Valley Bench 8-12 PZ
Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
- Transition T1A More details
- Transition T1B More details
- Restoration pathway R2A More details
- Transition T2A More details
- Restoration pathway R3A More details
- Transition T3A More details
-
No transition or restoration pathway between the selected states has been described
Target ecosystem state
Select a state
Description
The reference state has a mix of grasses, forbs, and shrubs. Grasses provide the most annual production with shrubs secondary. The state has a diversity of cool and warm season species such as western wheatgrass, blue grama, and needleandthread, with Wyoming big sagebrush scattered throughout.
Resilience management
The reference state is the most resilient to disturbance. A mix of grass and shrubs provide a diversity of root systems which maximized ecological processes such as decomposition, mineralization, and soil aggregation. This in turn maximizes water infiltration and protection from erosion.
Submodel
State 2
Degraded: Decadent Sagebrush
Description
Big sagebrush dominates the plant community. Western wheatgrass and blue grama remain scattered and in low vigor. If blue grama is present, it frequently appears low in stature in shallow rooted patches. As the site continues to lose herbaceous species due to multiple feedbacks, bare ground increases and a surface soil crust developes. This soil surface condition retards water infiltration and grass establishment/recruitment and allows the site to persist in a big sagebrush state.
Production, species composition, and diversity are drastically reduced. Water cycle, nutrient cycle, and biotic integrity have been severely affected. As litter amounts decrease, bare areas increase. The semiarid environment coupled with loss of cover, magnifies soil surface crusting which impairs water infiltration subsequently increasing overland flow. In advanced stages of non-activity, big sagebrush will show signs of decadence and mortality.
Resilience management
This state has limited resilience to disturbance. Erosion is active with new gullies evident. Long-duration drought may affect and kill the sagebrush as well.
State 3
Degraded: Bare Ground, Snakeweed, Rabbitbrush, Annuals
Description
This state consists of mostly bare ground with some rabbitbrush, snakeweed, and annuals. Some blue grama may exist in patches along with Colorado rubberweed, and ring muhly.
Resilience management
Water and wind erosion is a very large concern in this state.
Mechanism
The major long-term driver is repetitive, high utilization grazing of grass species while not allowing for regrowth and recovery for multiple years. This type of management eventually decreases health and vigor of grasses, fine fuel and the site's ability to carry fire. Big sagebrush gains a competitive advantage due to deep root systems and natural grazing defenses. Eventually the bare soil forms a crust due to low aggregate stability and a high percentage of bare ground. This makes it difficult for recruits to germinate.
Mechanism
The major long-term driver is repetitive defoliation with high utilization during the growing season allowing for no rest and recovery of palatable species, causing death of grass and forb species. This in turn causes greater soil loss and erosion on the site. This coupled with a wholesale mechanical treatment of shrubs will denude the site and create feedback loops where ecological processes are poorly functioning. .
Mechanism
Short-term sagebrush treatment, coupled with range seeding, and a period of grazing rest for stand establishment. Shrub removal should not be wholesale but in a mosaic of patchiness as sagebrush is an important species for the health of the site.
It is also best to implement long-term grazing management strategies where indicator plant species are seldom defoliated during the critical growth period and have an opportunity to colonize and restore ecosystem health.
Transition T2A
Mechanism
A brush control event followed by repetitive defoliation at high utilization rates without rest or recovery, thereby inhibiting the germination of new plant species. New seedlings will not be allowed to germinate, produce roots and shoots and colonize the area. Drought following treatment will exacerbate the feedbacks which lead toward degredation.
Restoration pathway R3A
Mechanism
The plants, soil, and microbial community needs to be re-established. This will be a long-term, expensive endeavor.
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.