Loamy Overflow
Scenario model
Current ecosystem state
Select a state
Management practices/drivers
Select a transition or restoration pathway
-
Transition T1A
Introduction of exotic cool-season grasses
More details -
Transition T1B
Extended period of non-use or very light grazing, no fire
More details -
Transition T2A
Extended period of non-use or very light grazing, no fire
More details -
Transition T2B
Extended period of non-use or very light grazing, no fire
More details -
Restoration pathway R3A
Long term prescribed grazing with prescribed burning
More details -
Transition T3A
Extended period of non-use or very light grazing, no fire
More details -
Restoration pathway R4A
Successful range planting with prescribed grazing and prescribed burning
More details -
Restoration pathway R4B
Failed range planting
More details -
Restoration pathway R5A
Prescribed burning and/or chemical/mechanical brush management followed by successful range planting
More details -
Restoration pathway R5B
Prescribed burning and/or chemical/mechanical brush management followed by failed range planting
More details -
Transition T6A
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
The Reference State represents the natural range of variability that dominated the dynamics of this ecological site prior to European influence. The primary disturbance mechanisms for this site in the reference condition included periodic droughts, fire, and grazing by large herding ungulates. Timing of fires and grazing, coupled with weather events, dictated the dynamics that occur within the natural range of variability.
Three community phases have been identified. The community was generally co-dominated by warm-season and cool-season grasses. However, due to variations in the disturbance regime, such as warm periods with increased precipitation, the proportions may have shifted both spatially and temporally. Patches or thickets of shrubs and small trees may also have developed, particularly during periods of increased precipitation and infrequent fires.
Characteristics and indicators
Because of changes in disturbances and other environmental factors (particularly the widespread occurrence of exotic species), the Reference State is considered to no longer exist.
Resilience management
If intact, the reference state should probably 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 condition is contingent upon a monitoring protocol to guide management.
Submodel
Description
This state is similar to the State 1: Reference State but now has been colonized by exotic cool-season grasses, commonly Kentucky bluegrass, smooth brome, and/or quackgrass. Although the state is still dominated by native warm-season and cool-season grasses, an increase in these exotic cool-season grasses can be expected.
These exotic cool-season grasses can be quite invasive on the site and are particularly well adapted to heavy grazing. They also often form monotypic stands. As these exotic cool-season grasses increase, both forage quantity and quality become increasingly restricted to late spring and early summer due to the monotypic nature of the stand even though annual production may increase. Native forbs generally decrease in production, abundance, diversity, and richness compared to that of State 1: Reference State.
These exotic cool-season grasses have been particularly and consistently invasive under extended periods of no use and no fire. To slow or limit the invasion of these exotic grasses it is imperative that managerial options (e.g. prescribed grazing, prescribed burning) be carefully constructed and evaluated with respect to that objective. If management does not include measures to control or reduce these exotic cool-season grasses, the transition to State 3: Invaded State should be expected.
Annual production of this state can be quite variable, in large part due to the amount of exotic cool-season grasses. Production may, however, be expected to be within the range between that of State 1: Reference State Community Phase 1.1 (2900-4900 pounds per acre) and State 3: Invaded State (3200-5200 pounds per acre).
Characteristics and indicators
The presence of trace amounts of exotic cool-season grasses indicates a transition from State 1 to State 2. The presence of exotic biennial or perennial leguminous forbs (i.e., sweet clover, black medic) may not, on their own, indicate a transition from State 1 to State 2 but may facilitate that transition.
Resilience management
To slow or limit the invasion of these exotic grasses, it is imperative that managerial techniques (e.g., prescribed grazing, prescribed burning) be carefully constructed, monitored, and evaluated with respect to that objective.
Grazing management should be applied that enhances the competitive advantage of native grass and forb species. This may include: (1) early spring grazing when exotic cool-season grasses are actively growing and native cool-season grasses are dormant; (2) applying proper deferment periods allowing native grasses to recover and maintain or improve vigor; (3) adjusting overall grazing intensity to reduce excessive plant litter (above that needed for rangeland health indicator #14 – see Rangeland Health Reference Worksheet); (4) incorporating early heavy spring utilization which focuses grazing pressure on exotic cool-season grasses and reduces plant litter, provided that livestock are moved when grazing selection shifts from exotic cool-season grasses to native grasses.
Prescribed burning should be applied in a manner that maintains or enhances the competitive advantage of native grass and forb species. Prescribed burns should be applied as needed to adequately reduce/remove excessive plant litter and maintain the competitive advantage for native species. Timing of prescribed burns (spring vs. summer vs. fall) should be adjusted to account for differences in annual growing conditions and applied during windows of opportunity to best shift the competitive advantage to the native species.
Submodel
Description
This state is the result of invasion and dominance by the exotic cool-season grasses, commonly Kentucky bluegrass, smooth brome, and/or quackgrass. These exotic cool-season grasses can be quite invasive on the site and are particularly well adapted to heavy grazing. They also often form monotypic stands. As these exotic cool-season grasses increase, both forage quantity and quality become increasingly restricted to late spring and early summer due to the monotypic nature of the stand even though annual production may increase.
Native forbs generally decrease in production, abundance, diversity, and richness compared to that of State 1: Reference State. Common forbs often include white heath aster, goldenrod, common yarrow, and white sagebrush. Exotic forbs may also be prominent components on the site, including the noxious weeds Canada thistle and leafy spurge. Native shrubs such as western snowberry and rose often show marked increases. Once the state is well established, prescribed burning and grazing techniques have been largely ineffective in suppressing or eliminating the exotic, cool-season grasses even though some short-term reductions may appear successful.
Annual production on this state may vary (i.e. 3200 – 5200 lbs/acre) but may average around 4300 lbs/acre. However, collectively the exotic cool-season grasses Kentucky bluegrass, smooth brome, and/or quackgrass can account for 77-86% of the total production.
Characteristics and indicators
This site is characterized by exotic cool-season grasses constituting greater than 30 percent of the annual production and native grasses constituting less than 40 percent of the annual production.
Resilience management
Light or moderately stocked continuous, season-long grazing or a prescribed grazing system which incorporates adequate deferment periods between grazing events and proper stocking rate levels will maintain this State. Application of herbaceous weed treatment, occasional prescribed burning and/or brush management may be needed to manage noxious weeds and increasing shrub (e.g., western snowberry) populations.
Submodel
Description
This state typically results from the abandonment of cropland, hayland, or residences/ farmsteads. Vegetation is typically dominated by exotic cool-season grasses (i.e., Kentucky bluegrass, smooth brome, and/or quackgrass) with a variety of annual and weedy perennial forbs. This state will initially include a variety of annual forbs and grasses, some of which may be noxious weeds needing control. However, exotic cool- season grasses (such as Kentucky bluegrass, smooth brome, and/or quackgrass) come to dominate the site. Associated forbs and shrubs often include western snowberry, wild rose, common dandelion, Canada goldenrod, common yarrow, and Canada thistle. If the site is adjacent to woodlands, sprouts and seeds from the woodland species may begin to encroach and colonize the site.
Characteristics and indicators
Tillage has destroyed the native plant community, altered soil structure and biology, reduced soil organic matter, and resulted in the formation of a tillage induced compacted layer which is restrictive to root growth. Removal of perennial grasses and forbs results in decreased infiltration and increased runoff.
Resilience management
Continued tillage will maintain the state. Control of noxious weeds will be required.
Submodel
Description
This state historically existed as small patches of trees and/or shrubs scattered across the site, particularly in river valleys and near woodlands. Non-use and fire suppression since European influence has enabled this state to expand and become more widespread.
Characteristics and indicators
The dominance of woody species (by cover and production) distinguishes this state from other herbaceously dominated states.
Resilience management
This state is resistant to change in the long-term absence of fire. Restoration efforts would require the use of prescribed fire, mechanical treatment, and prescribed grazing. Considerable time and effort will be required to restore to other States.
Submodel
Mechanism
This transition from State 1: Reference State to State 2: Native/Invaded State is initiated by the colonization of exotic cool-season grasses, mainly Kentucky bluegrass, smooth brome and/or quackgrass. Non-use with no fire as well as chronic season-long or heavy late season grazing facilitates this transition. The threshold between the states is crossed when the exotic species become established on the site.
Constraints to recovery
Current knowledge and technology will not facilitate a successful restoration to Reference State.
Mechanism
This transition from State 1: Reference State to State 5: Wooded State occurs over extended periods of non-use (or very light grazing) and no fire. Adjacent or nearby stands of woody species can encroach onto the site vegetatively (e.g. rhizomes, root sprouts) or provide a seed source for colonization of the site. Common woody species often include western snowberry, chokecherry, silver buffaloberry, American plum, wild rose, hawthorn, and green ash.
Constraints to recovery
Current knowledge and technology will not facilitate a successful restoration to Reference State.
Mechanism
This transition pathway from the State 2: Native/Invaded State to State 3: Invaded State occurs with long-term non-use or very light grazing, and no fire. It may also occur with heavy season-long grazing (primarily Kentucky bluegrass).
A threshold may be crossed when both the exotic cool-season grasses exceed 30% of the community composition and native grasses account for less than 40% composition. Prescribed burning and/or prescribed grazing have been largely ineffective in reducing Kentucky bluegrass and smooth brome, even though these efforts may appear effective in the short term (e.g., within a growing season).
Constraints to recovery
). Variations in growing conditions (e.g., cool, wet spring) will influence effects of various management activities on exotic
cool-season grass populations.
Mechanism
This transition from State 2: Native/Invaded State to State 5: Wooded State occurs over extended periods of non-use (or very light grazing) and no fire, enabling adjacent or nearby stands of woody species to encroach onto the site vegetatively (e.g. rhizomes, root sprouts) or by providing a seed source for colonization of the site. Common woody species may include western snowberry, chokecherry, silver buffaloberry, American plum, wild rose, hawthorn, and green ash.
Constraints to recovery
The extended fire interval may make recovery doubtful due to the abundance of exotic cool-season grasses and lack of native grasses. Fire intensity along with consumption of available fuels may cause incomplete or patchy burns. Continued recruitment of tree seeds from adjacent sites will hamper site restoration.
Reticence to undertake tree removal and the perception that trees may be a desirable vegetation component for wildlife habitat, carbon sequestration, aesthetics, etc. are some of the constraints to recovery. Managers wanting to manage the site for deer, livestock, or grassland nesting birds will need to consider the intensive management required to restore and maintain the site in State 2. The disturbance regime necessary to restore this site to State 2: Native/Invaded State is very labor intensive and costly; therefore, addressing woody removal earlier in the encroachment phase is the most cost-effective treatment for woody control.
Mechanism
This restoration pathway from State 3: Invaded State to State 2: Native/Invaded State may be accomplished with the implementation of long-term prescribed grazing and prescribed burning, assuming there is an adequate component of native grasses to respond to the treatments.
Both prescribed grazing and prescribed burning are likely necessary to successfully initiate this restoration pathway, the success of which depends upon the presence of a remnant population of native grasses in Community Phase 3.1. That remnant population, however, may not be readily apparent without close inspection. The application of several prescribed burns may be needed at relatively short intervals in the early phases of this restoration process, in part because many of the shrubs (e.g., western snowberry) sprout profusely following one burn. Early season prescribed burns have been successful; however, fall burning may also be an effective technique.
The prescribed grazing should include adequate recovery periods following each grazing event and stocking levels which match the available resources. If properly implemented, this will shift the competitive advantage from the exotic cool-season grasses to the native cool-season grasses.
Context dependence
Grazing management should be applied in a manner that enhances/maximizes the competitive advantage of native grass and forb species over the exotic species. This may include the use of prescribed grazing to reduce excessive plant litter accumulations above that needed for rangeland health indicator #14 (see Rangeland Health Reference Worksheet). Increasing livestock densities may facilitate the reduction in plant litter provided length and timing of grazing periods are adjusted to favor native species.
Grazing prescriptions designed to address exotic grass invasion and favor native species may involve earlier, short, intense grazing periods with proper deferment to improve native species health and vigor. Fall (e.g., September, October) prescribed burning followed by an intensive, early spring graze period with adequate deferment for native grass recovery may shift the competitive advantage to the native species, facilitating the restoration to State 2: Native/Invaded.
Prescribed burning should be applied in a manner that enhances the competitive advantage of native grass and forb species over the exotic species. Prescribed burns should be applied at a frequency which mimics the natural disturbance regime, or more frequently as is ecologically (e.g., available fuel load) and economically feasible. Burn prescriptions may need adjustment to: (1) account for change in fine fuel orientation (e.g., “flopped” Kentucky bluegrass); (2) fire intensity and duration by adjusting ignition pattern (e.g., backing fires vs head fires); (3) account for plant phenological stages to maximize stress on exotic species while favoring native species (both cool- and warm-season grasses).
Mechanism
This transition from State 3: Invaded State to State 5: Wooded State occurs during extended periods of non-use (or very light grazing) and no fire. Adjacent or nearby stands of woody species can encroach onto the site vegetatively (e.g. rhizomes, root sprouts) or provide a seed source for colonization of the site. Common woody species include western snowberry, chokecherry, silver buffaloberry, American plum, wild rose, hawthorn, and green ash.
Constraints to recovery
The extended fire interval may make recovery doubtful due to the abundance of exotic cool-season grasses and lack of native grasses. Fire intensity along with consumption of available fuels may cause incomplete or patchy burns. Continued recruitment of tree seeds from adjacent sites will hamper site restoration.
Constraints to recovery include the reticence to undertake tree removal and the perception that trees may be a desirable vegetation component for wildlife habitat, carbon sequestration, aesthetics, etc. Managers wanting to manage the site for deer, livestock, or grassland nesting birds will need to consider the intensive management required to restore and maintain the site in State 2. The disturbance regime necessary to restore this site to State 2: Native/Invaded State is very labor intensive and costly; therefore, addressing woody removal earlier in the encroachment phase is the most cost-effective treatment for woody control.
Mechanism
Restoration pathway from State 4: Go-Back State to State 2: Native/Invaded State can be accomplished with a successful range planting followed by the implementation of long-term prescribed grazing and prescribed burning to increase desirable natives and reduce native and exotic annual and pioneer plants.
It may be possible using selected plant materials and agronomic practices to approach something very near the functioning of State 2: Native/Invaded State. Application of chemical herbicides and the use of mechanical seeding methods using adapted varieties of the dominant native grasses are possible and can be successful. After establishment of the native plant species, management objectives must include the maintenance of those species, the associated reference state functions, and continued treatment of exotic grasses.
The prescribed grazing should include adequate recovery periods following each grazing event and stocking levels which match the available resources. If properly implemented, this will shift the competitive advantage from the exotic cool-season grasses to the native cool-season grasses.
Context dependence
). 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. Adding non-native species can impact the above and below ground biota. Elevated soil nitrogen levels have been shown to benefit smooth brome and Kentucky bluegrass more than some native grasses. As a result, fertilization, exotic legumes in the seeding mix, and other techniques that increase soil nitrogen may promote smooth brome and Kentucky bluegrass invasion.
The method or methods of herbaceous weed treatment will be site specific to each situation; but generally, the goal would be to apply the pesticide, mechanical control, or biological control (either singularly or in combination) in a manner that shifts the competitive advantage from the targeted species to the native grasses and forbs. The control method(s) should be as specific to the targeted species as possible to minimize impacts to non-target species.
Mechanism
This restoration pathway from State 4: Go-Back State to State 3: Invaded State results from a failed range planting.
Context dependence
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), and/or improper management.
Mechanism
This restoration pathway from State 5: Wooded State to State 2: Native/Invaded State can occur with prescribed burning and/or chemical/mechanical brush management followed by a successful range planting. Prescribed burning generally will require repeated treatments because many of the shrubs (e.g. western snowberry, chokecherry) sprout profusely following burning.
Context dependence
Fire intensity along with consumption of available fuels may cause incomplete or patchy burns. Ladder fuel and/or fuel loading are required for successfully controlling ponderosa pine (crown vs. ground fire). Continued recruitment of seeds (juniper and pine) from adjacent sites will hamper site restoration. Intensive management is required to restore and maintain the site in State 2: Native/Invaded State.
Grazing management should be applied in a manner that enhances/maximizes the competitive advantage of native grass and forb species over the exotic species. This may include the use of prescribed grazing to reduce excessive plant litter accumulations above that needed for rangeland health indicator #14 (see Rangeland Health Reference Worksheet). Increasing livestock densities may facilitate the reduction in plant litter provided length and timing of grazing periods are adjusted to favor native species.
Grazing prescriptions designed to address exotic grass invasion and favor native species may involve earlier, short, intense grazing periods with proper deferment to improve native species health and vigor. Fall (e.g., September, October) prescribed burning followed by an intensive, early spring graze period with adequate deferment for native grass recovery may shift the competitive advantage to the native species, facilitating the restoration to State 2: Native/Invaded.
Prescribed burning should be applied in a manner that enhances the competitive advantage of native grass and forb species over the exotic species. Prescribed burns should be applied at a frequency which mimics the natural disturbance regime, or more frequently as is ecologically (e.g., available fuel load) and economically feasible. Burn prescriptions may need adjustment to: (1) account for change in fine fuel orientation (e.g., “flopped” Kentucky bluegrass); (2) fire intensity and duration by adjusting ignition pattern (e.g., backing fires vs head fires); (3) account for plant phenological stages to maximize stress on exotic species while favoring native species (both cool- and warm-season grasses).
Mechanism
This restoration pathway from State 5: Wooded State to State 3: Invaded State can occur with prescribed burning and/or chemical/mechanical brush management followed by a failed range planting.
Context dependence
Fire intensity along with consumption of available fuels may cause incomplete or patchy burns. Continued recruitment of shrub tree seeds from adjacent sites and resprouting of existing shrubs will hamper site restoration. Intensive management is required to restore and maintain the site in State 3: Invaded State.
Mechanism
This transition from any plant community to State 4: Go-Back State. It is most commonly associated with the cessation of cropping without the benefit of range planting, 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 (plow pan), erosion, fertility, and/or herbicide/pesticide carryover). Thus, soil conditions should be assessed when considering restoration techniques.
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.