Natural Resources
Conservation Service
Ecological site R075XY059NE
Limy Loess Slopes
Accessed: 11/13/2024
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.
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): 075X–Central Loess Plains
Named “The Central Loess Plains,” MLRA 75 is located primarily in south-central Nebraska, with about 10 percent lying in north-central Kansas. The approximately 5.3 million acre landscape covers all or parts of 21 counties: mainly Phelps, Kearney, Adams, Clay, Fillmore, York, Hamilton, Seward, Butler, Saline, Thayer, Nuckolls, and Webster in Nebraska, with a significant presence in Republic and Washington counties in Kansas. The physical appearance primarily consists of gently rolling plains, with a number of narrow, shallow stream valleys. The river valleys are broader, and most feature a number of terraces. The northern border is defined by the Platte River. This MLRA is home to the unique ecological system called “The Rainwater Basin,” which is comprised of a 24,000 acre network of wetlands and uplands that occupy portions of 13 of the northern counties.
The elevation in MLRA 75 ranges from nearly 2,600 to less than 1,100 feet above sea level. The local relief averages from 10 to 25 feet, but may stretch to a maximum of 165 feet in some areas.
The predominate soil orders in this geographic area are mesic, ustic Mollisols, commonly represented by the Geary, Hastings, Holder, Holdrege, Kenesaw, Coly, and Uly soil series.
Loess overlays the surface of almost all of the uplands in this MLRA. Alluvial clay, silt, sand, and gravel are deposited in the stream and river valleys, and can be extensive in the major drainages. Terraces are common in the valleys along the river systems.
The average annual precipitation ranges from 23 to 36 inches, and the number of freeze-free days range from 150 to 200.
The matrix vegetation type is mixed-grass prairie, with big and little bluestem, switchgrass, Indiangrass, and sideoats and blue grama make up the bulk of the warm-season species, while western wheatgrass is the dominant cool-season grass.
Seventy two percent of the land in this MLRA has been broken out of native prairie and farmed; the land is primarily planted to corn, wheat, and grain sorghum, while only eighteen percent of the grasslands remain intact. Livestock grazing, primarily by cattle, is the main industry on these remnants. Irrigation of croplands uses over 90 percent of the total annual water withdrawal in this area.
Wildlife flourishes in this combination of crop and grassland environment, with both mule and white-tailed deer being the most abundant wild ungulates. A variety of smaller species, including coyote, raccoon, opossum, porcupines, muskrat, beaver, squirrel, and mink thrive in the region, as well as several upland bird species. Grassland bird populations are somewhat limited by the lack of contiguous native prairie and fragmented habitat created by the farmland.
The rivers, streams, and lakes harbor excellent fisheries, and an estimated tens of millions of migrating and local waterfowl use the wetland complexes. These complexes provide ideal habitat for a number of wading and shore bird species as well.
This landscape serves as a backdrop for a disturbance-driven ecosystem, evolving under the influences of herbivory, fire, and variable climate. Historically, these processes created a heterogeneous mosaic of plant communities and structure heights across the region. Any given site in this landscape experienced fire every 6 to 8 years. The 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. These people understood the value of fire as a tool, and that the highly palatable growth following a fire provided both excellent forage for their horses, and attracted grazing game animals such as bison and elk.
Even as post-European settlement's alteration of the fire regime allows the expansion of the woody component of the native prairie, introduction of eastern redcedar (ERC) as a windbreak species further facilitates invasion by this species.
While eastern redcedar is native to Nebraska, the historic population in MLRA 75 was limited to isolated pockets in rugged river drainages that were subsequently insulated from fire. Widespread plantings of windbreaks with eastern redcedar as a primary component have provided a seed source for the aggressive woody plant. The ensuing encroachment into the native grasslands degrades the native wildlife habit and causes significant forage loss for domestic livestock. However, since it is not a root sprouter, eastern redcedar is very susceptible to fire when under six feet tall. Management with prescribed fire is exceedingly effective if applied before this stage.
Larger redcedars can also be controlled with fire, but successful application requires the use of specifically designed ignition and holding techniques.
Fragmentation of the native grasslands by conversion to cropland, transportation corridors, and other developments have effectively disrupted the natural fire regime of this ecosystem. This has allowed encroachment by native and introduced shrubs and trees into the remnants of the native prairie throughout the MLRA. Aggressive fire suppression policies have exacerbated this process to the point that shrub and tree encroachment is a major ecological issue in the majority of both native and re-seeded grasslands.
Classification relationships
NRCS FOTG Section 1 - Nebraska Vegetation Zone 3.
Major Land Resource Area (MLRA): Major Land Resource Area (MLRA) 75 (USDA-Natural Resources Conservation Service, 2006)
Revision Notes:
A PROVISIONAL ECOLOGICAL SITE is a conceptual grouping of soil map unit components within a Major Land Resource Area (MLRA) based on the similarities in response to management. Although there may be wide variability in the productivity of the soils grouped into a Provisional Site, the soil vegetation interactions as expressed in the State and Transition Model are similar and the management actions required to achieve objectives, whether maintaining the existing ecological state or managing for an alternative state, are similar. Provisional Sites are likely to be refined into more precise group during the process of meeting the APPROVED ECOLOGICAL SITE DESCRIPTION criteria.
Ecological site concept
Limy Loess Slopes occupies a run-off position on the landscape on slopes of less than 30 percent. The soils associated with this site are effervescent due to the presence of calcium carbonate at or within 10 inches of the surface.
Associated sites
R075XY050NE |
Loamy Terrace Loamy Terrace: Located below and adjacent to the Limy Loess Slopes site. |
---|---|
R075XY058NE |
Loamy Plains Loamy Plains: Often located adjacent to Limy Loess Slopes, but is not effervescent. |
Similar sites
R075XY063NE |
Loess Breaks Loess Breaks: This site occupies a similar landscape position and has the same soils as Limy Loess Slopes, but has a slope of greater than 30%. |
---|---|
R075XY058NE |
Loamy Plains Loamy Plains: Often located adjacent to Limy Loess Slopes, but is not effervescent. |
Table 1. Dominant plant species
Tree |
Not specified |
---|---|
Shrub |
Not specified |
Herbaceous |
(1) Andropogon gerardii |
Physiographic features
Limy Loess Slopes occurs on nearly level to steeply sloping uplands or high terraces. The soils that house this site are very deep upland soils with silty (or loamy) surface layers and subsoils. On all slopes a primary identifying feature for this site is the presence of calcium carbonate at or within ten inches the soil surface. This site produces runoff to areas lower on the landscape and is subject to severe erosion by water in the absence of adequate vegetation. Livestock trailing on this site often leads to the formation of gullies.
Figure 2. Block Diagram
Table 2. Representative physiographic features
Landforms |
(1)
Hill
(2) Plain |
---|---|
Elevation | 1,130 – 2,765 ft |
Slope | 30% |
Water table depth | 80 in |
Aspect | Aspect is not a significant factor |
Climatic features
Like most Great Plains landscapes, the climate in this MLRA is under the sway of the continental effect. This creates a regime of extremes, with summer highs often in the triple digits, and winter lows plunging well below zero. Blizzards can occur anytime between early fall and late spring, often dropping the temperature more than 50 degrees in just a few hours. These events can pile up several feet of snow, often driven by winds in excess of 50 miles an hour. The resulting huge snow drifts can cause serious hardship for livestock, wildlife, and humans. Winters can be open, with bare ground for most of the season, or closed, with up to several feet of snow persisting until March. Most winters have a number of warm days, interspersed with dropping temperatures, usually associated with approaching cold fronts. Spring brings violent thunderstorms, hail, and high winds. Tornadoes occur frequently.
Daily winds range from an average of 14 miles per hour during the spring to 11 miles per hour during the late summer. Occasional strong storms may bring brief periods of high winds with gusts to more than 80 miles per hour.
Growth of native cool-season plants begins in early April and continues to about mid-June. Native warm-season plants begin growth in early June, and continue to early August. Green-up of cool-season plants may occur in September and October.
Table 3. Representative climatic features
Frost-free period (average) | 155 days |
---|---|
Freeze-free period (average) | 177 days |
Precipitation total (average) | 30 in |
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
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(1) AURORA [USC00250445], Aurora, NE
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(2) CLAY CTR [USC00251684], Saronville, NE
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(3) MINDEN [USC00255565], Minden, NE
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(4) RED CLOUD [USC00257070], Red Cloud, NE
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(5) SUPERIOR 4E [USC00258320], Hardy, NE
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(6) SURPRISE [USC00258328], Surprise, NE
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(7) BELLEVILLE [USC00140682], Belleville, KS
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(8) FRIEND 3E [USC00253065], Friend, NE
-
(9) HEBRON [USC00253735], Hebron, NE
-
(10) OSCEOLA [USC00256375], Osceola, NE
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(11) RAGAN [USC00257002], Alma, NE
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(12) FAIRMONT [USC00252840], Fairmont, NE
-
(13) HASTINGS 4N [USC00253660], Hastings, NE
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(14) YORK [USC00259510], York, NE
-
(15) GENEVA [USC00253175], Geneva, NE
Influencing water features
This site is an upland site and functions independently from ground and surface
water features.
Soil features
These very deep soils are characterized by thin (<7 inches) surface layers. (Under cultivation calcium carbonate is usually at the surface and throughout the entire soil depth, but often is leached in the upper 3 to 6 inches in non-cultivated areas.) Soil texture for both surface and subsoil layers of these soils range from silty to loamy. Organic matter content is generally low to moderately low in the surface layer.
Coly is the only major soil series associated with this ecological site.
Figure 7. Coly Soil Profile
Table 4. Representative soil features
Surface texture |
(1) Silt loam (2) Loam (3) Very fine sandy loam |
---|---|
Family particle size |
(1) Loamy |
Drainage class | Well drained |
Permeability class | Slow to moderate |
Soil depth | 60 – 80 in |
Available water capacity (0-40in) |
5.7 – 9.2 in |
Calcium carbonate equivalent (0-40in) |
6% |
Soil reaction (1:1 water) (0-40in) |
5.1 – 8.4 |
Subsurface fragment volume <=3" (Depth not specified) |
15% |
Ecological dynamics
Limy Loess Slopes sites developed under Northern Great Plains climatic conditions, light to severe grazing by bison and other large herbivores, sporadic natural or man-caused wildfires, and other biotic and abiotic factors which typically influence soil/site development. This continues to be a disturbance-driven site, by herbivory, fire, and variable climate. Changes occur in the plant communities due to weather variations, impacts of native and/or exotic plant and animal species, and management actions.
One of the primary impacts to this site introduced by European-man is season-long continuous grazing by domestic livestock. This management practice causes the repeated removal of the growing point and excessive defoliation of the leaf area of individual tall warm-season grasses. The resulting reduction of the ability of the plants to harvest sunlight depletes the root reserves, subsequently decreasing the root mass. This negatively impacts the ability of the plants to compete for life-sustaining nutrients, resulting in declining vigor and eventual mortality. The space created in the vegetative community is then occupied by a species that evades the negative grazing impacts by a growing season adaptation (such as a cool season), a shorter structure, or a reduced palatability mechanism.
The State-and-Transition Model (STM) is depicted below, and is made up of a Reference State, a Native/Invaded State, a Sod-busted State, and an Invaded Woody State. Each state represents the crossing of a major ecological threshold due to alteration of the functional dynamic properties of the ecosystem. The main properties observed to determine this change are the soil and vegetative communities and the hydrological cycle.
Each state may have one or more vegetative communities which 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.
Interpretations are primarily based on the Reference State, and have 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 have been interpreted from heavily grazed to lightly grazed areas, seasonal use pastures, and historical accounts. Plant communities, states, transitional pathways, and thresholds have been determined through similar studies and experience.
Growth of native cool-season plants begins about April 1, 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.
The species distribution and abundance on this site are also influenced by the degree of inclination and aspect of the local topography. Northern and eastern slopes typically are cooler and wetter, generally producing more biomass than the drier and warmer exposures. Severe inclines receive less grazing pressure than the more moderate slopes.
The following is a diagram illustrating the common plant communities that can occur on the site and the transition pathways between communities.
State and transition model
Figure 8. State and Transition Model
Figure 9. Limy Loess Slopes STM Legend
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
State 1 submodel, plant communities
Communities 1, 5 and 2 (additional pathways)
State 2 submodel, plant communities
State 3 submodel, plant communities
State 4 submodel, plant communities
State 1
Reference State
This state describes the range of vegetative community phases that occur on the Limy Loess Slopes site where the natural processes are mostly intact. The Reference Community is a representation of the native plant community phase that occupies a site that has been minimally altered by management. The Degraded Native Grass, the At-Risk Native Grass, and the Excessive Litter Communities are the phases that result from management decisions that are unfavorable for a healthy Reference Community. The Ephemeral Forb Community is the result of a high intensity disturbance event. High perennial grass cover and production allows for increased soil moisture retention, vegetative production, and overall soil quality.
Community 1.1
Mixed Native Grass
The Mixed Native Grass 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. This phase is dynamic, with fluid relative abundance and spatial boundaries between the dominant structural vegetative groups. These fluctuations are primarily driven by different responses of the species to changes in precipitation timing and abundance, and fire and grazing events. The potential vegetation consists of approximately 70-90 percent grasses and grass-like plants, 5-10 percent forbs, and 5-10 percent shrubs. Big bluestem, little bluestem, and sideoats grama are the primary species in this community. Secondary species include blue grama, and Indiangrass. Western wheatgrass occurs as a secondary species in the western portion of the MLRA. The site has a very diverse forb population. This plant community is highly productive, diverse, and resistant to short term stresses such as drought and short periods of heavy stocking. The well-developed root systems support resiliency when allowed adequate recovery periods between grazing events. When exposed to long-term or frequent over-grazing events without adequate rest, this plant community will degrade. Total annual production ranges from 2,000 to 3,250 pounds of air dry vegetation per acre.
Figure 10. 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 | 1845 | 2349 | 2840 |
Forb | 131 | 197 | 263 |
Shrub/Vine | 25 | 79 | 135 |
Total | 2001 | 2625 | 3238 |
Figure 11. Plant community growth curve (percent production by month). NE7501, Central Loess Plains, warm season dominant. Native warm season dominant growth curve MLRA 75.
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 | 3 | 7 | 21 | 33 | 18 | 8 | 6 | 3 | 1 | 0 |
Community 1.2
Degraded Native Grass Community
Little bluestem and sideoats grama are the dominant grasses. Big bluestem is declining, and this community phase signals a significant loss of production. This is due to continuous season-long grazing with inadequate recovery periods. Grazing-evasive warm-season and cool-season grasses increase. The composition of the forb component remains diverse, but the potential for encroachment by invasive woody species becomes more likely, due to fewer deep rooted species and a reduced fuel load to carry fire. While this plant community is less productive and less diverse than the representative plant community, it remains sustainable in regards to site/soil stability, watershed function, and biologic integrity. Total annual production ranges from 1,600 to 2,800 pounds of air dry vegetation per acre.
Figure 12. Plant community growth curve (percent production by month). NE7501, Central Loess Plains, warm season dominant. Native warm season dominant growth curve MLRA 75.
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 | 3 | 7 | 21 | 33 | 18 | 8 | 6 | 3 | 1 | 0 |
Community 1.3
At-Risk Native Grass Community
In this plant community, the more palatable tall warm-season grasses have been reduced to remnant populations by continued defoliation during their critical growth periods. Grazing-evasive warm-season and cool-season grasses increase significantly. Blue grama, sideoats grama and composite dropseed are the dominant warm season grasses. Bluegrass encroachment also occurs on flatter slopes. Soil health is affected by reduced efficiency in the nutrient, mineral, and hydrologic cycles as a result of decreases in plant litter and rooting depths. Total annual vegetative production declines to an average of 1,800 lbs./acre. Without a management change, this community is at-risk to degrade to the Native/Invaded Grass State.
Figure 13. Plant community growth curve (percent production by month). NE7502, Central Loess Plains, warm season at risk. Native warm season at risk, reduced tall warm season grasses with increased cool season grasses, growth curve MLRA 75.
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 | 3 | 10 | 21 | 26 | 18 | 10 | 8 | 3 | 1 | 0 |
Community 1.4
Excessive Litter Community
The Excessive Litter Community Phase describes the response of the community to the removal of the natural disturbances of herbivory and fire. As the undisturbed duff layer deepens, infiltration of the precipitation is interrupted and evaporation increases significantly, simulating drought-like conditions.
Community 1.5
Ephemeral Forb Community
This community describes the flush of forbs that occurs in response to a major disturbance, or combination of disturbances. Growing season wildfire followed by hail, extreme prolonged drought, or extreme defoliation by herbivores are all examples of these disturbances. The native warm-season grasses re-establish dominance with-in a few years of the event.
Pathway CP 1.1-1.2
Community 1.1 to 1.2
A shift from the Mixed Native Grass to the Degraded Native Grass community occurs with continuous season long grazing and inadequate recovery periods during the growing season.
Pathway CP 1.2-1.1
Community 1.2 to 1.1
A shift from the Degraded Native Grass community toward the Reference community can be achieved through prescribed grazing. Applying grazing pressure during the growth period of the undesirable cool season grasses, and allowing rest during the warm season growing season favors our desired species. This grazing regime will enable the deeply rooted tall warm season grasses to out compete the shallow rooted grazing evasive warm season and the cool season grasses. Appropriately timed prescribed fire will accelerate this process.
Conservation practices
Access Control | |
---|---|
Prescribed Grazing |
Pathway CP 1.3-1.2
Community 1.3 to 1.2
Reversing the downward trend to the previous community can be achieved with prescribed grazing early and late in the growing season to reduce undesirable cool season grasses. Targeting the peak growth period of cool season grasses with high intensity grazing events followed by rest will allow the tall native warm season grasses to rejuvenate. Appropriately timed prescribed fire will accelerate this process.
Conservation practices
Access Control | |
---|---|
Prescribed Grazing |
Pathway CP 1.4-1.1
Community 1.4 to 1.1
Re-introduction of the natural processes of herbivory and fire will allow the vegetation to return to the previous community.
Pathway CP 1.4-1.2
Community 1.4 to 1.2
Re-introduction of the natural processes of herbivory and fire will allow the vegetation to return to the previous community.
Pathway CP 1.4-1.3
Community 1.4 to 1.3
Re-introduction of the natural processes of herbivory and fire will allow the vegetation to return to the previous community.
Pathway CP 1.4-1.5
Community 1.4 to 1.5
A high-impact disturbance event, or combination of events causing excessive defoliation of the vegetation, i.e. a growing season wildfire followed by a significant hailstorm, or a prolonged intensive grazing event, or long-term drought, etc.
Pathway CP 1.5-1.1
Community 1.5 to 1.1
Restoration occurs naturally once the disturbance event has subsided. Allowing growing season rest will accelerate the recovery.
Pathway CP 1.5-1.2
Community 1.5 to 1.2
Restoration occurs naturally once the disturbance event has subsided. Allowing growing season rest will accelerate the recovery.
State 2
Native/Invaded Grass State
This state has been degraded from the Reference State and much of the native warm-season grass community has been replaced by less desirable plants. The loss of tall and mid- warm-season grasses has negatively impacted energy flow and nutrient cycling. Water infiltration is reduced due to the shallow root system and rapid runoff characteristics of the grazing-evasive plant communities. The Native Evaders/Invasives and the Smooth Bromegrass communities are the components of the Native/Invaded Grass State.
Community 2.1
Native Evaders/Invaded Grass
This plant community represents a shift from the Reference State across a plant community threshold. With continued grazing pressure, blue grama, Kentucky bluegrass, and composite dropseed will become the dominant plant species, with only trace remnants of the more palatable mid-warm-season grasses such as sideoats grama and little bluestem. Composite dropseed is a grazing-evasive warm-season mid-grass with low palatability. Continuous and heavy grazing pressure will maintain this plant community in a sod-bound condition. Forb richness and diversity has decreased. With the decline and loss of deeper penetrating root systems, a compacted layer may form in the soil profile below the more shallow replacement root systems. Grazing management practices that allow for adequate periods of recovery between grazing events will favor mid and tall warm-season grasses. Appropriately timed prescribed fire will accelerate the restoration process. Total annual production ranges from 500 to 900 pounds of air dry vegetation per acre.
Figure 14. Plant community growth curve (percent production by month). NE7503, Central Loess Plains, warm season/cool season co-dominant. Native warm season plant community encroached with cool season grasses growth curve MLRA 75.
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 | 3 | 9 | 27 | 25 | 12 | 10 | 10 | 3 | 1 | 0 |
Community 2.2
Smooth Bromegrass
This plant community contains predominately smooth bromegrass but also contains some native warm-season grass remnants. Production of smooth bromegrass-dominated plant communities is highly variable, depending upon the percentages of composition present and outside inputs such as fertilizer and weed control. Production can range from 2,200 lbs./acre to 2,900 pounds/acre in normal years on rangelands with a smooth bromegrass component of 50 percent or more. Clipping or ocular estimates of production should be conducted to verify current annual production.
Figure 15. Plant community growth curve (percent production by month). NE7504, Central Loess Plains, cool season dominant, warm season remnants. Cool season, smooth brome with native warm season remnants, plant community growth curve MLRA 75.
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 | 2 | 13 | 29 | 19 | 7 | 10 | 13 | 6 | 1 | 0 |
Pathway CP 2.1-2.2
Community 2.1 to 2.2
This community will be converted to a Smooth Bromegrass community through the following practices: introduced grass seeding, excessive warm season grazing, inadequate warm season rest, multi season haying and nitrogen fertilizing in spring and/or fall.
Pathway CP 2.2-2.1
Community 2.2 to 2.1
Restoration can be achieved by herbicide treatment and reseeding. If adequate native remnants are present, appropriately timed prescribed fire and a follow-up prescribed grazing program may achieve the desired results.
State 3
Sod-busted State
This threshold is crossed as a result of mechanical disturbance to facilitate production agriculture. If farming operations are suspended, the site can be abandoned, which will result in the Naturally Reclaimed Community, or be re-seeded to a desired perennial forage mixture, which is described as the Re-seeded Community. Permanent alterations of the soil community and the hydrological cycle make restoration to the original native Reference Community extremely difficult, if not impossible. Formation of a compacted plow pan in the soil profile is likely.
Community 3.1
Re-Seeded Grass
This plant community does not contain native remnants, and varies considerably depending on the seed mixture, the degree of soil erosion, the age of the stand, nitrogen fertilizer use, and past grazing management. Prescribed grazing with adequate recovery periods will be needed to maintain productivity and desirable species. Native range and seeded grasslands are ecologically different, and should be managed separately. Factors such as functional group, species, stand density, and improved varieties all impact the production level and palatability of the seedings. Species diversity is often limited, and when grazed in conjunction with native rangelands, uneven forage utilization may occur. Total annual production during an average year varies significantly depending on precipitation, management and grass species seeded. Single species stands of Big bluestem, Indiangrass or Switchgrass or well managed cool season grasses/legume plantings with improved varieties yield 3000-4000 lbs/acre/year.
Community 3.2
Natural Reclamation
This plant community consists of annual and perennial weeds and less desirable grasses. These sites have been farmed and abandoned without being reseeded. Soil organic matter/carbon reserves are reduced, soil structure is changed, and a plow-pan or compacted layer can be formed which decreases water infiltration. Residual synthetic chemicals may remain from farming operations. In early successional stages, this community is not stable. Erosion is a concern. Total annual production during an average year varies significantly depending on the succession stage of the plant community and any management applied to the system.
State 4
Invaded Woody State
Once the tree canopy cover reaches 15 percent with an average tree height exceeding 5 feet, the threshold is crossed to the Invaded Woody State. The primary coniferous interloper is Eastern redcedar. Locust, elm and green ash number among the deciduous native trees, along with several exotic introduced species. These woody species are encroaching due to lack of prescribed fire and other brush management practices. Typical ecological impacts are a loss of native warm season grasses, degraded forage productivity and reduced soil quality. This state consists of the Eastern Red Cedar/Locust Community.
Community 4.1
Eastern Red Cedar/Locust
This community has at least a 15 percent canopy of Eastern redcedar. Honey locust encroachment may occur as you move east within the MLRA, when brush management and prescribed burning is absent over an extended period of time. Generally this site is very conducive to cedar seedling invasion especially when adjacent to a seed source. Cedars will eventually dominate the site, resulting in a closed canopy, reduced forage production and limited livestock grazing and wildlife habitat value. Eastern redcedar control can usually be accomplished with prescribed burning while the trees are six foot tall or less and fine fuel production is over 1,500 pounds per acre. Trees of all heights can be controlled with the use of specifically adapted preparation, and ignition and holding techniques. Mechanical removal followed by a chemical treatment on stumps is effective on locust. Total annual production during an average year varies significantly, depending on the production level prior to encroachment and the percentage of canopy cover.
Figure 16. Plant community growth curve (percent production by month). NE7505, Central Loess Plains, woody encroachment. Woody plant encroachment with warm and cool season grasses growth curve MLRA 75.
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 | 3 | 8 | 12 | 20 | 25 | 14 | 5 | 8 | 4 | 1 | 0 |
Transition T1-2
State 1 to 2
Heavy grazing without adequate recovery periods will cause this state to lose a significant proportion of tall and mid- warm-season grass species and cross a threshold to the Native/Invaded State. Water infiltration and other hydrologic functions will be reduced due to the root matting presence of sod-forming grasses. With the decline and loss of deeper penetrating root systems, soil structure and biological integrity are catastrophically degraded to the point that recovery is unlikely. Once this occurs, it is highly unlikely that grazing management alone will return the community to the Reference State.
Transition T1-3
State 1 to 3
The Reference State is significantly altered by mechanical tillage to allow the site to be placed into production agriculture. The disruption to the plant community, the soil and the hydrology of the system make restoration to a true reference state unlikely.
Transition T1-4
State 1 to 4
Disruption of the natural fire regime and the planting of invasive exotic and native woody species can cause this state to shift to the Invaded Woody State.
Transition T 2-3
State 2 to 3
The state is significantly altered by mechanical tillage to allow the site to be placed into production agriculture. The disruption to the plant community, the soil and the hydrology of the system make restoration to a true reference state unlikely.
Transition T 2-4
State 2 to 4
Disruption of the natural fire regime and the planting of invasive exotic and native woody species can cause this state to shift to the Invaded Woody State.
Transition T 3-4
State 3 to 4
Disruption of the natural fire regime and the planting of invasive exotic and native woody species can cause this state to shift to the Invaded Woody State.
Restoration pathway R 1,2,3
State 4 to 1
Prescribed burning, wildfire, harvest, and brush management will move this plant community toward one of the herbaceous plant dominated plant communities. The forb component of a site with heavy tree density or canopy cover will initially increase following tree removal through mechanical brush management treatments and prescribed fire. If re-sprouting brush such as Honey locust or Siberian elm is present, stumps must be chemically treated immediately after mechanical removal. Ongoing brush management such as hand cutting, chemical spot treatments or periodic prescribed burning is required to prevent a return to this state.
Conservation practices
Brush Management | |
---|---|
Prescribed Burning | |
Prescribed Grazing |
Additional community tables
Table 6. Community 1.1 plant community composition
Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
---|---|---|---|---|---|---|
Grass/Grasslike
|
||||||
1 | Tall Warm Season Grasses | 1250–1700 | ||||
big bluestem | ANGE | Andropogon gerardii | 394–788 | 15–30 | ||
Indiangrass | SONU2 | Sorghastrum nutans | 0–263 | 0–10 | ||
switchgrass | PAVI2 | Panicum virgatum | 0–131 | 0–5 | ||
2 | Mid Warm Season Grasses | 945–1200 | ||||
little bluestem | SCSC | Schizachyrium scoparium | 656–919 | 25–35 | ||
sideoats grama | BOCU | Bouteloua curtipendula | 263–394 | 10–15 | ||
composite dropseed | SPCOC2 | Sporobolus compositus var. compositus | 0–131 | 0–5 | ||
sand dropseed | SPCR | Sporobolus cryptandrus | 0–131 | 0–5 | ||
3 | Native Cool Season Grasses | 70–400 | ||||
needle and thread | HECOC8 | Hesperostipa comata ssp. comata | 0–263 | 0–10 | ||
western wheatgrass | PASM | Pascopyrum smithii | 131–263 | 5–10 | ||
porcupinegrass | HESP11 | Hesperostipa spartea | 0–131 | 0–5 | ||
prairie Junegrass | KOMA | Koeleria macrantha | 0–131 | 0–5 | ||
green needlegrass | NAVI4 | Nassella viridula | 0–131 | 0–5 | ||
Scribner's rosette grass | DIOLS | Dichanthelium oligosanthes var. scribnerianum | 0–131 | 0–5 | ||
Canada wildrye | ELCA4 | Elymus canadensis | 0–53 | 0–2 | ||
4 | Short Warm Season Grasses | 70–175 | ||||
blue grama | BOGR2 | Bouteloua gracilis | 131–263 | 5–10 | ||
hairy grama | BOHI2 | Bouteloua hirsuta | 0–131 | 0–5 | ||
plains muhly | MUCU3 | Muhlenbergia cuspidata | 0–131 | 0–5 | ||
5 | Other Native Grasses and Grass-Likes | 107–175 | ||||
Grass, perennial | 2GP | Grass, perennial | 0–131 | 0–5 | ||
sedge | CAREX | Carex | 26–131 | 1–5 | ||
Forb
|
||||||
6 | Forbs | 120–350 | ||||
white heath aster | SYER | Symphyotrichum ericoides | 0–53 | 0–2 | ||
common sunflower | HEAN3 | Helianthus annuus | 0–53 | 0–2 | ||
Forb, perennial | 2FP | Forb, perennial | 0–53 | 0–2 | ||
Cuman ragweed | AMPS | Ambrosia psilostachya | 0–53 | 0–2 | ||
dotted blazing star | LIPU | Liatris punctata | 0–53 | 0–2 | ||
compassplant | SILA3 | Silphium laciniatum | 0–36 | 0–1 | ||
Baldwin's ironweed | VEBA | Vernonia baldwinii | 0–36 | 0–1 | ||
hoary verbena | VEST | Verbena stricta | 0–26 | 0–1 | ||
goldenrod | SOLID | Solidago | 0–26 | 0–1 | ||
stiff sunflower | HEPA19 | Helianthus pauciflorus | 0–26 | 0–1 | ||
rush skeletonplant | LYJU | Lygodesmia juncea | 0–26 | 0–1 | ||
beardtongue | PENST | Penstemon | 0–26 | 0–1 | ||
scurfpea | PSORA2 | Psoralidium | 0–26 | 0–1 | ||
upright prairie coneflower | RACO3 | Ratibida columnifera | 0–26 | 0–1 | ||
ragwort | SENEC | Senecio | 0–26 | 0–1 | ||
pussytoes | ANTEN | Antennaria | 0–26 | 0–1 | ||
white sagebrush | ARLU | Artemisia ludoviciana | 0–26 | 0–1 | ||
false boneset | BREU | Brickellia eupatorioides | 0–26 | 0–1 | ||
thistle | CIRSI | Cirsium | 0–26 | 0–1 | ||
purple prairie clover | DAPUA | Dalea purpurea var. arenicola | 0–26 | 0–1 | ||
Forb, annual | 2FA | Forb, annual | 0–26 | 0–1 | ||
Shrub/Vine
|
||||||
7 | Shrubs | 25–175 | ||||
Shrub (>.5m) | 2SHRUB | Shrub (>.5m) | 26–79 | 1–3 | ||
leadplant | AMCA6 | Amorpha canescens | 0–53 | 0–2 | ||
prairie rose | ROAR3 | Rosa arkansana | 0–53 | 0–2 | ||
western snowberry | SYOC | Symphoricarpos occidentalis | 0–53 | 0–2 | ||
smooth sumac | RHGL | Rhus glabra | 0–35 | 0–1 |
Interpretations
Animal community
LIVESTOCK – GRAZING INTERPRETATIONS:
This site is well adapted to managed grazing by domestic livestock. The predominance of herbaceous plants across all plant community phases best lends these sites to grazing by cattle but browsing livestock such as goats or sheep will more heavily utilize invasive forbs and brush. Carrying capacity and production estimates are conservative estimates that should be used only as guidelines in initial stages of grazing lands planning.
Suggested stocking rates (carrying capacity) for cattle under continuous season-long grazing under normal growing conditions are listed below:
-Mixed Native Grass; 2625 lbs/acre production and 0.72 AUM/acre carrying capacity*
-Degraded Native Grass; 2200 lbs/acre production and 0.6 AUM/acre carrying capacity*
If grazing distribution problems occur, stocking rates must be reduced to maintain plant health and vigor. Carrying capacity and production estimates are conservative estimates that should be used only as guidelines in the initial stages of the conservation planning process. Utilizing a rotational grazing system that allows for adequate rest and recovery will increase plant vigor and carrying capacity. 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 to document plant composition and production. More precise carrying capacity estimates can be calculated based on actual site information along with animal preference data, particularly when livestock 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.
WILDLIFE INTERPRETATIONS:
Major Land Resource Area (MLRA) 75 lies primarily within the loess mixed-grass prairie ecosystem mixed with tallgrass prairie in lower areas. Prior to European settlement, this area consisted of diverse grassland habitats interspersed with varying densities of depressional wetlands and limited woody riparian corridors. These habitats provided critical life cycle components for the grassland birds, prairie dogs and herds of roaming bison, elk, and pronghorn that historically occupied this landscape. Diverse populations of small mammals and insects provided a bountiful prey base for raptors and omnivores such as coyotes, foxes, raccoons and opossums. Native Americans, bobcats, wolves, and mountain lions occupied the apex predator niche. In addition, a wide variety of reptiles and amphibians thrived in this landscape.
The loess mixed-grass prairie was a disturbance-driven ecosystem with fire, herbivory and climate functioning as the primary disturbances. Following European settlement, elimination of fire, widespread conversion to cropland, and other sources of habitat fragmentation significantly altered the appearance and functionality of the entire ecosystem. The reduced stability of the system is reflected by major changes in the composition and abundance of the native flora and fauna. Introduced and invading species further degrade the ecological integrity of the plant and animal communities. Bison and prairie dogs were historically keystone species but free-roaming bison herds and nearly all prairie dogs have been extirpated. The loss of bison and fire as ecological drivers greatly influenced the character of the remaining native grasslands and the habitats that they provide. Fragmentation has reduced habitat quality for numerous area-sensitive species, as highlighted by the decline of the greater prairie chicken. Many grassland nesting bird populations such as dickcissel and Henslow's sparrow are also declining. In addition to free-ranging bison, extirpated species include pronghorn, wolves and swift fox.
Historically, an ecological mosaic of Loamy Plains, Clayey Plains, Limy Loess Slopes, Closed Upland Depression, Loamy Terrace, and Loamy Floodplain sites, provided habitat for species requiring unfragmented grasslands. Important habitat features and components found commonly or exclusively on modern day remnants include 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. Within MLRA 75, remaining Loamy Hills ecological sites provide grassland cover with an associated forb and limited shrub component.
In this fragmented landscape, native grassland bird populations face increasing competition from the opportunistic European starlings and house sparrows, and are subject to nest parasitism from brown-headed cowbirds.
Tree encroachment creates habitat that favors generalist species such as American robin and mourning dove, and provides perches for raptors, increasing the predation mortality.
Introduced species such as smooth bromegrass, reed canarygrass, Kentucky bluegrass, nodding plumeless thistle, and Canada thistle further degrade the biological integrity of many of these remnant prairies.
1. REFERENCE STATE: The predominance of tall and mid statured grasses plus a high diversity of forbs and shrubs in this community makes it ideal for grazers and mixed-feeders. Pollinating insects play a large role in maintaining the forb community and provide a food source for grassland birds and other grassland dependent species. The vegetative structural diversity provides habitat for reptiles, amphibians, and a wide array of native and introduced bird species including Henslow's sparrow, Western meadowlark, Northern bobwhite, and ringneck pheasants. The abundant prey base supports populations of Swainson’s hawk, burrowing, short-eared and great horned owls and other grassland raptors.
Western meadowlark and American crow over-winter in this habitat.
The diversity of grasses, forbs and shrubs provide high nutrition levels for small and large herbivores including moles, mice, ground squirrels, white-tailed jackrabbit, and whitetail deer. The structure of this plant community provides suitable thermal, protective and escape cover for small herbivores and grassland birds. Many wide-ranging predators utilize this plant community including coyote, badger, red fox and least and long-tailed weasels.
As the plant community degrades to more mid-grasses and fewer tall grasses, less winter and escape cover are provided. It also provides less cover for predators. As the plant community shifts from tall warm season grasses to mid-height grasses, it favors grassland birds that prefer shorter vegetation. This structural community provides better habitat for greater prairie chicken, lark bunting, and lark sparrow populations. Habitat in plant community 1.3 is much the same as 1.2 but provides less winter protection because of the reduced plant height and cover.
2. NATIVE/INVADED STATE: Although the amount of Kentucky bluegrass in this plant community varies, the generally lower structure height favors the suite of grassland birds that prefer more visual space. Increased dominance by Kentucky bluegrass with lower plant diversity provides less habitat for ringneck pheasant, Northern bob-white and mixed-feeders, such as whitetail deer and small mammals. Insect populations are somewhat reduced but still play a large role in maintaining the forb community and provide a moderate forage supply for grassland birds and other species.
The reduced stature of this plant community still provides suitable thermal, protective and escape cover for small herbivores and grassland birds.
3. SODBUSTED STATE: Natural regeneration; As opportunistic disturbance oriented species, Kentucky bluegrass and smooth bromegrass have become the prevalent grass species. The forb component exhibits lower diversity than the reference state and shifts towards increaser/ introduced forbs including sweetclover, Western yarrow, Cuman ragweed, Missouri goldenrod, Hoary verbena and Ironweed. Pollinator insect populations are still present, but experience a shift to generalist species.
The Savannah sparrow, American robin, western meadowlark are common birds that take advantage of the structure and composition of this plant community. The shorter stature of this plant community provides habitat for killdeer, horned lark, black-tailed jackrabbit (better suited to this plant community than white-tailed jackrabbit), and thirteen-lined ground squirrel. Prey populations are reduced and are more vulnerable to predation by raptors and mammalian predators. Burrowing owls may be associated with Richardson’s ground squirrel or other mammal burrows. The short stature of this plant community does not provide suitable thermal/protective cover and escape cover.
4. INVADED WOODY STATE: The Eastern Redcedar/ Locust Community provides habitat niches for white-tailed deer, wild turkey, raccoon, and Cooper’s, and sharp-shinned hawk among other species.
Birds that are habitat generalists, such as the Bell’s Vireo, common yellowthroat, Eastern kingbird, mourning dove, American goldfinch, Northern bobwhite, field sparrow, solitary vireo, and pigmy nuthatch use woody cover for nesting, food, and breeding habitats.
While a woody component of the grassland provides specific short-term habitats for some species, an expansive forest component is very detrimental to grassland wildlife species diversity and abundance overall.
Hydrological functions
Water is the principal factor limiting forage production on this site, which is dominated by soils in hydrologic group B. Permeability is moderate, and runoff potential is medium to high. In general, the infiltration rate is directly proportional to vegetative cover, while the run off potential is inversely proportional. An exception is sod-bound short grasses. The T erosion factor is 5.
(Refer to NRCS Section 4, National Engineering Handbook (NEH-4) for runoff quantities and hydrologic curves).
Recreational uses
This site provides hunting opportunities for upland game species, and white-tailed deer. The wide varieties of plants which bloom from spring until fall have an aesthetic value that appeals to visitors.
Wood products
No appreciable wood products are present on the site. Redcedar can be utilized for veneer and/or cedar furniture.
Other products
No appreciable other products.
Other information
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.
Supporting information
Inventory data references
Information presented here has been derived from NRI data, NRCS Soil Surveys, similar sites in adjacent MLRAs, and field observations from trained personnel.
Other references
High Plains Regional Climate Center, University of Nebraska. (http://hpcc.unl.edu, accessed 12/05/16)
Johnsgaard, P.A. 2001. “The Nature of Nebraska.” University of Nebraska Press.
LaGrange, T.G. 2015. Final Report submitted to EPA for the project entitled: Nebraska’s Wetland Condition Assessment: An Intensification Study in Support of the 2011 National Survey (CD# 97714601), and the related project entitled: Nebraska's Supplemental Clean Water Act §106 Funds, as Related to Participation in National Wetland Condition Assessment (I – 97726201). Nebraska Game and Parks Commission, Lincoln.
Muhs, Daniel R., E. Bettis III, J. Aleinikoff, J. McGeehin, J. Beann, G. Skipp, B. Marshall, H. Roberts, W. Johnson, and R. Benton.
"Origin and paleoclimatic significance of late Quaternary loess in Nebraska: Evidence from stratigraphy, chronology, sedimentology, and geochemistry" (2008). USGS Staff -- Published Research. Paper 162. http://digitalcommons.unl.edu/usgsstaffpub/162 Accessed 12/05/16.
U.S. Dept. of Agriculture. NRCS National Ecological Site Handbook. January, 2014.
U.S. Dept. of Agriculture. NRCS National Engineering Handbook, Section 4. August, 2011.
Personal communications with professional ecologists and wildlife experts.
Rolfsmeier, S.B. and G. Steinauer. 2010. "Terrestrial Ecological Systems and Natural Communities of Nebraska", (version IV)
Nebraska Natural Heritage Program.
USDA, NRCS. National Water and Climate Center, Portland, OR. http://wcc.nrcs.usda.gov Accessed 12/05/16.
USDA, NRCS.1997. National Range and Pasture Handbook .
USDA, NRCS. National Soil Information System, Information Technology Center, Fort Collins, CO. http://nasis.nrcs.usda.gov Accessed 12/05/16.
USDA, NRCS. 2002. The PLANTS Database, Version 3.5 http://plants.usda.gov Accessed 12/05/16. National Plant Data Center, Baton Rouge, LA.
USDA, NRCS Soil Surveys from Gosper, Phelps, Kearney, Adams, Hamilton, Polk, York, Butler, Seward, Saline, Fillmore, Clay, Franklin, Webster, Nuckolls, Thayer and Jefferson counties in Nebraska, and Republic and Washington counties in Kansas.
Contributors
Doug Whisenhunt
Acknowledgments
My appreciation for the hard work and diligence of the members of the MLRA 75 soils team, local practitioners team, and 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) | |
---|---|
Contact for lead author | |
Date | |
Approved by | |
Approval date | |
Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
-
Presence of water flow patterns:
-
Number and height of erosional pedestals or terracettes:
-
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
-
Number of gullies and erosion associated with gullies:
-
Extent of wind scoured, blowouts and/or depositional areas:
-
Amount of litter movement (describe size and distance expected to travel):
-
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
-
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
-
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
-
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
-
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:
Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
-
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
-
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:
-
Perennial plant reproductive capability:
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