Stony South Aspect
Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
-
Transition T1
grazing pressure
More details -
Transition T2
grazing pressure
More details -
No transition or restoration pathway between the selected states has been described
Target ecosystem state
Select a state
Description
State 1 Narrative:
Reference State represents grassland with no invasive or exotic weed species. State 1 is dominated by bluebunch wheatgrass. Native forbs are well represented but shrubs have a minor role. All functional and structural groups are present.
Stony South Slope is not as stable as Shallow Stony.
Reference community 1.1 is dominated by bluebunch wheatgrass
Reference State Community Phases:
1.1 Reference Bluebunch wheatgrass
Dominant Reference State Species: Bluebunch wheatgrass
At-risk Communities:
• South slopes receive a lot of solar radiation and droughty at times. A host of weed species are at home in this environment, so the risk of invasion is high
• Any community in the reference state is at risk of moving to State 2 as the seed source of cheatgrass and other invasive species is nearby and moving onto most sites annually.
Submodel
Description
State 2 Narrative:
State 2 represents grassland with some invasive species. Native species are present and dominant, but invasive species have gained a foothold that they do not easily relinquish. State 2 is transitional because unless management changes and weed suppression occurs, State 2 will transition onto State 3 (dominated by invasive species). The invasion can be either annual bromes, bulbous bluegrass, or broadleaf weeds.
The invasion can be either cheatgrass, bulbous bluegrass, or a broadleaf weeds such as tarweed.
Community Phases for State 2:
2.1 Native Grassland w/ Invasive Species
Bluebunch wheatgrass – Forbs – Invasive species
Dominant Species in State 2: bluebunch wheatgrass
Submodel
Description
State 3 Narrative:
State 3 represents sites that are dominated by invasive species and has crossed a biological threshold.
The invasive species can include cheatgrass, bulbous bluegrass, prickly lettuce and tarweed. In State 3 native bunchgrasses which were dominant in the Reference State are virtually missing and the other native, functional-structural groups have been altered.
Community Phases for State 3: Invasive species
Dominant Species in State 3: Invasive annual grasses, broadleaf weeds, or
short-lived perennial cool season grass
Resilience management
State 3 is considered non-reversible. Due to steep slopes, the hot, south slope and stones (surface rock and rock within the soil profile), and the equipment limitations thereof, seeding is not practical for the Stony South Slope ecological site.
Restoration of bluebunch wheatgrass, native forbs and the soil biotic crust would be very problematic at best on Stony South Slope. Seeds must germinate. Seedlings and plugged plants need soil moisture and time to become established. In most years, seeds and plugs may not have a chance as site conditions on Shallow Stony can change quickly. Drying winds and bright sun can turn a snowy or muddy site into a hard crust before plants are established. So, the timing of all recovery efforts would have an extremely narrow window of opportunity on Stony South Slope. Perhaps the only avenue for recovery would be to plant plugs of native species which is a very costly and risky proposition.
Submodel
Mechanism
T1 Transition from Reference State with no invasive species to State 2 a with a mixed stand of native plants and some invasive species. Previously the stand has not had alien species. The result of this transition is the presence of invasive species. Depending on seeds in the soil bank and what is growing nearby, bulbous bluegrass, tarweed or cheatgrass enter the stand of native species.
Primary Trigger: grazing pressure (heavy grazing intensity, season long grazing or frequent late spring grazing) to bluebunch wheatgrass and other palatable species.
Ecological process: consistent defoliation pressure to bluebunch wheatgrass and other palatable species results in poor vigor, shrinking crowns and plant mortality. This allow native forbs to increase and invasive species to colonize. Most sites in the Reference State have cheatgrass seed as the seed blows onto the sites annually. Cheatgrass is a prolific seeder and the seed is waiting for enough moisture to germinate and to compete with the native species for space, light and moisture. When the right year happens even pristine communities in the Reference State are susceptible to colonization by cheatgrass.
Indicators: decreasing cover of bluebunch wheatgrass and other palatable native species and the occurrence of invasive species on sites where they had been absent.
Mechanism
T2 Result: shift from State 2 native species with some invasive plants to State 3 which is dominated by invasive species. This transition occurs once the cover of invasive species is dominate and the cover of bluebunch wheatgrass is minor.
Primary Trigger: grazing pressure (heavy grazing intensity, season-long grazing, or late spring grazing) to bluebunch wheatgrass and other palatable species.
Ecological process: consistent defoliation pressure to bluebunch wheatgrass and other palatable species results is poor vigor, shrinking crowns and plant mortality. In a series of retrogressions palatable species are weakened, and the invasive species increase to fill the void. This continues until the stand is dominated by invasive species rather than natives. The site has lost its primary species that stabilize and protect the soil from wind and water erosion and has also lost the ability to retain adequate soil moisture for many of the native perennial species.
Indicators: Decreasing cover of bluebunch wheatgrass and increasing cover of invasive annual species. Increasing distance between bluebunch wheatgrass plants.
State 3 is considered non-reversible. Due to steep slopes, the hot, south slope and stones (surface rock and rock within the soil profile), and the equipment limitations thereof, seeding is not practical for the Stony South Slope ecological site.
Restoration of bluebunch wheatgrass, native forbs and the soil biotic crust would be very problematic at best on Stony South Slope. Seeds must germinate. Seedlings and plugged plants need soil moisture and time to become established. In most years, seeds and plugs may not have a chance as site conditions on Shallow Stony can change quickly. Drying winds and bright sun can turn a snowy or muddy site into a hard crust before plants are established. So, the timing of all recovery efforts would have an extremely narrow window of opportunity on Stony South Slope. Perhaps the only avenue for recovery would be to plant plugs of native species which is a very costly and risky proposition.
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
Liston, A, B.L. Wilson, W.A. Robinson, P.S. Doescher, N.R. Harris, and T. Svejar. 2003. The Relative Importance of Sexula Reproduction Versus Clonal Spread in an Arid Bunchgrass. Oecologia 137:216-225
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
Vallentine, John F. 1971. Range Development and Improvement. BYU Press, Provo, UT.
Model keys
Briefcase
Add ecological site groups and Major Land Resource Areas to your briefcase by clicking on the briefcase (
) icon wherever it occurs. Drag and drop items to reorder. Cookies are used to store briefcase items between browsing sessions. Because of this, the number of items that can be added to your briefcase is limited, and briefcase items added on one device and browser cannot be accessed from another device or browser. Users who do not wish to place cookies on their devices should not use the briefcase tool. Briefcase cookies serve no other purpose than described here and are deleted whenever browsing history is cleared.
Ecological site groups
Major Land Resource Areas
The Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.