a source of this invasion.

Characteristics and indicators. The major indication of entering this State is the abundant or significant presence of an introduced species, whether invasive or just an invader. To meet the terms of abundant or significant, the presence has to account for greater than or equal to ten percent cover of the community. Species considered in this category are Kentucky bluegrass, timothy, redtop bent, or smooth brome for non-native invaders; or cheatgrass for invasive species. Thistle and common dandelion are other species of concern on this ecological site.

Resilience management. These aggressive and persistent species will exclude many of the native species and are extremely difficult to reduce or remove from the community once established. These species are able to tolerate repeated defoliation and drastic climatic swings without losing their foothold in the community, creating a resistant and resilient community.

Community 3.1
Perennial Grasses/Non-Native Species

Figure 12. Clayey Overflow site that has a prominent cover of timothy.

Figure 13. Snow seep sites are difficult and will key to Clayey overflow, but in this instance, the dominant cover of timothy and shrubby cinquefoil suggest a perched water table, so not a clayey overflow site.

The Perennial Grasses/Non-Native Species Community Phase has maintained a representative sample of the perennial grasses and forbs that are typical of the site with a mixed shrub community. Non-native or invader species have established in the community and are a significant component in the community (ten percent or greater by foliar cover or five percent or greater by weight), and are prominent (referring to a more wide scale composition, not one isolated patch in an isolated portion of the landscape). Production of the desired perennial species is generally reduced but the total production is maintained or elevated due to the production potential of the non-native species. The species most common are Kentucky bluegrass, timothy, and common dandelion. However, smooth brome and redtop bent are also frequent components.

Resilience management. This plant community is resistant to change. These areas may be more prone to fire as fine fuels are more available. Plant diversity is moderate to poor. The plant vigor is diminished and replacement capabilities are limited due to the reduced number of cool-season grasses. Plant litter is noticeably more when compared to reference communities due to the potential biomass produced by the non-native species (species dependent). Soil erosion is variable depending on the species of invasion and the litter accumulation thus associated, 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 3.2
Perennial Grasses/Invasive Species

The Perennial Grasses/Invasive Species Community Phase has maintained a fractured sample of the perennial grasses and forbs that are typical of the site with invasive species. This plant community evolved under frequent and severe grazing. The shrub component has been impacted and possibly removed by heavy browsing, wildfire or human means. Weedy annuals and non-native species, as well as Idaho fescue and bluegrasses are the most dominant plants. Invasive species, most commonly cheatgrass, hold a significant (10 percent or greater) composition of the landscape, and are prominent (referring to a more wide scale composition, not isolated patches on the landscape). Wood's rose, rubber rabbitbrush may be more abundant than other shrubs, as they are strong resprouters and may quickly re-establish the site after a disturbance. The interspaces between plants have expanded leaving the amount of bare ground more prevalent and more soil surface exposed to erosive elements. With the decrease or loss of most desirable mid-stature cool-season grasses, Idaho fescue and bluegrass will persist on the site (bluegrass includes natives: Sandberg, mutton, Canby, and big; as well as introduced species: Kentucky). Timothy, dandelion, and other introduced species will increase if present on the site. Other noxious weeds such as Canada thistle may invade the site if a seed source is available. Production of the desired perennial species is generally reduced but the total production is maintained or elevated due to the production potential of the invasive species.

Resilience management. This plant community is resistant to continued herbivory. Annuals and invader species are effectively competing against the establishment of perennial cool-season grasses. Plant diversity is greatly altered and the herbaceous component is not intact. Recruitment of the major perennial grasses is not occurring and the replacement potential is low. The biotic integrity is missing. The state is unstable and is not protected from excessive erosion. Rill channels and gullies may be present on site and adjacent areas are impacted by excessive runoff. Water flow patterns and pedestalling are obvious. The watershed is not functioning.

Pathway CP3.1-3.2
Community 3.1 to 3.2

State 4
Disturbed

Although to a much smaller extent than in lower elevations, there are areas that have been accessed for irrigation convenience ditches or were part of a homestead. These areas have remnants of introduced species for haylands or have been left to recover and may be in at varying stages of succession. Or there are areas that are heavily impacted by recreational vehicles, parking, trails, roadways, or other land disturbances that have reduced or removed most native perennial vegetation and left a highly disturbed land. The Disturbed State could be drafted as a stand-alone box within the state and transition model diagram. No matter what state a site originally is ranked in, once the site is mechanically disturbed, or suffers a catastrophic or significant natural disaster that alters the soil properties (erosional, depositional, or chemical), the site potential is altered. The most prominent shift for this site tends to be a shift in the natural hydrology that is key to this site. This can include both the loss of or enhancement to the additional moisture to the site (seepage from irrigation ditches). Mechanical disturbances and reclamation practices using non-native species could qualify some stages of this state to be considered as a land use shift. The result is the shift in potential and response in management so that it is no longer similar to the reference community. The potential shifts are highly variable, so a dynamic state was captured to highlight the altered communities that exist on the landscape.

Characteristics and indicators. The soil disturbance and mechanical or physical removal of the vegetative canopy is the key characteristic of the Disturbed State. The initial indicators are the primary successional species that establish following a disturbance including Russian thistle, kochia, six weeks fescue, and sunflowers. These initial colonizers will then be followed by any seeded species, or other species from within the locations seed bank.

Resilience management. The Disturbed State is highly variable and in a state of flux as the successional processes occur. Continued disturbance of these communities is a potential threat; and the communities are at high risk of transitioning to the Invaded State.

Community 4.1
Disturbed Lands

The title Disturbed Lands is encompassing two broad classifications of these land types. Go-back fields or tilled areas form Type one. The soils were once cultivated or were impacted by cultivation pracites and have since been left to natural processes. Homestead and abandoned farming sites can be identified on the landscape (through photo-tone shifts in aerial photographs) and are generally a mix of natives and introduced herbaceous species as well as trees. Cottonwood breaks, elm, and other species of trees on these sites are key markers of old homestead locations. These sites are generally isolated or small in nature and are difficult to reclaim due to the introduced species that persist on the landscape and the shift in hydrology. If reclaimed, they do not respond to the natural disturbance regimes in the same manner that a native, mechanically undisturbed site would respond. The Clayey Overflow ecological site was incidental to disturbance by homesteading or irrigation processes. The extent of this type is limited on the landscape. A subset of Type one are those areas that were or currently are being impacted by recreation - camp sites, trails, parking areas, roadways. The varying stages of healing once abandoned, or the level and age of disturbance at each location leave a variable community. In a similar process, mined lands or lands affected by energy development including transmission corridors, transportation corridors and oil and gas development sites provide a host of successional processes. Many times, these locations are re-exposed to disturbance frequently by mechanical means leaving annual weeds and primary successional species as the dominate canopy. Older, established sites or abandoned locations, have established communities similar to those expected on go-back fields and may be stable in nature. The growth curve of this plant community will vary depending on the species that are selected for seeding. For a more accurate portrait of the growth curve for the seeded community, the species used and the climatic tendencies of the region must be considered.

Resilience management. The plant community is variable and depending on the age of the stand and the stage of successional tendencies that the location is in will determine how stable (resilient/resistant) the community is. Plant diversity is generally strong, but is usually lacking in the structural and functional groups that are desired on the site. Soil erosion is variable depending on the disturbance regime that is occurring on the site and will vary with the specific community that has established on a specific location. Site-specific evaluation is needed to determine the water flow and pedestalling as well as infiltration and runoff potential and associated risks for each community.

Transition T1-2
State 1 to 2

Many of these higher elevation communities are used for season or year-long grazing by cattle, sheep, or other livestock. Elk, deer, moose, and other wildlife also utilize these areas intensively throughout the year (specifically spring and fall). This frequent or high intensity herbivory weakens the ability for native grasses to persist in the community, and will begin to decline over time. Prolonged drought or unusually early warm temperatures over time dry the soils out impacting the grasses even harder. Lack of fire in this system allows sagebrush to become the majority of the composition in the community. Fire does not occur frequently, but has a shorter return interval than the lower elevation sagebrush communities.

Constraints to recovery. Rest or time for the native herbaceous species to recover as well as the necessary nursery source for these species are the major limitations to recovery for this community.

Transition T1-3
State 1 to 3

Seed sources are abundant for many non-native and invasive species. Drought stress, wildfire or prescribed burning and associated activities, and brush control provide opportunity and many times the seed source for invasion. Ground and soil disturbances by human activities are a primary source for seeds. However, wildlife are a major transporter of many seeds. These impacts by grazing large herbivores and the vehicular impacts including recreation create the niche for establishment while providing the seed source for an array of non-native and invasive species to invade.

Constraints to recovery. Once most introduced or invasive species establish, it is extremely difficult to control or remove these species from the system. Many times the cost effectiveness of wide scale treatment hinders the ability for many landowners from trying.

Restoration pathway R2-1
State 2 to 1

Treatment to thin the sagebrush canopy improves the sun exposure and moisture available to the herbaceous native vegetation. Complete removal of the sagebrush canopy may slow the recovery time and provides opportunity for negative shifts in the community, but it can be an effective means to recovery. Following canopy treatment, prescribed grazing to prevent damage to the grasses as they are re-establishing and to prevent damage to the shrub canopy, is required. The tools used to thin the canopy will vary depending on the exact composition of grasses remaining and the potential threats to the location.

Transition T2-3
State 2 to 3

Seed sources are abundant for cheatgrass, knapweed, and other invasive species. Drought stress, wildfire or prescribed burning, brush control, or ground/soil disturbance including impacts by grazing large herbivores or recreation create a niche for undesirable weeds to invade.

Constraints to recovery. The common invasive and introduced species are difficult to control or maintain, and the ability to eradicate these species from the system has not been successful. This challenge to removing these species is the constraint to recovery for these communities.

Restoration pathway R3-4
State 3 to 4

A long-term Integrated pest management plan that includes both pre- and post-treatment intense weed control is necessary to overcome a severe weed infestation. The treatment for this community is a seeding treatment following extensive seedbed preparation. Selecting herbaceous species that are adapted to the location and using either improved varieties, native seed, or in some cases an introduced species suited for the management use intended may be the only way to overcome some invasive species. A grazing management plant to incorporate rest into the system and rotation of use is needed to further allow recovery.

Transition T4-3
State 4 to 3

Following reclamation or restoration practices, the community is sensative to further disturbance or to climatic influences. Seeding failure or weed control failures promote rapid transitions back to the Invaded State. Further land disturbances or failure to change management of the lands are other means for this transition to occur. Wildfire, prescribed burning, drought, or frequent and severe grazing by large herbivores are a source disturbance.

Constraints to recovery. The inability to control climatic factors, the challenge of controlling invasive species, and the aversion to changing management practices and financial limitations are the major constraints to recovery for this community.