State 1
Reference State

The Reference State includes the plant communities that were best adapted to the unique combination of factors associated with this ecological site prior to European settlement. It was in a natural dynamic equilibrium with the historic biotic, abiotic, climatic factors on its ecological site in North America at the time of European immigration and settlement. There are three community phases: grass and sagebrush dominated, sagebrush dominated, and grass dominated. Plant community phase changes are driven by fire, drought, and/or insect or disease.

Characteristics and indicators. This state will not contain any non-native species in the plant community.

Community 1.1
Bonneville big sagebrush / Perennial cool season grasses / Forbs / Other native shrubs

Community Phase 1.1 is represented with 60 percent grasses, 25 percent forbs, and 15 percent shrubs. The dominant shrub visually and in production is Bonneville big sagebrush. The dominant grass is bluebunch wheatgrass and the dominant forb visually is arrowleaf balsamroot (Balsamorhiza sagittata).

Community 1.2
Bonneville big sagebrush / Other native shrubs / Perennial cool season grasses = Forbs

Bonneville big sagebrush has increased in the community from lack of disturbance. The sagebrush utilizes more resources causing grasses and forbs to decrease in the understory. The community composition is 40 percent grasses, 25 percent forbs, and 35 percent shrubs. This community will have between 10 to 20 percent bare ground.

Community 1.3
Perennial cool season grasses / Forbs / Fire tolerant shrubs

Localized hot fires reduce the shrub canopy allowing the grasses and forbs to increase in the burned patches. Aroga moth infestations may also reduce the sagebrush canopy. The plant community composition is 70 percent grasses, 20 percent forbs, and 10 percent shrubs. This community will have between 15 to 20 percent bare ground.

Pathway 1.1a
Community 1.1 to 1.2

Time without disturbance event that removes the shrub canopy.

Pathway 1.1b
Community 1.1 to 1.3

Normally mid-summer fire, insects, prolonged drought and pathogens that kill and/or reduces the dominant shrub overstory. Fire is the most effective of these disturbances.

Pathway 1.2a
Community 1.2 to 1.3

Normally a mid-summer fire. A fire that is hot enough and fast moving enough to kill sagebrush and stimulate the perennial cool season grasses, insects, prolonged drought and pathogens that kill and/or reduces the dominant shrub overstory. Fire is the most effective of these disturbances.

Pathway 1.3a
Community 1.3 to 1.1

Time without catastrophic event. This was probably dependent on a specific chain of climatic events.

State 2
Current Potential State

The Current Potential State (CPS) includes the biotic communities that would become established on the ecological site if all successional sequences were completed without interferences by humans under the present environmental conditions. Natural disturbances are inherent in its development. The CPS state may include acclimatized, naturalized or invasive nonnative species. There is no known way to effectively remove these plants from the site once they have become established. The level of occurrence of these plants in the CPS is such that careful management can prevent their domination of the site. This site is irreversibly changed. Plant communities within the CPS state may be managed and used for various purposes by man without significant alteration in plant community composition or production. It includes all the plant communities that exist in the Reference State with the inclusion of species that are non-native.

Characteristics and indicators. This state will be similar to the Reference State, except it will have non-native species in the plant community.

Community 2.1
Bonneville sagebrush / perennial cool season grass / forb other native shrub / non-native species

This community is represented with 60 percent grasses, 25 percent forbs, and 15 percent shrubs. The dominant shrub visually and in production is Bonneville big sagebrush. The dominant grass is bluebunch wheatgrass and the dominant forb visually is arrowleaf balsamroot. This community will have between 10 to 15 percent bare ground. This community will have notable amounts of non-native species.

Community 2.2
Bonneville sagebrush / other native shrub / perennial cool season grass = forb / non-native species

Bonneville sagebrush has increased in the community which has reduced the understory grasses and forbs. Other shrubs (notably) mountain snowberry, antelope bitterbrush and Utah serviceberry also often increase with lack of shrub removing disturbance. The community composition is 40 percent grasses, 25 percent forbs, and 35 percent shrubs. This community typically has bare ground between 10 to 20 percent. This community will have notable amounts of non-native species.

Community 2.3
Perennial Cool Season Grass / Forb / Fire Tolerant Shrub / Non-Native Species

Localized hot fires remove the shrub canopy allowing the grasses and forbs to increase in the burned patches. Aroga moth infestation can also remove patches of sagebrush. The plant community is represented with 70 percent grasses, 20 percent forbs, and 10 percent shrubs. This community will likely have around 15 to 20 percent bare ground. This community will have notable amounts of non-native species.

Pathway 2.1a
Community 2.1 to 2.2

Time without disturbance event that removes the shrub canopy. This was probably dependent on a specific chain of climatic events.

Pathway 2.1b
Community 2.1 to 2.3

Normally a mid-summer fire, insects, prolonged drought and pathogens that kill and/or reduces the dominant shrub overstory. Fire is the most effective of these disturbances.

Pathway 2.2a
Community 2.2 to 2.3

Normally a mid-summer fire. A fire that is hot enough and fast moving enough to kill sagebrush and stimulate the perennial cool season grasses, insects, prolonged drought and pathogens that kill and/or reduces the dominant shrub overstory. Fire is the most effective of these disturbances.

Pathway 2.3a
Community 2.3 to 2.1

Time without disturbance event that removes the shrub canopy. This was probably dependent on a specific chain of climatic events.

State 3
Tree State

The Tree State has only two described plant community phases, but many variations of the represented ones are present. The site will move to this state when there is a lack of fire (over exuberant fire control) and there is a source of Utah Juniper and/or pinyon seed. Movement from community phase to community phase can and often is accelerated by overgrazing. Cheatgrass will often be the dominant understory plant in this state. This state can persist for a long time until extreme conditions needed for a wildfire occur or some other management treatment is implemented.

Characteristics and indicators. This state will have noticeable cover of Utah junipers or pinyon.

Community 3.1
Utah Juniper / Bonneville big sagebrush / Native Perennials / Invasive Annuals

This community has a overstory of Utah juniper and singleleaf pinyon but still has an understory like community 2.1. This community will have around 20 to 35 percent bare ground. Introducing fire back to the site may return this site to State 2. Mechanical removal of juniper and pinyon can be used to reduce cover.

Community 3.2
Utah Juniper / Invasive Annuals

This community is present when 99 percent of the native plants have been removed from the plant community and only pinyon and juniper with a sparse understory of invasive annuals are left on the site. This community will have around 35 to 85 percent bare ground. The bare ground in this phase may accelerate soil erosion as there are few species to protect the soil surface.

Pathway 3.1a
Community 3.1 to 3.2

Overgrazing with or without drought over a prolonged period of time.

Pathway 3.2a
Community 3.2 to 3.1

Fire, insects, prolonged drought and pathogens that kill and/or reduces the dominant shrub overstory. Fire is the most effective of these disturbances.

State 4
Yellow rabbitbrush / Invasive Annuals

This state occurs when this site is overgrazed for an extended time. This state may also occur with the combination of drought and over grazing or drought and fire with either no seeding following the fire or a failed seeding. The dominant aspect of the plant community is cheatgrass brome, yellow rabbitbrush, and a small amount of Bonneville big sagebrush.

Characteristics and indicators. This state is dominated by shrubs other than big sagebrush and annual grasses.

Community 4.1
Yellow rabbitbrush / invasive annuals = native perennials

This plant community occurs when the site is overgrazed for a prolonged period. Drought, fire, mechanical disturbance, and other like disturbances will speed up the process. The plant community composition is about 40 percent yellow rabbitbrush, 50 percent non-native/invasive annuals, and 10 percent native perennials. This community will have between 20 to 35 percent bare ground.

Community 4.2
Invasive annuals

This plant community has lost the Bonneville big sagebrush and the invasive annuals have taken space away from the Sandburg bluegrass. The plant community composition is about 88 percent non-native/invasive annuals and 12 percent native perennials. This community will have around 20 to 40 percent bare ground.

Pathway 4.1a
Community 4.1 to 4.2

Increased fire frequency (from 10 to 15 years to 3 to 5 years) and intensity without follow-up management. Overgrazing can move this change along faster.

Pathway 4.2a
Community 4.2 to 4.1

Time and management of grazing alone or along with other disturbances where human and/or naturalized introduction of native and/or introduced perennial plant species takes place.

State 5
Seeded Range State

The Seede State exists when the site is cultivated and/or burned and planted to Introduced perennial plants and/or in some situations a mix of native grasses and forbs.

Characteristics and indicators. This state will be dominated by seeded grass and forbs in the plant community.

Community 5.1
Introduced perennial plants

The plant community consists of introduced and in some situations native grasses, forbs and sometimes native and/or introduced half-shrubs and/or shrubs. Community Phase 5.1 is often as productive as the Current Potential State.

Community 5.2
Native shrubs = Introduced perennial plants

This phase occurs when weather conditions create the kind of episodic situation that allows Bonneville big sagebrush to move back onto the site.

Pathway 5.1a
Community 5.1 to 5.2

Time without catastrophic event. This was probably dependent on a specific chain of climatic events. Also heavy prolonged cattle grazing can cause this to happen.

Pathway 5.2a
Community 5.2 to 5.1

Time and management of grazing alone or along with other disturbances where human intervention takes place to move the community back.

Transition T1a
State 1 to 2

Introduction of non-native species into the ecosystem.

Transition T2a
State 2 to 3

Prolonged drought, overgrazing, extreme lengthening of the fire interval frequency. This takes place when the sagebrush canopy gets so dense that it destroys the perennial grass and forb understory and the fire frequency is increased from 20 to 40 years to 60 to 90 years and there is an introduction of Utah Juniper.

Transition T2b
State 2 to 4

Prolonged drought and/or prolonged overgrazing. Most often it is a combination of the two conditions that bring this condition into existence. Continued overgrazing and increase of the fire frequency over a very prolonged period of time i.e. 3 to 5 year fire frequency interval.

Transition T3b
State 3 to 4

Continued overgrazing and increase of fire frequency over a very prolonged period of time i.e. 3 to 5 year fire frequency interval.

Transition T3a
State 3 to 5

Human caused disturbance i.e. mechanical treatment and seeding; chemical treatment and seeding etc.

Transition T4a
State 4 to 5

Human caused disturbance i.e. mechanical treatment and seeding; chemical treatment and seeding etc.

Restoration pathway R5a
State 5 to 2

Time with proper management that favors the native plants as they move back onto the site.

Transition T5a
State 5 to 3

Prolonged drought, overgrazing, extreme lengthening of the fire interval frequency. This takes place when the sagebrush canopy gets so heavy that it destroys the perennial grass and forb understory and the fire frequency is increased from 20 to 40 years to 60 to 90 years and there is an introduction of Utah Juniper.

Transition T5b
State 5 to 4

Continued overgrazing and increase of fire frequency over a very prolonged period of time i.e. 8 to 12 year fire frequency interval.