Shallow Marsh
Scenario model
Current ecosystem state
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Management practices/drivers
Select a transition or restoration pathway
- Transition T1a More details
- Transition T2 More details
- Transition T2 More details
- Restoration pathway R2 More details
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No transition or restoration pathway between the selected states has been described
Target ecosystem state
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Description
This state represents the natural range of variability that dominates the dynamics of this ecological site. This state is typically dominated by cool-season grass and grass-like species. Before European settlement, the primary disturbance mechanisms for this site in the reference condition included periodic fire, grazing by large herding ungulates, and fluctuations in the water table and ponding frequency and duration. Timing of fires and grazing coupled with weather events dictated the dynamics that occurred within the natural range of variability. Today the primary disturbance is from a lack of fire, concentrated livestock grazing, and weather fluctuations. Species that are desirable for livestock and wildlife can decline and a corresponding increase in less desirable species will occur.
Submodel
Description
This state is characterized by an effective drying of the site due to the presence of reed canarygrass, or due to an increase in bare ground due to trampling caused by excessive use (which leads to increased evapotranspiration). It is also characterized by the dominance of highly competitive species. The variety of reed canarygrass that is present in phase 2.1 is considered non-native. Often the species that dominate the site in phase 2.2 are also non-native invasive species. In either case, the biotic integrity of the site is greatly diminished, and typically diversity is much lower.
Submodel
Mechanism
This transition occurs as a result of prolonged periods with a lack of adequate disturbance. Areas protected from grazing and/or fire will begin to build up litter beyond the capability of the site to cycle the organic matter into the soil. This favors the highly competitive strains of reed canarygrass which can increase to complete dominance of the site. This transition leads to a shift across a threshold to the Reed Canarygrass Community Phase (2.1) within the Degraded State (State 2).
Mechanism
This transition occurs with cessation of cropping practices being applied to any plant community phase on this ecological site. This transition can also occur with severe prolonged grazing such as areas adjacent to watering sites. This transition leads to the Introduced Forbs/Foxtail Barley Plant Community Phase (2.2) within the Degraded State (State 2).
Mechanism
This transition occurs with cessation of cropping practices being applied to any plant community phase on this ecological site. This transition can also occur with severe prolonged grazing such as areas adjacent to watering sites. This transition leads to the Introduced Forbs/Foxtail Barley Plant Community Phase (2.2) within the Degraded State (State 2).
Mechanism
This restoration pathway may be initiated with high levels of prescribed grazing management over a long period of time. The success of this restoration pathway depends on the presence of a remnant population of native grass and grass-like species, or the presence of these species in nearby similar sites. This remnant population may not be readily apparent without close inspection. Wetland restoration techniques may need to be employed to secure this restoration pathway.
Model keys
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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.