Natural Resources
Conservation Service
Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
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Transition T1A
Frequent and severe defoliation, land disturbance, wind erosion.
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Transition T1B
Long-term (> 10 years), continuous season-long grazing or rotational grazing with inadequate recovery periods.
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Transition T1C
Rotational grazing with multiple grazing occupations during the growing season with inadequate growing season recovery time.
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Transition T1D
Woody encroachment with no fire or brush management.
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Transition T1E
Tillage to facilitate production agriculture.
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Restoration pathway R2A
Removal of disturbance with long-term (> 10 years) prescribed grazing.
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Transition R2B
Removal of disturbance with long-term (> 10 years) prescribed grazing.
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Restoration pathway R2C
Removal of disturbance with long-term (> 10 years) prescribed grazing.
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Transition T2A
Woody encroachment with no fire or brush management.
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Restoration pathway R2D
Removal of disturbance with long-term (> 10 years) prescribed grazing.
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Restoration pathway R3A
Long-term (>15 years) prescribed grazing with adequate growing season recovery time. This restoration may not be feasible.
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Transition T3A
Frequent and severe defoliation, land disturbance, wind erosion.
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Transition T3B
Rotational grazing with multiple grazing occupations during the growing season with inadequate growing season recovery time.
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Transition T3C
Woody encroachment with no fire or brush management.
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Transition T3D
Tillage to facilitate production agriculture.
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Restoration pathway R4A
Long-term (more than 15 years) prescribed grazing with adequate growing season recovery periods. This restoration may not be feasible.
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Transition T4A
Frequent and severe defoliation, land disturbance, wind erosion.
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Restoration pathway R4B
Long-term (>15 years) prescribed grazing with adequate growing season recovery time. This restoration may not be feasible.
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Transition T4B
Woody encroachment with no fire or brush management.
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Transition T4C
Tillage to facilitate production agriculture.
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Restoration pathway R5A
Prescribed burning, timber harvest, brush management.
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Restoration pathway R5B
Prescribed burning, timber harvest, brush management.
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Restoration pathway R5C
Prescribed burning, timber harvest, brush management.
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Restoration pathway R5D
Prescribed burning, timber harvest, brush management.
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Restoration pathway R5E
Prescribed burning, timber harvest, brush management.
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Transition T6A
Frequent and severe defoliation, land disturbance, wind erosion.
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Transition T6B
Woody encroachment with no fire or brush management.
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No transition or restoration pathway between the selected states has been described
Target ecosystem state
Select a state
Description
The Reference State (1) describes the range of vegetative communities that occur on the Sands 17-22" PZ ecological site where the range of natural variability under historic conditions and disturbance regimes is mostly intact. The Reference State developed under the combined influences of climatic conditions, periodic fire activity, grazing by large herbivores, and impacts from small mammals and insects. High perennial grass cover and production allows for increased soil moisture retention, vegetative production and overall soil quality.
The Reference State includes three community phases which are the Reference Community (1.1), the At-Risk Community (1.2) and the Excessive Litter Community (1.3), The Reference Community serves as a description of the native plant community that occurs on the site when the natural disturbance regimes are intact or closely mimicked by management practices. The At-Risk Community results from management actions that are unfavorable for a healthy Reference Community. The Excessive Litter Community occurs when herbivory and fire are eliminated from the landscape.
Dominant plant species
sand bluestem (Andropogon hallii), grass
prairie sandreed (Calamovilfa longifolia), grass
switchgrass (Panicum virgatum), grass
little bluestem (Schizachyrium scoparium), grass
needle and thread (Hesperostipa comata ssp. comata), grass
porcupinegrass (Hesperostipa spartea), grass
Submodel
Description
The Eroded State (2) can be reached from any plant community in the Reference State (1), the Native/Invaded Grass State (3), the Shortgrass Sod State (4), or the Sodbusted State (6). This state is the result of heavy disturbance, usually frequent and severe defoliation. The Eroded State can also develop with vehicle traffic, livestock trailing, or other heavy disturbances. Long-term drought or dormant season wildfire coupled with the heavy disturbance will accelerate the move to the Eroded State. The Eroded State (2) includes two plant communities which are the Blowout Community (2.1) and the Early Seral Community (2.2).
Dominant plant species
blowout grass (Redfieldia flexuosa), grass
sandhill muhly (Muhlenbergia pungens), grass
sand bluestem (Andropogon hallii), grass
lemon scurfpea (Psoralidium lanceolatum), grass
Texas croton (Croton texensis), grass
Submodel
Description
The Native/Invaded Grass State (3) transitioned from the Reference State (1) and much of the native warm-season tall- and midgrass components have been replaced by warm-season shortgrasses and upland sedges. Non-native, cool-season grasses have invaded the plant community. This State is the result of long-term grazing management that did not provide adequate recovery time for warm-season tall- and midgrasses and mid-statured cool-season grasses. The management that typically results in the Shortgrass Sod State is heavy, continuous, season long grazing but heavy rotational grazing with inadequate growing season recovery periods can also cause this transition.
The loss of warm-season tall- and midgrasses negatively impacts energy flow and nutrient cycling and alters hydrologic function. Runoff is higher and infiltration is lower than the Reference State. This state is somewhat resistant to change. The Native/Invaded Grass State includes the Native/Non-Native Grass Community (3.1).
Dominant plant species
blue grama (Bouteloua gracilis), grass
hairy grama (Bouteloua hirsuta), grass
sand dropseed (Sporobolus cryptandrus), grass
prairie sandreed (Calamovilfa longifolia), grass
Kentucky bluegrass (Poa pratensis), grass
Cuman ragweed (Ambrosia psilostachya), grass
prairie sunflower (Helianthus petiolaris), grass
Submodel
Description
The Shortgrass State (4) transitioned from either the Reference State (1) or the Native/Invaded Grass State (3) and much of the native warm-season tall- and midgrass components have been replaced by warm-season shortgrasses and upland sedges. This state occurs with rotational grazing systems which include multiple grazing occupations that do not allow adequate growing season recovery time. The plant community is dominated by warm-season shortgrass, cool-season grass, and grass-likes.
The loss of warm-season tall- and midgrasses negatively impacts energy flow and nutrient cycling and alters hydrologic function. Runoff is higher and infiltration is lower than the Reference State. This state is resistant to change. The Shortgrass State includes the Shortgrass Community (4.1).
Dominant plant species
blue grama (Bouteloua gracilis), grass
hairy grama (Bouteloua hirsuta), grass
sedge (Carex), grass
Submodel
Description
The Invaded Woody State (5) is the result of woody encroachment. Once the tree canopy cover reaches 15 percent with an average tree height exceeding five feet, the threshold to the Invaded Woody State has been crossed. Woody species are increasing due to the lack of prescribed fire, brush management, or other woody tree removal. Typical ecological impacts are a loss of native grasses, reduce diversity of functional and structural groups, reduced forage production, and reduced soil quality. Prescribed burning, wildfire, timber harvest and brush management will move the Invaded Woody State toward a grass dominated state. If the Invaded Woody State transitioned from Eroded State (2), the Native/Invaded Grass State (3), the Shortgrass Sod State (4) or the Sodbusted State (6), the land cannot return to the Reference State (1) as the native plant community, soils, and hydrologic function had been too severely impacted prior to the woody encroachment to allow the return to the Reference State through woody species removal alone. The Invaded Woody State includes one community, the Invaded Woody Community (5.1).
Dominant plant species
eastern redcedar (Juniperus virginiana), tree
blue grama (Bouteloua gracilis), grass
needle and thread (Hesperostipa comata ssp. comata), grass
Kentucky bluegrass (Poa pratensis), grass
Submodel
Description
The threshold to the Sodbusted State (6) is crossed as a result of mechanical disturbance to facilitate production agriculture. If farming operations are suspended, the site can be seeded to native grasses and forms resulting in the Reseeded Native Grass Community (6.1), be seeded to a tame pasture forage mixture resulting in the Seeded Pasture Community (6.2) or be abandoned with no seeding which will result in the Natural Reclamation Community (6.3). Permanent alterations of the soil, plant community, and hydrologic cycle make restoration to the Reference State (1) extremely difficult, if not impossible.
Submodel
Mechanism
The Eroded State (2) can be reached from any plant community of the Reference State (1). The Eroded State occurs with frequent and severe defoliation. Heavy, continuous grazing most often causes this transition, but it can also occur with rotational grazing when plants are not given adequate growing season recovery time before the paddocks or pastures are re-grazed. This process is accelerated when accompanied by additional disturbances, such as dormant season wildfire or extended drought (generally below average precipitation for 10 or more years). Heavy disturbance, such as vehicle traffic or livestock trailing can also cause this transition. The reduction in plant canopy and litter cover allows wind erosion to develop, creating large areas of blowing sand.
Transition T1B
Long-term (> 10 years), continuous season-long grazing or rotational grazing with inadequate recovery periods.
Mechanism
The Reference State (1) transitions to the Native/Invaded Grass State (3) in response to long-term (greater than ten years), heavy, seasonal grazing beginning in June. The Reference State loses a significant proportion of warm-season, tall- and midgrasses and crosses a threshold to the Native/Invaded Grass State. Non-native, cool-season grasses, typically Kentucky bluegrass invade the site, eventually becoming subdominant to co-dominant.
Transition T1C
Rotational grazing with multiple grazing occupations during the growing season with inadequate growing season recovery time.
Mechanism
The Reference State (1) typically transitions to the Shortgrass State (4) in response to rotational grazing with multiple grazing occupations during the growing season without adequate growing season recovery time. The Reference State loses a significant proportion of warm-season, tall- and midgrasses and crosses a threshold to the Shortgrass Sod State. Deep rooted plants are replaced by shallow rooted, sod- forming grasses which tend to form root mats and water infiltration is reduced. Forage production and plant species diversity have significantly declined. Initially, the plant community is a mosaic, with shortgrass and mixed grass communities intermingled but as the management continues the plant community becomes dominated by shortgrasses.
Mechanism
Long-term (more than ten years) disruption of the natural fire regime and the encroachment of invasive exotic and native woody species with no woody species management can cause the Reference State (1) to transition to the Invaded Woody State (5).
Mechanism
The Reference State (1) has been significantly altered by tillage to facilitate production agriculture. When the land is no longer cropped, the resulting state is the Sodbusted State (6). The disruption to the plant community, the soil, and the hydrology of the system prevent restoration to a true Reference State.
Restoration pathway R2A
Removal of disturbance with long-term (> 10 years) prescribed grazing.
Mechanism
The Eroded State (2) can be restored to the Reference State (1) with long term (10 or more years) prescribed grazing. Initially, grazing management that incorporates concentrated short-term animal impact (such as feeding hay on the blowout) will encourage growth of early successional grasses and forbs. When either human-caused disturbance or livestock concentration caused the transition from the Reference State, removal of the disturbance along with appropriate grazing management is needed. With long term prescribed grazing, succession progresses, and the land will eventually return to the Reference State. Land that entered the Eroded State from the Native/Invaded Grass State (3), the Shortgrass State (4), or the Sodbusted State (6) cannot return directly to the Reference State (1) as the plant community composition was significantly altered before the land entered the Eroded State.
Mechanism
The Eroded State (2) can be returned to the Native/Invaded Grass State (3) with long term (10 or more years) prescribed grazing. Initially, grazing management that incorporates concentrated short-term animal impact (such as feeding hay on the blowout) will encourage growth of early successional grasses and forbs. When either human-caused disturbance or livestock concentration caused the transition to the Eroded State, removal of the disturbance along with appropriate grazing management is needed. With long term prescribed grazing, succession progresses, and the land will eventually return to the Native/Invaded Grass State.
Restoration pathway R2C
Removal of disturbance with long-term (> 10 years) prescribed grazing.
Mechanism
The Eroded State (2) can be returned to the Shortgrass State (4) with long term (10 or more years) prescribed grazing. Initially, grazing management that incorporates concentrated short- term animal impact (such as feeding hay on the blowout) will encourage growth of early successional grasses and forbs. When either human-caused disturbance or livestock concentration caused the transition to the Eroded State, removal of the disturbance along with appropriate grazing management is needed. With long term prescribed grazing, succession progresses, and the land will eventually return to the Shortgrass State.
Mechanism
Long-term (more than ten years) disruption of the natural fire regime and the encroachment of invasive exotic and native woody species with no woody species management can cause the Eroded State (1) to transition to the Invaded Woody State (5).
Restoration pathway R2D
Removal of disturbance with long-term (> 10 years) prescribed grazing.
Mechanism
The Eroded State (2) can be returned to the Sodbusted State (5) with long term (10 or more years) prescribed grazing. Initially, grazing management that incorporates concentrated short- term animal impact (such as feeding hay on the blowout) will encourage growth of early successional grasses and forbs. When either human-caused disturbance or livestock concentration caused the transition to the Eroded State, removal of the disturbance along with appropriate grazing management is needed. With long term prescribed grazing, succession progresses, and the land will eventually return to the Sodbusted State. Re-seeding may be needed to return to any community other than the Natural Reclamation Community (5.3).
Restoration pathway R3A
Long-term (>15 years) prescribed grazing with adequate growing season recovery time. This restoration may not be feasible.
Mechanism
Long-term (more than 15 years) prescribed grazing with adequate growing season recovery periods will move the Native/Invaded Grass State (3) toward the Reference State (1). The amount of time required for, and feasibility of this restoration depends upon the abundance of warm-season tall- and midgrasses and cool-season bunch grasses remaining in the plant community and the degree to which non-native grasses have invaded the plant community. This restoration may not be feasible.
Mechanism
The Invaded Native Grass State (3) transitions to the Eroded State (2) with frequent and severe defoliation. Heavy, continuous grazing most often causes this transition, but it can also occur with rotational grazing when plants are not given adequate growing season recovery time before the paddocks or pastures are re-grazed. This process is accelerated when accompanied by additional disturbances, such as dormant season wildfire or extended drought (generally below average precipitation for 10 or more years). Heavy disturbance, such as vehicle traffic or livestock trailing can also cause this transition. The reduction in plant canopy and litter cover allows wind erosion to develop, creating large areas of blowing sand.
Transition T3B
Rotational grazing with multiple grazing occupations during the growing season with inadequate growing season recovery time.
Mechanism
The Native/Invaded Grass State (3) typically transitions to the Shortgrass State (4) in response to rotational grazing with multiple grazing occupations during the growing season without adequate growing season recovery time. The Native/Invaded Grass State loses a significant proportion of warm-season, tall- and midgrasses and crosses a threshold to the Shortgrass Sod State. Deep rooted plants are replaced by shallow rooted, sod- forming grasses which tend to form root mats and water infiltration is reduced. Forage production and plant species diversity have significantly declined.
Mechanism
Long-term (more than ten years) disruption of the natural fire regime and the encroachment of invasive exotic and native woody species with no woody species management can cause the Native/Invaded Grass State (3) to transition to the Invaded Woody State (5).
Mechanism
The Native/Invaded Grass State (3) has been significantly altered by tillage to facilitate production agriculture. When the land is no longer cropped, the resulting state is the Sodbusted State (5). The disruption to the plant community, the soil, and the hydrology of the system prevent restoration to a Native/Invaded Grass State.
Restoration pathway R4A
Long-term (more than 15 years) prescribed grazing with adequate growing season recovery periods. This restoration may not be feasible.
Mechanism
Long-term (more than 15 years) prescribed grazing with adequate growing season recovery periods will move the Shortgrass State (4) toward the Reference State (1). The amount of time required for, and feasibility of this restoration depends upon the abundance of warm-season tall- and midgrasses and cool-season bunch grasses remaining in the plant community. This restoration may not be feasible.
Mechanism
The Shortgrass State (4) transitions to the Eroded State (2) with frequent and severe defoliation. Heavy, continuous grazing most often causes this transition, but it can also occur with rotational grazing when plants are not given adequate growing season recovery time before the paddocks or pastures are re-grazed. This process is accelerated when accompanied by additional disturbances, such as dormant season wildfire or extended drought (generally below average precipitation for 10 or more years). Heavy disturbance, such as vehicle traffic or livestock trailing can also cause this transition. The reduction in plant canopy and litter cover allows wind erosion to develop, creating large areas of blowing sand.
Restoration pathway R4B
Long-term (>15 years) prescribed grazing with adequate growing season recovery time. This restoration may not be feasible.
Mechanism
Long-term (more than 15 years) prescribed grazing with adequate growing season recovery periods will move the Shortgrass State (4) toward the Native/Invaded Grass State (3). The amount of time required for, and feasibility of this restoration depends upon the abundance of warm-season tall- and midgrasses and cool-season bunch grasses remaining in the plant community. This restoration may not be feasible.
Mechanism
Long-term (more than ten years) disruption of the natural fire regime and the encroachment of invasive exotic and native woody species with no woody species management can cause the Shortgrass State (4) to transition to the Invaded Woody State (5).
Mechanism
The Shortgrass State (4) has been significantly altered by tillage to facilitate production agriculture. When the land is no longer cropped, the resulting state is the Sodbusted State (6).
Mechanism
The Invaded Woody State (5) can be restored to the Reference State (1) through prescribed burning, wildfire, timber harvest, or brush management. The forb component may initially increase following tree removal. Ongoing brush management such as hand cutting, chemical spot treatments, or periodic prescribed burning is required to prevent a return to the Invaded Woody State. The heavier the existing canopy cover, the greater the energy input required to return to the Native/Invaded Grass State by management practices. The amount of time required for this restoration to occur depends on the severity and duration of the encroachment. Land that transitioned to the Invaded Woody State from the Eroded State (2), the Native/Invasive Grass State (3), the Shortgrass State (4), or the Sodbusted State (6) cannot be restored to the Reference State through the removal of woody species as the native plant community, soils, and hydrologic function have been too severely impacted for that restoration to occur with removal of brush alone.
Mechanism
The Invaded Woody State (5) can be restored to the Eroded State (2) through prescribed burning, wildfire, timber harvest, or brush management. The forb component may initially increase following tree removal. Ongoing brush management such as hand cutting, chemical spot treatments, or periodic prescribed burning is required to prevent a return to the Invaded Woody State. The heavier the existing canopy cover, the greater the energy input required to return to the Eroded State by management practices. The amount of time required for this restoration to occur depends on the severity and duration of the encroachment. Land that transitioned to the Invaded Woody State from Eroded State cannot be restored to the Reference State (1) through the removal of woody species as the native plant community, soils, and hydrologic function have been too severely impacted for that restoration to occur with removal of brush alone.
Mechanism
The Invaded Woody State (5) can be restored to the Native/Invaded State (3) through prescribed burning, wildfire, timber harvest, or brush management. The forb component may initially increase following tree removal. Ongoing brush management such as hand cutting, chemical spot treatments, or periodic prescribed burning is required to prevent a return to the Invaded Woody State. The heavier the existing canopy cover, the greater the energy input required to return to the Native/Invaded Grass State by management practices. The amount of time required for this restoration to occur depends on the severity and duration of the encroachment. Land that transitioned to the Invaded Woody State from Native/Invaded State cannot be restored to the Reference State (1) through the removal of woody species as the native plant community, soils, and hydrologic function have been too severely impacted for that restoration to occur with removal of brush alone.
Mechanism
The Invaded Woody State (5) can be restored to the Shortgrass State (4) through prescribed burning, wildfire, timber harvest, or brush management. The forb component may initially increase following tree removal. Ongoing brush management such as hand cutting, chemical spot treatments, or periodic prescribed burning is required to prevent a return to the Invaded Woody State. The heavier the existing canopy cover, the greater the energy input required to return to the Shortgrass State by management practices. The amount of time required for this restoration to occur depends on the severity and duration of the encroachment. Land that transitioned to the Invaded Woody State from Shortgrass Sod State cannot be restored to the Reference State (1) through the removal of woody species as the native plant community, soils, and hydrologic function have been too severely impacted for that restoration to occur with removal of brush alone.
Mechanism
The Invaded Woody State (5) can be restored to the Sodbusted State (6) through prescribed burning, wildfire, timber harvest, or brush management. The forb component may initially increase following tree removal. Ongoing brush management such as hand cutting, chemical spot treatments, or periodic prescribed burning is required to prevent a return to the Invaded Woody State. The heavier the existing canopy cover, the greater the energy input required to return to the Sodbusted State by management practices. The amount of time required for this restoration to occur depends on the severity and duration of the encroachment. Land that transitioned to the Invaded Woody State from Sodbusted State cannot be restored to the Reference State (1) through the removal of woody species as the native plant community, soils, and hydrologic function have been too severely impacted for that restoration to occur with removal of brush alone.
Mechanism
The Sodbusted State (5) will transition to the Eroded State (2) with frequent and severe defoliation. Heavy, continuous grazing most often causes this transition, but it can also occur with rotational grazing when plants are not given adequate growing season recovery time before the paddocks or pastures are re-grazed. This process is accelerated when accompanied by additional disturbances, such as dormant season wildfire or extended drought. Heavy disturbance, such as vehicle traffic or livestock trailing can also cause this transition. The reduction in plant canopy and litter cover allows wind erosion to develop, creating large areas of blowing sand.
Mechanism
Long-term (more than ten years) disruption of the natural fire regime and the encroachment of invasive exotic and native woody species with no woody species management can cause the Sodbusted State (6) to transition to the Invaded Woody State (5).
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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.
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