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Ecological site R065XY023NE

Wet Subirrigated

Last updated: 2/04/2025
Accessed: 03/11/2025

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General information

Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.

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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): 065X–Nebraska Sand Hills

The Nebraska Sand Hills (MLRA 65) is located in Nebraska (98 percent) and South Dakota (2 percent) and encompasses approximately 13.2 million acres (534,201 hectares) or 20,625 square miles (53,420 square kilometers). The largest town in the MLRA is North Platte, Nebraska and numerous small towns and villages are located within the MLRA, including the county seats of Arthur, Bartlett, Bassett, Brewster, Greeley, Hyannis, Mullen, Thedford, and Tryon, Nebraska. The Niobrara River is near the northern boundary while the North Platte River flows along the southwest boundary of the area. The North Loup, Middle Loup, Calamus, Snake, and Dismal Rivers and Long Pine Creek occur in the central and eastern portion of the area.

Fort Niobrara, Crescent Lake, and Valentine National Wildlife Refuges and portions of the Nebraska National Forest, including the Bessey Ranger District and Samuel R. McKelvie National Forest, are located within this MLRA. The Bessey Ranger District includes the largest human-planted forest in the United States and is home to the Bessey Tree Nursery which is listed on the National Register of Historic Places.

This MLRA is defined by an 8,000 year-old landscape of sand hills dominated by rolling to steep sand dunes with narrow, elongated, nearly level to steeply sloping valleys between the dunes. Dune heights range from 10 to 400 feet (3 to 130 meters) and slopes may exceed twenty-five percent. Dune complexes often extend for several miles in a northwest to southeast direction. These Quaternary sand dunes are derived from the underlying Tertiary Ogallala and Arikaree Groups, which formed when rivers deposited sediments from erosional detritus after the uplift of the Rocky Mountains to the west. The Nebraska Sand Hills are the largest sand dune area in the Western Hemisphere and one of the largest grass-stabilized dune regions in the world. The soils of the MLRA are principally derived from deep eolian sand.

The Ogallala aquifer underlies the MLRA and is the most extensive and heavily used aquifer of the high plains between the Rocky Mountains and Mississippi River. The aquifer is at its thickest in the Sand Hills which are a primary recharge are for the aquifer. Numerous small permanent and intermittent lakes and wetlands occur in the MLRA. While the dominant source of water for these lakes is precipitation, groundwater discharge is important to maintaining these lakes especially in drier years. A number of these lakes, especially in the western portion of the MLRA are alkaline.

Considered to be a western extension of the tallgrass prairie, the matrix vegetation is a unique mix of species that is sometimes identified as sandhills prairie. Sand bluestem, prairie sandreed, Indiangrass, switchgrass, sand lovegrass, little bluestem, and needle and thread are the primary grasses. Porcupinegrass is a significant cool-season grass in the eastern portion of the MLRA while blue grama and hairy grama are important warm-season grasses in the western portion due to differences in precipitation. Soils which have a high water table support a tallgrass prairie dominated by big bluestem, switchgrass, Indiangrass, prairie cordgrass, and a variety of grass-likes. The endangered plant blowout penstemon (Penstemon haydenii) is found in this MLRA.

More than ninety percent of the land in MLRA 65 is native grassland utilized by grazing livestock. Areas along streams and in subirrigated valleys are utilized for prairie hay. Wetlands, legume hay, and irrigated cropland make up the balance of the land area with corn being the principal irrigated crop.

Wildlife flourishes in this native grassland environment. Historically large bison herds occupied the landscape. White-tailed deer, mule deer, pronghorn, black tailed jackrabbit, and coyote are now the major mammalian species. Upland sandpiper, lark bunting, grasshopper sparrow, western meadowlark, long-billed curlew, sharp-tailed grouse, and greater prairie chicken are common avian species. The mosaic of grassland and wetlands provide excellent habitat for wading and shorebird species as well.

This landscape serves as a backdrop for a disturbance-driven ecosystem, which developed under the influences of herbivory, fire, and periodic long-term drought. Historically, these processes created a heterogeneous mosaic of plant communities and vegetative structure across the region. Any given site in this landscape experienced fire every six to ten years. Fires were caused by lightning strikes and also were set by Native Americans, who used fire for warfare, signaling, and to refresh the native grasses. Indigenous peoples 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 animals such as bison, elk, and pronghorn.

The natural fire regime has been disrupted by aggressive fire suppression policies which have facilitated woody species encroachment by both native and introduced shrubs and trees into the native prairie. The most common encroacher is eastern redcedar. While eastern redcedar is native to the landscape, it was present only in trace amounts due to the periodic fires. Widespread plantings of windbreaks with eastern redcedar as a primary component have provided a seed source for this aggressive woody plant causing encroachment into native grasslands, especially in the eastern and central Sand Hills. This encroachment causes significant forage loss for domestic livestock and degrades the native wildlife habit. Since it is not a root-sprouter, eastern redcedar is very susceptible to fire when under six feet tall making management with prescribed fire very effective when applied before trees reach this stage.

Classification relationships

►USDA-NRCS (2022)◄
Land Resource Region – G, Central Feed Grains and Livestock Region
Major Land Resource Area (MLRA) –65, Nebraska Sand Hills

►Fenneman (1916) Physiographic Regions ◄
Division – Interior Plains
Province – Great Plains
Section – High Plains

►USDA-USFS (2007) Ecoregions◄
Domain – Dry
Division – Temperate Steppe
Province – Great Plains Steppe (332)
Section – Mixed Grass Steppe

►EPA Ecoregions (Omernik 1997)◄
I – Great Plains (9)
II – West-Central Semi-Arid Prairies (9.3)
III – Nebraska Sandhills (44)
IV – Sandhills (44a), Alkaline Lakes Area (44b), Wet Meadow and Marsh Plain (44c), Lakes Area (44d)

Ecological site concept

The Wet Subirrigated ecological site is a run-on site found on interdunes and stream valleys. Slopes range from 0 to 1 percent. Soils are very deep and formed in eolian sands or sandy or loamy alluvium. The surface layer textures typically are loamy fine sand, fine sandy loam, or loam. The surface layer ranges from 3 to 10 inches thick. Subsurface soil textures range from fine sandy loam to silt loam. Soils are somewhat poorly to poorly drained. Permeability is moderate to rapid. Wet Subirrigated ecological sites have a seasonally high water table at 6 to 18 inches.

The historic vegetation of the Wet Subirrigated ecological site is tallgrass prairie. Vegetation in the Reference Community (1.1) is dominated by warm-season tallgrasses with cool-season tall- and midgrasses being subdominant. The dominant grasses include big bluestem, prairie cordgrass, switchgrass, and Indiangrass. Bluejoint, northern reedgrass, slender wheatgrass, and plains bluegrass are important to the site. Long-term excessive grazing pressure will shift the plant community toward one that is dominated by cool- season grasses and that is susceptible to invasion by non-native cool-season grasses.

Associated sites

R065XY022NE	Wet Land Wet Land ecological sites frequently occur adjacent to Wet Subirrigated ecological sites, but Wet Land sites occupy a lower landscape position.
R065XY024NE	Subirrigated Wet Subirrigated and Subirrigated ecological sites are often adjacent and intermixed in the landscape, but Wet Subirrigated sites occupy a lower landscape position.

R065XY022NE

Wet Land

Wet Land ecological sites frequently occur adjacent to Wet Subirrigated ecological sites, but Wet Land sites occupy a lower landscape position.

R065XY024NE

Subirrigated

Wet Subirrigated and Subirrigated ecological sites are often adjacent and intermixed in the landscape, but Wet Subirrigated sites occupy a lower landscape position.

Similar sites

R065XY024NE	Subirrigated Subirrigated ecological site occur on the same landscape as Wet Subirrigated sites but on a slightly higher position. Subirrigated sites have a seasonal high water table at 18 to 36 inches while the seasonal high water table of Wet Subirrigated sites is at 6 to 18 inches.
R065XY022NE	Wet Land Wet Land ecological sites occur on the same landscape as Wet Subirrigated sites but on the lowest landscape position. The water table on Wet Land sites occurs at 6 inches or less below the surface while the seasonal high water table of Wet Subirrigated sites is at 6 to 18 inches.

R065XY024NE

Subirrigated

Subirrigated ecological site occur on the same landscape as Wet Subirrigated sites but on a slightly higher position. Subirrigated sites have a seasonal high water table at 18 to 36 inches while the seasonal high water table of Wet Subirrigated sites is at 6 to 18 inches.

R065XY022NE

Wet Land

Wet Land ecological sites occur on the same landscape as Wet Subirrigated sites but on the lowest landscape position. The water table on Wet Land sites occurs at 6 inches or less below the surface while the seasonal high water table of Wet Subirrigated sites is at 6 to 18 inches.

Table 1. Dominant plant species

Tree	Not specified
Shrub	Not specified
Herbaceous	(1) Andropogon gerardii (2) Panicum virgatum

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Physiographic features

The Wet Subirrigated ecological site occurs on level to nearly level areas of interdunes of sandhills and floodplains of river valleys. Soil water is close to the soil surface and the site has a seasonal high water table at 6 to 18 inches during a portion of the growing season. The site receives run-off from areas higher on the landscape. Sites located on interdunes do not typically experience flooding while sites on floodplains are flooded rarely to occasionally for brief periods of time.

Table 2. Representative physiographic features

Landforms	(1) Sandhills > Interdune > Swale (2) Sandhills > Interdune (3) Valley > Flood plain (4) River valley > Flood plain
Runoff class	Negligible to very high
Flooding duration	Brief (2 to 7 days)
Flooding frequency	None to occasional
Ponding frequency	None
Elevation	1,970 – 3,940 ft
Slope	3%
Water table depth	6 – 18 in
Aspect	Aspect is not a significant factor

Climatic features

The mean average annual precipitation is typically 14 to 25 inches but has varied from 12 to 34 inches in the driest to wettest season. Approximately 70 percent of the annual precipitation occurs during the growing season from mid- April to late September. The average annual snowfall varies from about 34 inches to about 42 inches. The wind velocity is high throughout the year, averaging 10 to 12 miles per hour. Maximum wind velocities generally occur in the spring.

The average date of first frost in the fall is September 25, and the last frost in the spring is about May 8. July is the hottest month and January is the coldest. It is not uncommon for the temperature to reach 100 degrees Fahrenheit during the summer. Summer humidity is low, and evaporation is high. The winters are characterized with frequent northerly winds, producing severe cold with temperatures dropping to as low as negative 30 degrees Fahrenheit.

Growth of native cool-season plants begins in late March and continues to late June. Native warm-season plants begin growth in mid-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)	109-126 days
Freeze-free period (characteristic range)	131-143 days
Precipitation total (characteristic range)	19-26 in
Frost-free period (actual range)	103-129 days
Freeze-free period (actual range)	129-146 days
Precipitation total (actual range)	18-27 in
Frost-free period (average)	117 days
Freeze-free period (average)	137 days
Precipitation total (average)	22 in

Characteristic range

Actual range

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Figure 2. Monthly precipitation range

Characteristic range

Actual range

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Figure 3. Monthly minimum temperature range

Characteristic range

Actual range

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Figure 4. Monthly maximum temperature range

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Figure 5. Monthly average minimum and maximum temperature

Figure 6. Annual precipitation pattern

Figure 7. Annual average temperature pattern

Climate stations used

(1) ALLIANCE MUNI AP [USW00024044], Alliance, NE
(2) ARTHUR [USC00250365], Arthur, NE
(3) ATKINSON 3SW [USC00250420], Atkinson, NE
(4) BARTLETT 1S [USC00250525], Bartlett, NE
(5) BREWSTER [USC00251130], Brewster, NE
(6) CHAMBERS [USC00251590], Chambers, NE
(7) CRESCENT LAKE NWR [USC00252000], Oshkosh, NE
(8) ELLSWORTH 15 NNE [USC00252647], Ellsworth, NE
(9) ELSMERE 9 ENE [USC00252680], Johnstown, NE
(10) ERICSON 8 WNW [USC00252770], Burwell, NE
(11) GREELEY [USC00253425], Greeley, NE
(12) HYANNIS [USC00254100], Hyannis, NE
(13) KILGORE 1NE [USC00254432], Kilgore, NE
(14) KINGSLEY DAM [USC00254455], Keystone, NE
(15) MERRIMAN [USC00255470], Merriman, NE
(16) MULLEN [USC00255700], Mullen, NE
(17) MULLEN 21 NW [USC00255702], Whitman, NE
(18) NEWPORT [USC00255925], Newport, NE
(19) NORTH PLATTE RGNL AP [USW00024023], Maxwell, NE
(20) PURDUM [USC00256970], Purdum, NE
(21) ROSE 10 WNW [USC00257318], Long Pine, NE
(22) SWAN LAKE [USC00258360], Amelia, NE
(23) VALENTINE NWR [USC00258755], Valentine, NE
(24) WHITMAN 5 ENE [USW00094079], Whitman, NE

Soil features

The soils associated with Wet Subirrigated ecological site are very deep and formed in eolian sand or in loamy or sandy alluvium. Slopes range from 0 to 3 percent. Soil textures in the surface layers are loamy fine sand, fine sandy loam, or loam. Subsoil textures are sand, fine sand, loamy sand, or loamy fine sand. The combined thickness of the surface layer typically ranges from 3 to 10 inches thick, but it may be thicker. Soil surface structure is typically weak fine granular, weak very fine granular, or weak medium subangular blocky structure parting to weak fine granular structure

Runoff as evidenced by patterns of rills, water flow patterns, gullies or pedestalled plants is very low due to the low slope gradient, the high intake rate of these soils, and the high plant density. Rills and gullies should not be present. Water flow patterns if present are barely distinguishable and pedestalling of plants should not be present. If the site is grazed when the seasonal water table is at its highest, hummocking will occur which may be mistaken for pedestalling of plants. Litter typically falls in place and signs of movement are uncommon. Chemical and physical crusts are rare to not present. Cryptobiotic crusts are present, typically covering 1 to 2 percent of the soil surface.

The major soil series correlated to this ecological site are Hoffland, Loup, and Tryon. Other soils correlated to this site include Almeria, Crowther, Cullison, Gannett, Gus, and Lawet. Additional information can be found in the various soil survey reports. Contact the local USDA Service Center for soil survey reports that include more details specific to your location or visit Web Soil Survey (https://websoilsurvey.sc.egov.usda.gov).

Table 4. Representative soil features

Parent material	(1) Eolian deposits (2) Alluvium
Surface texture	(1) Loamy fine sand (2) Fine sandy loam (3) Loam
Family particle size	(1) Sandy
Drainage class	Somewhat poorly drained to poorly drained
Permeability class	Moderate to rapid
Soil depth	80 in
Surface fragment cover <=3"	Not specified
Surface fragment cover >3"	Not specified
Available water capacity (0-40in)	3.3 – 6.9 in
Calcium carbonate equivalent (0-40in)	40%
Electrical conductivity (0-40in)	4 mmhos/cm
Sodium adsorption ratio (0-40in)	5
Soil reaction (1:1 water) (0-40in)	5.3 – 8.4
Subsurface fragment volume <=3" (Depth not specified)	9%
Subsurface fragment volume >3" (Depth not specified)	Not specified

Ecological dynamics

Wet Subirrigated ecological sites developed under Northern Great Plains climatic conditions, light to severe grazing by bison and other large herbivores, sporadic natural or man-caused fire, 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. The plant diversity allows for high resistance to drought. The site is extremely resilient, and well adapted to Northern Great Plains climatic conditions.

The introduction of domestic livestock by European settlers along with season-long, continuous grazing and annual late summer haying had a profound impact on the vegetation of the Wet Subirrigated ecological site. Season-long, continuous grazing causes a repeated removal of the growing point and excessive defoliation of the leaf area of the more palatable warm-season tallgrasses, reducing the ability of the plants to harvest sunlight thereby depleting root reserves and subsequently decreasing root mass. The ability of the plants to compete for nutrients is impaired, resulting in decreased vigor and eventual mortality. Species that evade negative grazing impacts through mechanisms such as a growing season adaptation (i.e., cool-season), growing points located near the soil surface, a shorter structure, or reduced palatability will increase. As this site deteriorates, big bluestem, prairie cordgrass, switchgrass, and Indiangrass will decrease in frequency and production while bluejoint, northern reedgrass, slender wheatgrass, and plains bluegrass will increase. As this management continues, warm-season grasses continue to decrease, and the site becomes dominated by native cool-season grasses. The Wet Subirrigated site is susceptible to invasion by non-native cool-season grasses.

The State and Transition Model (STM) is depicted below and includes a Reference State (1) and an Invaded Grass State (2). 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 description following the diagram.

Interpretations are primarily based on the Reference Community (1.1), which 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 8. State and Transition Model Diagram, Wet Subirrigated ecological site, MLRA 65.

More interactive model formats are also available. View Interactive Models

More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective text

Ecosystem states

1. Reference State

2. Invaded Grass State

T1A	-	Heavy grazing, repeated haying, or interseeding.

State 1 submodel, plant communities

1.1. Reference Community

1.2. Degraded Native Grass Community

1.3. At-Risk Community

1.1A	-	Annual haying followed by heavy grazing in the fall. Moderate, continuous summer grazing.
1.2A	-	Appropriately timed haying. Rotational grazing with adequate growing season recovery periods.
1.2B	-	Repeated, annual haying in mid-summer. Continuous summer grazing.
1.3A	-	Early or rotational haying. Rotational grazing prior to onset of rapid growth of warm-season grasses with adequate growing season recovery time.

State 2 submodel, plant communities

2.1. Non-Native Grass Community

State 1
Reference State

The Reference State (1) describes the range of vegetative communities that occur on the Wet Subirrigated ecological site where the range of natural variability under historic conditions and disturbance regime 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 three community phases which are the Reference Community (1.1), the Degraded Native Grass Community (1.2) and the At-Risk Community (1.3), The Reference Community 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 Degraded Native Grass and At-Risk Communities results from management actions that are unfavorable for a healthy Reference Community.

Dominant plant species

big bluestem (Andropogon gerardii), grass
switchgrass (Panicum virgatum), grass
prairie cordgrass (Spartina pectinata), grass
bluejoint (Calamagrostis canadensis), grass
northern reedgrass (Calamagrostis stricta ssp. inexpansa), grass
plains bluegrass (Poa arida), grass

Community 1.1
Reference Community

Interpretations are primarily based on the Reference or Big Bluestem-Switchgrass (Andropogon gerardii-Panicum virgatum) Community (1.1). This plant community serves as a description of the native plant community that occurs on the site when the historic 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 fire and grazing events and to changes in precipitation timing and abundance. This site developed with grazing by large herbivores and is well suited for grazing by domestic livestock. This plant community consists chiefly of warm-season, tallgrasses and cool-season, tall- and midgrasses. Big bluestem, switchgrass, prairie cordgrass, and Indiangrass are the dominant grasses. Grasses of secondary importance include Indiangrass, bluejoint, northern reedgrass, plains bluegrass, and slender wheatgrass. Grass-likes occur in the understory. Forbs typically include American licorice, scouringrush horsetail, blackeyed Susan, and giant goldenrod. The potential vegetative composition is 80 to 90 percent grasses, 5 to 10 percent grass-likes, and 5 to 10 percent forbs by weight. Natural fire played a significant role in the succession of this site. Wildfires have been actively controlled in recent times, reducing forb diversity. This plant community can be found on areas that are managed with prescribed grazing, prescribed burning, or rotational haying. This resilient community is well adapted to the Northern Great Plains climatic conditions. Plant diversity promotes strong drought tolerance, site and soil stability, a high level of hydrologic function, and a high degree of biotic integrity. These factors create a suitable environment for a healthy and sustainable plant community.

Dominant plant species

big bluestem (Andropogon gerardii), grass
switchgrass (Panicum virgatum), grass
prairie cordgrass (Spartina pectinata), grass

Figure 9. 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	4200	4750	5250
Forb	80	250	250
Total	4280	5000	5500

Figure 10. Plant community growth curve (percent production by month). NE6543, NE/SD Sandhills, Native Grass, Wet. Warm-season dominant, cool-season subdominant, mid & tall grasses.

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
J	F	M	A	M	J	J	A	S	O	N	D
0	0	0	5	20	35	25	10	5	0	0	0

Community 1.2
Degraded Native Grass Community

The Degraded Native Grass or Switchgrass-Prairie Cordgrass (Panicum virgatum-Spartina pectinata) Community (1.2) historically developed with annual haying or moderate summer grazing followed by heavy grazing in the fall. It can also develop with rotational grazing with inadequate growing season recovery time. As compared to the Reference Community (1.1), switchgrass and prairie cordgrass have increased while big bluestem and Indiangrass have decreased as a proportion of production. Plant diversity has decreased with the more palatable grasses and forbs being suppressed due to heavy utilization levels. While this plant community remains dominated by warm-season tallgrasses and cool-season tall- and midgrasses, there has been a shift in relative dominance. Switchgrass, prairie cordgrass are the dominant grasses. Grasses of secondary importance include big bluestem, bluejoint, northern reedgrass, plains bluegrass, slender wheatgrass, and western wheatgrass. Grass-likes remain in the understory but are often of lesser importance than in the Reference Community. The potential vegetative composition is 80 to 90 percent grasses, 5 to 10 percent grass-likes, and 5 to 10 percent forbs by weight. This plant community tends to be resilient with short to moderate term disturbances and it is also relatively resistant to change. This community can be maintained with moderate grazing which allows for adequate growing season recovery or with rotational haying. Haying or grazing prior to the rapid growth periods of the warm-season tallgrasses will improve warm-season grass vigor and return the community to the Reference Community. Repeated, annual, mid-summer haying or seasonal grazing in the summer will move the plant community to the At-Risk Community (1.3).

Dominant plant species

prairie cordgrass (Spartina pectinata), grass
switchgrass (Panicum virgatum), grass
bluejoint (Calamagrostis canadensis), grass
northern reedgrass (Calamagrostis stricta ssp. inexpansa), grass
plains bluegrass (Poa arida), grass

Figure 11. 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	3800	4050	4500
Forb	200	450	500
Total	4000	4500	5000

Figure 12. Plant community growth curve (percent production by month). NE6544, NE/SD Sandhills, Hayed and Grazed Subirrigated Meadows. Warm-season dominant, cool-season subdominant, mid and tall grasses.

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
J	F	M	A	M	J	J	A	S	O	N	D
0	0	0	10	20	25	20	15	10	0	0	0

Community 1.3
At-Risk Community

The At-Risk or Bluejoint-Northern Reedgrass (Calamagrostis canadensis-Calamagrostis stricta ssp. inexpansa) Community (1.3) historically developed with long term, annual haying in the mid-summer. The plant community is dominated by cool-season grasses. As compared to the Reference Community (1.1) bluejoint, northern reedgrass, slender wheatgrass, and prairie cordgrass have increased while big bluestem, switchgrass, and Indiangrass have decreased. As the management continues the reedgrasses will become aggressive and increase, further reducing the warm-season tallgrass. Bluejoint, northern reedgrass, and prairie cordgrass are the dominant grasses. Grasses of secondary importance include slender wheatgrass, western wheatgrass, and plains bluegrass. The potential vegetative composition is 70 to 80 percent grasses, 10 to 20 percent grass-likes, and 5 to 10 percent forbs. This plant community tends to be resilient with short to moderate term disturbances and the community is resistant to change. This community can be maintained with moderate grazing which allows for adequate growing season recovery or with rotational haying. Haying or grazing prior to the rapid growth periods of the warm-season tallgrasses will improve warm-season grass vigor and return the community to the Degraded Native Grass Community (1.2). Repeated, annual, mid-summer haying or seasonal grazing in the summer will facilitate the further encroachment of non-native cool-season grasses and the community will transition to the Invaded Grass State (2).

Dominant plant species

bluejoint (Calamagrostis canadensis), grass
northern reedgrass (Calamagrostis stricta ssp. inexpansa), grass
plains bluegrass (Poa arida), grass
slender wheatgrass (Elymus trachycaulus), grass
prairie cordgrass (Spartina pectinata), grass

Figure 13. 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	3300	3515	3700
Forb	0	185	400
Total	3300	3700	4100

Figure 14. Plant community growth curve (percent production by month). NE6545, NE/SD Sandhills, Hayed and Grazed Cool-Season Meadows. Cool-season dominant, warm-season subdominant, mid & tall grasses.

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
J	F	M	A	M	J	J	A	S	O	N	D
0	0	5	15	30	25	10	5	10	0	0	0

Pathway 1.1A
Community 1.1 to 1.2

Annual haying followed by heavy grazing in the fall or moderate, continuous summer grazing will move the Reference Community (1.1) to the Degraded Native Grass Community (1.2). Haying or grazing at set times during the growing season will reduce plant diversity and reduce the vigor of the warm-season tallgrasses.

Pathway 1.2A
Community 1.2 to 1.1

Timely haying and/or rotational grazing will return the Degraded Native Grass Community (1.2) to the Reference Community (1.1). Haying or grazing prior to the onset of warm-season grass' rapid growth will improve vigor of warm-season grasses. This early haying also reduces cool-season grass vigor allowing warm-season grasses to be more competitive. The early haying also improves hay quality. Delaying grazing until after a killing frost in the fall will also improve warm-season grass vigor allowing them to increase in abundance.

Pathway 1.2B
Community 1.2 to 1.3

Continued annual haying in mid-summer or continued moderate summer grazing will favor cool-season grasses, moving the Degraded Native Grass Community (1.2) to the At-Risk Community (1.3).

Pathway 1.3A
Community 1.3 to 1.2

Early or rotational haying or rotational grazing beginning early in the growing season combined with adequate growing season recovery time will return the At-Risk Community (1.3) to the Degraded Native Grass Community (1.2). Haying or grazing prior to the onset of active warm-season grass growth will reduce competition by cool-season grasses and will improve warm-season grass vigor. Early haying also improves the quality of the hay. Grazing after a killing frost in the fall will also help to reduce cool season grasses.

State 2
Invaded Grass State

The Invaded Grass State (2) transitioned from the Reference State (1) and a large portion of the native, warm-season tallgrass and native cool-season grass components have been replaced by non-native cool-season grasses. Encroachment by non-native, cool-season grasses is typically caused by heavy, continuous or heavy, continued seasonal grazing, repetitive haying, or a combination of heavy grazing and repetitive haying. Prolonged absence of grazing and fire may also produce a plant community dominated by non-native, cool-season grasses. While the non-native grasses may enter the plant community through encroachment from adjacent introduced grass plantings, this State most often develops when meadows are interseeded with non-native species. In the past, interseeding with non-native species was a common practice. This attempt to improve forage production profoundly impacted the nature of the Wet Subirrigated site. Due to the aggressive nature of the typical non-native grasses found in this State, return to the Reference State is highly unlikely.

Dominant plant species

reed canarygrass (Phalaris arundinacea), grass
creeping meadow foxtail (Alopecurus arundinaceus), grass

Community 2.1
Non-Native Grass Community

The Non-Native Grass or Reed Canarygrass-Creeping Meadow Foxtail (Phalaris arundinacea-Alopecurus arundinaceus) Community is dominated by non-native grasses or in the case of reed canarygrass of non-native cultivars of native grasses. Non-native grasses are present in the plant community due to encroachment from nearby sites or past interseeding of non-native forage grasses to improve cool-season grass production. While reed canary grass and creeping meadow foxtail are typically the dominant non-native grasses, other non-native grasses such as quackgrass, red top, and timothy may be present in the plant community. Monocultures develop when aggressive non-native grasses are seeded resulting in serious negative repercussions on numerous pollinators and other wildlife species. Once established, this community becomes difficult to alter due to the aggressiveness of the non-native grasses. This plant community, when managed as pastureland or hayland has a high production potential but forage quality is diminished as compared to native plant communities.

Dominant plant species

reed canarygrass (Phalaris arundinacea), grass
creeping meadow foxtail (Alopecurus arundinaceus), grass
quackgrass (Elymus repens), grass

Transition T1A
State 1 to 2

Historically, the Reference State (1) transitioned to the Invaded Grass State (2) with heavy grazing or with long term repeated haying. This transition also occurs when non-native grasses are interseeded into the plant community. Once non-native grasses have established, the plant community is very difficult to alter due to the aggressive nature of the non-native grasses and restoration to the Reference State is highly unlikely.

Additional community tables

Table 8. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Warm-Season Tallgrass			2500–4000
	prairie cordgrass	SPPE	Spartina pectinata	750–1500	–
	big bluestem	ANGE	Andropogon gerardii	750–1500	–
	switchgrass	PAVI2	Panicum virgatum	750–1500	–
	Indiangrass	SONU2	Sorghastrum nutans	250–750	–
	Grass, perennial	2GP	Grass, perennial	0–100	–
2	Cool-Season Grasses			500–1500
	bluejoint	CACA4	Calamagrostis canadensis	250–500	–
	northern reedgrass	CASTI3	Calamagrostis stricta ssp. inexpansa	250–500	–
	slender wheatgrass	ELTRT	Elymus trachycaulus ssp. trachycaulus	100–500	–
	plains bluegrass	POAR3	Poa arida	250–500	–
	western wheatgrass	PASM	Pascopyrum smithii	0–250	–
	foxtail barley	HOJU	Hordeum jubatum	0–100	–
	Grass, perennial	2GP	Grass, perennial	0–100	–
3	Grass-Likes			250–500
	sedge	CAREX	Carex	50–500	–
	rush	JUNCU	Juncus	0–250	–
	bulrush	SCIRP	Scirpus	0–250	–
	spikerush	ELEOC	Eleocharis	0–150	–
Forb
4	Native Forbs			250–500
	Forb, perennial	2FP	Forb, perennial	0–250	–
	Cuman ragweed	AMPS	Ambrosia psilostachya	0–50	–
	scouringrush horsetail	EQHY	Equisetum hyemale	0–50	–
	American licorice	GLLE3	Glycyrrhiza lepidota	0–50	–
	Pennsylvania smartweed	POPE2	Polygonum pensylvanicum	0–50	–
	blackeyed Susan	RUHI2	Rudbeckia hirta	0–50	–
	giant goldenrod	SOGI	Solidago gigantea	0–50	–
	white heath aster	SYER	Symphyotrichum ericoides	0–50	–
	prairie ironweed	VEFA2	Vernonia fasciculata	0–50	–
	great blue lobelia	LOSI	Lobelia siphilitica	0–50	–
	swamp milkweed	ASIN	Asclepias incarnata	0–50	–
	spotted joe pye weed	EUMAB4	Eutrochium maculatum var. bruneri	0–50	–

Table 9. Community 1.2 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Warm-Season Tallgrass			2250–3600
	prairie cordgrass	SPPE	Spartina pectinata	900–1800	–
	switchgrass	PAVI2	Panicum virgatum	900–1800	–
	big bluestem	ANGE	Andropogon gerardii	450–900	–
	Indiangrass	SONU2	Sorghastrum nutans	0–225	–
	Grass, perennial	2GP	Grass, perennial	0–225	–
2	Native Cool-Season Grass			450–1350
	bluejoint	CACA4	Calamagrostis canadensis	225–450	–
	northern reedgrass	CASTI3	Calamagrostis stricta ssp. inexpansa	224–450	–
	plains bluegrass	POAR3	Poa arida	225–450	–
	slender wheatgrass	ELTRT	Elymus trachycaulus ssp. trachycaulus	90–450	–
	western wheatgrass	PASM	Pascopyrum smithii	0–450	–
	Grass, perennial	2GP	Grass, perennial	0–225	–
	foxtail barley	HOJU	Hordeum jubatum	0–135	–
3	Grass-Like			225–675
	sedge	CAREX	Carex	45–450	–
	rush	JUNCU	Juncus	0–225	–
	bulrush	SCIRP	Scirpus	0–225	–
	spikerush	ELEOC	Eleocharis	0–135	–
5	Warm-Season Midgrass			0–225
	marsh muhly	MURA	Muhlenbergia racemosa	0–225	–
	Grass, perennial	2GP	Grass, perennial	0–90	–
6	Non-Native Cool-Season Grass			0–225
	reed canarygrass	PHAR3	Phalaris arundinacea	0–225	–
Forb
4	Forb			225–450
	Cuman ragweed	AMPS	Ambrosia psilostachya	0–90	–
	Pennsylvania smartweed	POPE2	Polygonum pensylvanicum	0–90	–
	blackeyed Susan	RUHI2	Rudbeckia hirta	0–90	–
	white heath aster	SYER	Symphyotrichum ericoides	0–90	–
	prairie ironweed	VEFA2	Vernonia fasciculata	0–90	–
	Forb, perennial	2FP	Forb, perennial	0–90	–
	giant goldenrod	SOGI	Solidago gigantea	0–45	–
	scouringrush horsetail	EQHYA	Equisetum hyemale var. affine	0–45	–
	American licorice	GLLE3	Glycyrrhiza lepidota	0–45	–
	cinquefoil	POTEN	Potentilla	0–45	–

Table 10. Community 1.3 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Warm-Season Tallgrass			740–1665
	prairie cordgrass	SPPE	Spartina pectinata	555–1295	–
	big bluestem	ANGE	Andropogon gerardii	0–555	–
	switchgrass	PAVI2	Panicum virgatum	185–555	–
	Indiangrass	SONU2	Sorghastrum nutans	0–185	–
	Grass, perennial	2GP	Grass, perennial	0–74	–
2	Native Cool-Season Grass			1110–2775
	bluejoint	CACA4	Calamagrostis canadensis	370–925	–
	northern reedgrass	CASTI3	Calamagrostis stricta ssp. inexpansa	370–925	–
	plains bluegrass	POAR3	Poa arida	296–925	–
	slender wheatgrass	ELTRT	Elymus trachycaulus ssp. trachycaulus	74–555	–
	western wheatgrass	PASM	Pascopyrum smithii	0–185	–
	foxtail barley	HOJU	Hordeum jubatum	0–185	–
	Grass, perennial	2GP	Grass, perennial	0–74	–
3	Grass-like			370–740
	sedge	CAREX	Carex	74–555	–
	rush	JUNCU	Juncus	37–185	–
	bulrush	SCIRP	Scirpus	0–185	–
	spikerush	ELEOC	Eleocharis	0–185	–
5	Warm-Season Midgrass			0–185
	marsh muhly	MURA	Muhlenbergia racemosa	0–185	–
	Grass, perennial	2GP	Grass, perennial	0–74	–
6	Non-Native Cool-Season Grass			0–370
	reed canarygrass	PHAR3	Phalaris arundinacea	0–370	–
	creeping meadow foxtail	ALAR	Alopecurus arundinaceus	0–370	–
	quackgrass	ELRE4	Elymus repens	0–185	–
	Grass, perennial	2GP	Grass, perennial	0–185	–
Forb
4	Forb			185–370
	Forb, perennial	2FP	Forb, perennial	0–185	–
	white heath aster	SYER	Symphyotrichum ericoides	0–111	–
	prairie ironweed	VEFA2	Vernonia fasciculata	0–111	–
	Cuman ragweed	AMPS	Ambrosia psilostachya	0–74	–
	Pennsylvania smartweed	POPE2	Polygonum pensylvanicum	0–74	–
	cinquefoil	POTEN	Potentilla	0–37	–
	blackeyed Susan	RUHI2	Rudbeckia hirta	0–37	–
	giant goldenrod	SOGI	Solidago gigantea	0–37	–
	scouringrush horsetail	EQHY	Equisetum hyemale	0–37	–
	American licorice	GLLE3	Glycyrrhiza lepidota	0–37	–

Interpretations

Animal community

LIVESTOCK - GRAZING INTERPRETATIONS:
Grazing by domestic livestock is the major income-producing industry 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*
►Reference Community (1.1)
Average Production (lb./acre, air-dry): 5,000
Stocking Rate (AUM/acre): 1.37
►Degraded Native Grass Community (1.2)
Average Production (lb./acre, air-dry): 4,500
Stocking Rate (AUM/acre): 1.23
►At-Risk Community (1.3)
Average Production (lb./acre, air-dry): 3,700
Stocking Rate (AUM/acre): 1.01
*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:
The Sandhills Prairie ecosystem consists of diverse grassland habitats interspersed with varying densities of Sandhills lakes and limited woody riparian corridors. The majority of this ecosystem is intact. 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 Sandhills Prairie was a disturbance-driven ecosystem with fire, herbivory, and climate functioning as the primary disturbances. Following European settlement, elimination of fire and overgrazing altered the appearance and functionality of the 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 influenced the character of the remaining native grasslands and the habitats that they provide. Fragmentation in MLRA 65 is limited and area sensitive grassland birds such as greater prairie chicken and sharp-tailed grouse continue to thrive here. The mosaic of sites continues to provide habitat for species requiring unfragmented grasslands, 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.

In the absence of fire and grazing, heavy litter buildup can occur on this site hindering the movement of young birds, especially quail and prairie chickens. Increased litter buildup results in decreased forb abundance and diversity and an accompanying decrease in insects, a critical food source for young birds. Introduced species such as cheatgrass, Kentucky bluegrass, and introduced forbs may be present but degradation of the biotic integrity from non-native species in this precipitation zone on ecological site is limited.

Disruption of the natural fire regime and accompanying woody encroachment is the greatest threat to ecosystem dynamics in this MLRA. Lack of fire facilitates tree and shrub encroachment degrades grassland habitats and creates habitats that favor generalist species such as American robin and mourning dove. Woody species provide perches for raptors, increasing the predation mortality on native bird populations. Woody encroachment is most severe in the eastern half of the MLRA but is a threat across the MLRA.

Hydrological functions

Th majority of the soils correlated to the Wet Subirrigated ecological site are in Hydrologic Soil Group D due to high water tables. Although soils are permeable, high water tables limit infiltration during wet seasons. Surrounding upland areas typically have permeable soils and surface inflow peaks on these sites are often muted. Many areas are seasonally flooded for short periods during times of higher precipitation.

For the interpretive plant community, rills and gullies are not typically present. Water flow patterns should be barely distinguishable if at all present. Pedestals are not present. Litter falls in place and signs of movement are not common. Chemical and physical crusts are rare to non-existent. Cryptogamic crusts may be present but are not significant for hydrologic considerations. Overall, this site has the appearance of being very stable and very productive.

Recreational uses

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

Wood products

No appreciable wood products are present on the site.

Other products

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

Other information

Revision Notes: “This PROVISIONAL ecological site concept has been through the quality control and quality assurance processes to ensure that the site meets the NESH standards for a provisional ecological site that provides basic compiled information in one location. This site should not be considered an Approved ESD until further data entry and editing is completed.

Site Development and Testing Plan:
Future work is needed to validate the information in this Provisional Ecological Site Description. Additional data collection and evaluation may also be needed to develop this ESD to the Approved, then Correlated level. This could include field activities to collect low, medium and high intensity sampling, soil correlations, and analysis of that data. Field reviews of the project plan should be done by soil scientists and vegetation specialists. A final field review, peer review, quality control, and quality assurance reviews of the ESD will be needed to produce the final document. Annual reviews of the Project Plan are to be conducted by the Ecological Site Technical Team. The project plan is ES-R065XY013NE - MLRA 65.

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 were also used. Those involved in developing this site include Dave Cook, Rangeland Management Specialist, NRCS; Dwight Hale, Engineer, NRCS; Sheila Luoma, Resource Conservationist, NRCS; Marla Shelbourn, Rangeland Management Specialist, NRCS; Dave Steffen, Rangeland Management Specialist, NRCS.

There are four records located in SCS-RANGE-417 with a sample period of 1982-1983. This information was collected from Lincoln, Logan, Loup, and Sheridan Counties in Nebraska.

Other references

Bleed, A. S., Flowerday, C. A., 1998. An Atlas of the Sand Hills. Conservation and Survey Division, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln.

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. 2023.

The PLANTS Database (http://plants.usda.gov, 12/27/2023). National Plant Data Team, Greensboro, NC USA.

Contributors

Kim Stine
Doug Whisenhunt
Nadine Bishop

Approval

Suzanne Mayne-Kinney, 2/04/2025

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: Dave Cook, Emily Helms, Jeff Nichols, Myra Richardson, Nadine Bishop
Contact for lead author	Jeff Nichols: jeffrey.nichols@usda.gov
Date	11/30/2024
Approved by	Suzanne Mayne-Kinney
Approval date
Composition (Indicators 10 and 12) based on	Annual Production