Deep Hardland 16-21" PZ
Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
-
Transition T1A
Absence of disturbance and natural regeneration over time, may be coupled with excessive grazing pressure
More details -
Restoration pathway R2A
Adequate rest from defoliation and removal of woody canopy, followed by reintroduction of historic disturbance regimes
More details -
No transition or restoration pathway between the selected states has been described
Target ecosystem state
Select a state
State 1
Grassland State
Description
The reference plant community for this site is a Shortgrass/Blue grama Dominant Community (1.1). A few midgrasses can be found in small depressions along with a small number of moisture dependent forbs. Very little woody plants are found. A few cholla cactus, prickly pear, or occasional yucca will be present, usually only 1 to 2% of the total plant community. Blue grama dominates with a lesser amount of buffalograss present. Western wheatgrass and vine mesquite may occur in low places that catch and hold more moisture. The major perennial forbs are scarlet globemallow, chocolate daisy, slimleaf scurfpea, prairie coneflower, and baby white aster. Annual forbs are more abundant in years of above average spring rainfall. As a rule, forbs contribute around 5 to 8 % of the total production. This site is not highly diverse as the clayey soils along with relatively low rainfall limit the range of species adapted to the site.
With continued heavy grazing pressure brings about a new plant community, the Degraded Shortgrass Community (1.2). The soil becomes more compacted, rainfall infiltration is reduced, and water runoff increases. Western wheatgrass, the only cool-season grass present, decreases under grazing pressure. Long-term abuse coupled with drought will often leave the turf open in places. Increasing species such as broom snakeweed can gain a foothold.
Submodel
State 2
Shrub/Forb State
Description
If long-term heavy grazing continues, a threshold will be crossed from a Grassland State (1) to a Shrub/Forb State (2). In this degraded state, blue grama loses its bunchgrass characteristics and assumes a sod bound appearance. The shortgrass species are so resistant to grazing that it is uncommon for them to be killed out, but they can be weakened dramatically. Weedy and/or halfshrub species such as broom snakeweed may increase and dominate this site along with perennial three-awn and annuals. In the eastern portions of MLRA 77C, mesquite is a common invader. In the western portions of MLRA 77C, cholla and other cacti species may invade and possibly dominate the site.
Submodel
Mechanism
Due to heavy continuous grazing pressure and brush invasion of broom snakeweed, cholla, and pricklypear, the Grassland State will transition to the Shrub/Forb State.
Mechanism
With the application of several conservation practices such as Brush Management, Pest Management, and Prescribed Grazing, the Grassland State can be restored from the Shrub/Forb State.
Relevant conservation practices
| Practice | External resources |
|---|---|
|
Brush Management |
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|
Prescribed Grazing |
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|
Integrated Pest Management (IPM) |
Model keys
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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.