State 1
Reference State - Shrub Steppe with No Invasive Species

State 1 Narrative: State 1 represents shrub steppe with no invasive or exotic weed species. All the functional, structural groups are represented by one or more native species. Reference State Community Phases: 1.1 Reference Bluebunch wheatgrass – bitterbrush 1.2 Bunchgrass Bluebunch wheatgrass 1.3 Shrub Steppe Bitterbrush – bluebunch wheatgrass 1.4 Heavy Shrub Bitterbrush – needle and thread Communities 1.1, 1,2 and 1.3 can shift to the other two communities and back again. Dominate Reference State Species: Antelope bitterbrush – bluebunch wheatgrass At-risk Communities: • All communities in the reference state are at risk of moving to State 2. The seed source of cheatgrass is nearby and blowing onto most sites annually • Community Phases 1.1, 1.2 and 1.3 have high amounts of bluebunch wheatgrass cover and are at low risk of moving to State 3 • Community Phase 1.4 is at-risk because of low density for bluebunch wheatgrass. Community 1.4 should be seeded after fire • Any community with more than 40% bitterbrush cover • When fire kills the Idaho fescue plants, these sites should be seeded after fire • Community 1.4, and any site with low cover of bluebunch wheatgrass, and any site with moderate to heavy cover of cheatgrass should be seeded after fire

Community 1.1
Reference

Community 1.2
Bunchgrass

Community 1.3
Shrub Steppe

Community 1.4
Heavy Shrub

Community 1.4, heavy shrub, is dominated by bitterbrush with needleandthread as sub-dominate. There is not enough bluebunch wheatgrass remaining for community 1.4 to shift back to the other communities in the reference state.

Pathway 1.1a
Community 1.1 to 1.2

1.1a Result: Shift from reference community to bunchgrass community. Shrub cover (bitterbrush and sagebrush) is all but eliminated, while bluebunch wheatgrass has a moderate increase in cover. The community shifts from a shrub steppe to a bunchgrass appearance. Causes: Moderate-severity fire is complete enough and hot enough to remove most of the shrubs. Fire is not hot enough to affect the soil conditions. The fire removes surface vegetation but has no impact on the crown of bunchgrasses. So, bunchgrasses and forbs return post-fire with good vigor. Post-fire the bunchgrasses are now more susceptible to grazing damage. Burned rangeland pastures will need two growing seasons recovery prior to resuming grazing, or to be lightly grazed but only during dormant season the first two years post-fire. Beyond two years for the bunchgrasses to expand, moderate grazing intensity, and both critical period & growing season deferments must be implemented on burned pastures. Ecological process: Fire kills sagebrush and it does not have any sprouting ability. A few sagebrush plants remain, but only in patches that did not burn. The reduction in sagebrush releases resources and increases light for grasses and forbs. Bluebunch wheatgrass and other bunchgrasses have good vigor post-fire and expand via tillering and new seedlings.

Pathway 1.2b
Community 1.1 to 1.3

1.2b Result: shift from bunchgrass or reference community to shrub steppe community. There is a moderate increase in bitterbrush while bunchgrasses have a moderate corresponding decrease. Causes: With excessive grazing pressure (heavy grazing intensity, season long grazing or frequent late spring grazing) and a period of no fire, bitterbrush and sagebrush increase its cover while bluebunch wheatgrass suffers a big decline. The increased shade and grazing pressure cause lower bunchgrass vigor and a decline. Ecological process: With consistent defoliation pressure plant vigor decreases to such a degree that grass roots begin to die. So, bluebunch wheatgrass experiences shrinking crowns and some plant mortality. The open niche space allows bitterbrush and sagebrush to set new seedlings and expand. Needleandthread, a prolific seeder, expands with many seedlings.

Pathway 1.2a
Community 1.2 to 1.1

1.2a Result: Shift from bunchgrass community to reference community. There is a minor reduction of bluebunch wheatgrass cover and a minor increase of bitterbrush. Causes: Over time with no fire bitterbrush and sagebrush will re-enter the community. With a slight increase in shade and some grazing pressure, perennial bunchgrasses experience a slight decline. Ecological process: With some consistent defoliation pressure Idaho fescue and bluebunch wheatgrass have lower vigor and shrinking crowns. Bitterbrush and sagebrush set new seedlings and expand. Rodents cache bitterbrush seed in the soil. Post-fire some of this cached seed will germinate. Also, spots with soil disturbance receive sagebrush seed from remnant plants in unburned patches or from adjacent sites, seed germinates in the spring and a few sagebrush seedlings establish.

Pathway 1.1b
Community 1.3 to 1.1

1.1b Result: Shift from shrub steppe community to reference community or to bunchgrass community. Shrub cover is reduced by two-thirds which is coupled with a significant increase in the cover of native bunchgrasses. Causes: Moderate-severity fire is patchy and dependent on temperature, wind, fuel load and fuel moisture. Some areas burn completely while other areas are unburned to lightly burned. Fire is not hot enough to affect the soil conditions. Fire removes surface vegetation but has no impact on the root crown of bunchgrasses. So, bunchgrasses and forbs return post-fire. Post-fire the bunchgrasses are now more susceptible to grazing damage. Burned rangeland pastures will need two growing seasons recovery prior to resuming grazing, or to be lightly grazed but only during dormant season the first two years post-fire. Beyond two years, for the bunchgrasses to continue to expand, the grazing plan must consider moderate grazing intensity, and both critical period & growing season deferments. Ecological process: Bluebunch wheatgrass and other bunchgrasses have good vigor post-fire and expand via tillering and new seedlings. The reduction in bitterbrush releases resources and increases light for grasses and forbs. Bunchgrasses must have high vigor both pre- and post-fire, to expand its cover.

Pathway 1.2c
Community 1.3 to 1.4

1.2c Result: Shift from shrub steppe community to heavy shrub community. Bitterbrush and needleandthread have a big increase in cover while bluebunch wheatgrass is reduced significantly. Invasive annual grasses have not invaded but Community 1.4 is most at risk and, is the segue between Reference State and States 2 & 3. Causes: With no fire, more shade and grazing pressure (heavy grazing intensity, season long grazing or frequent late spring grazing), the bunchgrasses experience weakened vigor and declining crowns. Grazing animals selectively target and eliminate most of the remaining bluebunch wheatgrass plants from the community. Bitterbrush and needleandthread both expand. Ecological process: With consistent defoliation pressure plant vigor decreases to such a degree that grass roots die. Bluebunch wheatgrass experiences shrinking crowns and a lot of plant mortality. Bitterbrush and needleandthread, however, set new seedlings and expand. The open niche space gives bitterbrush and sagebrush opportunity to set new seedlings. Needleandthread, a prolific seeder, expands with many seedlings.

State 2
Shrub Steppe with Invasive Species

State 2 Narrative: State 2 represents invasion by annual grasses and is the gradation between Reference State and State 3. State 2 is shrub steppe with the inclusion of invasive annual grasses such as cheatgrass. The loss if soil biological crusts and annual grass seed blowing onto the site annually contributes to the annual grass invasion. All the native functional, structural groups are still represented by one or more species. This state can occur with or without bitterbrush. For communities 2.1, 2.2, and 2.3 the amount of cheatgrass is minor. Cheatgrass is more prominent in community 2.4. Once a community has been invaded by cheatgrass the chance of going back to State 1 is small. This state can occur with or without bitterbrush. Community Phases for State 2: Same four communities as for Reference State. Dominate State 2 Species: Bitterbrush, bluebunch wheatgrass Pathways within State 2: Same as for Reference State

Community 2.1
Reference

Community Phases for State 2: Same four communities as for Reference State. Dominate State 2 Species: Bitterbrush, bluebunch wheatgrass

Community 2.2
Bunchgrass

Community 2.3
Shrub Steppe

Community 2.4
Heavy Shrub

State 3
Annual Grasses

State 3 Narrative: State 3 represents communities dominated by invasive annual species and has crossed a biological threshold. Virtually all the native functional, structural groups are missing. This state can occur with or without shrubs. Important species can include cheatgrass, Japanese brome, medusahead, ventenata, mustard, prickly lettuce and diffuse knapweed. Community Phases for State 3: 3.1 Shrub – Annual Grass Bitterbrush – Annual bromes 3.2 Annual Grass Annual bromes Dominate State 3 Species: Annual grasses such as cheatgrass, with or without shrubs The main species can include Japanese brome, medusahead, ventenata, mustard, prickly lettuce and diffuse knapweed. This state can occur with or without shrubs.

Community 3.1
Shrub Annual Grass

Community 3.2
Annuals Grass

Pathway 3.1a
Community 3.1 to 3.2

3.1a Result: shift from shrub-annual brome community to annual brome community Causes: Moderate intensity fire kills most or all sagebrush. Annual bromes and other invasive species fully occupy the site.

State 4
Seeded Grasses

State 4 Narrative: State 4 represents a site that has been seeded to desirable grasses such as Secar Snake River wheatgrass, Sherman big bluegrass, crested wheatgrass or intermediate wheatgrass. The communities in State 4 are stable as long as they maintain 0.8 plant / sq. ft. or greater of the desired grasses Dominate Species for State 4: Desirable seeded grass species with or without shrubs and legumes Community Phases for State 4: 4.1 Seeded Grass 4.2 Shrub – Seeded Grass

Community 4.1
Seeded Grasses

State 4 Narrative: State 4 represents a site that has been seeded to desirable grasses such as Secar Snake River wheatgrass, Sherman big bluegrass, crested wheatgrass or intermediate wheatgrass. The communities in State 4 are stable as long as they maintain 0.8 plant / sq. ft. or greater of the desired grasses Dominate Species for State 4: Desirable seeded grass species with or without shrubs and legumes Community Phases for State 4: 4.1 Seeded Grass 4.2 Shrub – Seeded Grass

Community 4.2
Shrub Grass

Pathway 4.1a
Community 4.1 to 4.2

4.1a Result: Shift from seeded grass to shrub-grass community. Shrubs colonize the site and increase cover and density while seeded grasses decline Causes: Excessive grazing pressure (heavy grazing intensity, season long grazing or frequent late spring grazing) on seeded grasses reduce plant vigor. Grass root crowns shrink in size and some grasses die allowing shrubs to re-enter the site. Ecological Process: With consistent defoliation pressures seeded grasses experiences poor plant vigor to such a degree that grass roots begin to die. So, the seeded grasses experience shrinking crowns and some mortality. This gives shrubs the opportunity to set new seedlings and expand its cover. Increased shade from the new sagebrush plants also plays a role in this process.

Pathway 4.2a
Community 4.2 to 4.1

4.2a Result: Shift from shrub-grass to seeded grass community. The shrub layer is decreased to all but eliminated and grasses increase to dominate the community. Causes: (1) For communities with fire sensitive shrubs (sagebrush, bitterbrush) and a good population of desirable grasses, the best course of action is to reduce the shrubs by fire, chemical or mechanical treatment, and to use proper grazing management to ensure grasses recover. (2) For communities with fire tolerant shrubs (rabbitbrush, three-tip sage) and a good population of desirable grasses, the best course of action is to reduce the shrubs by chemical treatment and use proper grazing management to ensure grasses recover. (3) Communities that do not have much seeded grass remaining will require a seedbed to be prepared and a seeding operation. Seedbed preparation can use a combination of fire, mechanical tillage and chemical application. Post-seeding the site will need 1-2 years of rest while the seeded grasses are established. Broadleaf weed control may also be necessary. Afterward, proper grazing must be used to maintain the stand.

Transition T1
State 1 to 2

T1 Result: shift from Reference State to State 2 with a few annual grasses. Ecological process: annual grass seeds blow onto the site awaiting an opportunity to colonize. Loss of soil biological crusts also contributes to the invasion be annual grasses. Primary trigger: soil disturbances from rodent or badger activity provide great opportunity for invasive annual species. Fire, drought and grazing pressure can create holes in the plant community. Indicators: A few annual grasses have colonized the site.

Transition T2
State 2 to 3

T2 Result: shift from State 2 with a few annuals to State 3 which is dominated by annual grasses. This transition occurs once the cover of bluebunch wheatgrass declines to less than 10% and invasive species cover is greater than 40%. Primary trigger: Grazing pressure (heavy grazing, season long grazing or frequent late spring grazing) causes low vigor and reduced cover of bluebunch wheatgrass. Initially both needleandthread and the annual grasses increase. As the grazing pressure continues, needleandthread will also decrease. Secondary trigger: repeated fire which is not a common occurrence in MLRA 8. Ecological process: With consistent defoliation pressures bluebunch wheatgrass and needleandthread experience poor plant vigor to such a degree that grass roots begin to die. So, bunchgrasses have shrinking crowns and some mortality. This gives invasive annual grasses opportunity to expand its cover to a position of dominance. Indicators: Significant decline in vigor and cover of one or more of the dominant reference state species – bluebunch wheatgrass, bitterbrush. Increasing cover of annual grasses. Increasing canopy gaps between bluebunch wheatgrass plants.

Restoration pathway R1
State 3 to 4

Equipment limitations from surface rock and rock in the profile will cause issues and some treatment options may not be feasible on some sites. R1 Result: shift from State 3 dominated by annual grasses to State 4 seeded grasses. This restoration transition is not likely to occur without significant time and inputs for weed control, seedbed preparation, seeding operation and post-seeding management & weed control. Two years of weed control, 1-2 years of deferment post-seeding, and proper grazing management afterward.

Restoration pathway R2
State 4 to 2

R2 Result: Shift from State 3 back to State 2. This restoration transition does not occur without a significant commitment of time & resource inputs to restore ecological processes, native bunchgrasses, bitterbrush and native forb species. Attention needs to be paid to each step of the process: weed control, seedbed preparation, seeding and planting operations and post-seeding management. Shifting from State 3 to State 4: If the goal is to restore back to a native plant community, State 3 must first be shifted to State 4. It will take two years or longer to kill annual species and to exhaust the seedbank of invasive species. Site will then need to be seeded to perennial species such as crested wheatgrass to restore soil properties before native species can survive and thrive on site. The seeded species rebuild some of the basic soil properties including increased soil organic matter, increased soil moisture, and likely would also require the soil’s pore spaces, bulk density and soil microorganisms to return before the native species that used to survive in this ecological site can return. The site would also need several years of no significant fires and proper grazing management as well. See narrative for R1 transition above.   Shifting from State 4 to State 2: This assumes that the shift from State 3 to State 4 has been successful. Introduced grasses must be killed before seeding native species. The seeding of native species should occur in two steps: (1) a seeding of native bunchgrasses so that broadleaf weeds may be controlled, (2) a re-introduction of sagebrush and native forbs. The site would also need several years of no significant fires and proper grazing management as well to ensure plant establishment and vigor. Shrubs and native forbs should not be planted until broadleaf weeds have been controlled.

Transition T3
State 4 to 3

T3 Result: Transition from State 4 seeded grass to State 3 annual grasses. This transition occurs when the desirable seeded grasses become minor to the dominant annual grasses. Primary trigger: grazing pressure on the seeded grasses reduce the vigor and density of key bunchgrass species. Ecological process: the unraveling of the seeded grass community begins with weakened vigor and less cover of the seeded grasses. Invasive annual grasses colonize the site and become more and more common with the loss of each bunchgrass. Ecological process: consistent defoliation pressure causes weakened vigor, roots dying and less cover for the seeded grasses. Invasive annual grasses colonize the site and become more and more common with the loss of each bunchgrass plant. Indicators: shrinking crowns and mortality of desirable species, increasing caps gaps between seeded plants, increasing cover by annual grasses. References: Boling M., Frazier B., Busacca, A., General Soil Map of Washington, Washington State University, 1998 Daubenmire, R., Steppe Vegetation of Washington, EB1446, March 1968 Davies, Kirk, Medusahead Dispersal and Establishment in Sagebrush Steppe Plant Communities, Rangeland Ecology & Management, 2008 Environmental Protection Agency, map of Level III and IV Ecoregions of Washington, June 2010 Miller, Baisan, Rose and Pacioretty, “Pre and Post Settlement Fire regimes in mountain Sagebrush communities: The Northern Intermountain Region Natural Resources Conservation Service, map of Common Resource Areas of Washington, 2003 Rapid Assessment Reference Condition Model for Wyoming Sagebrush, LANDFIRE project, 2008 Rocchio, Joseph & Crawford, Rex C., Ecological Systems of Washington State. A Guide to Identification. Washington State Department of Natural Resources, October 2015. Pages 156-161 Inter-Mountain Basin Big Sagebrush. Rouse, Gerald, MLRA 8 Ecological Sites as referenced from Natural Resources Conservation Service-Washington FOTG, 2004 Soil Conservation Service, Range Sites for MLRA 8 from 1980s and 1990s Tart, D., Kelley, P., and Schlafly, P., Rangeland Vegetation of the Yakima Indian reservation, August 1987, YIN Soil and Vegetation Survey