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Ecological site R066XY036NE

Loamy 18-22 P.Z.

Last updated: 11/18/2024
Accessed: 12/21/2024

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General information

Approved. An approved ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model, enough information to identify the ecological site, and full documentation for all ecosystem states contained in the state and transition model.

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Figure 1. Mapped extent

Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.

MLRA notes

Major Land Resource Area (MLRA): 066X–Dakota-Nebraska Eroded Tableland

The Dakota-Nebraska Eroded Tableland (MLRA 66) occurs in north-central Nebraska (56 percent) and south-central South Dakota (44 percent). MLRA 66 is approximately 3.6 million acres and covers all or parts of twelve counties between the two states. The northern border of the MRLA bisects Tripp County, South Dakota, just south of the town of Winner. Valentine is in the northeastern corner of Cherry County, Nebraska and is located on the MLRA’s southwestern border. From there, the MLRA stretches southeast to the northwestern corner of Antelope County, Nebraska and the town of O’Neil, Nebraska in Holt County its southeastern border.

The MLRA occupies a smooth fluvial plain primarily consisting of broad intervalley areas with terraces, river breaks, and local badlands along the well-defined major drainages. The slopes range from nearly level tablelands to steep ridges and drainages. The elevation ranges from 1,970 to 2,950 feet. The Keya Paha, Elkhorn, and the Niobrara Rivers flow through the MLRA. The Niobrara is a designated National Scenic River.

Layers of shaly chalk and limestone marine sediments overlaying the Cretaceous Niobrara Formation make up the bulk of the MLRA, though the western and southwestern portions exhibit surface eolian deposits. The floors of the major drainages are underlain by deposits of alluvial sand and gravel. The dominant soil orders in this MLRA are mesic, ustic or aridic Mollisols and Entisols. Loamy and sandy are the primary soil textures in this landscape.

Twenty-seven percent of the land in this MLRA has been broken out of native prairie and farmed, while sixty-six percent of the grasslands remain intact. The remaining acres are divided between forest, urban development, and other uses. Livestock grazing, primarily by cattle, is a major industry. Corn, winter wheat, and grain sorghum are the primary commodity crops but a significant number of acres are planted to forage sorghum and alfalfa for harvest as hay. With limited irrigation available, and annual precipitation averaging from 18 inches in the west to 25 inches in the east, crop production is marginal across most of the MLRA.

The historical matrix vegetation type is mixed-grass prairie. Big bluestem, sand bluestem, prairie sandreed, little bluestem, sideoats grama, and blue grama make up the bulk of the warm-season species. Western wheatgrass, green needlegrass, and needle and thread are the dominant cool-season grasses. Large- and small-patch vegetative communities are found primarily along the riparian zones, on lowland sites, and in closed depressions. Woodlands make up about 3 percent of MLRA 66 and consist primarily of green ash, bur oak, and hackberry. Ponderosa pines can be found on steeper sites in the western portion of the landscape.

Wildlife flourishes in this combination of crop and grassland environments. In a landscape historically occupied by bison herds, white-tailed and mule deer are now the most abundant wild ungulates. Pronghorns also number among the remaining native grazers. A variety of smaller species, including coyote, raccoon, opossum, porcupines, muskrat, beaver, squirrel, prairie dogs, and mink, thrive in the region. Grassland birds, including several upland game birds, are common across the MLRA.

This landscape serves as a backdrop for a disturbance-driven ecosystem, evolving under the influences of herbivory, fire, and variable climate. Historically, these processes created a heterogeneous mosaic of plant communities and structure heights across the region. Any given site in this landscape burned every six to ten years, with most of the MLRA experiencing a six to eight year fire regime. The fires were caused by lightning strikes and were also set by Native Americans, who used fire for warfare, signaling, and to refresh the native grasses. Indigenous inhabitants understood the value of fire as a tool, and that the highly palatable growth following a fire provided excellent forage for their horses and attracted grazing game animals such as bison and elk.

Land use patterns by post-European settlers have greatly altered the historical fire regime, allowing the expansion of woody species. Fragmentation of the native grasslands by conversion to cropland, transportation corridors, and other developments has contributed to disruption of the natural fire regime of this ecosystem. The most common encroaching woody species is eastern redcedar. While eastern redcedar is native to the landscape, the historic population in MLRA 66 was limited to isolated pockets in rugged river drainageways that were protected from wildfire. Widespread plantings of windbreaks with eastern redcedar as a primary component provide a seed source for the aggressive woody plant which further facilitates woody encroachment. Encroachment of native and introduced shrubs and trees into the native grasslands degrades wildlife habit and causes significant forage loss for domestic livestock. Aggressive fire suppression policies have exacerbated this process to the point that shrub and tree encroachment is a major ecological threat to grasslands throughout most of the MLRA.

Classification relationships

►EPA◄
Level IV Ecoregions of the Conterminous United States
43—Northwestern Great Plains:
43i—Keya Paha Tablelands.

►USDA◄
Land Resource Regions and Major Land Resource Areas (USDA-NRCS, 2006)
Land Resource Region: G—Western Great Plains Range and Irrigated Region:
Major Land Resource Area (MLRA): 66 Dakota-Nebraska Eroded Tableland.

Ecological site concept

There is a significant decline in precipitation from east to west across MLRA 66 which impacts plant community composition and annual production. For the purpose of ecological site development, the Loamy site is divided into two ecological sites to address this precipitation gradient and its impacts to the site. The Loamy 18-22" PZ typically occurs west of a line that extends from Johnstown, Nebraska to Witten, South Dakota.

The Loamy site is located on upland landscapes and does not receive any additional moisture from runoff or overflow. Slopes typically range from 0 to 20 percent but may be as steep as 40 percent. Soils are deep to very deep and formed in loamy alluvium, loamy residuum, or loess. Soil surface textures ranging from loamy fine sand, fine sandy loam, loam, to silt loam.

Vegetation in the Reference Plant Community (1.1) consists of a mix of cool- and warm-season grasses. Dominant grasses include needle and thread, and western wheatgrass. Other significant grasses include green needlegrass, big bluestem, and little bluestem. Forbs are common and diverse. Shrubs include leadplant, western sandcherry and rose. The site is susceptible to invasion of non-native, cool-season grasses, especially Kentucky bluegrass and smooth brome.

Much of this site has been converted to commodity crop agriculture, primarily corn, wheat, milo, and alfalfa. Livestock grazing is the primary use of the intact native rangeland.

Associated sites

R066XY059NE	Thin Upland The Thin Upland ecological site is often found adjacent to but on a higher landscape position than Loamy 18-22 PZ ecological sites.
R066XY062NE	Shallow To Gravel The Shallow to Gravel ecological site is often found interspersed throughout an area with Loamy 18-22 PZ ecological sites.
R066XY066NE	Loamy Terrace The Loamy Terrace ecological site is often found adjacent to but on a lower landscape position than Loamy 18-22 PZ ecological sites.

R066XY059NE

Thin Upland

The Thin Upland ecological site is often found adjacent to but on a higher landscape position than Loamy 18-22 PZ ecological sites.

R066XY062NE

Shallow To Gravel

The Shallow to Gravel ecological site is often found interspersed throughout an area with Loamy 18-22 PZ ecological sites.

R066XY066NE

Loamy Terrace

The Loamy Terrace ecological site is often found adjacent to but on a lower landscape position than Loamy 18-22 PZ ecological sites.

Similar sites

R066XY066NE	Loamy Terrace The Loamy Terrace ecological site has similar surface soil textures but occurs in a lower landscape position compared to the Loamy 18-22 PZ ecological site.
R066XY059NE	Thin Upland The Thin Upland and Loamy 18-22" PZ ecological sites occur on similar landscape positions and have similar surface soil textures but Thin Upland sites are calcareous at or near the surface while Loamy 18-22 PZ ecological sites are not.

R066XY066NE

Loamy Terrace

The Loamy Terrace ecological site has similar surface soil textures but occurs in a lower landscape position compared to the Loamy 18-22 PZ ecological site.

R066XY059NE

Thin Upland

The Thin Upland and Loamy 18-22" PZ ecological sites occur on similar landscape positions and have similar surface soil textures but Thin Upland sites are calcareous at or near the surface while Loamy 18-22 PZ ecological sites are not.

Table 1. Dominant plant species

Tree	Not specified
Shrub	Not specified
Herbaceous	(1) Nassella viridula (2) Pascopyrum smithii

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Physiographic features

This site occurs on gently undulating to moderately steep rolling plains, flats and low hills.

Figure 2. Block diagram of the Loamy site

Table 2. Representative physiographic features

Landforms	(1) Hillslope (2) Flat (3) Plain (4) Knoll
Runoff class	Very low to very high
Flooding frequency	None
Ponding frequency	None
Elevation	1,200 – 3,500 ft
Slope	40%
Water table depth	80 in
Aspect	Aspect is not a significant factor

Climatic features

MLRA 66 is considered to have a continental climate with cold winters and hot summers, low humidity, light rainfall, and much sunshine. Extremes in temperature may also abound. The climate is the result of this MLRA’s location near the geographic center of North America. There are few natural barriers on the northern Great Plains and the winds move freely across the plains and account for rapid changes in temperature.

Annual precipitation ranges from 18 to 25 inches per year. The normal average annual temperature is about 48°F. January is the coldest month with average temperatures ranging from about 19°F (Bonesteel, SD) to about 23°F (Ainsworth, NE). July is the warmest month with temperatures averaging from about 73°F (Harrington, SD) to about 75°F (Gregory, SD). The range of normal average monthly temperatures between the coldest and warmest months is about 54°F. This large annual range attests to the continental nature of the climate this area. Hourly winds average about ten miles per hour annually, ranging from about 11 miles per hour during the spring to about nine miles per hour during the summer. Daytime winds are generally stronger than nighttime and occasional strong storms may bring brief periods of high winds with gusts to more than 50 miles per hour.

Growth of native cool-season plants begins mid to late March and continues to late June. Native warm-season plants begin growth in early May and continue to late August. Green-up of cool-season plants may occur in September and October when adequate soil moisture is present.

Table 3. Representative climatic features

Frost-free period (characteristic range)	108-120 days
Freeze-free period (characteristic range)	129-139 days
Precipitation total (characteristic range)	20-23 in
Frost-free period (actual range)	96-124 days
Freeze-free period (actual range)	121-151 days
Precipitation total (actual range)	20-24 in
Frost-free period (average)	113 days
Freeze-free period (average)	135 days
Precipitation total (average)	21 in

Characteristic range

Actual range

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Figure 3. Monthly precipitation range

Characteristic range

Actual range

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Figure 4. Monthly minimum temperature range

Characteristic range

Actual range

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Figure 5. Monthly maximum temperature range

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Figure 6. Monthly average minimum and maximum temperature

Figure 7. Annual precipitation pattern

Figure 8. Annual average temperature pattern

Climate stations used

(1) AINSWORTH [USC00250050], Ainsworth, NE
(2) SPRINGVIEW [USC00258090], Springview, NE
(3) WINNER [USC00399367], Winner, SD
(4) WOOD [USC00399442], Wood, SD
(5) MISSION [USC00395620], Mission, SD
(6) HARRINGTON [USC00393574], Tuthill, SD
(7) MARTIN 5 E [USC00395285], Martin, SD
(8) MISSION 14 S [USC00395638], Mission, SD
(9) VALENTINE MILLER FLD [USW00024032], Valentine, NE
(10) KILGORE 1NE [USC00254432], Kilgore, NE
(11) LONGVALLEY [USC00394983], Long Valley, SD

Soil features

The soils correlated to the Loamy 18-22 PZ ecological site are deep and very deep, well drained, and formed in loess, eolian deposits, loamy alluvium, and loamy residuum. Soil surface textures are loamy fine sand, fine sandy loam, loam, or silt loam. Soils typically have a dark surface layer that is 6 to 20 inches thick. Slopes are typically 0 to 20 percent but may be up to 40 percent.

This site should show slight to no evidence of rills, wind scoured areas or pedestalled plants. Water flow paths are broken should not be distinguishable, and litter should fall and remain in place. The soil surface is stable and intact. Sub-surface soil layers are not restrictive to water movement and root penetration. These soils are susceptible to water erosion when cover is absent. The hazard of water erosion increases on slopes greater than about 10 percent.

The major soil series correlated to the Loamy 18-22" PZ ecological site include Jansen, Paka, Johnstown, and Hennings. Other series include Josburg, Kadoka, Keya, O'Neill, Ree, Rosebud, Verdigre, and Vetal. More information can be found in the various soil survey reports. Contact the local USDA Service Center for soil survey reports that include more detail specific to your location or visit Web Soil Survey (https://websoilsurvey.sc.egov.usda.gov).

Figure 9. Jansen series profile

Table 4. Representative soil features

Parent material	(1) Alluvium (2) Residuum (3) Eolian deposits (4) Loess
Surface texture	(1) Loam (2) Fine sandy loam (3) Silt loam
Family particle size	(1) Loamy
Drainage class	Well drained
Permeability class	Slow to moderately rapid
Soil depth	40 – 80 in
Surface fragment cover <=3"	8%
Surface fragment cover >3"	Not specified
Available water capacity (Depth not specified)	3.5 – 8.7 in
Calcium carbonate equivalent (Depth not specified)	5%
Electrical conductivity (Depth not specified)	2 mmhos/cm
Sodium adsorption ratio (Depth not specified)	3
Soil reaction (1:1 water) (Depth not specified)	5.1 – 8.4
Subsurface fragment volume <=3" (Depth not specified)	26%
Subsurface fragment volume >3" (Depth not specified)	2%

Ecological dynamics

Loamy 18-22 PZ ecological sites developed under Northern Great Plains climatic conditions, light to severe grazing by bison and other large herbivores, sporadic natural or human-caused wildfire, and other biotic and abiotic factors that typically influence soil and site development. This continues to be a disturbance-driven site with herbivory, fire, and variable climate being the primary disturbances. Changes occur in the plant communities due to short-term weather variations, impacts of native and exotic plant and animal species, and management actions.

One of the primary impacts to the Loamy 18-22 PZ site introduced by European settlers is season-long, continuous grazing by domestic livestock. This management practice causes the repeated removal of the growing point and excessive defoliation of the leaf area of individual warm-season tallgrasses. The resulting reduction of the ability of the plants to harvest sunlight depletes the root reserves, subsequently decreasing the root mass. This negatively impacts the ability of the plants to compete for life-sustaining nutrients, resulting in declining vigor and eventual mortality. The space created in the vegetative community is then occupied by a species that evades the negative grazing impacts by a growing season adaptation (such as a cool season), a shorter structure, a growing point that remains near ground level, or a reduced palatability mechanism.

The State and Transition Model (STM) is depicted below and includes a Reference State (1), a Native-Invaded Grass State (2), an Invaded Grass State (3), a Shortgrass Sod State (4), an Early Seral State (5), an Invaded Woody State (6), and a Sodbusted State (7). Each state represents the crossing of a major ecological threshold due to the alteration of the functional dynamic properties of the ecosystem. The primary properties observed to determine this change are soil stability, vegetative communities, and the hydrologic cycle. Each state may have one or more plant communities that fluctuate in species composition and abundance within the normal parameters of the state. Within each state, communities may degrade or recover in response to natural and man caused disturbances such as variation in the degree and timing of herbivory, presence or absence of fire, and climatic and local fluctuations in the precipitation regime. The processes that cause the movement between the states and communities are discussed in more detail in the state and community descriptions following the diagram.

Interpretations are primarily based on the Reference Community (1.1). It has been determined by study of rangeland relic areas, areas protected from excessive disturbance, and areas under long-term rotational grazing regimes. Trends in plant community dynamics ranging from heavily grazed to lightly grazed areas, seasonal use pastures, and historical accounts have been used as well. Plant communities, states, transitional pathways, and thresholds have been determined through similar studies and experience.

State and transition model

Custom diagram

Standard diagram

Figure 10. State and Transition Model Diagram. MLRA 66 Loamy 18-22" PZ Ecological Site.

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Click on state and transition labels to scroll to the respective text

T1A	-	Repeated continuous seasonal grazing, rotational summer grazing with inadequate recovery periods, or prolonged (> 10 years) nonuse with no fire with invasion of non-native cool-season grasses.
T1B	-	Long term (> 10 years) continuous season long grazing or rotational grazing with inadequate growing season recovery periods.
T1C	-	Long term (> 10 years) heavy grazing or other heavy disturbance.
T1D	-	Woody encroachment with no prescribed burning or woody species management.
T1E	-	Tillage to facilitate production agriculture.
R2A	-	Long-term (> 15 years) prescribed grazing during spring or spring and fall.
T2A	-	Continued invasion of non-native cool-season grasses facilitated by seasonal grazing in summer, continuous season long grazing, rotational grazing with inadequate growing season recovery periods or non-use with no fire.
T2B	-	Long term (> 10 years) continuous seasonal grazing in the spring months.
T2C	-	Long term (> 10 years) heavy grazing or other heavy disturbance.
T2D	-	Woody encroachment with no prescribed burning or woody species management.
T2E	-	Tillage to facilitate production agriculture.
R3A	-	Long-term (> 15 years) prescribed grazing during spring or spring and fall.
T3A	-	Long term (> 10 years) heavy grazing or other heavy disturbance.
T3B	-	Woody encroachment with no prescribed burning or woody species management.
T3D	-	Tillage to facilitate production agriculture.
R4A	-	Long-term (> 15 years) prescribed grazing. This restoration may not be feasible.
R4B	-	Long-term (> 15 years) prescribed grazing. This restoration may not be feasible.
T4A	-	Long term (> 10 years) heavy grazing or other heavy disturbance.
T4B	-	Woody encroachment with no prescribed burning or woody species management.
T4C	-	Tillage to facilitate production agriculture.
T5A	-	Woody encroachment with no prescribed burning or woody species management.
T5B	-	Tillage to facilitate production agriculture.
R6A	-	Prescribed burning, wildfire, timber harvest, brush management.
R6B	-	Prescribed burning, wildfire, timber harvest, brush management.
R6C	-	Prescribed burning, wildfire, timber harvest, brush management.
R6D	-	Prescribed burning, wildfire, timber harvest, brush management.
R6E	-	Prescribed burning, wildfire, timber harvest, brush management.
R6F	-	Prescribed burning, wildfire, timber harvest, brush management.
T7A	-	Woody encroachment with no prescribed burning or woody species management.

State 1 submodel, plant communities

1.1. Reference Community

1.2. At-Risk Community

1.1A	-	Grazing or haying with inadequate growing season recovery periods.
1.2A	-	Prescribed grazing or haying with adequate growing season recovery periods.

State 2 submodel, plant communities

2.1. Native Cool-Season-Invasive Cool-Season Grass Community

State 3 submodel, plant communities

3.1. Invaded Grass Community

State 4 submodel, plant communities

4.1. Shortgrass Sod Community

State 5 submodel, plant communities

5.1. Shortgrass/Annuals Community

State 6 submodel, plant communities

6.1. Invaded Woody Community

State 7 submodel, plant communities

7.1. Reseeded Native Grass Community

7.2. Seeded Pasture Community

7.3. Natural Reclamation Community

State 1
Reference State

The Reference State (1) describes the range of vegetative communities that occur on the Loamy 18-22" 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 the Reference Community (1.1) and the At-Risk Community (1.2). The Reference Community (1.1) serves as a description of the native plant community that naturally 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. All community phases are susceptible to eastern redcedar invasion and subject to crossing a threshold into the Invaded Woody State (4).

Dominant plant species

green needlegrass (Nassella viridula), grass
western wheatgrass (Pascopyrum smithii), grass
blue grama (Bouteloua gracilis), grass
needle and thread (Hesperostipa comata ssp. comata), grass
threadleaf sedge (Carex filifolia), other herbaceous

Community 1.1
Reference Community

Interpretations are primarily based on the Reference or Green Needlegrass-Western Wheatgrass-Little Bluestem (Nassella viridula-Pascopyrum smithii-Schizachyrium scoparium) Community (1.1). This plant community serves as a description of the native plant community that occurs on the site when the natural disturbance regimes are intact or are closely mimicked by management practices. This phase is dynamic, with fluid relative abundance and spatial boundaries between the dominant structural vegetative groups. These fluctuations are primarily driven by different responses of the species to changes in precipitation timing and abundance, and to fire and grazing events. This site developed with grazing by large herbivores and is well suited for grazing by domestic livestock. This plant community is dominated by cool-season grasses while warm-season tall- and midgrasses are subdominant. The principal grasses are green needlegrass, needle and thread, western wheatgrass. Big bluestem and little bluestem are also important components of the plant community. Grama grasses and sedges occur as an understory. Common forbs include white sagebrush, blazing star, prairie coneflower, goldenrod and scurfpeas. Leadplant and rose are common shrubs, with western snowberry occurring in patches across the site. The potential vegetation is about 80 to 90 percent grasses or grass-like plants, 5 to 10 percent forbs, and 5 to 10 percent shrubs. Natural fire played a significant role in the succession of this site by limiting the extent of eastern redcedar. Wildfires have been actively controlled in recent times, allowing eastern redcedar encroachment. This plant community can be found on areas that are managed with prescribed grazing, prescribed burning, and may be found on areas receiving occasional periods of short-term rest. This resilient community is well adapted to the Northern Great Plains climatic conditions. Plant diversity promotes strong tolerance to drought, site and soil stability, a functional hydrologic cycle, and a high degree of biological integrity. These factors create a suitable environment for a healthy and sustainable plant community.

Dominant plant species

green needlegrass (Nassella viridula), grass
western wheatgrass (Pascopyrum smithii), grass
little bluestem (Schizachyrium scoparium), grass
needle and thread (Hesperostipa comata ssp. comata), grass

Figure 11. Annual production by plant type (representative values) or group (midpoint values)

Table 5. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Grass/Grasslike	1550	2210	3050
Forb	125	195	275
Shrub/Vine	125	195	275
Total	1800	2600	3600

Figure 12. Plant community growth curve (percent production by month). NE6635, Eroded Tableland, cool-season dominant, warm-season subdominant.

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
J	F	M	A	M	J	J	A	S	O	N	D
		5	10	25	30	15	5	5	5

Community 1.2
At-Risk Community

The At-Risk or Blue Grama-Western Wheatgrass (Bouteloua gracilis-Pascopyrum smithii) Community (1.2) develops under continuous seasonal grazing, continuous season-long grazing, or rotational grazing with inadequate growing-season recovery periods. The dominant grasses and grass-likes are blue grama, western wheatgrass, and threadleaf sedge. Needle and thread and green needlegrass are also significant on the site. Other grasses that may be present include buffalograss, sideoats grama, prairie junegrass, red threeawn, and little bluestem. Forbs include white sagebrush, goldenrod, scurfpea, cuman ragweed, tarragon, scarlet globemallow. Dominant shrubs in this community include western snowberry and wild rose. Prairie sagewort may also be present in significant amounts. The potential vegetation is approximately 80 to 90 percent grasses and grass-like species, five to 10 percent forbs, five to 10 percent shrubs, and 0 to 3 percent trees. Compared to the Reference Community (1.1), shortgrass species including blue grama, bluegrass, sedge, and buffalograss have increased while cool-season bunchgrasses and the warm-season, tall- and midgrasses have decreased in relative abundance. Annual bromes, Kentucky bluegrass, smooth bromegrass, and annual forbs may have begun to invade and may be present in trace amounts. While plant diversity is relatively high, the structure of the community is dominated by shortgrasses. The dominant herbaceous species are very adapted to grazing; however, tall- and midgrass species and palatable forbs will decrease in the community through long-term overgrazing. Soil erosion is low. Because of the sod forming habit of the shortgrass species, water infiltration is reduced, and runoff is moderate.

Dominant plant species

western wheatgrass (Pascopyrum smithii), grass
blue grama (Bouteloua gracilis), grass
threadleaf sedge (Carex filifolia), other herbaceous

Figure 13. Annual production by plant type (representative values) or group (midpoint values)

Table 6. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Grass/Grasslike	1010	1650	2285
Forb	95	150	205
Shrub/Vine	95	150	205
Tree	0	50	105
Total	1200	2000	2800

Figure 14. Plant community growth curve (percent production by month). NE6635, Eroded Tableland, cool-season dominant, warm-season subdominant.

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
J	F	M	A	M	J	J	A	S	O	N	D
		5	10	25	30	15	5	5	5

Pathway 1.1A
Community 1.1 to 1.2

A shift from the Reference Community (1.1) to the At-Risk Community (1.2) occurs with continuous season-long grazing or rotational grazing with inadequate growing-season recovery periods. Repetitive haying without allowing adequate recovery periods during the growing season will also cause this shift.

Pathway 1.2A
Community 1.2 to 1.1

Prescribed grazing with appropriate stocking rates and with adequate growing-season recovery periods or haying with adequate growing season recovery time will return the At-Risk Community (1.2) to the Reference Community (1.1). Appropriately timed prescribed fire will accelerate this process.

State 2
Native/Invaded Grass State

The Native/Invaded Grass State (2) has been degraded from the Reference State (1) and much of the native warm-season grass community has been replaced by native cool-season grasses and non-native cool-season grasses. Non-native species are typically 15 percent or more of the plant community composition by weight. The Native/Invaded Grass State developed under repeated seasonal grazing during the summer or under extended periods (more than 10 years) of non-use with no fire. With extended periods of non-use, a thick litter layer develops This thatch layer favors cool-season species and the invasion of non-native cool-season grasses, especially Kentucky bluegrass. The loss of warm-season, tall- and midgrasses has negatively impacted energy flow and nutrient cycling. Water infiltration is reduced due to the shallow root system and rapid runoff characteristics of the current plant communities. As the management continues, the plant community will become dominated by non-native cool-season grasses and sedges causing the Native/Invaded Grass State to transition to the Invaded Grass State (3). The Native/Invaded Grass State includes the Native Cool-Season-Invasive Cool-Season Grass Community (2.1).

Dominant plant species

western wheatgrass (Pascopyrum smithii), grass
smooth brome (Bromus inermis), grass
Kentucky bluegrass (Poa pratensis), grass
needle and thread (Hesperostipa comata ssp. comata), grass
green needlegrass (Nassella viridula), grass

Community 2.1
Native Cool-Season-Invasive Cool-Season Grass Community

In the Native Cool-Season-Invasive Cool-Season Grass Community or Western Wheatgrass-Kentucky Bluegrass (Pascopyrum smithii-Poa pratensis) Community (2.1) the more palatable cool-season grasses have been reduced and the warm-season tall- and midgrasses have been reduced to remnant populations by continued defoliation during their critical growth periods. Initially, the dominant grasses include Kentucky bluegrass, western wheatgrass, needleandthread, and green needlegrass. Other grasses may include blue grama, buffalograss, threeawn, and prairie Junegrass. Sedges flourish in the understory. The dominant forbs include cuman ragweed, scurfpeas, white sagebrush, and verbenas. Dominant shrubs in this community include snowberry, rose, and plains pricklypear. As the current management continues, non-native grasses increase, replacing native cool-season grasses. Compared to the Reference Community (1.1), cool-season bunchgrasses and warm-season tall- and midgrasses have decreased, plant diversity has declined, infiltration has decreased, and runoff has increased. Kentucky bluegrass and smooth brome have become established on the site and these nonnative cool-season grasses are typically more than 15 percent of the plant community composition by weight. With continued, repeated seasonal grazing during the summer or extended periods of nonuse with no fire, non-native cool-season grasses will continue to increase. Cool, moist climatic conditions also tend to increase the dominance of Kentucky bluegrass. Soil erosion remains low. Soil health is affected by reduced efficiency in the nutrient, mineral, and hydrologic cycles as a result of decreases in plant litter and rooting depths. Total annual vegetative production declines significantly. When Kentucky bluegrass is dominant due to nonuse with no fire, the increasing thatch layer inhibits water infiltration and increases runoff. This plant community is resistant to change, and if disturbed, it is resilient. Kentucky bluegrass increases under grazing pressure. If the management continues, the plant community will become dominated by Kentucky bluegrass, smooth bromegrass, and annual bromes, the site will transition to the Invaded Grass State (3).

Dominant plant species

prairie sagewort (Artemisia frigida), shrub
Kentucky bluegrass (Poa pratensis), grass
western wheatgrass (Pascopyrum smithii), grass
needle and thread (Hesperostipa comata ssp. comata), grass
green needlegrass (Nassella viridula), grass
threadleaf sedge (Carex filifolia), other herbaceous
curlycup gumweed (Grindelia squarrosa), other herbaceous

Figure 15. Annual production by plant type (representative values) or group (midpoint values)

Table 7. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Grass/Grasslike	1460	2040	2770
Shrub/Vine	120	210	325
Forb	120	190	275
Tree	0	60	130
Total	1700	2500	3500

Figure 16. Plant community growth curve (percent production by month). NE6637, Eroded Tableland, warm-season dominant, cool-season subdominant.

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
J	F	M	A	M	J	J	A	S	O	N	D
		5	8	15	24	23	15	5	5

State 3
Invaded Grass State

The Invaded Grass State (3) occurs when non-native cool-season grasses dominate the site and are than 30 percent of the plant community composition by weight. Smooth brome tends to dominate the site with long term heavy grazing while Kentucky bluegrass tends to dominate the site with non-use and no fire due to thatch buildup. The loss of warm-season, tall- and midgrasses and increase of non-native cool-season grasses has negatively impacted energy flow and nutrient cycling. Water infiltration is reduced due to the shallow root system and rapid runoff characteristics of the current plant community. Long term (more than 15 years) prescribed grazing which includes concentrated grazing in the spring and fall and no grazing during the summer months may restore the plant community to the Native/Invaded State (2). The feasibility of this restoration depends upon the amount of native grasses remaining in the plant community. The fewer the native grasses present, the less likely that restoration is possible. The Invaded Grass State includes the Invaded Grass Community (3.1).

Dominant plant species

Kentucky bluegrass (Poa pratensis), grass
smooth brome (Bromus inermis), grass
western wheatgrass (Pascopyrum smithii), grass
green needlegrass (Nassella viridula), grass
prairie sagewort (Artemisia frigida), other herbaceous

Community 3.1
Invaded Grass Community

The Invaded Grass or Kentucky Bluegrass-Smooth Brome (Poa pratensis-Bromus inermis) Community (3.1) develops when fire and herbivory are excluded from the system. It can also develop with heavy, continuous, season long grazing or with heavy, continuous, seasonal grazing during the summer months. The plant community is dominated by non-native cool-season grasses, typically Kentucky bluegrass or smooth brome. Western wheatgrass, needlegrass, or other native cool-season grasses may be present. Forbs present typically include white sagebrush, goldenrod, scurfpea, and Cuman ragweed. Infiltration is moderately reduced as is energy capture while runoff has increased. Soil erosion is low. and plant diversity is significantly reduced. When the plant community is dominated by smooth brome production can be relatively high but the grass matures early in the growing season resulting in a forage that is palatable for a brief period of time. Production can be increased significantly when the site is managed as pastureland with prescribed grazing, herbaceous weed control, and fertilization.

Dominant plant species

smooth brome (Bromus inermis), grass
Kentucky bluegrass (Poa pratensis), grass

State 4
Shortgrass Sod State

The Shortgrass Sod State (4) most of the native warm-season tall- and midgrasses and cool-season bunchgrasses have been replaced by warm-season shortgrasses and sedges. The loss of warm-season tall- and midgrass and cool-season bunchgrass functional groups has negatively impacted energy flow and nutrient cycling. Water infiltration has been reduced while runoff has been increased due to the relatively shallow root systems of existing plant community. The Shortgrass Sod State includes the Shortgrass Sod Community (4.1).

Dominant plant species

blue grama (Bouteloua gracilis), grass
Fendler's threeawn (Aristida purpurea var. fendleriana), grass
threadleaf sedge (Carex filifolia), other herbaceous
white sagebrush (Artemisia ludoviciana), other herbaceous
Cuman ragweed (Ambrosia psilostachya), other herbaceous

Community 4.1
Shortgrass Sod Community

The Shortgrass Sod or Blue Grama-Threadleaf Sedge (Bouteloua gracilis-Carex filifolia) Community (4.1) develops with heavy continuous season-long grazing or repeated seasonal grazing, especially when grazing occurs in the spring and early summer. It can also develop with heavy rotational grazing when inadequate recovery periods are not implemented. Blue grama, sedges, and buffalograss are the dominant species. Minor species include western wheatgrass, threeawn, needle and thread, and sand dropseed. Common forbs include Cuman ragweed, white sagebrush, curlycup gumweed, and tarragon. Prairie sagewort and pricklypear are the dominant shrubs. When compared to the Reference Community (1.1), blue grama and buffalograss have increased significantly. The tallgrasses, if present, are remnants. Midgrasses, other than sand dropseed, are present only in trace amounts. Annual production has decreased significantly. This plant community is resistant to change, as the dominant species tolerate overgrazing. The thick sod prevents establishment of other species. Bare ground is usually less than 10 percent. Infiltration has decreased and runoff has increased. Soil erosion is low due to the sod forming habit of blue grama and threadleaf sedge. This could be advantageous for heavy use areas such as calving and lambing units since the grazing tolerant species will control erosion. In these situations, however, nutrient runoff is a potential resource concern.

Dominant plant species

blue grama (Bouteloua gracilis), grass
threadleaf sedge (Carex filifolia), other herbaceous

Figure 17. Annual production by plant type (representative values) or group (midpoint values)

Table 8. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Grass/Grasslike	705	1275	1640
Forb	70	110	155
Shrub/Vine	25	75	125
Tree	0	40	80
Total	800	1500	2000

State 5
Early Seral State

The Early Seral State (5) occurs with long term, heavy, concentrated grazing (continuous, season long, seasonal, or rotational with inadequate growing season recovery periods). Palatable warm-season grasses have been eliminated from plant community and have been replaced by less palatable warm-season grasses such as Fendler's threeawn and annual grasses such as cheatgrass. In some cases, remnant native grasses are present where protected from grazing, such as within shrub canopy. Litter levels are low and there is a significant amount of bare ground. Runoff is high and water infiltration is low. Soil erosion through both wind and water has increased significantly when compared to the other herbaceous states. Biotic integrity, hydrologic function, and site stability have been severely degraded. The Early Seral State includes the Shortgrass/Annuals Community (5.1).

Dominant plant species

prairie sagewort (Artemisia frigida), shrub
Fendler threeawn (Aristida purpurea var. longiseta), grass
cheatgrass (Bromus tectorum), grass
curlycup gumweed (Grindelia squarrosa), other herbaceous
Cuman ragweed (Ambrosia psilostachya), other herbaceous

Community 5.1
Shortgrass/Annuals Community

The Shortgrass/Annuals or Threeawn-Cheatgrass (Aristida-Bromus tectorum) Community (5.1) developed under continuous heavy grazing or other excessive disturbances including heavy use areas, calving pastures, and prairie dog towns. Dominant grasses include threeawn, cheatgrass, and rosettegrass. Blue grama, buffalograss, western wheatgrass, sixweeks fescue, and sedges may also be present. Forbs include white sagebrush, fetid marigold, Cuman ragweed, pussytoes, bigbract verbena, and other early successional forbs. This plant community is susceptible to invasion of Canada thistle and other non-native species due to the high percentage of bare ground. The potential plant community contains approximately 80 percent grasses and grass-likes and 15 to 20 percent forbs. Compared to the Reference Community (1.1) annual grasses and the percent of bare ground have increased significantly. Native cool-season grasses have decreased and are now a minor component of the plant community. Native, warm-season tall- and midgrasses are typically absent but may be present at trace levels. Plant diversity is low. This plant community is very resistant to change due to the loss of plant diversity and overall soil disturbance. Soil erosion potential is high due to the large amount of bare ground and the dominance of the dominance of shallow rooted plants. Runoff has increased and water infiltration has decreased. Significant inputs and time are required to move this plant community towards another community and will not be possible through grazing management alone due to the loss of plant diversity with the corresponding loss of the seed bank, the decreased hydrologic function, and the amount of soil erosion that has occurred. Seeding or renovation will be needed to improve vegetative production and will move the plant community to the Sodbusted State (7). If management changes are not made following this renovation, the vegetation will move to the Natural Reclamation Community (7.1) which is similar to the Shortgrass/Annuals Community.

Dominant plant species

Fendler's threeawn (Aristida purpurea var. fendleriana), grass
prairie threeawn (Aristida oligantha), grass
cheatgrass (Bromus tectorum), grass
rosette grass (Dichanthelium), grass
white sagebrush (Artemisia ludoviciana), other herbaceous
Cuman ragweed (Ambrosia psilostachya), other herbaceous
fetid marigold (Dyssodia papposa), other herbaceous
bigbract verbena (Verbena bracteata), other herbaceous

State 6
Invaded Woody State

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, reduced diversity of functional and structural groups, reduced forage production, and reduced soil quality. Prescribed burning, wildfire, timber harvest and brush management will move this state toward a grass dominated state. Land that transitioned to the Invaded Woody State from the Native/Invaded Grass State (2), Invaded Grass State (3), Shortgrass Sod State (4), Early Seral State (5), or Sodbusted State (7) cannot transition to the Reference State (1) through removal of woody species as the native plant community, soils, and hydrologic function have been too severely impacted for that restoration to occur. The Invaded Woody State includes one community, the Invaded Woody Community (6.1).

Dominant plant species

eastern redcedar (Juniperus virginiana), tree
ponderosa pine (Pinus ponderosa), tree
blue grama (Bouteloua gracilis), grass
western wheatgrass (Pascopyrum smithii), grass
Kentucky bluegrass (Poa pratensis), grass

Community 6.1
Invaded Woody Community

The Invaded Woody or Eastern Redcedar-Ponderosa Pine (Juniperus virginiana-Pinus ponderosa) Community (6.1) has at least 15 percent canopy cover of eastern redcedar or ponderosa pine. Encroaching trees are primarily eastern redcedar but may include ponderosa pine or deciduous trees and shrubs. In the absence of fire and brush management, this ecological site is very susceptible to eastern redcedar and, when conditions are conducive to germination, ponderosa pine seedling invasion, especially when adjacent to a seed source. Historically, periodic fire prevented woody species encroachment confining ponderosa pine and juniper to ridges and the steepest portions of the site. Fire suppression facilitates the encroachment of eastern redcedar, ponderosa pine, and other woody species onto the less steep portion of the Loamy 18-22 PZ ecological site. With long-term fire suppression, this plant community will develop extensive ladder fuels which can lead to a removal of most tree species with a wildfire. With properly managed intensive grazing, encroachment of deciduous trees will typically be minimal; however, this will not impact encroachment of coniferous species. The herbaceous component decreases proportionately in relation to the percent canopy cover, with the reduction being greater under a coniferous overstory. Eastern redcedar control can usually be accomplished with prescribed burning while the trees are six feet tall or less and fine fuel production is greater than 1,500 pounds per acres. Larger red cedars can also be controlled with prescribed burning, but successful application requires the use of specifically designed ignition and holding techniques (https://www.loesscanyonsburning group.com). Resprouting brush must be chemically treated immediately after mechanical removal to achieve effective treatment. The forb component will initially increase following tree removal. To prevent return to a woody dominated community, ongoing brush management such as hand cutting, chemical spot treatments, or periodic prescribed burning is required. When compared to the Reference Community (1.1), ponderosa pine or eastern redcedar have increased significantly. As the buildup of duff increases, the grass component of the plant community will decrease dramatically and annual production of the understory decreases significantly. Total annual production during an average year varies significantly, depending on the production level prior to encroachment and the percentage of canopy cover. While the tree canopy provides excellent protection from the weather for livestock and wildlife, decreased forage production reduces the carrying capacity for both domestic livestock and wildlife and significantly reduces habitat for grassland birds. This plant community is resistant to change and resilient given normal disturbances. In higher canopy cover situations, the soil erosion will increase in relation the plant community from which this plant community originated. The hydrologic function is also significantly altered under higher canopy cover. Infiltration is reduced and runoff is typically increased because of a lack of herbaceous cover and the rooting structure provided by the herbaceous species. Total annual production during an average year varies significantly, depending on the production level prior to encroachment and the percentage of canopy cover.

Dominant plant species

eastern redcedar (Juniperus virginiana), tree
ponderosa pine (Pinus ponderosa), tree
blue grama (Bouteloua gracilis), grass
western wheatgrass (Pascopyrum smithii), grass
Kentucky bluegrass (Poa pratensis), grass

State 7
Sodbusted State

The threshold to the Sodbusted State (7) is crossed as a result of mechanical disturbance to facilitate production agriculture. If farming operations are suspended, the site can be abandoned, which will result in the Natural Reclamation Community (7.3), or be seeded to a tame pasture forage mixture, the Seeded Pasture Community (7.2) or to a mixture of native grasses and forbs, the Reseeded Native Grass Community (7.1). Permanent alterations of the soil community and the hydrologic cycle make restoration to the Reference State (1) extremely difficult, if not impossible. Formation of a compacted plowpan in the soil profile is likely.

Community 7.1
Reseeded Native Grass Community

The Reseeded Native Grass Community (7.1) does not contain native remnants, and varies considerably depending upon the seed mixture, the degree of soil erosion, the age of the stand, fertility management, and past grazing management. Native range and grasslands seeded to native species are ecologically different and should be managed separately. Factors such as functional group, species, stand density, and improved varieties all impact the production level and palatability of the seedings. Species diversity is often limited, and when grazed in conjunction with native rangelands, uneven forage utilization may occur. Total annual production during an average year varies significantly depending upon precipitation, management, and grass species seeded. Prescribed grazing including appropriate utilization levels, adequate growing-season recovery periods, and timing of grazing that favor the productivity, health, and vigor of the seeded species is required to maintain this community. Periodic prescribed burning and brush management may also be needed.

Community 7.2
Seeded Pasture Community

The Seeded Pasture Community (7.2) does not contain native remnants and varies considerably depending upon the extent of soil erosion, the species seeded, the quality of the stand that was established, the age of the stand, and management of the stand since establishment. There are several factors that make seeded tame pasture a different grazing resource than native rangeland and land seeded to a native grass mixture. Factors such as species selected, stand density, improved varieties, and harvest efficiency all impact production levels and palatability. Species diversity on seeded tame pasture is often limited to a few species. When seeded pasture and native rangelands or seeded pasture and seeded rangeland are in the same grazing unit, uneven forage utilization will occur. Improve forage utilization and stand longevity by managing this community separately from native rangelands or land seeded to native grass species. Total annual production during an average year varies significantly depending on the level of management and species seeded. Improved varieties of warm-season or cool-season grasses are recommended for optimum forage production. Fertilization, weed management, and prescribed grazing including appropriate utilization levels, adequate growing-season recovery periods, and timing of grazing that favor the productivity, health, and vigor of the seeded species are required to maintain this community. Periodic prescribed burning and brush management may also be needed.

Community 7.3
Natural Reclamation Community

The Natural Reclamation Community (7.3) consists of annual and perennial weeds and less desirable grasses. These sites have been farmed and abandoned without being reseeded. Soil organic matter and carbon reserves are reduced, soil structure is changed, and a plowpan or compacted layer can form, which decreases water infiltration. Residual synthetic chemicals may remain from farming operations. In early successional stages, this community is not stable. The hazard of erosion is a resource concern. Total annual production during an average year varies significantly depending on the succession stage of the plant community and any management applied to the system.

Transition T1A
State 1 to 2

Repeated continuous seasonal grazing or rotational summer grazing with inadequate recovery periods will cause the Reference State (1) to lose a significant portion of warm-season tall- and midgrass species and cross a threshold to the Native/Invaded Grass State (2). Extended periods (greater than ten years) of non-use with no fire favors cool-season species and the invasion of Kentucky bluegrass and also facilitates this transition. Annual haying conducted during the same time-frame each summer will also cause this transition. Water infiltration and other hydrologic functions will be reduced due to the root-matting presence of sod-forming grasses. With the decline and loss of deeper-penetrating root systems, soil structure and biological integrity may be degraded to the point that recovery is unlikely. Once this occurs, it is highly unlikely that grazing management alone will return the community to the Reference State.

Transition T1B
State 1 to 4

The Reference State (1) can transition to the Shortgrass Sod State (4) with long term (more than ten years), heavy, continuous, season long grazing or heavy, rotational grazing with inadequate growing season recovery periods. Continuous, heavy seasonal grazing (grazing during the same time frame each year) in the spring and early summer will also case this transition. Water infiltration and other hydrologic functions will be reduced due to the root-matting presence of sod-forming grasses. With the decline and loss of deeper-penetrating root systems, soil structure and biological integrity may be degraded to the point that recovery is unlikely. Once this occurs, it is highly unlikely that grazing management alone will return the community to the Reference State.

Transition T1C
State 1 to 5

The Reference State (1) will transition to the Early Seral State (5) when management consists of long term, heavy, concentrated grazing (continuous season long, continuous seasonal, or rotational grazing with inadequate growing season recovery periods). This transition may also occur with severe defoliation from rodents or other heavy disturbance.

Transition T1D
State 1 to 6

Disruption of the natural fire regime and the encroachment of invasive exotic and native woody species can cause the Reference State (1) to shift to the Invaded Woody State (6).

Transition T1E
State 1 to 7

The Reference State (1) is significantly altered by tillage to facilitate production agriculture. The disruption to the plant community, soil, and hydrology of the system makes restoration unlikely.

Restoration pathway R2A
State 2 to 1

Long-term (more than fifteen years or more) prescribed grazing with adequate growing season recovery periods and appropriate stocking rates timed to coincide with the rapid growth phase of the cool-season grasses will return the Native/Invaded Grass State (2) to the Reference State (1). The length of time required depends upon the amount of native grasses remaining in the plant community. This restoration may not be feasible if there is an inadequate amount of native plants remaining in the plant community. Appropriately timed prescribed burning may accelerate this process.

Transition T2A
State 2 to 3

Continued seasonal, continuous season long, or rotational summer grazing with inadequate recovery periods will cause the Native/Invaded Grass State (2) to lose most, if not all, warm-season tall- and midgrass species and cross a threshold to the Invaded Grass State (3). Continued non-use with no fire increases the invasion of Kentucky bluegrass and also facilitates this transition. Water infiltration and other hydrologic functions will be reduced due to the root-matting presence of sod-forming grasses. With the decline and loss of deeper-penetrating root systems, soil structure and biological integrity may be degraded to the point that recovery is unlikely. Once this occurs, it is highly unlikely that grazing management alone will return the community to the Native/Invaded Grass State.

Transition T2B
State 2 to 4

The Native/Invaded Grass State (2) can transition to the Shortgrass Sod State (4) with long term (more than ten years) continuous seasonal grazing in the spring. Heavy, rotational grazing with inadequate growing season recovery periods may also cause this change.

Transition T2C
State 2 to 5

The Native/Invaded Grass State (2) will transition to the Early Seral State (5) when management consists of long term, heavy, concentrated grazing (continuous season long, continuous seasonal, or rotational grazing with inadequate growing season recovery periods). This transition may also occur with severe defoliation from rodents or other heavy disturbance.

Transition T2D
State 2 to 6

Disruption of the natural fire regime and the encroachment of invasive exotic and native woody species can cause the Native/Invaded Grass State (2) to shift to the Invaded Woody State (6).

Transition T2E
State 2 to 7

The Native/Invaded Grass State (2) is significantly altered by tillage to facilitate production agriculture. The disruption to the plant community, soil, and hydrology of the system makes restoration unlikely.

Restoration pathway R3A
State 3 to 2

With long term (more than fifteen years) seasonal prescribed grazing in the spring or in the spring and fall the amount of non-native cool-season grasses can be reduced and be replaced by native grasses if an adequate amount of remnant native grasses are present in the plant community. If native grasses have been eliminated, or nearly eliminated, from the plant community, this restoration will not be possible.

Transition T3A
State 3 to 5

The Invaded Grass State (3) will transition to the Early Seral State (5) when management consists of long term, heavy, concentrated grazing (continuous season long, continuous seasonal, or rotational grazing with inadequate growing season recovery periods). This transition may also occur with severe defoliation from rodents or other heavy disturbance.

Transition T3B
State 3 to 6

Disruption of the natural fire regime and the encroachment of invasive exotic and native woody species can cause the Invaded Grass State (3) to shift to the Invaded Woody State (6).

Transition T3D
State 3 to 7

The Invaded Grass State (3) is significantly altered by tillage to facilitate production agriculture. The disruption to the plant community, soil, and hydrology of the system makes restoration unlikely.

Restoration pathway R4A
State 4 to 1

Long term (more than fifteen years) prescribed grazing may move the Shortgrass Sod State (4) to the Reference State (1) if adequate amounts of native, warm-season, tall- and midgrasses and native cool-season grasses remain in the plant community. This transition may not be feasible when the warm-season tall- and midgrasses and native cool-season grasses have been reduced to trace levels.

Restoration pathway R4B
State 4 to 2

Long term (more than fifteen years) prescribed grazing may move the Shortgrass Sod State (4) to the Native/Invaded Grass State (2) if adequate amounts of native, warm-season, tall- and midgrasses and native cool-season grasses remain in the plant community. This transition may not be feasible when the warm-season tall- and midgrasses and native cool-season grasses have been reduced to trace levels.

Transition T4A
State 4 to 5

The Shortgrass Sod State (4) will transition to the Early Seral State (5) when management consists of long term, heavy, concentrated grazing (continuous season long, continuous seasonal, or rotational grazing with inadequate growing season recovery periods). This transition may also occur with severe defoliation from rodents or other heavy disturbance.

Transition T4B
State 4 to 6

Disruption of the natural fire regime and the encroachment of invasive exotic and native woody species can cause the Shortgrass Sod State (4) to shift to the Invaded Woody State (6).

Transition T4C
State 4 to 7

The Shortgrass Sod State (4) is significantly altered by tillage to facilitate production agriculture. The disruption to the plant community, soil, and hydrology of the system makes restoration unlikely.

Transition T5A
State 5 to 6

Disruption of the natural fire regime and the encroachment of invasive exotic and native woody species can cause the Early Seral State (5) to shift to the Invaded Woody State (6).

Transition T5B
State 5 to 7

The Early Seral State (5) is significantly altered by tillage to facilitate production agriculture.

Restoration pathway R6A
State 6 to 1

Prescribed burning, wildfire, harvest, and brush management will move the Invaded Woody State (6) to the Reference State (1). The forb component ma 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 Reference 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 Native/Invaded Grass State (2), Invaded Grass State (3), Shortgrass Sod State (4), Early Seral State (5), or the Sodbusted State (7), cannot be restored to the Reference State through removal of woody species as the native plant community, soils, and hydrologic function have been too severely impacted for that restoration to occur.

Restoration pathway R6B
State 6 to 2

Prescribed burning, wildfire, harvest, and brush management will move the Invaded Woody State (6) to the Native/Invaded Grass State (2). The forb component ma 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 Reference 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 Native/Invaded Grass State, Invaded Grass State (3), Shortgrass Sod State (4), Early Seral State (5), or the Sodbusted State (7), cannot be restored to the Reference State (1) through removal of woody species as the native plant community, soils, and hydrologic function have been too severely impacted for that restoration to occur.

Restoration pathway R6C
State 6 to 3

Prescribed burning, wildfire, harvest, and brush management will move the Invaded Woody State (6) to the Invaded Grass State (3). The forb component ma 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 Reference 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 Native/Invaded Grass State (2), Invaded Grass State, Shortgrass Sod State (4), Early Seral State (5), or the Sodbusted State (7), cannot be restored to the Reference State (1) through removal of woody species as the native plant community, soils, and hydrologic function have been too severely impacted for that restoration to occur.

Restoration pathway R6D
State 6 to 4

Prescribed burning, wildfire, harvest, and brush management will move the Invaded Woody State (6) to the Shortgrass Sod State (4). The forb component ma 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 Reference 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 Native/Invaded Grass State (2), Invaded Grass State (3), Shortgrass Sod State, Early Seral State (5), or the Sodbusted State (7), cannot be restored to the Reference State (1) through removal of woody species as the native plant community, soils, and hydrologic function have been too severely impacted for that restoration to occur.

Restoration pathway R6E
State 6 to 5

Prescribed burning, wildfire, harvest, and brush management will move the Invaded Woody State (6) to the Early Seral State (5). The forb component ma 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 Reference 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 Native/Invaded Grass State (2), Invaded Grass State (3), Shortgrass Sod State (4), Early Seral State, or the Sodbusted State (7), cannot be restored to the Reference State (1) through removal of woody species as the native plant community, soils, and hydrologic function have been too severely impacted for that restoration to occur.

Transition R6F
State 6 to 7

Prescribed burning, wildfire, harvest, and brush management will move the Invaded Woody State (6) to the Sodbusted State (7). The forb component ma 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 Reference 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 Native/Invaded Grass State 2), Invaded Grass State (3), Shortgrass Sod State (4), Early Seral State (5), or the Sodbusted State, cannot be restored to the Reference State (1) through removal of woody species as the native plant community, soils, and hydrologic function have been too severely impacted for that restoration to occur.

Restoration pathway T7A
State 7 to 6

Disruption of the natural fire regime and the encroachment of invasive exotic and native woody species can cause the Sodbusted State (7) to shift to the Invaded Woody State (6).

Additional community tables

Table 9. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Cool-Season Bunchgrass			520–780
	green needlegrass	NAVI4	Nassella viridula	130–650	–
	needle and thread	HECOC8	Hesperostipa comata ssp. comata	130–520	–
	porcupinegrass	HESP11	Hesperostipa spartea	0–130	–
	prairie Junegrass	KOMA	Koeleria macrantha	26–130	–
	Scribner's rosette grass	DIOLS	Dichanthelium oligosanthes var. scribnerianum	0–52	–
2	Cool-Season Rhizomatous Grass			260–650
	western wheatgrass	PASM	Pascopyrum smithii	260–650	–
3	Warm-Season Midgrass			130–390
	little bluestem	SCSC	Schizachyrium scoparium	52–260	–
	sideoats grama	BOCU	Bouteloua curtipendula	52–208	–
	plains muhly	MUCU3	Muhlenbergia cuspidata	0–130	–
	prairie dropseed	SPHE	Sporobolus heterolepis	0–130	–
	sand dropseed	SPCR	Sporobolus cryptandrus	0–26	–
	Grass, perennial	2GP	Grass, perennial	0–26	–
4	Warm-Season Tallgrass			52–260
	big bluestem	ANGE	Andropogon gerardii	52–260	–
	switchgrass	PAVI2	Panicum virgatum	0–130	–
	Indiangrass	SONU2	Sorghastrum nutans	0–130	–
	Grass, perennial	2GP	Grass, perennial	0–52	–
5	Warm-Season Shortgrass			52–260
	blue grama	BOGR2	Bouteloua gracilis	52–260	–
	buffalograss	BODA2	Bouteloua dactyloides	0–130	–
	threeawn	ARIST	Aristida	0–78	–
	Grass, perennial	2GP	Grass, perennial	0–52	–
7	Grass-Like			52–260
	threadleaf sedge	CAFI	Carex filifolia	52–260	–
	Grass-like (not a true grass)	2GL	Grass-like (not a true grass)	0–130	–
Forb
9	Forb			130–260
	scurfpea	PSORA2	Psoralidium	26–78	–
	white sagebrush	ARLU	Artemisia ludoviciana	26–78	–
	Forb, native	2FN	Forb, native	0–78	–
	goldenrod	SOLID	Solidago	26–78	–
	scarlet globemallow	SPCO	Sphaeralcea coccinea	26–52	–
	white heath aster	SYER	Symphyotrichum ericoides	0–52	–
	Cuman ragweed	AMPS	Ambrosia psilostachya	26–52	–
	Nuttall's sensitive-briar	MINU6	Mimosa nuttallii	26–52	–
	false boneset	BREU	Brickellia eupatorioides	26–52	–
	blacksamson echinacea	ECAN2	Echinacea angustifolia	26–52	–
	stiff sunflower	HEPA19	Helianthus pauciflorus	26–52	–
	bush morning-glory	IPLE	Ipomoea leptophylla	0–52	–
	dotted blazing star	LIPU	Liatris punctata	26–52	–
	upright prairie coneflower	RACO3	Ratibida columnifera	26–52	–
	tarragon	ARDR4	Artemisia dracunculus	0–52	–
	blue-eyed grass	SISYR	Sisyrinchium	0–26	–
	rush skeletonplant	LYJU	Lygodesmia juncea	0–26	–
	lacy tansyaster	MAPI	Machaeranthera pinnatifida	0–26	–
	scarlet beeblossom	GACO5	Gaura coccinea	0–26	–
	beardtongue	PENST	Penstemon	0–26	–
	pussytoes	ANTEN	Antennaria	0–26	–
	swamp verbena	VEHA2	Verbena hastata	0–26	–
Shrub/Vine
10	Shrub			130–260
	leadplant	AMCA6	Amorpha canescens	26–130	–
	prairie sagewort	ARFR4	Artemisia frigida	26–78	–
	rose	ROSA5	Rosa	26–78	–
	western snowberry	SYOC	Symphoricarpos occidentalis	26–78	–
	Shrub (>.5m)	2SHRUB	Shrub (>.5m)	0–52	–
	plains pricklypear	OPPO	Opuntia polyacantha	0–52	–

Table 10. Community 1.2 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Cool-Season Bunchgrass			100–400
	needle and thread	HECOC8	Hesperostipa comata ssp. comata	100–300	–
	green needlegrass	NAVI4	Nassella viridula	20–160	–
	prairie Junegrass	KOMA	Koeleria macrantha	20–60	–
	Scribner's rosette grass	DIOLS	Dichanthelium oligosanthes var. scribnerianum	20–60	–
	Grass, perennial	2GP	Grass, perennial	0–40	–
	porcupinegrass	HESP11	Hesperostipa spartea	0–40	–
2	Cool-Season Rhizomatous Grass			300–600
	western wheatgrass	PASM	Pascopyrum smithii	300–600	–
3	Warm-Season Midgrass			40–200
	sand dropseed	SPCR	Sporobolus cryptandrus	20–100	–
	little bluestem	SCSC	Schizachyrium scoparium	0–60	–
	sideoats grama	BOCU	Bouteloua curtipendula	20–60	–
	plains muhly	MUCU3	Muhlenbergia cuspidata	0–20	–
	Grass, perennial	2GP	Grass, perennial	0–20	–
4	Warm-Season Tallgrass			0–40
	big bluestem	ANGE	Andropogon gerardii	0–40	–
	switchgrass	PAVI2	Panicum virgatum	0–20	–
	Grass, perennial	2GP	Grass, perennial	0–20	–
5	Warm-Season Shortgrass			100–400
	blue grama	BOGR2	Bouteloua gracilis	100–200	–
	threeawn	ARIST	Aristida	0–20	–
7	Grass-like			40–240
	threadleaf sedge	CAFI	Carex filifolia	40–240	–
	Grass-like (not a true grass)	2GL	Grass-like (not a true grass)	0–100	–
8	Non-Native Cool-Season Grass			40–100
	Kentucky bluegrass	POPR	Poa pratensis	20–100	–
	smooth brome	BRIN2	Bromus inermis	10–80	–
	cheatgrass	BRTE	Bromus tectorum	0–60	–
	field brome	BRAR5	Bromus arvensis	0–60	–
Forb
9	Forb			100–200
	white sagebrush	ARLU	Artemisia ludoviciana	20–100	–
	sweetclover	MELIL	Melilotus	0–100	–
	Forb, introduced	2FI	Forb, introduced	0–100	–
	goldenrod	SOLID	Solidago	20–80	–
	scurfpea	PSORA2	Psoralidium	20–80	–
	tarragon	ARDR4	Artemisia dracunculus	20–60	–
	white heath aster	SYER	Symphyotrichum ericoides	20–60	–
	curlycup gumweed	GRSQ	Grindelia squarrosa	20–60	–
	dotted blazing star	LIPU	Liatris punctata	20–60	–
	swamp verbena	VEHA2	Verbena hastata	0–60	–
	Cuman ragweed	AMPS	Ambrosia psilostachya	20–60	–
	yellow salsify	TRDU	Tragopogon dubius	0–60	–
	Forb, native	2FN	Forb, native	0–60	–
	bush morning-glory	IPLE	Ipomoea leptophylla	0–40	–
	false boneset	BREU	Brickellia eupatorioides	0–40	–
	scarlet globemallow	SPCO	Sphaeralcea coccinea	20–40	–
	stiff sunflower	HEPA19	Helianthus pauciflorus	0–20	–
	upright prairie coneflower	RACO3	Ratibida columnifera	0–20	–
	pussytoes	ANTEN	Antennaria	0–20	–
	rush skeletonplant	LYJU	Lygodesmia juncea	0–20	–
	lacy tansyaster	MAPI	Machaeranthera pinnatifida	0–20	–
Shrub/Vine
10	Shrub			100–200
	prairie sagewort	ARFR4	Artemisia frigida	20–100	–
	western snowberry	SYOC	Symphoricarpos occidentalis	20–100	–
	Shrub (>.5m)	2SHRUB	Shrub (>.5m)	0–60	–
	plains pricklypear	OPPO	Opuntia polyacantha	0–60	–
	rose	ROSA5	Rosa	20–60	–
	leadplant	AMCA6	Amorpha canescens	0–40	–
Tree
11	Tree			0–100
	boxelder	ACNE2	Acer negundo	0–60	–
	bur oak	QUMA2	Quercus macrocarpa	0–60	–
	eastern redcedar	JUVI	Juniperus virginiana	0–60	–
	green ash	FRPE	Fraxinus pennsylvanica	0–60	–
	common hackberry	CEOC	Celtis occidentalis	0–60	–
	ponderosa pine	PIPO	Pinus ponderosa	0–60	–
	Rocky Mountain juniper	JUSC2	Juniperus scopulorum	0–60	–
	Tree	2TREE	Tree	0–60	–

Table 11. Community 2.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Cool-Season Rhizomatous Grass			125–500
	western wheatgrass	PASM	Pascopyrum smithii	125–500	–
2	Cool-Season Bunchgrass			25–300
	porcupinegrass	HESP11	Hesperostipa spartea	25–200	–
	needle and thread	HECOC8	Hesperostipa comata ssp. comata	0–125	–
	prairie Junegrass	KOMA	Koeleria macrantha	0–50	–
	Grass, perennial	2GP	Grass, perennial	0–50	–
	Scribner's rosette grass	DIOLS	Dichanthelium oligosanthes var. scribnerianum	0–25	–
3	Warm-Season Midgrass			25–250
	sideoats grama	BOCU	Bouteloua curtipendula	0–125	–
	sand dropseed	SPCR	Sporobolus cryptandrus	25–125	–
	Grass, perennial	2GP	Grass, perennial	0–50	–
4	Warm-Season Shortgrass			50–250
	blue grama	BOGR2	Bouteloua gracilis	25–125	–
	threeawn	ARIST	Aristida	25–125	–
	Grass, perennial	2GP	Grass, perennial	0–60	–
5	Grass-like			25–250
	threadleaf sedge	CAFI	Carex filifolia	25–200	–
	sedge	CAREX	Carex	0–125	–
6	Non-native Grasses			500–1250
	Kentucky bluegrass	POPR	Poa pratensis	375–875	–
	smooth brome	BRIN2	Bromus inermis	125–750	–
	cheatgrass	BRTE	Bromus tectorum	25–250	–
Forb
7	Forb			125–250
	sweetclover	MELIL	Melilotus	0–150	–
	goldenrod	SOLID	Solidago	25–125	–
	white sagebrush	ARLU	Artemisia ludoviciana	25–125	–
	Forb, introduced	2FI	Forb, introduced	0–125	–
	white heath aster	SYER	Symphyotrichum ericoides	25–100	–
	curlycup gumweed	GRSQ	Grindelia squarrosa	25–75	–
	Forb, native	2FN	Forb, native	0–75	–
	yellow salsify	TRDU	Tragopogon dubius	25–75	–
	slimflower scurfpea	PSTE5	Psoralidium tenuiflorum	25–75	–
	Cuman ragweed	AMPS	Ambrosia psilostachya	25–75	–
	tarragon	ARDR4	Artemisia dracunculus	25–75	–
	hoary verbena	VEST	Verbena stricta	0–75	–
	upright prairie coneflower	RACO3	Ratibida columnifera	0–50	–
	dotted blazing star	LIPU	Liatris punctata	0–50	–
	false boneset	BREU	Brickellia eupatorioides	0–50	–
	western marbleseed	ONBEO	Onosmodium bejariense var. occidentale	0–50	–
	pussytoes	ANTEN	Antennaria	0–25	–
	rush skeletonplant	LYJU	Lygodesmia juncea	0–25	–
	scarlet globemallow	SPCO	Sphaeralcea coccinea	0–25	–
	blacksamson echinacea	ECAN2	Echinacea angustifolia	0–25	–
	bush morning-glory	IPLE	Ipomoea leptophylla	0–25	–
	lacy tansyaster	MAPI	Machaeranthera pinnatifida	0–25	–
Shrub/Vine
8	Shrub			125–250
	western snowberry	SYOC	Symphoricarpos occidentalis	50–250	–
	Shrub (>.5m)	2SHRUB	Shrub (>.5m)	0–125	–
	rose	ROSA5	Rosa	25–75	–
	prairie sagewort	ARFR4	Artemisia frigida	25–75	–
	plains pricklypear	OPPO	Opuntia polyacantha	0–50	–
Tree
9	Tree			0–75
	boxelder	ACNE2	Acer negundo	0–75	–
	bur oak	QUMA2	Quercus macrocarpa	0–75	–
	eastern redcedar	JUVI	Juniperus virginiana	0–75	–
	green ash	FRPE	Fraxinus pennsylvanica	0–75	–
	common hackberry	CEOC	Celtis occidentalis	0–75	–
	ponderosa pine	PIPO	Pinus ponderosa	0–75	–
	Rocky Mountain juniper	JUSC2	Juniperus scopulorum	0–75	–
	Tree	2TREE	Tree	0–75	–

Table 12. Community 4.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Warm-Season Shortgrass			300–600
	blue grama	BOGR2	Bouteloua gracilis	225–525	–
	buffalograss	BODA2	Bouteloua dactyloides	75–225	–
	threeawn	ARIST	Aristida	15–150	–
	Grass, perennial	2GP	Grass, perennial	0–45	–
2	Cool-Season Grass			0–150
	western wheatgrass	PASM	Pascopyrum smithii	0–75	–
	needle and thread	HECOC8	Hesperostipa comata ssp. comata	0–45	–
	Scribner's rosette grass	DIOLS	Dichanthelium oligosanthes var. scribnerianum	0–30	–
	Grass, perennial	2GP	Grass, perennial	0–30	–
3	Warm-Season Midgrass			0–105
	sand dropseed	SPCR	Sporobolus cryptandrus	15–105	–
	Grass, perennial	2GP	Grass, perennial	0–30	–
4	Grass-Like			30–180
	threadleaf sedge	CAFI	Carex filifolia	30–180	–
	sedge	CAREX	Carex	0–30	–
5	Non-Native Cool-Season Grass			225–450
	Kentucky bluegrass	POPR	Poa pratensis	225–450	–
	cheatgrass	BRTE	Bromus tectorum	15–120	–
	field brome	BRAR5	Bromus arvensis	15–120	–
	smooth brome	BRIN2	Bromus inermis	0–75	–
Forb
6	Forb			75–150
	curlycup gumweed	GRSQ	Grindelia squarrosa	15–90	–
	sweetclover	MELIL	Melilotus	0–75	–
	Forb, introduced	2FI	Forb, introduced	0–75	–
	white sagebrush	ARLU	Artemisia ludoviciana	15–75	–
	hoary verbena	VEST	Verbena stricta	0–60	–
	tarragon	ARDR4	Artemisia dracunculus	15–60	–
	slimflower scurfpea	PSTE5	Psoralidium tenuiflorum	15–45	–
	goldenrod	SOLID	Solidago	15–45	–
	yellow salsify	TRDU	Tragopogon dubius	15–45	–
	Forb, native	2FN	Forb, native	0–45	–
	white heath aster	SYER	Symphyotrichum ericoides	15–30	–
	Cuman ragweed	AMPS	Ambrosia psilostachya	15–30	–
	pussytoes	ANTEN	Antennaria	0–15	–
	false boneset	BREU	Brickellia eupatorioides	0–15	–
	scarlet globemallow	SPCO	Sphaeralcea coccinea	0–15	–
	western marbleseed	ONBEO	Onosmodium bejariense var. occidentale	0–15	–
	dotted blazing star	LIPU	Liatris punctata	0–15	–
	rush skeletonplant	LYJU	Lygodesmia juncea	0–15	–
Shrub/Vine
7	Shrub			30–120
	prairie sagewort	ARFR4	Artemisia frigida	15–75	–
	plains pricklypear	OPPO	Opuntia polyacantha	0–45	–
	western snowberry	SYOC	Symphoricarpos occidentalis	15–45	–
	Shrub (>.5m)	2SHRUB	Shrub (>.5m)	0–30	–
	rose	ROSA5	Rosa	0–30	–
Tree
8	Tree			0–75
	boxelder	ACNE2	Acer negundo	0–45	–
	common hackberry	CEOC	Celtis occidentalis	0–45	–
	green ash	FRPE	Fraxinus pennsylvanica	0–45	–
	bur oak	QUMA2	Quercus macrocarpa	0–45	–
	eastern redcedar	JUVI	Juniperus virginiana	0–45	–
	Rocky Mountain juniper	JUSC2	Juniperus scopulorum	0–45	–
	ponderosa pine	PIPO	Pinus ponderosa	0–45	–
	Tree	2TREE	Tree	0–45	–

Interpretations

Animal community

LIVESTOCK - GRAZING INTERPRETATIONS:
Grazing by domestic livestock is one of the major income-producing industries in the area. Rangeland in this area may provide year-long forage for cattle, sheep, or horses. During the dormant period, the protein levels of the forage may be lower than the minimum needed to meet livestock (primarily cattle and sheep)requirements. The following table lists suggested stocking rates for cattle under continuous season-long grazing under normal growing conditions. These are conservative estimates that should be used only as guidelines in the initial stages of the conservation planning process. Often, the current plant composition does not entirely match any particular plant community (as described in this ecological site description). Because of this, a field visit is recommended, in all cases, to document plant composition and production. More precise carrying capacity estimates should eventually be calculated using this information along with animal preference data, particularly when grazers other than cattle are involved. With consultation of the land manager, more intensive grazing management may result in improved harvest efficiencies and increased carrying capacity.

Production and Carrying Capacity*
Community 1.1, Reference Community: 2,600 lbs/acre, 0.71 AUM/acre
Community 1.2, At-Risk Grass Community: 2,000 lbs/ac, 0.55 AUM/acre
Community 2.1, Native Cool-Season-Invasive Cool-Season Grass Community: 2,500 lbs/ac, 0.69 AUM/acre
Community 4.1, Shortgrass Sod Community: 1,500 lbs/ac, 0.38 AUM/ac

*Based upon the following conditions: continuous season-long grazing by cattle under average growing conditions, 25 percent harvest efficiency. Air dry forage requirements based on 3 percent of animal body weight, or 912 lbs/AU/month.

WILDLIFE INTERPRETATIONS:
Major Land Resource Area (MLRA) 66 lies primarily within the Mixed-grass prairie ecosystem. Though European settlers have converted about a quarter of this landscape to farmland, the majority of the prairie is still intact. This area still consists of diverse grassland habitats interspersed with varying densities of depressional wetlands and limited woody riparian corridors. These habitats historically provided critical life cycle components for the grassland birds, prairie dogs, and herds of roaming bison, elk, and pronghorn. Bobcats, wolves, and mountain lions occupied the apex predator niche. Diverse populations of small mammals and insects still provide a bountiful prey base for raptors and omnivores such as coyotes, foxes, raccoons, and opossums. In addition, a wide variety of reptiles and amphibians thrive in this landscape.

The Mixed-Grass Prairie was a disturbance-driven ecosystem with fire, herbivory, and climate functioning as the primary disturbances. Following European settlement, elimination of fire, overgrazing, and some habitat fragmentation significantly altered the appearance and functionality of the entire ecosystem. Bison and prairie dogs were historically keystone species, but free-roaming bison herds have been extirpated in this region. The loss of bison and fire as ecological drivers greatly influenced the character of the remaining native grasslands and the habitats that they provide. Fragmentation has reduced habitat quality for numerous area-sensitive species, as highlighted by the decline of the greater prairie chicken.

Historically, an ecological mosaic of the sites provided habitat for species requiring unfragmented grasslands. Most of these important habitat features and components are intact, providing upland nesting habitat for grassland birds and game birds; nesting and escape cover for waterfowl; forbs and insects for brood-rearing habitat; and a forage source for small and large herbivores.

Disruption of the natural fire regime and lack of appropriate grazing management are the greatest threats to the ecosystem dynamics today. Tree and shrub encroachment from lack of fire creates habitat that favors generalist species such as American robin and mourning dove, and provides perches for raptors, increasing the predation mortality on native bird populations. Introduced species such as smooth bromegrass, Kentucky bluegrass, nodding plumeless thistle (musk thistle), and Canada thistle further degrade the biological integrity of many areas of the prairie.

Hydrological functions

Water is the principal factor limiting forage production on this site. This site is dominated by soils in hydrologic group B. Infiltration and runoff potential for this site varies from moderate to high depending on soil hydrologic group, slope, and ground cover. In many cases, areas with greater than 75 percent ground cover have the greatest potential for high infiltration and lower runoff. An example of an exception would be where shortgrasses form a strong sod and dominate the site. Areas where ground cover is less than 50 percent have the greatest potential to have reduced infiltration and higher runoff (refer to Section 4, NRCS National Engineering Handbook for runoff quantities and hydrologic curves).

For the interpretive plant community, rills and gullies should not typically be present. Water flow patterns should be barely distinguishable if at all present. Pedestals are only slightly present in association with bunchgrasses such as little bluestem. Litter typically falls in place, and signs of movement are not common. Chemical and physical crusts are rare to non-existent. Cryptogamic crusts are present but only cover 1-2 percent of the soil surface. Overall, this site has the appearance of being very stable and productive.

Recreational uses

This site provides hunting opportunities for upland game species. The wide variety of plants which bloom from spring until fall have an aesthetic value that appeals to visitors.

Wood products

No appreciable wood products.

Other products

Seed harvest of native plant species can provide additional income on this site.

Other information

Field Offices (Counties)
Nebraska:
Ainsworth (Brown, Keya Paha, and Rock)
Neligh (Antelope)
O'Neill (Holt )
Valentine (Cherry)

South Dakota:
Burke (Gregory)
Martin (Bennett and Shannon)
White River (Mellette and Todd)
Winner (Tripp)

Supporting information

Inventory data references

Information presented here has been derived from NRCS clipping data and other inventory data. Field observations from range-trained personnel also were used. Those involved in developing this site include Wayne Bachman, Soil Scientist, NRCS; Stan Boltz, Range Management Specialist, NRCS; Chuck Markley, Soil Scientist, NRCS; Anna Ferguson, Soil Conservationist, NRCS; Roger Hammer, Soil Scientist, NRCS; Dana Larsen, Range Management Specialist, NRCS; Dave Schmidt, Rangeland Management Specialist, NRCS; Kim Stine, Rangeland Management Specialist, NRCS.

Other references

High Plains Regional Climate Center, University of Nebraska.(http://www.hprcc.unl.edu/)
U.S. Department of Agriculture, Natural Resources Conservation Service. 2003. National Range and Pasture Handbook. (https://www.nrcs.usda.gov/national-range-and-pasture-handbook)
U.S. Department of Agriculture, Natural Resources Conservation Service. National Water and Climate Center. (http://www.wcc.nrcs.usda.gov/climate).
U.S. Department of Agriculture, Natural Resources Conservation Service. 2021b. National Soil Information System. (https://www.nrcs.usda.gov/resources/education-and-teaching-materials/national-soil-information-system-nasis).
U.S. Department of Agriculture, Natural Resources Conservation Service. 2021c. National soil survey handbook, title 430-VI. (http://soils.usda.gov/technical/handbook/).
Soil Survey Staff. 2021. Web soil survey. U.S. Department of Agriculture, Natural Resources Conservation Service. (https://websoilsurvey.sc.egov.usda.gov/)
USDA, NRCS. 2001. The PLANTS Database, Version 3.1 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA USA.
USDA, NRCS, various published Soil Surveys

Contributors

Stan Boltz
Doug Whisenhunt
Nadine Bishop

Approval

Suzanne Mayne-Kinney, 11/18/2024

Acknowledgments

Many thanks to the members of the soils, local practitioners and technical teams, as well as the editor.

This Ecological Site was approved for publication in March of 2021.

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Rangeland health reference sheet

Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.

Author(s)/participant(s)	Original Author: Stan Boltz Version V participants: Emily Helms, Nadine Bishop, Jeff Nichols
Contact for lead author	jeffrey.nichols@usda.gov
Date	11/18/2024
Approved by	Suzanne Mayne-Kinney
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
None. Rills are not expected on this site.
Presence of water flow patterns:
Typically, none. Water flow patterns are not expected on the more gentle slopes. On steeper slopes (>15 percent) water flow patterns may occur but will be barely visible and discontinuous.
Number and height of erosional pedestals or terracettes:
Typically, none. Bunchgrasses may be slightly pedestalled (0.5 inch/1.25 cm) with no exposed roots on steeper slopes (greater than 15 percent), becoming more common as slopes become steeper.
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground is typically 5 percent or less. Multi-year drought and/or wildfire can increase bare ground to 10 percent for up to two years following the disturbance.

Bare ground is exposed mineral soil that is not covered by vegetation (basal and/or foliar canopy), standing dead vegetation, gravel/rock, and visible biological crust (e.g., lichen, mosses, algae).
Number of gullies and erosion associated with gullies:
None. Gullies are not expected on this site.
Extent of wind scoured, blowouts and/or depositional areas:
None. Wind-scoured areas and depositional areas are not expected on this site.
Amount of litter movement (describe size and distance expected to travel):
Litter should fall in place. Slight amount of movement of fine litter (less than 12 inches) from water is possible, but not normal. Litter movement from wind is not expected.
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil stability ratings should typically be 5 to 6, normally 6. Surface organic matter adheres to the soil surface. Soil surface fragments will typically retain structure indefinitely when dipped in distilled water.
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
The A-horizon should be 8 to 23 inches (20-58 cm) thick. Soil is dark grayish brown, very dark grayish brown, or dark gray (values of 3 to 4) when dry and very dark grayish brown, very dark brown, or very dark gray (values of 2 or 3) when moist. Structure is typically weak fine granular or weak medium subangular blocky parting to weak medium and fine granular. Some soils are weak coarse blocky, weak medium platy, or weak coarse prismatic parting to weak fine or medium subangular blocky structure.

Major soil series correlated to this site include Jansen, Paka, Johnstown, and Hennings.
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
The functional/structural groups provide a combination of rooting depths and structure which positively influences infiltration. Combination of shallow and deep rooted species (mid & tall rhizomatous and tufted perennial cool-season grasses) with fine and coarse roots positively influences infiltration. Invasion of introduced cool-season grasses such as annual bromes, Kentucky bluegrass, and smooth brome may have an adverse impact on infiltration and runoff. Woody encroachment may also negatively influence infiltration. Eastern redcedar encroachment may also negatively influence infiltration.

The expected composition of the plant community is 80 to 90 percent perennial grasses and grass-likes, 5 to 10 percent forbs, and 5 to 10 percent shrubs. The perennial grass and grass-like component is made up of C3 bunchgrasses (20-30%), C3 rhizomatous grasses (10-25%), C4 tallgrasses (2-10%), C4 midgrasses (5-15%), grass-likes (2-10%), and C4 shortgrasses (2-10%).
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None. A compaction layer should not be present.
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):

Dominant:
Phase 1.1
1. Native, perennial, C3 bunchgrass, 520-780 #/ac, 20-30% (3 species minimum): green needlegrass, needle and thread, porcupinegrass, prairie Junegrass, Scribner’s rosettegrass.
2. Native, perennial, C3 rhizomatous grass, 260-650 #/ac, 20-25% (1 species minimum): western wheatgrass.

Phase 1.2
1. Native, perennial, C3 rhizomatous grass, 300-600 #/ac, 15-30% (1 species minimum): western wheatgrass.

Phase 1.3
1. Native, perennial, C3 rhizomatous grass, 180-450 #/ac, 10-25% (1 species minimum): western wheatgrass.

Sub-dominant:
Phase 1.1
1. Native, perennial, C4 midgrass, 130-390 #/ac, 5-15% (2 species minimum): little bluestem, plains muhly, prairie dropseed, sideoats grama, sand dropseed.

Phase 1.2
1. Native, perennial, C3 bunchgrass, 100-400 #/ac, 5-20% (4 species minimum): green needlegrass, needle and thread, porcupinegrass, prairie Junegrass, Scribner’s rosettegrass.
2. Native, perennial, C4 shortgrass, 100-400 #/ac, 5-20% (1 species minimum): blue grama, threeawn.
3. Grass-likes, 40-240 #/ac, 2-12% (1 species minimum): threadleaf sedge

Phase 1.3
1. Non-native, C3 grass, 180-360 #/ac, 10-20% (1 species minimum): Kentucky bluegrass, smooth brome, cheatgrass, field brome.

Other:
Minor - Phase 1.1
1. Native forbs, 130-260 #/ac, 5-10%: forbs present vary from location to location.
2. Shrubs, 130-260 #/ac, 5-10%: prairie sagewort, leadplant, plains pricklypear, rose, western snowberry.
3. Native, perennial, C4 tallgrass, 52-260 #/ac, 2-10%: big bluestem, Indiangrass, switchgrass.
4. Native, perennial, C4 shortgrass, 52-260 #/ac, 2-10%: blue grama, buffalograss, threeawn.
5. Grass-likes, 52-260 #/ac, 2-10%: threadleaf sedge, other sedges.

Minor - Phase 1.2
1. Native forbs, 100-200 #/ac, 5-10%: forbs present vary from location to location.
2. Shrubs, 100-200 #/ac, 5-10%: prairie sagewort, western snowberry, rose, leadplant, plains pricklypear.
3. Non-native, C3 grass, 100-200 #/ac, 5-10%: Kentucky bluegrass, smooth brome, cheatgrass, field brome.
4. Native, perennial, C4 midgrass, 40-200 #/ac, 2-10%: little bluestem, sideoats grama, plains muhly, sand dropseed.
5. Native tree, 0-100 #/ac, 0-5%: Trees present vary from location to location.

Minor - Phase 1.3
1. Forb, 90-180 #ac, 5-10%: forbs present vary from location to location.
2. Shrub, 90-180 #/ac, 5-10%: shrubs present vary from location to location.
3. Native, perennial, C3 bunchgrass, 36-180 #/ac, 2-10%: needle and thread, green needlegrass, prairie Junegrass, Scribner's rosette grass.
4. Grass-like, 18-180 #/ac, 1-10%: threadleaf sedge, other sedges.
5. Native, perennial, C4 shortgrass, 36-90 #/ac, 2-5%: blue grama, threeawn.
6. Native, perennial, C4 midgrass, 18-90 #/ac, 1-5%: sideoats grama, sand dropseed.
7. Native tree, 0-90 #/ac, 0-5%: trees present vary from location to location.

Trace - Phase 1.2
1. Native, perennial, C4 tallgrass, 0-40 #/ac, 0-2%: big bluestem, switchgrass

Trace - Phase 1.3
1. Native, perennial, C4 tallgrass, 0-36 #/ac, 0-2%: big bluestem, switchgrass.

Additional:
The Reference Community (1.1) consists of eight F/S groups. These groups are, in order of relative abundance, native, perennial, C3, bunchgrass; native, C3 rhizomatous grass; native, perennial, C4, midgrass; native forbs = shrubs; native, perennial, C4, tallgrass = native, perennial, C4 shortgrass = grass-likes.

The Degraded Native Grass Community (1.2) consists of ten F/S groups. These groups are, in order of relative abundance, native, perennial, C3, rhizomatous grass; native, perennial, C3, bunchgrass = native, perennial, C4, shortgrass; grass-likes; non-native, C3 grass = native forb = shrub; native, perennial, C4, midgrass; native trees; and native, perennial, C4, tallgrass.

The At-Risk Community also includes ten F/S groups which are native, perennial, C3 rhizomatous grass; non-native C3 grass; native, perennial, C4 shortgrass = native forb = shrub; native, perennial, C3 bunchgrass; grass-like; native tree; native, perennial, C4 tallgrass.
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Bunch grasses have strong, healthy centers with few (less than 3 percent) dead centers. Shrubs may show some dead branches (less than 5 percent) as plants age.
Average percent litter cover (%) and depth ( in):
Plant litter cover is evenly distributed throughout the site and is expected to be 80 to 90 percent and at a depth of 0.50 to 1.0 inch (1.3 to 2.6 cm). Litter cover during and following drought can range from 50 to 60 percent. Excessive Kentucky bluegrass litter may impact the functionality of the site.
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
The representative value (RV) for annual production is 2,600 pounds per acre on an air dry weight basis. Low and High production years should yield 1,800 and 3,600 pounds per acre respectively.
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
No non-native invasive species are present. Annual bromes (cheatgrass and Japanese/field), leafy spurge, absinth wormwood, common mullein, sulphur cinquefoil, Canada thistle, smooth brome, Kentucky bluegrass, and eastern redcedar are known invasives that have the potential to become dominant or co-dominant on this site. Consult the state noxious weed and state watch lists for potential invasive species. Note: species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants.
Perennial plant reproductive capability:
All perennial species exhibit high vigor relative to recent weather conditions. Perennial grasses should have vigorous rhizomes or tillers; vegetative and reproductive structures are not stunted. All perennial species should be capable of reproducing annually.

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Ecosystem states

1. Reference State

2. Native/Invaded Grass State

3. Invaded Grass State

4. Shortgrass Sod State

5. Early Seral State

6. Invaded Woody State

7. Sodbusted State

States 1, 5, 6 and 7 (additional transitions)

1. Reference State

5. Early Seral State

6. Invaded Woody State

7. Sodbusted State

States 2, 5, 6 and 7 (additional transitions)

2. Native/Invaded Grass State

5. Early Seral State

6. Invaded Woody State

7. Sodbusted State

States 3, 7 and 4 (additional transitions)

3. Invaded Grass State

7. Sodbusted State

4. Shortgrass Sod State

T1A	-	Repeated continuous seasonal grazing, rotational summer grazing with inadequate recovery periods, or prolonged (> 10 years) nonuse with no fire with invasion of non-native cool-season grasses.
T1B	-	Long term (> 10 years) continuous season long grazing or rotational grazing with inadequate growing season recovery periods.
T1C	-	Long term (> 10 years) heavy grazing or other heavy disturbance.
T1D	-	Woody encroachment with no prescribed burning or woody species management.
T1E	-	Tillage to facilitate production agriculture.
R2A	-	Long-term (> 15 years) prescribed grazing during spring or spring and fall.
T2A	-	Continued invasion of non-native cool-season grasses facilitated by seasonal grazing in summer, continuous season long grazing, rotational grazing with inadequate growing season recovery periods or non-use with no fire.
T2B	-	Long term (> 10 years) continuous seasonal grazing in the spring months.
T2C	-	Long term (> 10 years) heavy grazing or other heavy disturbance.
T2D	-	Woody encroachment with no prescribed burning or woody species management.
T2E	-	Tillage to facilitate production agriculture.
R3A	-	Long-term (> 15 years) prescribed grazing during spring or spring and fall.
T3A	-	Long term (> 10 years) heavy grazing or other heavy disturbance.
T3B	-	Woody encroachment with no prescribed burning or woody species management.
T3D	-	Tillage to facilitate production agriculture.
R4A	-	Long-term (> 15 years) prescribed grazing. This restoration may not be feasible.
R4B	-	Long-term (> 15 years) prescribed grazing. This restoration may not be feasible.
T4A	-	Long term (> 10 years) heavy grazing or other heavy disturbance.
T4B	-	Woody encroachment with no prescribed burning or woody species management.
T4C	-	Tillage to facilitate production agriculture.
T5A	-	Woody encroachment with no prescribed burning or woody species management.
T5B	-	Tillage to facilitate production agriculture.
R6A	-	Prescribed burning, wildfire, timber harvest, brush management.
R6B	-	Prescribed burning, wildfire, timber harvest, brush management.
R6C	-	Prescribed burning, wildfire, timber harvest, brush management.
R6D	-	Prescribed burning, wildfire, timber harvest, brush management.
R6E	-	Prescribed burning, wildfire, timber harvest, brush management.
R6F	-	Prescribed burning, wildfire, timber harvest, brush management.
T7A	-	Woody encroachment with no prescribed burning or woody species management.

State 1 submodel, plant communities

1.1. Reference Community

1.2. At-Risk Community

1.1A	-	Grazing or haying with inadequate growing season recovery periods.
1.2A	-	Prescribed grazing or haying with adequate growing season recovery periods.