Shallow Marsh
Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
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Transition T1A
Invasion by exotic plants, no-use no fire, heavy season-long grazing, decrease in water regime
More details - Transition T1B More details
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Restoration pathway R2A
Increased water depth
More details -
Transition T2A
Tillage with increased eutrophication and sedimentation
More details -
Restoration pathway R3A
Successful wetland restoration or seeding, increased water depth, chemical treatment and/or sediment/nutrient removal, with successful buffer or upland restoration
More details -
Restoration pathway R4A
Cessation of annual cropping, successful wetland restoration/seeding, prescribed fire, vegetation management
More details -
Restoration pathway R4B
Cessation of annual cropping, failed wetland restoration/seeding, no-use and no fire
More details -
Restoration pathway T5A
Cessation of annual cropping
More details -
No transition or restoration pathway between the selected states has been described
Target ecosystem state
Select a state
Description
This state represents the natural range of variability that dominated the dynamics of this ecological site prior to European settlement. Historically, the primary disturbance mechanisms for this site in the reference condition were large fluctuations of the water table, water levels, soil saturation, and water chemistry (e.g., brackishness/ salinity/ alkalinity). Periodic fire and grazing by large herding ungulates were also historical disturbances that influenced this site but to a much lesser degree. Climate, weather, and drawdown events (combined with the timing of fires and grazing) dictated the dynamics that occurred within the natural range of variability.
Presently, the main disturbances are climate, weather events, water level fluctuations, lack of fire, concentrated livestock grazing, and agronomic activities on adjacent ecological sites (e.g., tillage, fertilizer and herbicide use, drainage).
The Reference State is composed of four community phases. These phases are largely due to weather and climate factors resulting in considerable fluctuations in water levels and water chemistry (e.g., brackishness). Brackishness, along with water depth, is also a major factor influencing vegetation of the site. Brackishness can be natural due to the type of hydrology and soils of the site. Exotic perennial plant species do not exist in this state.
Characteristics and indicators
Exotic species and hydrologic manipulation would not be present on this site when it is in State 1: Reference State
Resilience management
If intact, the reference state should be managed with current disturbance regimes which has permitted the site to remain in reference condition as well as maintaining the quality and integrity of associated ecological sites. Maintenance of the reference state is contingent upon a monitoring protocol to guide management.
Submodel
Description
This state is characterized by the colonization and establishment of minor amounts of exotic plants. Reed canarygrass is native to North America, but exotic strains (largely Eurasian) have been widely introduced and, along with their hybrids, can be quite invasive. Hybrid cattail, the hybrid between narrowleaf cattail and broadleaf cattail is also a common exotic. Canada thistle is also known to invade the site during dry periods. Although the site is still dominated by native plants, an increase in exotic plants can be expected. Unless a prescribed grazing and/or prescribed burning program is implemented or an increase in water depth drowns out exotic species, a transition to State 3: Invaded State can be expected.
Characteristics and indicators
The presence of trace amounts of exotic species/hybrids (e.g., cattail, reed canarygrass) indicates a transition from State 1 to State 2.
Resilience management
Implementation of management techniques and monitoring procedures designed to limit or control exotic species/hybrids.
Submodel
Description
This state occurs when the site becomes dominated by exotic plants. Common exotics of the site include exotic strains/hybrids of reed canarygrass or hybrid cattail. Other exotic species may include Canada thistle, purple loosestrife, flowering rush, and exotic strains/hybrids of common reed. Once the state is established, restoration efforts have proven difficult (see Restoration R3A).
Characteristics and indicators
This site is characterized by exotic species/hybrids dominating the site and controlling the ecological processes (i.e. approximately 30 to 40%).
Resilience management
Once established, reed canarygrass and hybrid cattail are very resilient and will withstand grazing, haying pressure and non-use.
Submodel
Description
This state is highly variable depending on the level and duration of disturbance related to the T5A pathway. In this MLRA, the most probable origin of this state is plant succession following crop abandonment. This plant community will initially include a variety of annual forbs and grasses, some of which maybe noxious weeds.
Characteristics and indicators
Tillage has destroyed the native plant community, altered soil structure and biology, increased eutrophication, reduced soil organic matter, and results in the formation of a tillage induced compacted layer which is restrictive to root growth. Noxious weeds, if present, will need to be managed.
Resilience management
Continued tillage will maintain the state. Control of noxious weeds will be required.
Submodel
Mechanism
This is the transition from the State 1: Reference State to State 2: Native/Invaded State resulting from the colonization and establishment of exotic plants, often exotic strains of reed canarygrass or hybrid cattail. Canada thistle is also known to invade the site during dry periods.
Heavy season-long grazing, prolonged periods of non-use and no fire, and a decrease in the water regime of the site are often involved with this transition. Excessive litter accumulation provides conditions favorable to hybrid cattail or exotic strains/hybrids of reed canarygrass which can quickly spread to form virtual monocultures. As a result, the transition to State 3: Invaded State can be expected.
Constraints to recovery
Restoration to State 1 is dependent upon hydrology, condition of adjacent upland ecological sites (i.e., cropland), and abundance of exotic species.
Mechanism
This is the transition from State 1: Reference State to State 3: Invaded State. Although the State 3: Invaded State often forms via State 2: Native/Invaded State, this direct transition to State 3: Invaded State can occur with tillage of the Shallow Marsh ecological site or adjacent upland with an associated increase in eutrophication and sedimentation resulting in vegetation dominance by hybrid cattail or exotic strains/hybrids of reed canarygrass.
Constraints to recovery
Restoration to State 1 is dependent upon hydrology, condition of adjacent upland ecological sites (i.e., cropland), and abundance of exotic species.
Context dependence
Tillage with increased eutrophication and sedimentation
Mechanism
This restoration pathway from State 2: Native/Invaded State to State 1: Refence State is initiated by an increase in water depth sufficient to drown out invasive exotic species. Success of this pathway is dependent upon the invasive species present in State 2 Native/Invaded State. Hybrid cattail, reed canary grass, or perhaps exotic strains of common reed will likely persist with increased water levels, whereas foxtail barley, dock, or Canada and sow thistle will drown out.
Context dependence
Hydrological restoration/management to remove exotic species/hybrids which may necessitate chemical control. Adjacent upland ecological sites will need to remain intact or reseeded to native species in order to prevent sedimentation and nutrient loading to Shallow Marsh ecological site. Prescribed grazing techniques may provide a short-term reduction in reed canarygrass density; however, a combination of mowing and prescribed burning may be more effective than prescribed grazing alone.
Mechanism
The transition from State 2: Native/Invaded State to State 3: Invaded State can occur with tillage within the site or on adjacent upland sites resulting in an increase in eutrophication and sedimentation leading to a dominance of hybrid cattail or exotic strains/hybrids of reed canarygrass. Studies indicate that a threshold may exist in the transition to this Native/Invaded State on some upland ecological sites when Kentucky bluegrass exceeds 30% of the plant community and native grasses represent less than 40% of the plant community composition. Similar thresholds may exist for exotic strains of reed canarygrass and hybrid cattail on this site.
Constraints to recovery
Restoration to State 2 is dependent upon hydrology and abundance of exotic species/hybrids.
Mechanism
This restoration pathway from State 3: Invaded State to State 2: Native/Invaded State results from a successful wetland restoration through hydrological restoration, planting, increased water regime, chemical treatment, and/or sediment/nutrient removal. A successful upland restoration is also needed to reduce the likelihood of exotic plant invasion or continued sedimentation or nutrient loading.
Context dependence
Reed canarygrass and hybrid cattail are difficult to control, largely due to vigorous spreading rhizomes, high seed production, and a large seed bank. Various control techniques may show signs of success but are often short-term with vegetation reverting within a few years. Adjacent upland ecological sites will need to remain intact or be reseeded to native species to prevent sedimentation and nutrient loading to Shallow Marsh ecological site.
Prescribed grazing (e.g., heavy seasonal), high-intensity burns, and herbicides have shown some success in reducing the dominance by reed canarygrass. However, within several years the vegetation often reverts.
Herbicides can be effective in reducing or eliminating hybrid cattail and can be followed by reseeding (or plugging) desirable species. Prescribed burning has also been effective during dry periods where fire temperatures may kill rhizomes and seeds. Although expensive, mechanical removal of the substrate has also been an effective technique.
Mechanism
This restoration pathway from State 4: Go-Back State to State 2: Native/Invaded State results from cessation of annual cropping, successful wetland restoration/seeding/plugging, prescribed burning, and vegetation management
Context dependence
If manipulated, hydrology needs to be restored. Elevated soil nitrogen levels and sedimentation have been shown to benefit reed canarygrass and hybrid cattail. Sedimentation may need to be removed to preexisting conditions. A successful range planting will include proper seedbed preparation, weed control (both prior to and after the planting), selection of adapted native species representing functional/structural groups inherent to the State 1, and proper seeding technique. Management (e.g. prescribed grazing, prescribed burning) during and after establishment must be applied in a manner that maintains the competitive advantage for the seeded native species.
Mechanism
This restoration pathway from State 4: Go-Back State to State 3: Invaded State results from cessation of annual cropping followed by a failed wetland restoration/seeding with no use and no fire.
Context dependence
Failure to restore hydrology and failed range plantings can result from many causes, both singularly and in combination, including: drought, poor seedbed preparation, improper seeding methods, seeded species not adapted to the site, insufficient weed control, herbicide carryover, poor seed quality (purity & germination), improper management.
Mechanism
This transition from any plant community to State 4: Go-Back State. Most commonly, it is associated with the cessation of cropping without the benefit of restoration efforts, resulting in a “go-back” situation. Soil conditions can be quite variable on the site, in part due to variations in the management/cropping history (e.g. development of a tillage induced compacted layer, erosion, fertility (degree of eutrophication), sedimentation herbicide/pesticide carryover). Thus, soil conditions should be assessed when considering restoration techniques.
Model keys
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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.