Sands
Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
-
Transition T1A
Heavy continuous grazing, heavy soil disturbance, wind erosion
More details -
Transition T1B
Heavy continuous grazing, non-use, no fire, invasion
More details -
Transition T1C
Conifer invasion, no fire
More details -
Transition T1D
Tillage
More details -
Transition T2B
Seeding, long term prescribed grazing, exclusion of use
More details -
Transition T2A
Tillage
More details -
Transition T3A
Heavy continuous grazing, heavy soil disturbance, wind erosion
More details -
Transition T3B
Heavy continuous grazing
More details -
Transition T3C
Tillage
More details -
Restoration pathway T4A
Long term prescribed grazing, prescribed burning
More details -
Transition T4C
Conifer invasion, no fire
More details -
Transition T4B
Tillage
More details -
Restoration pathway T5A
Brush management, prescribed burning
More details -
Restoration pathway T5B & T5D
Brush management, prescribed burning,
More details -
Restoration pathway T5C
Brush management
More details -
Transition T5E
Brush management, tillage
More details -
Restoration pathway T6A
Seeding
More details -
Restoration pathway T6B
Seeding, cropped and abandoned
More details -
No transition or restoration pathway between the selected states has been described
Target ecosystem state
Select a state
Description
The Reference State represents the natural range of variability that dominated the dynamics of this ecological site (ES). This state was dominated by warm-season grasses with cool-season grasses being subdominant. Before Europeans settled in North America, the primary disturbance mechanisms for this site in the reference condition included periods of below and above average precipitation, sporadic fire, and herbivory by insects and large ungulates. Frequent surface fires (every 3 to 5 years), grazing, and weather events dictated the dynamics that occurred within the natural range of variability. The less grazing tolerant tall warm-season grasses and cool-season grasses would have declined. Prairie sandreed would have increased with ongoing disturbance. With severe, prolonged disturbance, plant vigor can rapidly decline and this state can move towards an active blowout. Today, a similar state can be found on areas that are properly managed with grazing and/or prescribed burning, and sometimes on areas receiving occasional short periods of rest.
Submodel
Description
The Eroded State is a result of heavy, continuous grazing or from over utilization during extended periods of drought. These soils are very susceptible to wind erosion. A soil disturbance from livestock or from some mechanical means combined with wind will initiate the eroded state. Continuous wind erosion will bury existing vegetation and create a blowout situation. Extended periods of drought will enhance this process. The blowout area will become very sparsely vegetated with remaining area bare soil. An active blowout area will be mostly bare soil.
Submodel
Description
The Native/Invaded State represents the more common range of variability that exists with higher levels of grazing management, but in the absence of periodic fire due to fire suppression. This state is dominated by warm-season grasses with cool-season grasses being subdominant. It can be found on areas that are properly managed with grazing and/or prescribed burning and sometimes on areas receiving occasional short periods of rest. Grazing tolerant will increase with disturbance.
Submodel
Description
The Invaded State is a result of encroachment mainly by invasive introduced cool-season grasses. The ecological processes are not functioning, especially the biotic processes and the hydrologic functions. The introduced cool-season grasses cause reduced infiltration and increased runoff. Preliminary studies indicate this threshold may exist when Kentucky bluegrass exceeds 30 percent of the plant community and native grasses represent less than 40 percent of the plant community composition. The opportunity for high intensity spring burns is severely reduced by early green-up and increased moisture and humidity at the soil surface, and grazing pressure cannot cause a reduction in sod-grass dominance. Production is limited to the sod-forming species. Infiltration continues to decrease and runoff increases, energy capture into the system is restricted to early season low producing species. Nutrient cycling is limited by root depth of the dominate species.
Submodel
Description
The Conifer/Invaded State is dominated (canopy exceeds 20 percent of total surface area) by areas where trees have become established or have encroached onto the site due to the absence of periodic fire. This state is dominated by eastern redcedar and Rocky Mountain juniper with cool-season grasses being subdominant. The plant community can develop into a closed canopy that impedes the reproductive capability of the major native perennial grass species. A single eastern redcedar tree with a 7 foot crown diameter eliminates the equivalent of 3 pounds of forage. Further, the forage potential of a pasture with 250 mature eastern redcedar trees per acre (or one tree every thirteen feet) is reduced by 50 percent. It is suggested that reducing stocking rates by 10 percent for every 50 trees per acre. The increase in tree canopy which is a result of a disruption of the natural and human related fire regimes that occurred prior to European settlement of North America, which kept trees from encroaching much of the grasslands.
Submodel
Mechanism
Heavy, continuous grazing (stocking levels well above carrying capacity for extended portions of the growing season and often at the same time of year each year) or with heavy soil surface disturbance (livestock or mechanical) and wind erosion will cause a shift over a threshold and convert this plant community to the 2.1 Active Blowout Plant Community Phase within the Eroded State (State 2).
Mechanism
Non-use and/or no surface fire for extended periods of time (typically for 10 or more years) causing litter levels to become high enough to reduce native grass vigor, diversity, and density, heavy, continuous grazing, or the invasion of non-native plant species will likely lead this state over a threshold resulting in the Native-Invaded State (State 3).
Mechanism
No surface fire for extended periods of time (typically for 10 or more years) causing litter levels to become high enough to reduce native grass vigor, diversity, and density, and invasion of conifer will likely lead this state over a threshold leading to the 5.1 Eastern Redcedar-Rocky Mountain Juniper/Needle and Thread Plant Community Phase within the Conifer/Invaded State (State 5).
Mechanism
Tillage will cause a shift over a threshold leading to the 6.1 Annual Crops Plant Community Phase within the Crop Production State (State 6).
Mechanism
Seeding coupled with long-term prescribed grazing (moderate stocking levels coupled with adequate recovery periods, or other grazing systems such as high-density, low-frequency intended to treat specific species dominance, or periodic light to moderate stocking levels possibly including periodic rest) and exclusion of use from livestock grazing may lead the Eroded State (State 2) over a threshold to the Native/Invaded State (State 3).
Mechanism
Tillage will cause a shift over a threshold leading to the 6.1 Annual Crops Plant Community Phase within the Crop Production State (State 6).
Mechanism
Heavy, continuous grazing (stocking levels well above carrying capacity for extended portions of the growing season and often at the same time of year each year) or with heavy soil disturbance (livestock or mechanical and wind erosion will cause a shift over a threshold and convert this plant community to the 2.1 Active Blowout Plant Community Phase and the Eroded State (State 2).
Mechanism
Heavy, continuous grazing (stocking levels well above carrying capacity for extended portions of the growing season and often at the same time of year each year), will likely lead this state over a threshold leading to the 4.1 Kentucky Bluegrass-Prairie Sandreed-Needleandthread Community Phase within the Invaded State (State 4). Grazing repeatedly in the early growing season can expedite this shift by causing mechanical disturbance due to trampling.
Mechanism
Tillage will cause a shift over a threshold leading to the 6.1 Annual Crops Plant Community Phase within the Crop Production State (State 6).
Mechanism
Long-term prescribed grazing (moderate stocking levels coupled with adequate recovery periods, or other grazing systems such as high-density, low-frequency intended to treat specific species dominance, or periodic light to moderate stocking levels possibly including periodic rest) coupled with prescribed burning occurring at relatively frequent intervals (every 3 to 5 years) and a return to normal disturbance regime levels may lead the Invaded State (State 4) over a threshold to the Native/Invaded State (State 3).
Relevant conservation practices
| Practice | External resources |
|---|---|
|
Prescribed Grazing |
|
|
Integrated Pest Management (IPM) |
Mechanism
No surface fire for extended periods of time (typically for 10 or more years) causing litter levels to become high enough to reduce native grass vigor, diversity, and density, and invasion of conifer will likely lead this state over a threshold leading to the 5.2 Eastern Redcedar-Rocky Mountain Juniper/Kentucky Bluegrass Plant Community Phase within the Conifer/Invaded State (State 5).
Mechanism
Tillage will cause a shift over a threshold leading to the 6.1 Annual Crops Plant Community Phase within the Crop Production State (State 6).
Mechanism
Brush management which would include the mechanical removal of the conifers, coupled with prescribed burning occurring at relatively frequent intervals (3 to 5 years) and a return to normal disturbance regime levels may lead this 5.1 Eastern Redcedar-Rocky Mountain Juniper/Needle and Thread Plant Community Phase within the Conifer/Invaded State (State 5) over a threshold to the Reference State (State 1).
Mechanism
Brush management, which would include the mechanical removal of the conifers, coupled with prescribed burning may lead this 5.2 Eastern Redcedar-Rocky Mountain Juniper/Kentucky Bluegrass Plant Community Phase within the Conifer/Invaded State (State 5) over a threshold to the Native/Invaded State (State 3).
Brush management, which would include the mechanical removal of the conifers, coupled with prescribed burning prescribed burning occurring at relatively frequent intervals (every 3 to 5 years) and a return to normal disturbance regime levels may lead this 5.3 Eastern Redcedar-Rocky Mountain Juniper Plant Community Phase within the Conifer/Invaded State (State 5) over a threshold to the Native/Invaded State (State 3).
Mechanism
Brush management, which would include the mechanical removal of the conifers, may lead this 5.2 Eastern Redcedar-Rocky Mountain Juniper/Kentucky Bluegrass Plant Community Phase within the Conifer/Invaded State (State 5) over a threshold to the Invaded State (State 4).
Mechanism
Brush management, which would include the mechanical removal of the conifers, coupled with tillage will cause a shift over a threshold leading to the 6.1 Annual Crops Plant Community Phase within the Crop Production State (State 6).
Mechanism
Seeding may lead this Crop Production State (State 6) over a threshold to the Native/Invaded State (State 3).
Mechanism
Seeding may lead this Crop Production State (State 6) over a threshold to the Invaded State (State 4).
Cropping followed by abandonment may lead this plant community phase over a threshold to the Invaded State (State 4) and more specifically to the 4.2 Annual Pioneer-Perennial Pioneer Plant Community Phase.
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.