State 1
Reference

The Reference state of this ecological site is dominated by a mix of native grasses and forbs, many species being salt-tolerant. The plant communities in the Reference state evolved with grazing by large herbivores and are suited for managed grazing by domestic livestock.

The primary salt-tolerant grass species found at this site in the Reference state include alkali sacaton (Sporobolus airoides), Nutall alkaligrass (Puccinellia nuttalliana), and saltgrass (Distichlis spicata). Other major grass, sedge, and rush species include needlelfeaf sedge (Carex duriuscula), western wheatgrass (Pascopyrum smithii) and slender wheatgrass (Elymus trachycaulus), Sandberg bluegrass (Poa secunda), arctic rush (Juncus arcticus), and basin wildrye (Leymus cinereus).

Shrub composition and cover is generally limited at this site but can include greasewood (Sarcobatus vermiculatus) and rubber rabbitbrush (Ericameria nauseous). Forb cover can include goldenweed (Pyrrocoma sp.), arrowgrass (Triglochin sp.), and other perennial and annual forbs. Each plant community within the reference state differs in percent composition and canopy cover.

Three important processes occur in the Reference state and result in community changes: 1) Changes to the hydrologic regime; 2) Disturbances such as herbivory and drought; and 3) Specific salinity concentration within plant rooting depth.

Characteristics and indicators. Community occurrence as well as shifts between communities are a result of localized variation in the hydrology, small-scale disturbance, or localized soil salinity levels. Sites with the water table closer to the surface or inundated for longer periods of time are more likely to result in the Sedge/Grass community. Sites that have higher salinity concentrations are more likely to result in the Alkali Sacaton/Basin Wildrye community.

Resilience management. Resilience in the Reference state of this ecological site is strongly tied to hydrologic function. When the hydrologic system is functioning properly, resilience is high. If changes in the hydrologic regime occur due to natural or anthropogenic disturbances. Resilience decreases.

Community 1.1
Sedge and Rush

The Sedge and Rush community occurs where the seasonal water table is closer to the surface, near the 20 inch concept of the ecological site. The additional water allows for species better adapted to wetter conditions and less salt-tolerant. The dominant grasslike species in this community include needleleaf sedge (Carex duriuscula) and arctic rush (Juncus arcticus). A variety of forbs including goldenweed (Pyrrocoma sp.), horsetail (Equisetum sp.), and aster species (Symphyotrichum sp.). Although shrubs are uncommon at this ecological site, greasewood (Sarcobatus vermiculatus) and rubber rabbitbrush (Ericameria nauseosa) can occasionally occupy small portions of the canopy. Production values range from 950 to 2,300 pounds per acre, averaging 1,500 pounds per acre.

This community evolved with grazing by large herbivores and is suited for managed grazing by domestic livestock.

Resilience management. This community is moderately to highly resilient because of its reliable water supply and moderate biodiversity. Disturbances that alter the hydrologic regime or native plant cover can cause a transition to the Disturbed state.

Community 1.2
Alkali Sacaton and Basin Wildrye

This community is dominated by salt-tolerant plant species. This community occurs when saline concentrations are high and the seasonal water table is slightly deeper in the soil profile. The primary overstory species are alkali sacaton (Sporobolus airoides) and basin wildrye (Leymus cinereus), western wheatgrass, slender wheatgrass, Sandberg bluegrass, scratchgrass (Muhlenbergia asperifolia), and Nutall's alkaligrass (Puccinellia nuttalliana). Perennial forbs such as horsetail, aster, and various vetch species make up less than 10 percent of the overall canopy cover. Greasewood and rubber rabbitbrush can occur on sites but are less common, and do not occupy over 15 percent canopy cover.

This community has evolved with historic grazing by large herbivores and is suited for managed grazing. Production can range from 2,000 to 3,500 pounds per acre, averaging 3,000 pounds per acre. This is a critical community able to be highly productive under saline soil conditions.

Resilience management. This community is moderately to highly resilient because of its reliable water supply and moderate biodiversity. Disturbances that alter the hydrologic regime or native plant cover can cause a transition to the Disturbed state.

Pathway 1.1A
Community 1.1 to 1.2

Sedge and Rush

Alkali Sacaton and Basin Wildrye

The transition from Community 1.1 to Community 1.2 is a result of localized abiotic conditions involving the depth to seasonal water table and saline concentrations in the rooting depth of the plants. Community 1.2 consists of plants more tolerant of saline conditions and less available moisture.

Context dependence.Saline concentrations in the rooting depth of the soil can change rapidly and result in a mosaic between communities 1.1 and 1.2. Water table depths fluctuate throughout the season, however average seasonal depth varies across the landscape.

State 2
Grazing Resistant

The Grazing Resistant state is a result of continuous grazing by domestic livestock at high intensity. The grazing-related disturbances lead to a decrease in diversity, promoting species that are able to tolerate heavy grazing. Dominant salt-tolerant species include scratchgrass (Muhlenbergia asperifolia) and Sandberg bluegrass. Other dominant plants include arctic rush, and western wheatgrass.

Hydrology is functioning in this state, but the biotic integrity is at risk due to a lack of species diversity. Lack of diversity as well as grazing pressure can also lead to an increase in invasive species establishment.

Characteristics and indicators. This site is indicated by a lack of overall diversity in the plant composition as well as an increased overstory in grazing-tolerant plants. Continued heavy grazing makes these characteristics more pronounced and can eventually result in transition to the disturbed community if not managed.

Resilience management. This state is moderately resilient. Resilience is gained by the shallow depth of a seasonal water table, which can moderate the impact of drought conditions. However, the lack of diversity makes this site more susceptible to the impacts of disturbances such as insect damage, disease, herbivory, and fire.

Community 2.1
Short Stature Grass

The Short Stature Grass community is a result of continuous, high-intensity grazing. Much of the diversity of the Reference state is lost. The composition and canopy cover of grazing-tolerant, often rhizomatous species increases. The loss of diversity also creates opportunities for invasive species establishment. The primary grass species present are Sandberg bluegrass, slender wheatgrass, and western wheatgrass, and less palatable salt-tolerant species like alkali sacaton. Total production is less for this community than for communities in the Reference state. Production ranges from 600 to 2,000 pounds per acre, averaging 1,250 pounds per acre.

If overgrazing continues for extended periods of time and invasive species occupy more of the composition and canopy, this state can transition to the Disturbed state.

Resilience management. This site has moderate resilience as a result of the additional water availability from seasonal water table levels. Resilience is lost on this site due to lack of diversity and the potential establishment of non-native species.

State 3
Disturbed

The Disturbed state is a result of natural or anthropogenic disturbances to the ecological site. The two primary disturbances that impact this site are plowing and haying practices, followed by abandonment and activities that alter the natural hydrologic regime. These disturbances lead to the introduction and establishment of non-native species. Following the disturbance, the common grass species that establish are meadow foxtail (Alopecurus spp.), foxtail barley (Hordeum jubatum), and quackgrass (Elymus repens). Common forbs include Canada thistle (Cirsium arvense) and povertyweed (Iva axillaris).

Characteristics and indicators. This state is dependent on disturbances that displace native vegetation and create opportunities for invasive species establishment. The severity and frequency of the disturbance can often dictate the level of establishment of invasive species. Alteration of hydrology that cannot be restored has the potential to shift create a shift to a new ecological site.

Resilience management. This site has low resilience and biotic integrity due to the composition of non-native plant species. Mechanical treatments followed by reseeding and prescribed grazing will aid in the transition back to the Reference state. For restoration to be successful, the historic hydrologic regime must be functional with reliable seasonal water table levels. Regardless of intervention and restoration techniques, some invasive species such as foxtail barely and meadow foxtail may continue to persist to some degree.

Community 3.1
Foxtail Barley and Quackgrass

This community occurs after an ecological site has been plowed or cropped and then improperly managed or abandoned. The two primary grasses that begin to dominate the site after this occurs are foxtail barely (Hordeum jubatum) and quackgrass (Elymus repens). Foxtail barley is well adapted to saline conditions as well as disturbed sites and is able to rapidly establish after abandonment. Quackgrass is highly competitive with native vegetation and is able to quickly increase canopy cover on a site. Invasive forbs can also be present on site, including povertyweed (Iva axillaris) and field sowthistle (Sonchus arvensis).

Total annual production varies with this community but tends to be lower than any community in the Reference state. Production ranges from 1,000 to 1,900 pounds per acre, averaging 1,500 pounds per acre.

Resilience management. This site has low resilience due to lack of diversity and invasive species recruitment. Once established, the dominant plants of this community outcompete and prevent return of desired and native species.

Community 3.2
Invasive Species

This community is disturbance-driven. Specific disturbances drive a transition from native vegetation to one dominated by invasive species. The severity or frequency of the respective disturbance plays a role in how quickly invasive species can establish and to what extent. Disturbances such as continuous intensive grazing, plowing followed by abandonment, or any disturbance which interrupts the hydrologic cycle are particularly impactful. This community is dominated by invasive grass and forb species including meadow foxtail, quackgrass, povertyweed, Canada thistle, and other annual forbs.

Production for this community is lower than in most other states and communities. The production range is 500 to 1,400 pounds per acre, averaging 1,000 pounds per acre.

Resilience management. This community has low resilience due to the lack of native vegetation and the impact of current or past disturbances. Once invasive established, it is difficult and resource intensive to remove them completely.

Pathway 3.1A
Community 3.1 to 3.2

The transition from Community 3.1 to Community 3.2 is a result of localized abiotic conditions and presence of available seed sources of invasive species. Composition of invasive species in Community 3.2 is more diverse and foxtail barely and quackgrass comprise a lower percentage of the canopy. Other invasive species are able to rapidly establish and contribute to a greater overall portion of canopy cover and production.

Context dependence.This transition can also be a result of site specific saline concentrations. Levels of salinity can dictate which plants are able to establish at a given site.

Pathway 3.2A
Community 3.2 to 3.1

Transition T1A
State 1 to 2

Reference

Grazing Resistant

The transition from the Reference state to the Grazing Resistant state is driven by grazing-related disturbances. Continuous grazing or extended periods of intense grazing can reduce the presence of grazing-intolerant species, decrease diversity, and increase canopy cover of increaser species. If grazing practices continue and mitigation measures are not taken, this can eventually cause a transition to the Disturbed state.

Constraints to recovery.The primary constraint to recovery is improper grazing management. Resting periods and decreased grazing intensity will be needed for recovery and restoration towards the Reference state.

Context dependence.The transition from the Reference state to the Grazing Resistant state can be affected by seasonal weather patterns and other disturbances such as drought or fire.

Transition T1B
State 1 to 3

The transition from the Reference state to the Disturbed state is a result of both natural and anthropogenic disturbances. High-severity disturbances and those outside of the natural disturbance regime are more likely to initiate a transition from the Reference state. The primary disturbances impacting this ecological site resulting in transition include agricultural plowing and abandonment, drought, fire, and alteration of the hydrologic regime.

Constraints to recovery.Constraints to recovery vary based on disturbance history. Non-functioning hydrology can severely limit restoration. Continued disturbances, even low in severity, as well as potential invasive species establishment can also constrain recovery.

Context dependence.Restoration is affected by seasonal weather patterns, current disturbance regimes, and the severity of past disturbances. If the site has a significant canopy cover and composition of invasive species, this will also impact management decisions and the likelihood of restoration success.

Restoration pathway R2A
State 2 to 1

Grazing Resistant

Reference

Restoration from the Grazing Resistant state to the Reference state requires a change in grazing practices. Less intensive grazing with periods of rest can facilitate natural return to the Reference state. Removal of invasive species and seeding may be required depending on conditions.

Context dependence.Restoration success is dependent on successful grazing plans and adaptive management. Restoration time can be decreased through seeding and rest from grazing. Other disturbances such as drought, fire, or alteration of the hydrologic function can slow restoration or initiate transition to the Disturbed state.

Transition T2A
State 2 to 3

The transition from the Grazing Resistant state to the Disturbed state is a mechanism of severe or repeated disturbance, often outside the historic disturbance regime for the ecological site. The most common disturbances to initiate the transition are continuous intensive grazing, fire, drought, and alteration of the hydrologic regime. These disturbances result in the removal of grazing-resistant species, which allows for the establishment of fast-establishing invasive species.

Constraints to recovery.Restoration to the Grazing Resistant state is dependent on severity of initial disturbance and absence of disturbances during recovery time. If the hydrologic regime has been altered, function will need to be returned before successful restoration can occur.

Context dependence.Restoration likelihood is affected by seasonal weather patterns, current disturbance regimes, and severity of past disturbances. If the site has a significant canopy cover and composition of invasive species, this will also impact management decisions and the likelihood of restoration success.

Restoration pathway R3A
State 3 to 1

Restoration from the Disturbed state to the Reference state requires removal of invasive species and restoration of the hydrologic regime to historic depth and seasonal duration if it has been altered. Removal of invasive species can be achieved through mechanical and chemical treatments, targeted grazing, or a combination of the three. Success of invasive species removal is improved if planting or seeding of native species is completed afterward.

Context dependence.Restoration success is dependent on ability to restore hydrologic function a level of invasive species establishment. Time without further disturbance also increases restoration success.

Restoration pathway R3B
State 3 to 2

Restoration from the Disturbed state to the Grazing Resistant state requires removal of invasive species and restoration of the hydrologic regime to historic depth and seasonal duration if it has been altered. Removal of invasive species can be achieved through mechanical and chemical treatments, targeted grazing, or a combination of the three. Success of invasive species removal is improved if planting or seeding of native species is completed afterward.

Context dependence.Restoration success is dependent on the ability to restore hydrologic function a level of invasive species establishment. Time without further disturbance also increases restoration success.