SR Shrubby Mountain South 16-20 PZ
Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
- Transition T1.1 More details
- Transition T1.2 More details
- Restoration pathway R2.1 More details
- Transition T2.1 More details
- Restoration pathway R3.1 More details
- Transition T3.1 More details
-
No transition or restoration pathway between the selected states has been described
Target ecosystem state
Select a state
Description
The potential native plant community is dominated by mountain big sagebrush, antelope bitterbrush, and bluebunch wheatgrass. Taller shrubs, such as bitter cherry and serviceberry, are prominent in the stand. Squaw apple, needlegrasses and buckwheat are common. Vegetative composition of the community it approximately 40 percent grasses, 5 percent forbs, and 55 percent shrubs. Approximate ground cover is 60 to 70 percent (basal and crown).
Submodel
Description
Recognized by the need to mechanically treat the juniper woodland prior to initiating a prescribed burn. Sagebrush is stressed and dying (Juniper Sagebrush Steppe phase). Juniper Sagebrush Steppe phase with juniper dominance, Idaho fescue beneath tree canopies, bareground interspaces with a trace of bluebunch wheatgrass and an increase in Sandberg bluegrass. As the juniper woodland matures, sagebrush and bluebunch wheatgrass are eliminated and the potential for soil erosion increases (Juniper Woodland phase). In this state all of the ecological processes are controlled by juniper.
Submodel
Description
This state is dominated in the understory by cheatgrass and in the overstory by either juniper (Phase 3.1) or rabbitbrush (Phase 3.2). Sagebrush and the deep-rooted perennial bunch grasses have almost been entirely replaced in the understory of the plant community by cheatgrass and Sandberg bluegrass. This state has developed as a result of continued improper grazing in the absence of fire (T1.2) and this transition moves the plant community to the juniper woodland shallow-rooted grasses phase (3.1).
Submodel
Description
This state is dominated by cheatgrass and shallow-rooted grasses in the understory with junipers (4.1) or rabbitbrush (4.2) in the overstory. This state is recognized by the soil erosion that is occurring or has occurred on site. Since this state has occurred through widespread erosion from State 2 (T2.1) or State 3 (T3.1), the increase in bare ground makes the site more susceptible to increased wind and/or water erosion. Abiotic factors control site resources and ecological functions. Rehabilitation of this state may not be practical or possible due to extreme soil loss.
Submodel
Mechanism
Continued fire suppression will result in Juniper dominating the site and being large enough to be protected from fire damage.
Mechanism
Severe overgrazing and/or drought cause a significant reduction in deep rooted perennial bunchgrasses facilitating cheatgrass invasion and/or Sandberg bluegrass increase and the potential for juniper dominance. Continued abusive grazing eliminates bunchgrasses, facilitates cheatgrass as the dominant understory and juniper as the dominate overstory. Juniper out competes sagebrush creating the Juniper Woddland Shallow-rooted grass community phase (3.1). Continued abusive grazing with fire eliminates bunchgrasses, cheatgrass and/or Sandberg bluegrass dominates understory with an overstory of rabbitbrush (3.2).
Mechanism
Mechanical removal of western juniper can return this site to the Reference State (State 1). Care must be taken to ensure that the desired perennial herbaceous vegetation is intact and able to respond to the release of water and nutrients. May require seeding of native grasses and shrubs.
Relevant conservation practices
| Practice | External resources |
|---|---|
|
Brush Management |
|
|
Prescribed Grazing |
Mechanism
As western juniper continues to dominate the site and perennial herbaceous vegetation becomes sparse, soil movement increases. The risk of an irreversible transition over an abiotic threshold to the juniper woodland erosional phase of State 4 increases with increasing slope and increasing bare ground.
Mechanism
Mechanical removal of western juniper with seeding of grasses and shrubs can return this site to the Reference State. Requires seeding of native grasses and shrubs.
Relevant conservation practices
| Practice | External resources |
|---|---|
|
Brush Management |
|
|
Range Planting |
Mechanism
Severe overgrazing in combination with lack of fire creates potential for an irreversible transition to the Juniper Woodland Shallow-rooted grass erosional phase (4.1) within State 4. Abusive grazing and/or severe drought increases bareground facilitating wind and water erosion of soil. The Sandberg bluegrass, cheatgrass, rabbitbrush phase (3.2) will also transition to State 4 with similar disturbances or with frequent fire return intervals.
Model keys
Briefcase
Add ecological sites 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 sites
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.