Natural Resources
Conservation Service
Ecological site R073XY114KS
Loess Hills
Last updated: 10/02/2019
Accessed: 11/24/2024
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.
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): 073X–Rolling Plains and Breaks
This ESD is located in the Rolling Plains and Breaks Major Land Resource Area (MLRA) 73 of the Central Great Plains Winter Wheat and Range Region of the United States. MLRA 73 is in Kansas (78 percent) and Nebraska (22 percent). It makes up about 21,485 square miles (13,750,400 acres). The towns of Hays, Great Bend, and Dodge City, Kansas; and Alma, Curtis, Holdrege, and McCook, Nebraska are in this MLRA. The MLRA is bisected by Interstate 70. The Platte River is at the northern edge of the area, and the Arkansas River is at the southern edge.
Classification relationships
Major land resource area (MLRA): 073-Rolling Plains and Breaks
Ecological site concept
The Loess Hills ecological site occurs on narrow ridges and divides with steep slopes. The slopes of this site range from greater than 30% to near vertical. The steep side slopes are broken with series of short and shallow slope slips, referred to as "terracettes" or "catsteps." The spatial extent of this site is occupied in the northern part of MLRA 73.
This is a new ecological site in MLRA 73. Formerly a place holder id# in ESIS of R073XY016NE. Now recognized as R073XY114KS. The range site was formally recognized as Loess Breaks in MLRA 72.
Associated sites
| R073XY100KS |
Loamy Plains The Loamy Plains ecological site is commonly located adjacent to or in coordination with the Loess Hills site. The Loamy Plains ecological site occurs on relatively flat ridges, plains, and only occasionally on moderately steep side slopes. This site is located where extra moisture from drainage or overflow is not received, therefore produces runoff to areas lower on the landscape. |
|---|
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
Not specified |
Physiographic features
The western half of MLRA 73 and areas along the Arkansas River have remnants of the Tertiary river-laid sediments washed out onto the plains from erosion of the prehistoric Rocky Mountains in Colorado. In the valley of the Arkansas River, the wind reworked these sediments, forming a hummocky dune surface of eolian sand. A loess mantle occurs on the higher ground in the western half of the area. The Tertiary-age Ogallala and White River Formations cover Cretaceous Pierre Shale in the northern part of the area. The Ogallala Formation consists of loose to well cemented sand and gravel, and the White River Formation consists of ashy claystone and sandstone. Pierre Shale and Niobrara Chalk are at the surface in the valleys of the Republican, Smoky Hill, and Saline Rivers. Fort Hays limestone of the Niobrara Formation and Blue Hill shale of the Carlile Formation are at the surface in the valleys of the Saline and Smoky Hill Rivers. Shale can be seen exposed in the eastern half of this MLRA, in Kansas. Quaternary and more recent sand and gravel partially cover the shale in the river valleys.
The principal parent material of the Loess Hills site is calcareous loess.
This site occurs as areas on steep to very steep loess slopes that have experienced mass movement that can be enhanced by water erosion. The mass movement creates a series of loess faces above the tops of slump blocks. The tops of these slump blocks form terracettes, which are commonly referred to as "catsteps." The depth and height of these catsteps intensifies with increasing slope.
Vertical faces of loess, areas of broken sod, and deep gullies are common on this site. Vehicular traffic is very limited on this site. This site produces runoff to areas lower on the landscape.
This site is subject to severe erosion by water if the vegetative cover is reduced or absent by such things as continuous defoliation without periodic rest and fire events. Vehicular traffic on this site is very limited to impossible.
A primary identifying feature for this site is the presence of calcium carbonate throughout the soil profile.
Figure 2. Loess Hills in NW, Frontier Cty., Nebraska.
Table 2. Representative physiographic features
| Landforms |
(1)
Hill
(2) Drainageway |
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 610 – 914 m |
| Slope | 30 – 60% |
| Ponding depth | 0 cm |
| Water table depth | 203 cm |
Climatic features
For MLRA 73 the average annual precipitation is 19 to 30 inches (48 to 76 centimeters). Most of the rainfall occurs as high-intensity, convective thunderstorms during the growing season. The maximum precipitation occurs from the middle of spring to the early autumn months. Precipitation in winter occurs as snow. The annual snowfall ranges from about 17 inches (45 centimeters) in the southern part of the area to 24 inches (60 centimeters) in the northern part. The average annual temperature is 48 to 56 degrees F (9 to 14 degrees C). The freeze-free period averages 180 days and ranges from 145 to 210 days, increasing in length from northwest to southeast. The following weather data originated from weather stations chosen across the geographical extent of the ecological site, and will likely vary from the data for the entire MLRA. The climate data derives from the Natural Resources Conservation Service (NRCS) National Water and Climate Center. The data-set is from 1981-2010.
Table 3. Representative climatic features
| Frost-free period (average) | 142 days |
|---|---|
| Freeze-free period (average) | 160 days |
| Precipitation total (average) | 610 mm |
Figure 3. Monthly precipitation range
Figure 4. Monthly average minimum and maximum temperature
Figure 5. Annual precipitation pattern
Figure 6. Annual average temperature pattern
Climate stations used
-
(1) FRANKLIN #2 [USC00253037], Bloomington, NE
-
(2) NORTH PLATTE EXP FARM [USC00256075], North Platte, NE
-
(3) EUSTIS 2 NW [USC00252790], Eustis, NE
-
(4) TRENTON DAM [USC00258628], Trenton, NE
-
(5) HAYES CENTER 1NW [USW00024020], Hayes Center, NE
-
(6) MOOREFIELD [USC00255655], Moorefield, NE
-
(7) OXFORD 6NNW [USC00256454], Oxford, NE
Influencing water features
There are no water features of the Loess Hills ecological site or adjacent wetland/riparian regimes that influence the vegetation and/or management of the site to make it distinctive from other ecological sites.
Figure 7. Fig.7-1 from National Range & Pasture Handbook.
Soil features
This site is dominated by steep to very steep slopes of loess breaks, and includes narrow ridges and divides separating these loess faces. The slope of the soils in this site range from 20 percent to nearly vertical with slopes dominantly exceeding 30 percent. Those slopes under 30 percent are primarily on the included narrow ridges and divides.
The soils on this site are very deep and have thin, normally calcareous, silty surface layers. The content of organic matter is generally low to moderately low in the surface layer. The silty substratum is calcareous with relatively low inherent fertility, and generally has a calcium carbonate equivalent (CCE) of less than 15 percent.
Water flow patterns should be evident on most of this site due to slope and vegetation morphology. They may be broken and irregular in appearance or connected with some minor erosion. This site should exhibit slight to no evidence of rills or wind-scoured areas. Pedestaled plants would be common, especially in water flow patterns. Sub-surface soil layers are non-restrictive to water movement and root penetration. Included within this site are surfaces that have broken sod and are generally unstable on the steepest slopes and within gullies. The soils on this site are highly susceptible to both wind and water erosion when void of vegetative protection.
Major soil series correlated to this ecological site include Coly with greater than 30% slopes and Sulco.
These attributes represent 0-40 inches in depth or to the first restrictive layer.
Figure 8. Sulco soil series profile.
Table 4. Representative soil features
| Surface texture |
(1) Loam (2) Silt loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderate |
| Soil depth | 0 – 152 cm |
| Surface fragment cover <=3" | 0% |
| Surface fragment cover >3" | 0% |
| Available water capacity (0-101.6cm) |
19.56 – 40.61 cm |
| Calcium carbonate equivalent (0-101.6cm) |
0 – 15% |
| Electrical conductivity (0-101.6cm) |
0 – 4 mmhos/cm |
| Sodium adsorption ratio (0-101.6cm) |
0 – 9 |
| Soil reaction (1:1 water) (0-101.6cm) |
7.4 – 9 |
| Subsurface fragment volume <=3" (Depth not specified) |
0% |
| Subsurface fragment volume >3" (Depth not specified) |
0% |
Ecological dynamics
The grasslands of Major Land Resource Area (MLRA) 73, the Rolling Plains and Breaks, located in south-central Nebraska and central Kansas, evolved under sub-humid (20-40 inch precipitation range) climates, characterized by much the same weather extremes of temperatures, rainfall, and snowfall we are familiar with today. As a result of glacial activity and other natural forces, then and later, plants have migrated from their places of origin, so that today MLRA 73 grasslands are simple-to-complex mixtures of perennial grasses and forbs, plus a few native annuals and biennials. Species composition has been modified by the introduction of Kentucky bluegrass and cool-season annual and perennial grasses, particularly Japanese brome (Launchbaugh and Owensby, 1978).
Through the ages to modern times, wildfires – many started by lightning, but most by primitive people – influenced development of fire-tolerant grasses and suppressed woody vegetation (Sauer, 1950). Certain woody plants, however, always were present as natural components of some grasslands. Browsing by animals and frequent prairie fires were largely responsible for maintaining “normal” amounts of woody species (Dyksterhuis, 1958). In primitive time, numerous large herbivores subjected herbaceous vegetation to grazing stress. After the last glacial retreat, bison emerged as the major dominant large grazer, although the prairies and plains simultaneously supported many pronghorn antelope, elk, deer, prairie dogs, rabbits, rodents, and insects. And each exerted grazing pressures on the vegetation (Launchbaugh and Owensby, 1978). There is little doubt that during and long before Spanish explorations into this area, most of the grassland was used almost continuously throughout the year by one roving herd of buffalo after another and other grazing animals (early exploration accounts reviewed by Dary in 1974; diaries of early Kansas residents cited by Choate and Fleharty in 1975). Grazing and trampling by bison and their associates were often intensive, as was uncontrolled grazing by livestock in the late 1800s after most of the wild grazers had been eliminated.
The plant communities for the Loess Hills ecological site are dynamic due to the complex interaction of many ecological processes. The interpretive plant community for this site is the Reference Plant Community. The Reference Community has been determined by the study of rangeland relic areas, areas protected from excessive disturbance, areas under long term rotational grazing strategies, literature of plant communities from the early 1900s, and local expertise. Trends in plant community dynamics ranging from heavily grazed to lightly grazed areas, seasonal use pastures, and historical accounts have also been used.
This ecological site is made up of a Grassland State and a Woody State. The Grassland State is characterized by non-broken land (no tillage), warm-season bunchgrasses, sod-forming grasses, forbs, and shrubs. The Woody State is characterized by a community made up of primarily eastern redcedar, with few remnant native grasses making up the understory and very few forbs.
Vegetation changes are expected within this ecological site and will be dependent on the geographical location of the site inside Major Land Resource Area (MLRA) 73. Variation in precipitation east and west is not as affected as is temperature north and south. The northern part of MLRA 73 is characterized by cooler temperatures and a shorter growing season in respect to the southern end. As a result, cool-season bunchgrasses and sod-formers proliferate. Growth of native cool-season plants begins about April 15, and continues to about June 15. Native warm-season plants begin growth about May 15, and continue to about August 15. Green-up of cool-season plants may occur in September and October if adequate moisture is available (weather data from National Climate Data Center, 1980-2010).
The Loess Hills ecological site developed with occasional fires as part of the ecological processes. Historically, it is believed that the fires were infrequent, randomly distributed, and started by lightning at various times throughout the season when thunderstorms were likely to occur. It is also believed that pre-European inhabitants may have used fire as a management tool for attracting herds of large, migratory herbivores (bison, elk, deer, and pronghorn). The impact of fire over the past 100 years has been relatively insignificant due to the human control of wildfires and the lack of acceptance of prescribed fire as a management tool in the sub-humid, High Plains and Smoky Hills area.
The degree of herbivory (feeding on herbaceous plants) has a significant impact on the dynamics of the site. Historically, periodic grazing by herds of large, migratory herbivores was a primary influence. Secondary influences of herbivory by species such as prairie dogs, grasshoppers, gophers, and root-feeding organisms impacted the vegetation historically, and continue to this day.
The management of herbivory by humans through grazing of domestic livestock and/or manipulation of wildlife populations has been a major influence on the ecological dynamics of the site. This management, coupled with the High Plains and Smoky Hills climate, largely dictates the plant communities for the site.
Drought cycles were part of the natural range of variability within the site and historically have had a major impact upon the vegetation. The species composition changes according to the duration and severity of the drought cycle (Albertson and Weaver, 1940).
The Loess Hills ecological site occurs on the sloping parts of the landscape, at 30% slopes or greater. The site is generally not a preferred grazing area because of the steepness of the slopes. Adjacent sites are much flatter and generally receive the majority of the grazing pressure resulting in grazing distribution problems.
The general response of this site to long-term continuous grazing pressure is to gradually lose the vigor and reproductive potential of the tall- and midgrass species, and to shift the plant community toward shortgrass species.
The tall- and mid-grass species generally escape excessive grazing pressure on the steeper, less accessible areas. These grasses maintained on the steep area help to provide a source for these species to repopulate the site after long periods of drought and/or overgrazing. The use of grazing management that includes needed distribution tools, proper stocking, and adequate recovery periods during the growing season, helps to restore this site to its productive potential.
The following diagram illustrates pathways that the vegetation on this site may take from the Reference Plant Community as influencing ecological factors change. There may be other states or plant communities not shown in the diagram, as well as noticeable variations within those illustrated and described in the following sections.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 2 submodel, plant communities
State 1
Grassland State
The Grassland State is supported by empirical data, historical data, local expertise and photographs. This state is defined by three native plant communities that are a result of periodic fire, drought, and grazing. These events are part of the natural disturbance regime and climatic process. The Reference Plant Community consists of warm-season tall- and midgrasses, forbs, and shrubs. Plant community 1.2 is made up primarily of little bluestem with blue grama as subdominant component. The At-Risk Community is made blue or hairy grama, forbs, shrubs, annuals, and/or woody species (mainly eastern redcedar).
Community 1.1
Reference Community
Figure 9. Catsteps or terracettes on the Loess Hills site.
Figure 10. Landscape view of Loess Hills site in Frontier, Cty., NE.
The Reference Community is supported by empirical data, historical data, local expertise, and photographs. The potential vegetation is a mixed grass prairie consisting of approximately 90 percent grasses and grass-like plants, 5 percent forbs, and 2 percent shrubs and cacti. Little bluestem, sideoats grama, plains muhly and Fendler threeawn are the dominant grasses in this community. Subdominant species include big bluestem, switchgrass, composite dropseed, and sand dropseed. Warm-season shortgrasses make up 10% of the production by weight and include blue grama, buffalograss, and hairy grama. This community has a diverse forb population, most of which occur in small amounts. Shrubs and cacti include buckbrush, leadplant, sand sagebrush, winterfat, and soapweed yucca. The cool-season grasses play a minor component in this plant community, which includes needleandthread, green needlegrass, and western wheatgrass. Combined they make up 10% of the total annual production, by weight, per acre, for the year. Both are a valuable forage plant in late spring and/or early summer. Needleandthread appears to be more prevalent in the northern part of MLRA 73. The Reference Plant Community is diverse and productive. Litter is uniformly distributed with very little movement off-site, and natural plant mortality is very low. This community is resistant to many disturbances with the exception of heavy, long-term continuous grazing, tillage, and/or development into urban or other uses. Total annual production ranges from 1,000 to 3,000 pounds of air-dried vegetation per acre per year and will average 2,200 pounds. These production figures are the fluctuations expected during favorable, normal, and unfavorable years due to the timing and amount of precipitation and temperature. Total annual production should not be confused with species productivity, which is annual production and variability by species throughout the extent of the community phase.
Figure 11. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
| Plant type | Low (kg/hectare) |
Representative value (kg/hectare) |
High (kg/hectare) |
|---|---|---|---|
| Grass/Grasslike | 1009 | 2219 | 3026 |
| Forb | 78 | 174 | 235 |
| Shrub/Vine | 34 | 73 | 101 |
| Total | 1121 | 2466 | 3362 |
Figure 12. Plant community growth curve (percent production by month). KS7301, Big Bluestem, Little Bluestem, Sideoats Grama.
| 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 | 8 | 25 | 30 | 25 | 10 | 2 | 0 | 0 | 0 |
Community 1.2
Midgrass Community
This plant community defines a shift in plant composition, function, and structure from that of the midgrass-tallgrass community to a mid- and shortgrass community. The tallgrass big bluestem is decreasing in composition and vigor with continuous defoliation. Little bluestem is a midgrass that is increasing in composition, production, and vigor. Big bluestem will be replaced by a dominance of little bluestem, sideoats grama, and blue grama. The dominant plant in this community phase is little bluestem. Other species include sideoats grama and blue grama. If established woody species are present, they will continue to increase in composition with no implementation of prescribed fire. Timing of defoliation (grazing, wildfire, hail, etc.) will have an impact on the proportions of species within the community such as western wheatgrass, needleandthread, and sedge species. Due to a decrease in plant litter, the effective precipitation is reduced, causing a decline in total annual production compared to the Reference Plant Community. The total average annual production of this site is approximately 2,000 pounds per acre (air-dry weight).
Community 1.3
At-Risk Community
The At-Risk Plant Community is vulnerable to degradation and to exceeding the resilience limits of the Grassland State and transitioning to the Woody State. The At-Risk Community Phase is considered to be a stage in a transition process that is reversible if management is changed. This plant community defines a shift in plant composition, function, and structure from that of a Midgrass Community to a Shortgrass Plant Community. Midgrasses, such as little bluestem and sideoats grama, are decreasing in composition, production, and vigor with continuous defoliation. Midgrasses will be replaced by the shortgrasses blue grama, hairy grama, buffalograss, and various annuals, forbs, and shrubs. Increasing grazing pressure will further reduce midgrass species, shifting the plant community toward a more sod-bound blue grama and buffalograss condition. Timing of defoliation (grazing, wildfire, hail, etc.) will have an impact on the proportions of species within the community such as western wheatgrass, needleandthread, and if remnant species are present. Due to a decrease in plant litter, the effective precipitation is reduced, causing a decline in total annual production compared to the Midgrass Plant Community. Forb diversity has drastically decreased. The shrub species present will depend upon the location within the MLRA. Dependent upon establishment and use of prescribed fire, woody species could be at infestation levels greater than 15%. The total average annual production of this site is approximately 1,500 pounds per acre (air-dry weight).
Pathway 1.1 to 1.2
Community 1.1 to 1.2
The following describes the mechanisms of change from plant community 1.1 to plant community 1.2. These mechanisms include management controlled by repetitive heavy use, no rest or recovery of the key forage species, and no forage and animal balance for many extended grazing seasons. This type of management for periods greater than 10 years will shift functional and structural plant group dominance towards plant community 1.2.
Pathway 1.2 to 1.1
Community 1.2 to 1.1
The following describes the mechanisms of change from plant community 1.2 to plant community 1.1. Management (10-15 years) that includes adequate rest and recovery during the growing season of the key forage species (big bluestem, little bluestem, and sideoats grama) within the Reference Plant Community. If woody species are present, prescription fires every 4-6 years will be necessary for their removal and/or maintenance.
Conservation practices
| Prescribed Burning | |
|---|---|
| Prescribed Grazing |
Pathway 1.2 to 1.3
Community 1.2 to 1.3
The following describes the mechanisms of change from plant community 1.2 to plant community 1.3. Long term (>10years) management that includes continuous, heavy use of the native vegetation. Management void of a forage and animal balance and inadequate rest and recovery of native grasses during the growing season.
Pathway 1.3 to 1.2
Community 1.3 to 1.2
The following describes the mechanisms of change from plant community 1.3 to plant community 1.2. Management (approximately 10 years) that includes adequate rest and recovery of the key forage species in the midgrass community 1.2 (little bluestem and sideoats grama). Implement prescription fires at a frequency of 6-8 years. Dependent upon the level of woody vegetation encroachment, the fire return interval might need to be adjusted to two consecutive years of prescribed fires.
Conservation practices
| Prescribed Burning | |
|---|---|
| Prescribed Grazing |
State 2
Woody State
This state is dominated by a tree and/or shrub plant community. The increase and spread of trees results from an absence of fire. Woody plants can increase up to 34% from a lack of fire, according to a study from 1937 to 1969, in contrast to a 1% increase on burned areas (Bragg and Hulbert, 1976). Periodic burning tends to hinder the establishment of most woody species and favors forbs and grasses. However, it should be pointed out that not all unburned areas have a woody plant invasion. Hydrologic function is affected by the amount of vegetative cover. Canopy interception loss can vary from 25.4% to 36.7% (Thurow and Hester, 1997). A small rainfall event is usually retained in the foliage and does not reach the litter layer at the base of the tree. Only when canopy storage is reached and exceeded does precipitation fall to the soil surface. Interception losses associated with the accumulation of leaves, twigs, and branches at the base of trees are considerably higher than losses associated with the canopy. The decomposed material retains approximately 40% of the water that is not retained in the canopy (Thurow and Hester, 1997). Soil dynamic property changes affected include biological activity, infiltration rates, and soil fertility. Special planning will be necessary to assure that sufficient amounts of fine fuel are available to carry fires with enough intensity to control woody species. In some locations the use of chemicals as a brush management tool may be desirable to initiate and accelerate this transition. Birds, small mammals, and livestock are instrumental in the distribution of seed and accelerating the spread of most tree and shrubs common to this site. The speed of encroachment varies considerably and can occur on both grazed and non-grazed pastures. Many species of wildlife, especially bobwhite quail, turkey, and white-tailed deer benefit from the growth of trees and shrubs for both food and cover. Conversely, the presence of trees is considered detrimental to populations of greater prairie chickens and other grassland birds. When management for specific wildlife populations is desirable, these options should be considered in any brush management plan.
Community 2.1
Tree and/or Brush Community
Figure 13. Eastern redcedars, Lincoln Cty., NE. Photo by Tecklenburg.
Figure 14. Understory of eastern redcedars.
This community is dominated by trees with a canopy cover usually greater than 15-20%. The tree species characterizing this community includes eastern redcedar. When tree encroachment occurs on areas that have been subjected to long-term continuous overgrazing, the associated grasses will usually consist of composite dropseed, purpletop tridens, purple lovegrass, Kentucky bluegrass, and Scribner’s rosette grass. Trees will also invade areas where both grazing and fire have been excluded for many years. A heavy accumulation of plant mulch and litter retards herbage growth. This provides a favorable habitat for seed germination and establishment of many woody species. Grass yields are significantly reduced, by 10 to 30 percent of the total vegetative production, due to the competition from woody species. The combination of less water entering the soil and strong ability by the trees to extract water, means that little water has a chance to drain beneath the root zone. Therefore, invasion of trees (primarily juniper) and shrubs on large areas that were once primarily grassland has strong implications for recharge of aquifers. It can be a common occurrence to have seeps and springs stop flowing in conjunction with increases in tree and shrub cover (Thurow and Hester, 1997). In this plant community, the amount of available forage is heavily dependent upon the predominant woody species cover and the kind(s) of livestock and/or wildlife utilizing the site. A prescribed burning program, mechanical brush removal, and periodic rest and recovery accompanied by prescribed grazing can return the plant community to one dominated by grasses and forbs. The time frame will be dependent upon the canopy cover percentage and remnant native grass population remaining. Special planning will be necessary to assure that sufficient amounts of fine fuel are available to carry fires with enough intensity to control woody species. Use of labeled herbicides and mechanical removal as a brush management tool will usually be necessary to reduce fire-resistant populations like honeylocust in order to accelerate the recovery of desired vegetative cover. Some landowners rely on the browsing habits of goats to suppress the woody growth.
Transition 1 to 2
State 1 to 2
Changes from a Grassland State to a Woody State lead to changes in hydrologic function, forage production, dominant functional and structural groups, and wildlife habitat. Understory plants may be negatively affected by trees and shrubs by a reduction in light, soil moisture, and soil nutrients. Increases in tree and shrub density and size have the effects of reducing understory plant cover and productivity, with desirable forage grasses often being most severely reduced (Eddleman, 1983). As vegetation cover changes from grasses to trees, a greater proportion of precipitation is lost throughout interception and evaporation; therefore, less precipitation is available for producing herbaceous forage or for deep drainage or runoff (Thurow and Hester, 1997). Tree and shrub establishment becomes increasingly greater while fine fuel loads decrease. As trees and shrubs increase at levels of greater than 20 percent canopy cover, the processes and functions that allow the Woody State to become resilient are active and dominate over the processes and systems inherent of the Grassland State. Using prescription fire as a standalone management tool is unsuccessful to eradicate the trees and shrubs due to a lack of fine fuel loads.
Restoration pathway 2 to 1
State 2 to 1
Restoration efforts will be costly, labor-intensive and can take many years, if not decades, to return to a Grassland State. Once canopy levels reach greater than 20 percent, estimated cost to remove trees is very expensive and includes high energy inputs. The technologies needed in order to go from an invaded Woody State to a Grassland State include but are not limited to: prescribed burning—the use of fire as a tool to achieve a management objective on a predetermined area under conditions where the intensity and extent of the fire are controlled; brush management—manipulating woody plant cover to obtain desired quantities and types of woody cover and/or to reduce competition with herbaceous understory vegetation, in accordance with overall resource management objectives; prescribed grazing—the controlled harvest of vegetation with grazing or browsing animals managed with the intent to achieve a specified objective. Grazing at an intensity that will maintain enough cover to protect the soil and maintain or improve the quantity and quality of desirable vegetation. When a juniper tree is cut and removed, the soil structure and the associated high infiltration rate may be maintained for over a decade (Hester, 1996). This explains why the area near the dripline usually has substantially greater forage production for many years after the tree has been cut. It also explains why runoff will not necessarily dramatically increase once juniper is removed. Rather, the water continues to infiltrate at high rates into soils previously ameliorated by junipers, thereby increasing deep drainage potential. In rangeland, deep drainage amounts can be 16 percent of the total rainfall amount per year (Thurow and Hester, 1997).
Additional community tables
Table 6. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Warm-season midgrass dominant 57% | 678–1401 | ||||
| little bluestem | SCSC | Schizachyrium scoparium | 673–1233 | – | ||
| sideoats grama | BOCU | Bouteloua curtipendula | 112–247 | – | ||
| plains muhly | MUCU3 | Muhlenbergia cuspidata | 0–123 | – | ||
| Fendler threeawn | ARPUL | Aristida purpurea var. longiseta | 0–45 | – | ||
| 2 | Warm-season tallgrass subdominant 16% | 112–392 | ||||
| big bluestem | ANGE | Andropogon gerardii | 90–370 | – | ||
| switchgrass | PAVI2 | Panicum virgatum | 0–123 | – | ||
| composite dropseed | SPCOC2 | Sporobolus compositus var. compositus | 6–45 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 6–45 | – | ||
| 3 | Warm-season shortgrass minor 10% | 101–247 | ||||
| blue grama | BOGR2 | Bouteloua gracilis | 112–247 | – | ||
| hairy grama | BOHI2 | Bouteloua hirsuta | 0–123 | – | ||
| buffalograss | BODA2 | Bouteloua dactyloides | 0–123 | – | ||
| 4 | Cool-season grasses minor component 10% | 101–247 | ||||
| green needlegrass | NAVI4 | Nassella viridula | 22–247 | – | ||
| western wheatgrass | PASM | Pascopyrum smithii | 56–247 | – | ||
| needle and thread | HECOC8 | Hesperostipa comata ssp. comata | 22–123 | – | ||
|
Forb
|
||||||
| 5 | Forbs minor component 5% | 22–129 | ||||
| dotted blazing star | LIPU | Liatris punctata | 6–22 | – | ||
| white prairie clover | DACA7 | Dalea candida | 6–22 | – | ||
| upright prairie coneflower | RACO3 | Ratibida columnifera | 6–22 | – | ||
| white heath aster | SYER | Symphyotrichum ericoides | 0–11 | – | ||
| aromatic aster | SYOB | Symphyotrichum oblongifolium | 0–11 | – | ||
| stemless four-nerve daisy | TEAC | Tetraneuris acaulis | 0–11 | – | ||
| nineanther prairie clover | DAEN | Dalea enneandra | 0–11 | – | ||
| purple prairie clover | DAPU5 | Dalea purpurea | 0–11 | – | ||
| blacksamson echinacea | ECAN2 | Echinacea angustifolia | 0–11 | – | ||
| stiffstem flax | LIRI | Linum rigidum | 0–11 | – | ||
| rush skeletonplant | LYJU | Lygodesmia juncea | 0–11 | – | ||
| Nuttall's sensitive-briar | MINU6 | Mimosa nuttallii | 0–11 | – | ||
| common evening primrose | OEBI | Oenothera biennis | 0–11 | – | ||
| scarlet beeblossom | OESU3 | Oenothera suffrutescens | 0–11 | – | ||
| white penstemon | PEAL2 | Penstemon albidus | 0–11 | – | ||
| silverleaf Indian breadroot | PEAR6 | Pediomelum argophyllum | 0–11 | – | ||
| beardtongue | PENST | Penstemon | 0–11 | – | ||
| slimflower scurfpea | PSTE5 | Psoralidium tenuiflorum | 0–11 | – | ||
| Cuman ragweed | AMPS | Ambrosia psilostachya | 0–11 | – | ||
| yellow sundrops | CASE12 | Calylophus serrulatus | 0–11 | – | ||
|
Shrub/Vine
|
||||||
| 6 | Shrubs and Cacti trace component 2% | 0–50 | ||||
| soapweed yucca | YUGL | Yucca glauca | 11–28 | – | ||
| western snowberry | SYOC | Symphoricarpos occidentalis | 0–17 | – | ||
| leadplant | AMCA6 | Amorpha canescens | 0–17 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 0–17 | – | ||
| plains pricklypear | OPPO | Opuntia polyacantha | 0–17 | – | ||
| skunkbush sumac | RHTR | Rhus trilobata | 0–17 | – | ||
| prairie rose | ROAR3 | Rosa arkansana | 0–11 | – | ||
Interpretations
Animal community
Wildlife Interpretations
This ecological site is on the sides of upland ridges that are dissected by deeply entrenched drainageways. Slopes are generally greater than 30 percent. The steep slopes make farming this site difficult, if not impossible, leaving the majority of these sites in native vegetation.
Historically, the predominance of grasses, forbs, and shrubs on this site supported grazers and mixed feeders such as bison, elk, deer, and pronghorn and a variety of grassland-associated birds and small mammals. Due to the heterogeneity inherent in all landscapes, some areas were not grazed uniformly by these historic large herds of grazing animals. This type of grazing enhanced habitat for wildlife by creating a mosaic pattern, or patchiness, of vegetative structural diversity throughout the landscape. Wildlife native to the site depend upon a plant community diverse in species and structure. This need is evident in the variability of known habitat requirements of grassland-associated wildlife. Low-growing shrubs offer escape and thermal cover for several species of wildlife. The southern exposure of this site often provides protection from cold winter winds for birds, mammals, insects, and reptiles. Animals, such as the coyote and fox, often prefer this site for denning and loafing as it affords easy digging and visual protection.
Periodic events such as prolonged drought, wildfire, disease, or high insect numbers will alter plant community diversity and structure and associated wildlife species. Plant community structure is highly dependent upon rainfall since the water-holding capacity of the site is very low.
Grazing Interpretations
Historical overgrazing has been the key element that has affected the declining condition on many range sites. It is during periods of overstocking that many of the preferred species are taken out of these sites, reducing production, vigor, and diversity. Many new grazing systems are being tested and tried, utilizing stocking rates, timing, stocking density, positive animal impacts, and other factors to enhance ecological site condition.
Calculating Safe Stocking Rates: Proper stocking rates should be incorporated into a grazing management strategy that protects the resource, maintains or improves rangeland health, and is consistent with management objectives. In addition to usable forage, safe stocking rates should consider ecological condition, trend of the site, past grazing use history, season of use, stock density, kind and class of livestock, forage digestibility, forage nutritional value, variation of harvest efficiency based on desirability preference of plant species and/or grazing system, and site grazeability factors (such as steep slopes, site inaccessibility, or distance to drinking water).
Often the current plant community does not entirely match any particular community phase as described in this Ecological Site Description. Because of this, a resource inventory is necessary to document plant composition and production. Proper interpretation of inventory data will permit the establishment of a safe initial stocking rate.
No two years have exactly the same weather conditions. For this reason, year-to-year and season-to season fluctuations in forage production are to be expected on grazing lands. Livestock producers must make timely adjustments in the numbers of animals or in the length of grazing periods to avoid overuse of forage plants when production is unfavorable and to make advantageous adjustments when forage supplies are above average.
Initial stocking rates should be improved through the use of vegetation monitoring and actual use records that include number and type of livestock, the timing and duration of grazing, and utilization levels. Actual use records over time will assist in making stocking rate adjustments based on the variability factors.
Average annual production must be measured or estimated to properly assess useable forage production and stocking rates.
Hydrological functions
Water is the principal factor limiting forage production on this site. Infiltration and runoff potential for this site varies from low to high. 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.
Recreational uses
This site provides hunting, hiking, photography, bird watching, and other opportunities. The wide varieties of plants that bloom from spring until fall have an aesthetic value that appeals to visitors.
Wood products
No appreciable wood products are present on the site.
Other products
None noted.
Other information
Site Development and Testing Plan
This site went through the approval process.
Supporting information
Inventory data references
Information presented here has been derived from NRCS clipping data, numerous ocular estimates and other inventory data. Field observations from experienced range trained personnel were used extensively to develop this ecological site description.
NRCS individuals involved in developing the Loess Breaks MLRA72 (South) ESD in 2001 include Tim Watson, Amanda Shaw, Susan Francis, Jon Deege, and Robert Schiffner from Kansas; Josh Saunders and Harvey Sprock from Colorado.
NRCS individuals involved in developing the Loess Breaks MLRA 72(North) ESD in 2001 include: Harvey Sprock from Colorado. Carol Eakins, Chuck Markley, Jeff Nichols, and Mary Schrader from Nebraska. Joan Gienger and Ted Houser from Kansas.
Range Condition Guides and Technical Range Site Descriptions for Kansas, Loess Breaks, USDA, Soil Conservation Service, August, 1967
Range Site Description for Kansas, Loess Breaks, USDA-Soil Conservation Service, September, 1983
Range Site Description for Nebraska, Thin Loess, USDA-Soil Conservation Service, August, 1981 Schacht, Walter H., Larsen, Dana. Section III
Ecological Site Description for Kansas, Loess Breaks North (R072XA016KS) and South (R072XB016KS), located in Ecological Site Information System (ESIS), 2007
Other references
Brady, N. and Weil R., 2008, The nature and properties of soils, 14th ed.
Bragg, T. and Hulbert, L., 1976. Woody plant invasion of unburned Kansas bluestem prairie. J. Range Management., 29:19-23.
Choate, J., and Fleharty, E., 1975. Synopsis of native, recent mammals of Ellis County, Kansas. Occasional Papers. The Museum, Texas Tech University. 37: 1-80.
Dyksteruis, E.J. 1958. Range conservation as based on sites and condition classes. J. Soil and Water Conserv. 13: 151-155.
Eddleman, L. 1983. Some ecological attributes of western juniper. P. 32-34 in Research in rangeland management. Agric. Exp. Stan. Oregon State Univ., Corvallis Spec. Rep. 682.
Hattin, D., 1962. Stratigraphy of the Carlile shale (upper cretaceous) in Kansas. Univ. Kans. Pub., State Geol. Survey of Kansas Bull. 156. 155 p.
Hester, J.W., 1996. Influence of woody dominated rangelands on site hydrology and herbaceous production, Edwards Plateau, Texas. M.S. Thesis, Texas A&M University, College Station, TX.
Holechek, J., Pieper, R., Herbel, C., Range Management: principles and practices.—5th ed.
Kuchler, A., A New Vegetation Map of Kansas. Ecology (1974) 55: pp. 586-604.
Launchbaugh, J., Owensby, C., Kansas Rangelands, Their Management Based on a Half Century of Research, and Bull. 622 Kansas Agricultural Experiment Station, October 1978.
Moore, R., Frye, J., Jewett, J., Lee, W., and O'Connor. H., 1951. The Kansas rock column. Univ. Kans. Pub., State Geol. Survey Kans. Bull. 89. 132p.
National Range and Pasture Handbook, USDA-NRCS, Chapter 7, Rangeland and Pastureland Hydrology and Erosion.
National Climatic Data Center, Weather data, web site http://www.ncdc.noaa.gov/. Available online. Accessed 4/12/2017.
Rangeland Cover Types of the United States, Society for Range Management 1994.
Swineford, A., McNeal, J., and Crumpton, C., 1954. Hydrated halloysite in the Blue Hill shale, pp. 158-170. From clay and clay minerals (2nd conf.). Natl. Acad. Sci.—Nat. Res. Council Pub. 327.
Soil Series—Official Series Descriptions, https://soilseries.sc.egov.usda.gov/osdname.asp. Available online. Accessed 4/12/2017.
Sauer, Carl, Grassland climax, fire, and man. 1950, J. Range Manage. 3: 16-21.
Thurow, T. and Hester, J., 1997. How an increase or reduction in juniper cover alters rangeland hydrology, In: C.A. Taylor, Jr. (ed.). Proc. 1997 Juniper Symposium. Texas Agr. Exp. Sta. Tech. Rep. 97-1. San Angelo, TX: 4:9-22.
USDA-Natural Resources Conservation Service—Soil Surveys and Web Soil Survey. Available online. Accessed 4/12/2017.
USDA Handbook 296, LRR and MLRA of the U.S., the Caribbean, and the Pacific Basin.
Waller, S., Moser, L., Reece, P., and Gates, G., Understanding Grass Growth 1985.
Weaver, J. and Albertson, F., Deterioration of Midwestern Ranges, Ecology, Vol. 21, No. 2, April 1940, pp. 216-236.
Contributors
Chris Tecklenburg
Approval
David Kraft, 10/02/2019
Acknowledgments
The ecological site development process is a collaborative effort, conceptual in nature, dynamic and is never considered complete. I thank all those who set the foundational work in the early 2000s in regards to this ESD. I thank all those who contributed to the development of this site. In advance, I thank those who would provide insight, comments and questions about this ESD in the future.
Non-discrimination Statement
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Persons with disabilities who require alternative means of communication for program information (e.g., Braille, large print, audiotape, American Sign Language, etc.) should contact the responsible Agency or USDA’s TARGET Center at (202) 720-2600 (voice and TTY) or contact USDA through the Federal Relay Service at (800) 877-8339. Additionally, program information may be made available
in languages other than English.
To file a program discrimination complaint, complete the USDA Program Discrimination Complaint Form, AD-3027, found online at How to File a Program Discrimination Complaint and at any USDA office or write a letter addressed to USDA and provide in the letter all of the information requested in the form. To request a copy of the complaint form, call (866) 632-9992. Submit your completed form or letter to USDA by:
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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) |
Chris Tecklenburg Revision 3-16-2017 from MLRA 72 Loess Breaks David Kraft, John Henry, Doug Spencer and Dwayne Rice Original Authors 2-2005 |
|---|---|
| Contact for lead author | Chris Tecklenburg (chris.tecklenburg@ks.usda.gov) |
| Date | 10/02/2019 |
| Approved by | David Kraft |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Slight evidence of rills may exist on steeper slopes. -
Presence of water flow patterns:
Typically none, if present (steeper slopes following intense storms) Short and not connected. -
Number and height of erosional pedestals or terracettes:
None to slight, in or near water flow paths. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
5-10% bare ground, with bare patches generally less than 6-8 inches in diameter. Extended drought can cause bare ground to increase upwards to 10-20% with bare patches reaching upwards to 8-12 inches in diameter. Cross-sectional viewing of this site appears to have more bare ground than vertical viewing due to exposed loess-steps. -
Number of gullies and erosion associated with gullies:
There are few, if any, gullies and there is no active headcutting and sides are covered with vegetation. -
Extent of wind scoured, blowouts and/or depositional areas:
Slight wind scouring is possible on areas of exposed loess. -
Amount of litter movement (describe size and distance expected to travel):
Movement of 1-3 feet is possible following intense rain storms. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Stability class rating anticipated to be 3-5 in interspaces at soil surface. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Average SOM is 0.5-1%. Soils are very deep. Surface texture is silt loam. The A-horizon is 0-4 inches in depth. Soil color is dark grayish brown (10YR 4/2) moist, weak fine platy structure to a depth of 2 inches, weak fine granular structure below 2 inches; strong effervescence. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Diverse grass, forb, shrub canopy, and root structure reduces raindrop impact and slows overland flow, providing increased time for infiltration to occur. Extended drought reduces short-, mid-, and bunchgrasses causing decreased infiltration and increased runoff following intense storms. However, exposed loess has more of an effect on infiltration and runoff than the composition of the plant community on steeper slopes. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None -
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:
Warm-season midgrass dominant 57%. Little bluestem 600-1100, sideoats grama 100-220, plains muhly 0-110, Fendler threeawn 0-40Sub-dominant:
Warm-season tallgrass subdominant 16%. Big bluestem 80-330, switchgrass 0-110, composite dropseed 5-40, sand dropseed 5-40Other:
Warm-season shortgrasses minor 10%. Blue grama 100-220, buffalograss 0-110, hairy grama 0-110.
Cool-season grasses minor 10%. Needle and thread 20-110, green needlegrass 20-220, western wheatgrass 50-220Additional:
Forbs minor component 5%
Shrubs and cacti trace 2% -
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Typically minimal. Expect slight mortality/decadence during and following drought, fire and/or long-term lack of disturbance. -
Average percent litter cover (%) and depth ( in):
35-45% litter cover at 0.25 inch depth. Litter cover during and following extended drought ranges from 15-30%. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
1000 lbs./ac. low precip years, 3000 lbs./ac. average precip years, 2200 lbs./ac. above average precip years. After extended drought or the first growing season following wildfire, production may be significantly reduced by 450 – 750 lbs./ac. or more. -
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:
Invasive plants should not occur in the Reference Plant Community. However, cheatgrass, Russian thistle, kochia, other non-native annuals will invade following extended drought assuming a seed source is available. Blue grama, little bluestem, hairy grama, sand dropseed, red threeawn, threadleaf sedge, milkvetches, and small soapweed are the major native (non-invasive) increasers on this site. -
Perennial plant reproductive capability:
The number and distribution of tillers or rhizomes is assessed on perennial plants occupying the evaluation area. No reduction in vigor or capability to produce seed or vegetative tillers given the constraints of climate and herbivory.
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