Natural Resources
Conservation Service
Ecological site R080AY080OK
Shallow Clay Upland
Last updated: 9/19/2023
Accessed: 04/29/2026
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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): 080A–Central Rolling Red Prairies
MLRA 80A is characterized by dark red Permian sandstones or shales that are exposed on gently sloping plains. The dominant soil order in this MLRA is Mollisols. The soils in the area dominantly have a thermic soil temperature regime, an ustic soil moisture regime, and mixed, siliceous, or smectitic mineralogy. They generally are shallow to very deep, are well drained, and generally are loamy or clayey. These plains are dissected by rivers that flow from northwest to southeast. Major rivers of this MLRA include the Chickaskia and Bluff rivers in KS, the Salt Fork, Cimarron, North and South Canadian, Washita, Cache, Red River in OK, and branches of the Wichita River in TX.
Classification relationships
This ecological site is correlated to soil components at the Major Land Resource Area (MLRA) level which is further described in USDA Ag Handbook 296.
Ecological site concept
These sites are found on convex knolls and strongly sloping, to steep, hillsides, or side slopes along drainageways on uplands in the Central Rolling Red Prairies. Slopes range from 3 to 30 percent. Rock may appear on the surface and cover 15 to 20 percent of the site. The site is well suited for herbaceous vegetation, however, the shallow clay soils can limit productivity when compared to other sites. Vegetation is predominantly sideoats grama, blue grama, hairy grama, buffalograss, pricklypear, tall dropseed, switchgrass, and little bluestem. Abusive grazing may lead to denuding of the grasses and inevitable increases in bare ground. Removal of fire from the system may lead to an increase in woody plant encroachment.
Associated sites
R080AY083OK Shallow Upland
Shallow soils over sandstone.
Similar sites
R080AY083OK Shallow Upland
Shallow soils over sandstone.
Table 1. Dominant plant species
Tree Not specified
Shrub Not specified
Herbaceous (1) Bouteloua curtipendula
(2) Schizachyrium scopariumPhysiographic features
These sites occur on hills on uplands. Slopes can range from 5 to 45 percent but are typically less than 25 percent.
Figure 2. Shallow Clay Upland
Table 2. Representative physiographic features
Landforms (1) Hills > Hillslope
Runoff class Very high Elevation 850 – 1500 ft Slope 5 – 25 % Aspect Aspect is not a significant factor Table 3. Representative physiographic features (actual ranges)
Runoff class Not specified Elevation 0 ft Slope 5 – 45 % Climatic features
The climate is characterized by moist, cool, springs; hot, often dry summers; mild autumns; and mild to cold winters. Variation in timing and amounts of precipition from year to year is quite common. Drought cycles range from three to five years duration with occasionally longer periods occurring at unpredictable intervals. Above normal rainfall cycles are usually just as random, but shorter in duration.
Table 4 Representative climatic features
Frost-free period (characteristic range) 170-190 days Freeze-free period (characteristic range) 200-210 days Precipitation total (characteristic range) 40-40 in Frost-free period (actual range) 160-190 days Freeze-free period (actual range) 190-220 days Precipitation total (actual range) 40-40 in Frost-free period (average) 180 days Freeze-free period (average) 200 days Precipitation total (average) 40 in Characteristic rangeActual rangeBarLineFigure 3. Monthly precipitation range
Characteristic rangeActual rangeBarLineFigure 4. Monthly minimum temperature range
Characteristic rangeActual rangeBarLineFigure 5. Monthly maximum temperature range
BarLineFigure 6. Monthly average minimum and maximum temperature
Figure 7. Annual precipitation pattern
Figure 8 Annual average temperature pattern
Climate stations used
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(1) JEFFERSON [USC00344573], Medford, OK
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(2) MEEKER 5 W [USC00345779], Meeker, OK
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(3) PAULS VALLEY 4 WSW [USC00346926], Pauls Valley, OK
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(4) CHICKASHA EXP STATION [USC00341750], Chickasha, OK
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(5) CUSHING [USC00342318], Cushing, OK
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(6) EL RENO 1 N [USC00342818], El Reno, OK
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(7) NEWKIRK 1NW [USC00346278], Newkirk, OK
">Influencing water features
These upland site may shed some water via runoff during heavy rain events. The presence of good ground cover and deep rooted grasses can help facilitate infiltration and reduce sediment loss.
Wetland description
N/A
Figure 9.
Soil features
Soils are mapped for each county within the MLRA. Mapunits are representations of the major soil series component(s) and named accordingly. Each Mapunit is spatially represented on a digital soils map as polygons of different shapes and sizes. Within these Mapunits, there are often minor soil series components included. These minor components are soils that occur within a Mapunit polygon but are of small extent (15% or less of the Mapunit area). However, it is difficult to separate these minor soils spatially due to the scale of soil mapping.
Ecological sites are correlated at the component level of the soil survey. Therefore, a single Mapunit may contain multiple Ecological Sites just as it may contain multiple soil components. This is important to understand when investigating soils and Ecological Sites. A soil survey Mapunit may be correlated to a single Ecological Site based on the major component; however, there may be inclusional areas of additional Ecological Sites which are correlated to the minor components of that particular soil Mapunit.
Representative soil components for this site include:
Masham & Highview
These soils consists of shallow, well drained soils on crests and side slopes of hillslopes on low hills. These very slowly permeable soils formed in material weathered from red or grey shales of Permian age. Permeability is slow and runoff can be high. The high clay content can restrict plant available water and reduce overall vegetative productivity.
Figure 10.
Table 5. Representative soil features
Parent material (1) Residuum – clayey shale
Surface texture (1) Clay
(2) Clay loam
(3) Silty clay loam
Drainage class Well drained Permeability class Very slow to slow Soil depth 0 – 20 in Surface fragment cover <=3" 0 – 10 % Surface fragment cover >3" 0 – 4 % Available water capacity
(0-40in)1 – 3.5 in Calcium carbonate equivalent
(0-40in)Not specified Electrical conductivity
(0-40in)Not specified Sodium adsorption ratio
(0-40in)Not specified Soil reaction (1:1 water)
(0-40in)7.5 – 8.5 Subsurface fragment volume <=3"
(Depth not specified)0 – 10 % Subsurface fragment volume >3"
(Depth not specified)0 – 6 % Ecological dynamics
Like many sites across the Great Plains, this Shallow Clay Upland site evolved under periodic disturbances by fire, drought, and grazing(Frost 1998,Fuhlendorf 2009). The soils are well suited for herbaceous plant growth but are limited by their dense clay subsoil and depth to bedrock. The shallow clay soils and run-off upland position make the site susceptible to influence by drought. However, the reference state of this site is very resilient to natural disturbances. Alternative states include a woody encroached state and a eroded state.
The soils may vary from shallow clays to silty clays of varying thickness. Soils are typically shallow, ranging from seven to twenty inches in depth over shale. Because of slope, bare ground, and lower forage production, Shallow Clay Upland sites are not as well suited for grazing by domestic livestock as adjacent sites. Plant rooting depth is restricted and moisture holding capacity is low and often limits productivity. Occasional grazing will occur when slope and access are favorable. This site is characterized by low production when compared to surrounding sites and considerable bare ground which crusts easily. In areas where underlying bedrocks are fragmented, roots of perennial tallgrasses and other deep rooted plants can achieve deep penetration and survive.
The reference plant community is an open, mixed-grass prairie with a few forbs and scattered shrubs. Pre-settlement influences included grazing or browsing by endemic pronghorn antelope, deer and migratory bison, severe droughts and frequent wildfires. Wildfires, occurring through lightning strikes or intentionally set by Native Americans, had an impact on community structure. The wildfires favor grass vegetation and keep woody plant establishment low. Sparse fuels along this site may have reduced wildfire frequency when compared to other adjacent sites.
The herbaceous vegetation includes a mixture of midgrass and shortgrass along with a limited amount of forbs. The dominant species under reference conditions are sideoats grama, little bluestem, buffalograss, blue grama and silver bluestem. A limited and diverse amount of forbs are also common throughout the site.
In addition to the reference community, other plant communities can exist on this site and are usually the result of management practices. Following the absence of wildfire shrub and tree species will begin to increase. There are various transitional stages on this site, and transitional stage may result in a stable community for many years. While grazing may not lead to an increase in shrubs, it can reduce the fuel loads necessary to carry a wildfire that would restrict woody plant dominance.
The absence of wildfire will favor woody species, especially mesquite and/or eastern redcedar. Woody species will continue to increase in size and density until they dominate the community. This generally occurs when the woody plant cover exceeds 25 percent and shrubs dominate the ecological processes. Woody dominated sites lead to annual grass and forb species becoming more prevalent across the site. They will occupy many of the bare areas throughout the site during wet seasons, while only low vigor shortgrass will persist in shrub interspaces. When grass cover declines, litter, mulch, and soil organic matter also decline with consequential increases in bare ground, erosion and desertification occurring between shrubs.
Restoration from a woody grassland to a native prairie is possible, but can be prohibitively expensive. Dense brush cover and very limited seed sources will require brush control and re-seeding for restoration. The shallow, fine textured soils and steep slopes limit the types of mechanical treatments that can be utilized and care must be taken to not destroy the grass communities preventing erosion. Following brush management, re-seeding the site to a native mixture will be arduous, but necessary. Several years of limited grazing will be necessary along with periodic prescribed fires. Severe erosion and fertility losses during retrogression may prohibit the site to returning to the reference state.
Historically, the focus of conservation efforts has been on restoring woody encroached sites across the Great Plains. However, new data suggests that a more effective strategy involves addressing woody plants in the seed dispersal stage prior to the change in ecological states. Preserving intact prairie for both agricultural production and ecosystem services must become a priority for land managers and conservationist alike.
State and Transition Diagram:
The following State and Transition Model suggests pathways vegetation might take depending on how ecological processes are changed. Local professional guidance should always be sought before pursuing a treatment scenario.State and transition model
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textLand uses
Land use 1 submodel, ecosystem states
State 1 submodel, plant communities
Land use 1
RangelandWhile there is occasional evidence of prior cultivation, the dominant land use is rangeland on nearly all Shallow Clay Upland sites.
State 1.1
Reference GrasslandThe reference state represents the range of variability on the site under the historic natural disturbances. Community composition may shift, but the ecological processes remain intact.
Characteristics and indicators. This site has characteristic shallow clay soils. Native vegetation is intact but production can be limited due to poor infiltration and available water capacity.
Resilience management. With a fire return interval of less than 4 years and managed grazing that is balanced with the carrying capacity, this state may be maintained as a grassland reference state.
Dominant plant species
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sideoats grama (Bouteloua curtipendula), grass
State 1.2
Shrubland/GrasslandThe Shrubland/Grassland State occurs when fire is removed from the landscape for many years and woody plants are not controlled. The shrub canopy acts to intercept rainfall and increase evapotranspiration losses, creating a more xeric microclimate. Soil fauna and organic mulch are reduced exposing more soil surface to erosion in the shortgrass interspaces between the shrubs and trees. The exposed soil crusts readily and erosion can be a problem. However, within the woody canopy hydrologic processes stabilize and soil organic matter and mulch begin to increase and ecological processes eventually stabilize under the shrub canopy. Fires may be intermittent across this site because of sparse vegetation and bare ground. So, when woody species invasion begins, the site very slowly degrades as woody vegetation increases. The increase in bare ground ultimately leads to erosion.
Eastern redcedar, ashe juniper, or mesquite, usually dominate the Shrubland/Grassland Plant Community production. Even though the shrub canopy cover may remains relatively constant at approximately 25 percent, the trees and shrubs can account for 65 percent of the annual production. A common understory shrub is pricklypear. Shortgrasses and low quality annual grasses and forbs occupy the woody plant interspaces. Characteristic grasses are buffalograss, rough tridens, threeawns, hairy grama, and blue grama. Forbs found in this community include dotted gayfeather, croton, western ragweed, gaura and common broomweed. Annual forbs and grasses invade the bare ground if moisture is available in spring and summer. Grasses and forbs make up 35 percent or less of the annual biomass production. Production can vary considerably with seasonal moisture. The Shrubland/Grassland Plant Community provides good habitat cover for wildlife, but limited preferred forage, or browse, is available for livestock or wildlife. The woody plants are generally of low value as browse and forage production being mostly annuals is highly variable.
Without considerable energy inputs in brush control and proper grazing management, the shrubland will continue to thicken until the site stabilizes with the climate and soil factors.Dominant plant species
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eastern redcedar (Juniperus virginiana), tree
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honey mesquite (Prosopis glandulosa), shrub
State 1.3
ErodedThis state is the result of water erosion over bare soil. Most of the "A" horizon of the soil profile has been displaced. The remaining subsoil is very low in fertility. Some native grasses and forbs will persist in this state, however, production is greatly reduced.
Dominant plant species
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threeawn (Aristida), grass
Transition T1A
State 1.1 to 1.2In the absence of fire or other brush management strategies, woody species may begin to encroach on the site. If left unchecked, some woody species will begin to dominate the ecological functions of the site such as nutrient cycling and hydrologic cycle.
Transition T1B
State 1.1 to 1.3If these soils are subjected to sever disturbance by animals or equipment, they are prone to soil erosion. The site with higher slopes are particularly vulnerable. Once a significant amount of the soil surface is displaced, the site will transition to an eroded state.
Restoration pathway R2A
State 1.2 to 1.1Through the implementation of a prescribed burning program or alternative forms of brush management, the site may be restored to the reference state. Careful grazing management is often required to ensure proper fuel loads and allow for the recovery of herbaceous species.
Transition T2A
State 1.2 to 1.3If these soils are subjected to sever disturbance by animals or equipment, they are prone to soil erosion. The site with higher slopes are particularly vulnerable. Once a significant amount of the soil surface is displaced, the site will transition to an eroded state.
Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Dominant Midgrass 300–900 sideoats grama BOCU Bouteloua curtipendula 200–800 – little bluestem SCSC Schizachyrium scoparium 200–800 – 2 Shortgrass 200–500 blue grama BOGR2 Bouteloua gracilis 50–300 – hairy grama BOHI2 Bouteloua hirsuta 50–300 – buffalograss BODA2 Bouteloua dactyloides 50–300 – Texas grama BORI Bouteloua rigidiseta 0–20 – hairy woollygrass ERPI5 Erioneuron pilosum 0–20 – 3 Tallgrass 200–500 big bluestem ANGE Andropogon gerardii 0–300 – Indiangrass SONU2 Sorghastrum nutans 0–300 – switchgrass PAVI2 Panicum virgatum 0–300 – 4 Cool Season 50–100 Heller's rosette grass DIOL Dichanthelium oligosanthes 0–50 – western wheatgrass PASM Pascopyrum smithii 0–50 – Canada wildrye ELCA4 Elymus canadensis 0–50 – 5 Other Grass 50–300 composite dropseed SPCO16 Sporobolus compositus 10–100 – silver beardgrass BOLA2 Bothriochloa laguroides 10–100 – lovegrass ERAGR Eragrostis 10–100 – vine mesquite PAOB Panicum obtusum 0–50 – Forb6 Forbs 50–200 prairie clover DALEA Dalea 10–100 – Illinois bundleflower DEIL Desmanthus illinoensis 10–100 – fourvalve mimosa MIQU2 Mimosa quadrivalvis 10–100 – sunflower HELIA3 Helianthus 10–100 – white heath aster SYER Symphyotrichum ericoides 10–100 – milkvetch ASTRA Astragalus 0–50 – blazing star LIATR Liatris 10–50 – prairie broomweed AMDR Amphiachyris dracunculoides 10–50 – yellow sundrops CASE12 Calylophus serrulatus 0–50 – trailing krameria KRLA Krameria lanceolata 0–50 – Shrub/Vine7 Shrubs 0–150 sumac RHUS Rhus 0–150 – pricklypear OPUNT Opuntia 0–20 – Table 7. Community 1.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
Domestic livestock and white-tail deer are the dominant grazers and browsers of the site. Various songbirds and small mammals are also common at these sites. As the site changes towards a woody dominated community the habitat may favor some species over others. Management decisions should favor a vegetative state that creates quality habitat for desired animal species.
Hydrological functions
These sites occur on uplands and shed water to adjacent sites lower on the landscape. The presence of deep rooted tallgrasses can help facilitate percolation of water into the soil profile. Minimizing bare ground is very important in reducing soil erosion by water movement.
Recreational uses
Camping, fishing, hunting, hiking, bird watching, horseback riding and many other outdoor recreational practices.
Wood products
There are no significant wood produts from this site.
Other products
N/A
Other information
N/A
Supporting information
Inventory data references
The original information presented here was derived from Soil Conservation Service field observations of trained range personnel as well as clipping data done in Oklahoma. Range -417 clipping data is housed at the NRCS Stillwater state office and should be associated with vegplot data records in NASIS.
Type locality
Location 1: Payne County, OK Township/Range/Section T18N R1W S1 General legal description NE 1-T18N-R1W OSURR "Pasture 9" References
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Frost, C.C. 1998. Presettlement Fire Frequency Regimes of the United States: A First Approximation. Plant Conservation Program. North Carolina Department of Agriculture and Consumer Services, Raleigh, NC.
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Fuhlendorf, S.D., D.M. Engle, J. Kerby, and R. Hamilton. 2009. Pyric Herbivory: Rewilding Landscapes through the Recoupling of Fire and Grazing. Conservation Biology 23:588–598.
Other references
USDA-NRCS (Formerly Soil Conservation Service) Range Site Descriptions (1960s)
USDA-NRCS (Formerly Soil Conservation Service) Ag Handbook 296 (2006)Contributors
Dr. Jack Eckroat, Grazing Lands Specialist, NRCS, Oklahoma
Edits by Colin Walden, Soil Survey Office, Stillwater, OKApproval
Bryan Christensen, 9/19/2023
Acknowledgments
Site Development and Testing Plan: Future work, as described in a Project Plan, to validate the information in this Provisional Ecological Site Description is needed. This will include field activities to collect low, medium and high intensity sampling, soil correlations, and analysis of that data. Annual field reviews 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.
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) Mark Moseley Contact for lead author 100 USDA Suite 206, Stillwater, OK 74074 Date 05/21/2004 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
Very few rills. -
Presence of water flow patterns:
Distinct, particularly on steeper slopes. Not usually more than 1 foot deep. -
Number and height of erosional pedestals or terracettes:
Some, around small rocks and around bunchgrasses, but rarely more than 1 inch depth. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Up to 35%. -
Number of gullies and erosion associated with gullies:
Shallow soil limits formation of anything but small gullies. Usually these are on steeper slopes, are rounded, less than 1 – 2 feet deep and 2 – 3 feet wide. -
Extent of wind scoured, blowouts and/or depositional areas:
None. -
Amount of litter movement (describe size and distance expected to travel):
Litter can move 6 inches after a high intensity rainfall event. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Stability score 5 – 6. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Reddish brown 0 – 5 inches, strong sub-angular blocky structure, hard. Refer to specific description for component sampled. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Tall, mid-grass, and sod grass community randomly dispersed. Slopes and very slowly permeable soils result in high runoff. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
No compaction layer but fine texture and hard structure can be mistaken for compaction layer. -
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:
MIdgrass ShortgrassSub-dominant:
Tallgrasses Perennial ForbsOther:
Cool Season Grass/Grasslikes; WoodiesAdditional:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Due to the droughty nature of this site, some mortality will occur, especially with three-awns, sideoats grama and little bluestem. Death loss could be around 5%, higher in extremely dry, hot years. -
Average percent litter cover (%) and depth ( in):
Litter cover 30 - 50%. Less than .5 inches deep. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Reference production is 1,200 – 2,400 lb/acre, annually. -
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:
Main invasives are eastern redcedar unless the site is exposed to fire. -
Perennial plant reproductive capability:
All plants capable of reproducing at least every 2 – 3 years.
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