Ecological site R080BY144TX
Clayey Bottomland 26-33" PZ
Last updated: 10/10/2018
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.
Major Land Resource Area (MLRA): 080B–Texas North-Central Prairies
MLRA 80B consists of gently rolling, dissected plains with very steep hillsides and sideslopes and narrow flood plains associated with small streams. Loamy and clayey soils range from very shallow to deep and developed in sandstones, shales, and limestones of Pennsylvanian age.
This ecological site is correlated to soil components at the Major Land Resource Area (MLRA) level which is further described in USDA Ag Handbook 296.
Ecological site concept
These sites occur over tight clay alluvial soils on floodplains. The reference vegetation is native midgrass species with scattered forbs and some trees and shrubs along the watercourses. Without fire or other brush management, woody species may dominate the site, especially mesquite. These soils can be quite droughty during dry periods due to the high clay content.
Clay Loam 26-33" PZ
Clay Loam Site is often adjacent and up hill.
Shallow Clay 26-33" PZ
Shallow Clay Site is often adjacent and up hill.
Tight Sandy Loam 26-33" PZ
Tight Sandy Loam Site is often adjacent and uphill.
Loamy Bottomland 26-33" PZ
Loamy Bottomland is found on similar physiographic position and has somewhat more production.
Table 1. Dominant plant species
(1) Panicum obtusum
This site occurs on linear to concave flood plains and flood-plain steps in the Texas North-Central Prairies. The site is characteristically a water receiving site.
Table 2. Representative physiographic features
(2) Flood-plain step
|Runoff class||Medium to high|
|Flooding frequency||Rare to frequent|
|Elevation||750 – 2,400 ft|
|Water table depth||72 in|
|Aspect||Aspect is not a significant factor|
The climate is subtropical subhumid and is characterized by hot humid summers and relatively mild winters. Tropical maritime air controls the climate during spring, summer and fall. In winter and early spring, frequent surges of polar Canadian air cause sudden drops in temperatures and add considerable variety to the daily weather. The average first frost generally occurs about November 5 and the last freeze of the season usually occurs about March 19. The average frost free period ranges from 215 days in the northern counties, to 240 days in the south.
The average relative humidity in mid-afternoon is about 60 percent in the summer months. Humidity is higher at night, and the average at dawn is about 80 percent. The sun shines 75 percent of the time possible during the summer and 50 percent in winter. The prevailing wind direction is from the southwest and highest windspeeds occur during the spring months.
Approximately 75% of annual rainfall occurs between April 1 and October 31. Rainfall during the months of April through September typically occurs during thunderstorms which tend to be intense and brief, resulting in large amounts of rain in a short time. The wettest months of the year are May, June, September, and October. The driest months during the growing season are July and August. The winter months of November, December, January, and February are the driest months overall.
Average annual precipitation for the entire MLRA is approximately 28 inches. There is a noticeable difference in the average annual precipitation in the northern counties in comparison to the southern and western counties of this Major Land Resource Area. Jack, Clay, Young, and Palo Pinto Counties all have an average annual precipitation of more than 31 inches. Stephens, Eastland, McCulloch, and San Saba Counties all have an average annual precipitation of less than 28 inches.
Winters tend to be mild, with occasional periods of very cold temperatures which can be accompanied by strong northerly winds and freezing precipitation. Snow is infrequent and significant accumulations are rare. These periods of very cold weather are generally short-lived. Summers tend to be hot and dry. Drought conditions are common during most summers. Air temperatures of more than 95oF are common from mid-June through September. In the northern counties nearest to the Red River, temperatures are generally slightly cooler during winter months and slightly warmer during summer months than in the other counties in the North Central Prairie.
Table 3. Representative climatic features
|Frost-free period (average)||240 days|
|Freeze-free period (average)||268 days|
|Precipitation total (average)||33 in|
Figure 2. Monthly precipitation range
Figure 3. Monthly average minimum and maximum temperature
Influencing water features
These sites receive run off water from adjacent upland areas. Water shed from these bottomland areas should be minimal under reference vegetation.
Representative soil components for this ecological site include: Deleon, Westfork
The site is characterized by very deep clayey soils with very high shrink-swell potential.
Table 4. Representative soil features
(2) Alluvium – limestone
(1) Silty clay
|Drainage class||Moderately well drained to well drained|
|Permeability class||Very slow to slow|
|Soil depth||72 in|
|Surface fragment cover <=3"||2%|
|Surface fragment cover >3"||2%|
|Available water capacity
|8 – 10 in|
|Calcium carbonate equivalent
|Sodium adsorption ratio
|Soil reaction (1:1 water)
|6.1 – 8.4|
|Subsurface fragment volume <=3"
|Subsurface fragment volume >3"
The Clayey Bottomland Ecological Site occupies narrow bands of moderately well drained soils on nearly level flood plains of rivers and streams. Inundation by flood water occurs once or more times a year to once every 4 to10 years. Overflow from adjacent up-slope sites during rainy season may enhance plant growth, but the fine textured soils often restrict plant growth during dry years. Proper grazing management is made difficult by the proximity to water of the adjacent stream and the gentle slopes.
The reference plant community of the Clayey Bottomland site evolved under frequent fire and periodic heavy grazing by bison, pronghorn antelope, Rio Grande turkey and deer. It is postulated that fires re-occurred in four to six-year intervals in this region prior to European settlement (Frost 1998). The frequent fires likely were as influential in shaping the site into an open Mixed-grass Prairie Plant Community (1.1) as was the climate or grazing by bison and pronghorns.
White tridens , Arizona cottontop and vine-mesquite, buffalograss and Reverchon bristlegrass, characterized the Mixed-grass Prairie Plant Community (1.1). Little bluestem, switchgrass and Indiangrass probably occurred infrequently in areas of enhanced moisture relationships, or recent immature soil inclusions. Wildrye and Texas wintergrass were also common. Hackberry, elm, live oak and a very few shrubs and vines were scattered along the stream edge and drainages.
The Mixed-grass Community (1.1) was relatively stable and resilient within the climate, soil and fire regime until European settlement in the 1800’s. The mid 1800’s brought elimination of the bison herd, removal of the American Indian and a large increase of domestic livestock. The development of the windmill and barbed wire fencing during the 1870’s and 1980’s promoted overgrazing throughout the region. Overstocking by domesticated livestock induced a reduction of palatable grasses and forbs. Total herbage production declined as the grazing resistant shortgrasses and forbs began replacing the midgrasses and reference forbs. Texas wintergrass and buffalograss were major increasers under grazing. There was a concomitant decline in vegetative ground cover, mulch and soil organic matter.
The shift in composition of the plant cover and decline in soil properties favored woody plant encroachment. This, along with the reduction in intensity and frequency of fires, allowed invasion of species from adjacent sites or the increase of more grazing resistant endemic species. Under the above scenario, the site transitioned into a Shortgrass Plant Community (1.2) being invaded by woody plants. In this plant community grasses still dominate ecological processes, but the encroaching woody species contribute an increasing amount to the total annual production.
If the Shortgrass Community (1.2) is continuously overgrazed and fire is excluded, the transition toward woody plant dominance continues. The primary encroaching woody species are mesquite and pricklypear. Texas wintergrass, buffalograss and other unpalatable or more grazing resistant grasses increase and palatable climax forbs and midgrasses continue to decline. Grass cover, litter and soil organic matter decline as bare ground, erosion and other desertification processes increase. When the woody plant component reaches approximately 20 percent canopy, grazing management strategies, such as rest from grazing, generally will not reverse the transition to shrubland. A combination of proper grazing and prescribed burning should be successful in maintaining the grass dominant community, however. With continued livestock grazing and no brush management the Shortgrass Community (1.2) will transition into a Shortgrass/Mixed-brush Community (2.1), where woody plants dominate.
Mesquite often dominates the woody cover of the Shortgrass/Mixed-brush Community (2.1). Pricklypear and lotebush are characteristic understory shrubs. American elm and hackberry trees increase in size and density. The grass component is a mixture of midgrasses, shortgrasses and low quality forbs, initially. With continued livestock overgrazing buffalograss, threeawn and meadow dropseed, Texas wintergrass and annual bromes replace the more palatable mid and tall grasses and forbs. The transition to woodland can be reversed with moderately intensive mechanical and/or chemical brush control methods plus prescribed burning. Prescribed burning generally does not kill mesquite once plants reach >2 years of age, but fire can suppress mesquite of any age if the fire can cause top kill. Prescribed burning systems have been developed to aid in enhancing and utilizing this vegetation type.
If overgrazing continues and brush control practices are not applied, the woody canopy will increase in size and density until a dense woody plant dominant community develops. Woody plant dominance occurs at about 35 to 40 percent woody plant canopy cover. Upon reaching this threshold, the grassland component will not produce enough fine fuel for fires to effectively suppress the woody plants and expensive brush control practices are required to reverse the transition to dense woodland. The site transitions into a new plant community type, the Mixed-brush/Shortgrass Woodland (2.2) when this occurs.
The Mixed-brush/Shortgrass Woodland Community (2.2) is dominated by mesquite, elm, hackberry and mixed-brush. Western soapberry and pecan may become invasive. Texas wintergrass, buffalograss and annuals dominate the herbaceous layer. Once canopy cover exceeds 40 percent woody plants, forage production is very limited except in wet periods when annuals provide extra forage. Shortgrasses and cool-season grasses and forbs are present but sparse due to shading and competition from the woody plants. Annual bromes are often present during the cool-season, especially during wet periods. The trees and understory brush continue to increase in size and density regardless of grazing management. Large areas of bare ground may appear between woody plants where small depressions occur. Desertification, including erosion, continues in the interspaces until maximum ground cover by woody species is approached. Once shrub cover reaches potential the hydrologic processes, energy flow and nutrient cycling stabilize under the woody vegetation environment.
Major expense and energy are required to restore the Mixed-brush/Shortgrass Woodland Community (2.2) back to a grassland state. Restoration of site in this stage is very difficult to accomplish because of soil characteristics. Therefore, maintaining the site in at least the Shortgrass/Mixed-brush (2.1) stage, or better, the Shortgrass (1.2) stage, through controlled grazing and brush management, including the use of prescribed burning, is recommended.
The following diagram suggests some pathways that the vegetation on this site might take. There may be other states not shown on the diagram. This information is intended to show what might happen in a given set of circumstances; it does not mean that this would happen the same way in every instance. Local professional guidance should always be sought before pursuing a treatment scenario.
State and Transition Model:
State and transition model
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State 1 submodel, plant communities
State 2 submodel, plant communities
The Mixed-grass Prairie Community is the interpretative plant community for the Clayey Bottomland Ecological Site. It is an open prairie dominated by mid and shortgrasses with scattered elm and hackberry. The plant community provides good ground cover and protection from erosion during infrequent flooding events. Vine mesquite, white tridens, sideoats grama and Arizona cottontop are the dominant midgrasses throughout. Forbs include coreopsis, western ragweed, heath aster, Engelmann’s daisy, and annual forbs. Shrubs and vines are scarce but include fire resistant species. Mesquite may be present but kept as scattered multi-stemmed shrubs by repeated wildfires. The Mixed-grass Prairie Community produced 3000 to 6000 pounds per acre. The Shortgrass Prairie Community (1.2) is a shortgrass dominated prairie community being invaded by woody species. Woody species, especially pricklypear and mesquite, increase. The more palatable midgrasses and climax forbs begin to be replaced by less palatable or more grazing tolerant species. Texas wintergrass and buffalograss become dominant. Sideoats grama, white tridens, alkali sacaton, vine mesquite, and Arizona cottontop persist but are reduced in the composition of this vegetation type. Most of the perennial forbs remain in this plant community, although in lesser amounts. The encroaching woody species are generally less than four feet tall and the woody canopy varies between ten and twenty percent. Typically, mesquite, elm, hackberry, pricklypear, lotebush, tasajillo and bumelia were early and persistent encroaching woody species. Annual forage production is reduced, ranging from 2000 to 5000 pounds per acre.
Mixed-grass Prairie Community
The Mixed-grass Prairie Community (1.1) is the interpretative plant community for the Clayey Bottomland Ecological Site. It is an open prairie dominated by mid and shortgrasses with scattered elm and hackberry. The plant community provides good ground cover and protection from erosion during infrequent flooding events. Species composition varies from east to west in the MLRA, and from south to north, because of precipitation and latitude differences. Vine mesquite, white tridens, sideoats grama and Arizona cottontop are the dominant midgrasses throughout. Buffalograss and hairy grama are common shortgrasses with lesser amounts of Reverchon bristlegrass, sand dropseed, fall witchgrass, plains bristlegrass and Hall’s panicum. Texas wintergrass, Canada wildrye, Texas bluegrass and western wheatgrass are important parts of the cool-season grass component. Sedges are present, primarily in depressions. Forbs include coreopsis, western ragweed, heath aster, sagewort, verbena, greenthread, Engelmann’s daisy, vetch and annual forbs. Shrubs and vines are scarce and include fire resistant species such as bumelia, ephedra, greenbriar, clematis and lotebush. Mesquite may also be present but kept as scattered multi-stemmed shrubs by repeated wildfires. (See plant community composition table below for complete listing of probable species.) The Mixed-grass Prairie Community (1.1) produces as much as 6000 pounds herbage in good moisture years and as little as 3000 pounds in dry years. Production is often limited by the tight, droughty soils but could also exceed expectation during favorable growing conditions. Grasses and forbs contribute up to 90 percent of the total annual production. The midgrasses aide in the infiltration of rainfall into the moderately slowly permeable soil and reduced runoff. Litter and organic matter buildup was limited by soil characteristics, infrequent flooding and low herbage production during dry years. The Mixed-grass Prairie Community (1.1) furnished good forage for grass-eating type animals such as bison before settlement and for horses and cattle after settlement. Near reference conditions can be maintained on the site with proper stocking, prescribed grazing and frequent prescribed burning. Stocking rates must consider the kind of livestock and balance their numbers with current annual forage production and competition from other herbivores. Flexibility in animal numbers is important because of the tight nature of the soil and frequent flooding events. Livestock overgrazing, decrease in intensity and frequency of fires and no brush management will allow this plant community to transition into a Shortgrass Prairie Community (1.2) with various amounts of invading shrubs.
Figure 5. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
Figure 6. Plant community growth curve (percent production by month). TX3053, Mixed-grass Prairie Community. Mixed-grasses composed of mid, short and cool-season grasses..
Shortgrass Prairie Community
The Shortgrass Prairie Community (1.2) is a shortgrass dominated grassland community being invaded by woody species. Selective grazing by livestock and deer and the differential response of plants to defoliation caused changes in composition of the Mixed-grass Prairie Community (1.1). Woody species, especially pricklypear and mesquite, increase wherever continuous heavy grazing reduces grass cover, exposes soil and reduces fine fuel necessary for effective fires. As retrogression occurs the more palatable midgrasses and forbs begin to be replaced by less palatable or more grazing tolerant species. Texas wintergrass and buffalograss become dominant. Sideoats grama, white tridens, alkali sacaton, vine mesquite, and Arizona cottontop persist but are reduced in the composition of this vegetation type. Canada wildrye, Virginia wildrye and western wheatgrass generally decline also. Most of the perennial forbs remain in this plant community, although in lesser amounts. The encroaching woody species are generally less than four feet tall and subject to suppression by prescribed grazing and prescribed burning. The woody canopy varies between ten and twenty percent depending on length and severity of grazing and the timing and frequency of fires. Typically, mesquite, elm, hackberry, pricklypear, lotebush, tasajillo and bumelia were early and persistent encroaching woody species. Annual primary production is reduced, ranging from 2000 to 5000 pounds per acre depending on precipitation amounts and soil conditions. Grasses remain the dominant producers of forage. Heavy continuous grazing reduces plant cover, litter and mulch and increases bare ground exposing the soil to some erosion during flood events. There could also be some mulch and litter movement during flooding events. The change in species is small initially, but unless proper grazing and brush suppression by prescribed burning or individual plant treatments occur, the invading species continue to increase in size and density. Once the woody plants become dense enough (about 20 percent) to suppress grass growth and/or big enough (about 4 feet tall) to resist fire damage, a threshold in ecological succession is crossed. The Shortgrass Prairie Community (1.2) transitions into the Shortgrass/Mixed-brush Community (2.1) when this threshold is crossed.
Figure 7. Annual production by plant type (representative values) or group (midpoint values)
Table 6. Annual production by plant type
Figure 8. Plant community growth curve (percent production by month). TX3050, Shortgrass Prairie, 20% woody canopy. Shortgrasses are dominant and midgrasses are sub-dominant as tallgrasses are almost totally eliminated. Annuals and early successional forbs and grasses are abundant. Shrubs encroach from adjacent areas and increase in density and canopy..
Community 1.1 to 1.2
With continuous overgrazing, decrease in intensity and frequency of fires and no brush management, the Mixed-grass Prairie Community transitions into a Shortgrass Prairie Community (1.2) with invading shrubs becoming established.
Community 1.2 to 1.1
The retrogression is reversible to the Mixed-grass Prairie Community from the Shortgrass Prairie Community, however, with good grazing management that provides a competitive advantage to the grass component and provides fine fuels for periodic prescribed fires.
The Shortgrass/Mixed-brush Community (2.1) is characterized by a mixed mesquite, elm, hackberry and pecan overstory and a shortgrass herbaceous layer with a considerable cool-season component. All, but the more palatable woody species, have increased in size and density. Remnants of reference community grasses and forbs and less palatable species such as meadow dropseed, threeawn, silver bluestem, white tridens, buffalograss, fall witchgrass, halls panicum and annuals occur in the woody plant interspaces. Texas wintergrass and Virginia wildrye are persistent under and around woody plants where shading occurs. Japanese brome and rescue grass are often abundant during wet winters. Annual production ranges from approximately 2500 to 5500 pounds per acre. However, as much as forty percent of the production is made up of shrubs, vines and trees which may be out of livestock reach. The Mixed-brush/Shortgrass Woodland Community (2.2) is composed of common invaders such as mesquite and sometimes redberry juniper. Oaks, hackberry, elm, willow, western soapberry and pecan can form mixed specie woodlands along and away from stream edges. Trees and shrubs can reach 70 percent or more woody plant cover. Cool-season grasses, shortgrasses and low quality annual and perennial forbs occupy the woody plant interspaces. Grasses and forbs make up less than 30 percent of the annual production. Cool-season annuals such as filaree, little barley, rescue grass, Japanese brome can be abundant during wet winters and springs. Annual production ranges from 2500 to 5500 pounds per acre.
The Shortgrass/Mixed-brush Community (2.1) is characterized by a mixed mesquite, elm, hackberry and pecan overstory and a shortgrass herbaceous layer with a considerable cool-season component. This community is the result of years of selective grazing by livestock, suppression of fire and the differential response of plants to defoliation. Again as in the prior communities, livestock and wildlife have contributed seeds via their droppings. The diversity of the grassland component has decreased while unpalatable woody plants and annuals increase. All, but the more palatable woody species, have increased in size and density. Pricklypear, bumelia, lotebush, clematis and greenbriar are common understory shrubs/vines. Elm, willow, pecan, oak and hackberry are common. Western soapberry, mesquite and pecan can be invasive on disturbed or overgrazed areas and form thickets. Remnants of reference community grasses and forbs and less palatable species such as meadow dropseed, threeawn, silver bluestem, white tridens, buffalograss, fall witchgrass, halls panicum and annuals occur in the woody plant interspaces. Gaura, western ragweed, verbena, greenthread, coreopsis, curlycup gumweed, and prairie coneflower are common. Texas wintergrass and Virginia wildrye are persistent under and around woody plants where shading occurs. Japanese brome and rescue grass are often abundant during wet winters. As the grassland component declines, more soil is exposed to crusting, erosion and cracking when dry. Water erosion is not a serious problem, however, because of the shallow slopes. Higher interception loss of water by increased woody canopy combined with evaporation losses reduces rainfall effectiveness. Litter, soil organic matter and structure decline in the interspaces reducing water infiltration but hydrologic functions improve under the woody plant cover. Annual production ranges from approximately 2500 to 5500 pounds per acre, depending on soil, precipitation events, flooding events and dry cycles. However, as much as forty percent of the production is made up of shrubs, vines and trees which may be out of livestock reach. The woody plant component of the plant community begins to dominate structure and ecological functions within the community. The transition to dense woodland can be reversed at this stage with moderately expensive brush and weed control practices, possibly range planting and prescribed grazing. Unless such accelerated conservation practices are applied the woody plants will continue to increase in size and density. When the woody plant cover reaches 35 to 40 percent and the herbaceous component contributes less than 50 percent of the annual production, the Shortgrass/Mixed-brush Community (2.1) transitions into a Mixed-brush/Shortgrass Woodland Community (2.2).
Figure 10. Annual production by plant type (representative values) or group (midpoint values)
Table 7. Annual production by plant type
Figure 11. Plant community growth curve (percent production by month). TX3039, Shortgrass/Annuals/Mesquite/Shrubs Community. Shortgrass/Annuals/Mesquite and Shrubs – buffalograss, curlymesquite, broomweed, annual forbs and grasses, mesquite, lotebush.
Mixed-brush/Shortgrass Woodland Community
The Mixed-brush/Shortgrass Woodland Community (2.2) is the collective result of many years of overgrazing, introduction of seeds, lack of periodic fires and little brush management. Mesquite, and sometimes redberry juniper are common invaders. Oaks, hackberry, elm, willow, western soapberry and pecan can form mixed specie woodlands along and away from stream edges. Common understory shrubs are pricklypear, sumac, lotebush, tasajillo, catclaw acacia and wolfberry. Greenbriar and clematis may become frequent vines. With continued heavy grazing and no brush control, the trees and shrubs can reach 70 percent or more woody plant cover. Cool-season grasses, shortgrasses and low quality annual and perennial forbs occupy the woody plant interspaces. Characteristic warm-season grasses are meadow and sand dropseed, buffalograss, silver bluestem and three-awns. Alkali sacaton is common in depressions and salt spots. Texas wintergrass, Virginia wildrye and cool-season annuals are found in and around tree/shrub cover. Grasses and forbs make up less than 30 percent of the annual production. Forbs commonly found in this community include coreopsis, verbena, heath aster, dotted gayfeather, western ragweed, prairie coneflower, and curlycup gumweed. Cool-season annuals such as filaree, little barley, rescue grass, Japanese brome can be abundant during wet winters and springs. Annual production may range from 2500 in below average rainfall years to 5500 in above average rainfall years. Initially, the shrub canopy acts to intercept rainfall and increase transpiration losses. However, within the woody canopy hydrologic and ecological processes stabilize. Soil organic matter and mulch also begin to increase and eventually stabilize. The Mixed-brush/Shortgrass Woodland Community provides good cover for wildlife, but only limited and variable preferred forage, or browse, is available for livestock or wildlife. Restoration to a grassland state requires expensive and high energy brush control practices and range planting. Proper stocking, prescribed grazing and prescribed burning would then be necessary to maintain the desired community. Selective brush removal may provide a viable compromise between wildlife and livestock needs and improve the site for both.
Figure 12. Annual production by plant type (representative values) or group (midpoint values)
Table 8. Annual production by plant type
Figure 13. Plant community growth curve (percent production by month). TX3052, Mesquite/Mixed-brush/Shortgrass/Annuals Community. Mesquite/Mixed-brush woodland with cool-season component..
Community 2.1 to 2.2
Unless brush management and good grazing management are applied during this phase, the transition from the Shortgrass/Mixed-brush Community toward the Mixed-brush/Shortgrass/Annuals Community (2.2) will continue.
Community 2.2 to 2.1
The trend toward dense shrubland cannot be reversed with good grazing management alone. Accelerated brush management practices along with proper grazing are required to return this community to the Shortgrass/Mixed-brush Community.
Converted Land State
The Converted Land Community has been cultivated for cropland or pastureland purposes. Small grain or forage sorghum may be cropped. Permanent native and introduce pasture may also be planted. Sometimes the community may be abandoned and let “go back” to native species encroached by woody species.
Converted Land Community
The Clayey Bottomland Ecological Site is often Converted (3.0) and planted to crops or pecan orchards and/or pasture crops. Technical advice as to adapted crops, cropping systems, production, and cultivation practices are available from local NRCS or Extension offices. When abandoned from cropping, the site should be re-vegetated with adapted native plant mixtures. Cultivation and erosion may have reduced soil productivity but near historic forage production may be obtained with a native plant mix that approximates reference community species composition. Introduced species, such as coastal bermudagrass and Kleingrass, often require more care, but can also be productive as pasture. In any case brush management is required to prevent brush invasion from adjacent areas. If fields are abandoned and left to re-vegetate naturally, weedy grasses, forbs and shrubs will be the first species in secondary succession. Woody species will encroach and eventually dominate unless brush management practices such as individual plant treatments (IPT) and prescribed burning are applied.
Figure 15. Plant community growth curve (percent production by month). TX3003, Native Seeding. Native Seeding of grasses and forbs..
Figure 16. Plant community growth curve (percent production by month). TX3249, Introduced Seeding. Introduced seed mixtures used instead of native grass seed mixtures. This method will least likely reach the Historic Climax Community..
State 1 to 2
Due to heavy continuous grazing, no brush management, and no fires to keep the brush species in check, the Prairie State will transition into the Woodland State.
State 1 to 3
The transition to the Converted Land State from the Prairie State occurs when crop cultivation practices, plowing, range planting, pasture planting, pest management, and nutrient management are applied to cropland, pastureland or go back land.
Restoration pathway R2A
State 2 to 1
Major high cost and high energy, accelerating practices are required to restore the Woodland State back to the Prairie State. Generally, herbicidal brush management practices such as aerial spraying and/or individual plant treatments (IPT) along with other restoration practices such as range planting, grazing deferment, prescribed grazing and prescribed burning are necessary for the ecological site to return to the reference plant community.
State 2 to 3
The transition to the Converted Land State from the Woodland State occurs when crop cultivation practices, plowing, range planting, pasture planting, pest management, and nutrient management are applied to cropland, pastureland or go back land.
Additional community tables
Table 9. Community 1.1 plant community composition
|Group||Common name||Symbol||Scientific name||Annual production (lb/acre)||Foliar cover (%)|
|little bluestem||SCSC||Schizachyrium scoparium||200–400||–|
|vine mesquite||PAOB||Panicum obtusum||600–1200||–|
|white tridens||TRAL2||Tridens albescens||500–1000||–|
|Arizona cottontop||DICA8||Digitaria californica||250–500||–|
|alkali sacaton||SPAI||Sporobolus airoides||50–100||–|
|sideoats grama||BOCU||Bouteloua curtipendula||50–100||–|
|silver beardgrass||BOLAT||Bothriochloa laguroides ssp. torreyana||50–100||–|
|hairy grama||BOHI2||Bouteloua hirsuta||25–50||–|
|fall witchgrass||DICO6||Digitaria cognata||25–50||–|
|plains lovegrass||ERIN||Eragrostis intermedia||25–50||–|
|Reverchon's bristlegrass||SERE3||Setaria reverchonii||25–50||–|
|Drummond's dropseed||SPCOD3||Sporobolus compositus var. drummondii||25–50||–|
|Texas wintergrass||NALE3||Nassella leucotricha||300–600||–|
|Canada wildrye||ELCA4||Elymus canadensis||150–300||–|
|western wheatgrass||PASM||Pascopyrum smithii||100–200||–|
|Virginia wildrye||ELVI3||Elymus virginicus||50–100||–|
|cedar sedge||CAPL3||Carex planostachys||0–6||–|
|Cuman ragweed||AMPS||Ambrosia psilostachya||10–20||–|
|white sagebrush||ARLUA||Artemisia ludoviciana ssp. albula||10–20||–|
|purple prairie clover||DAPU5||Dalea purpurea||10–20||–|
|Engelmann's daisy||ENPE4||Engelmannia peristenia||10–20||–|
|trailing krameria||KRLA||Krameria lanceolata||10–20||–|
|dotted blazing star||LIPU||Liatris punctata||10–20||–|
|Florida mimosa||MIQUF||Mimosa quadrivalvis var. floridana||10–20||–|
|upright prairie coneflower||RACO3||Ratibida columnifera||10–20||–|
|white heath aster||SYERE||Symphyotrichum ericoides var. ericoides||10–20||–|
|Christmas cactus||CYLE8||Cylindropuntia leptocaulis||12–24||–|
|Texas live oak||QUFU||Quercus fusiformis||15–30||–|
|western soapberry||SASAD||Sapindus saponaria var. drummondii||15–30||–|
Many types of wildlife use the Clayey Bottomland Ecological Site. Being associated with flood plains and water courses, it probably received concentrated animal use at times. Deer, turkey and quail were plentiful, and bison often utilized the site heavily during migrations prior to European settlement. Grassland insects, reptiles, birds and mammals frequent the site, either as their base habitat or from the adjacent sites. Small mammals include rodents, jackrabbit, cottontail rabbit, raccoon, skunk, opossum and armadillo. Predators include coyote, fox and bobcat. Game birds, songbirds, and birds of prey were indigenous or frequent users. Except for bison, most indigenous wildlife species are still plentiful. White-tailed deer and turkey utilize the Clayey Bottomland site in its various states.
The site in reference condition is very suited to primary grass eaters such as cattle. With long term abusive grazing by livestock and no, or limited brush control, the Mixed-grass Prairie Community (1.1) transitions into a Woodland State (2.0). As woody plants increase it becomes better habitat for browse eating animals, such as deer and goats, because of the predominance of woody plants and cool season grasses. Livestock should be stocked in proportion to the available grass, forb and browse forage, keeping deer competition for forbs and browse in mind. If the animal numbers are not kept in balance with herbage and browse production through grazing management and good wildlife population management, the late Mixed-brush/Shortgrass Woodland (2.2) community will have little to offer as wildlife habitat except cover.
Plant Preference by Animal Kind:
These preferences are somewhat general in nature as the preferences for plants is dependent upon grazing experience, time of year, availability of choices, and total forage supply. This rating system provides general guidance as to animal preference for plant species. It also indicates possible competition between kinds of herbivores for various plants. Grazing preference changes from time to time, especially between seasons, and between animal kinds and classes. Grazing preference does not necessarily reflect the ecological status of the plant within the plant community.
Preferred – Percentage of plant in animal diet is greater than it occurs on the land
Desirable – Percentage of plant in animal diet is similar to the percentage composition on the land
Undesirable – Percentage of plant in animal diet is less than it occurs on the land
Not Consumed – Plant would not be eaten under normal conditions; only consumed when other forages not available.
Toxic – Rare occurrence in diet and, if consumed in any tangible amounts results in death or severe illness in animal
The Clayey Bottomland Ecological Site is a moderately well-drained, very slowly permeable bottomland on nearly level flood plains. It may receive water from surrounding soils and the site may be covered with by water during flooding events. Flooding occurs once in two to three years. Soil moisture holding capacity is high and percolation is slow. The soil generally cracks to great depth when dry, allowing rapid water intake when rainfall occurs on dry soil. When moist the soil is very slowly permeable, however. The deep soils, with moderate to good water holding capacity, are conducive to high herbage production during above average moisture years but restrictive to growth during normal or dry periods. Essentially no water passes through the soil profile to underground water.
In reference condition, the grassland vegetation probably intercepted and utilized much of the incoming rainfall in the soil profile. Litter and soil movement was slight. Standing plant cover, duff and organic matter decrease as the Mixed-grass Prairie Community (1.1) transitions to the Shortgrass Prairie Community (1.2). These processes continue in the spaces between woody plants in the Shortgrass/Mixed-brush Community (2.1) and the Mixed-brush/Shortgrass Woodland Community (2.2). Once the woodland matures, the hydrologic and ecological processes, nutrient cycling and energy flow stabilize within the woody plant canopy.
This site along with adjacent upland sites provides diverse scenic beauty and many opportunities for recreation and hunting. The clayey soils are not conducive to campsite or playground development.
Most of the woody species are useable as firewood. Mesquite is sometimes used for posts and charcoal. Pecan and mesquite are used for furniture and specialty products.
Jams and jellies are made from fruit bearing species. Honeybees are utilized to harvest honey from the many flowering plants, such as mesquite.
Inventory data references
Information presented has been derived from Clayey Bottomland 30-40 RSD (8-16-79) and Clayey Bottomland PE 31-44 (7-25-1972), literature, personal experience, field observations and personal contacts with range-trained personnel. Photos by: J.L. Schuster --taken at sheet 28 and 36 of Eastland County, TX.
Special thanks to the following for assistance and guidance with development of this ESD: John Paclik NRCS Graham, TX, Mark Moseley NRCS, Boerne, Texas and Justin Clary NRCS Temple, Texas.
1. Archer S. 1994. Woody plant encroachment into southwestern grasslands and savannas: rates, patterns and proximate causes. In Ecological implications of livestock herbivory in the West, pp.13-68. Edited by M. Vavra, W. Laycock, R. Pieper, Society for Range Management Publication. , Denver, CO.
2. Brown, J.K. and J.K. Smith (Editors). 2000. Wildland fire in Ecosystems; effects of fire on flora. Gen. Tech. Rep. RMRS-GTR-42-vol. 2. Ogden. UT: U.S.D.A., Forest Service, Rocky Mtn. Sta. 257p.
3. Frost, C. C. 1998. Pre-settlement fire frequency regions of the United States: A first approximation. Tall Timbers Fire Ecology Conference Proceedings No. 20
4. Milchunas, D.G. 2006. Responses of Plant Communities to grazing in the southwestern United States. USDA-Forest Service. Rocky Mtn. Sta. GTR. 169
5. Thurow T.L., 1991. Hydrology and erosion. Chapter 6 in: Grazing Management: An Ecological Perspective Edited by: R.K. Heitschmidt and J.W. Stuth. Timber Press, Portland, Oregon.
6. USDA/NRCS Soil Survey Manuals for Eastland County, Texas.
7. Plant symbols, common names and scientific names according to USDA/NRCS Texas Plant List (Unpublished)
8. Bestelmeyer, B. T., J.R. Brown, K. M. Havsted, R. Alexander, G. Chavez and J. E. Hedrick. 2003. Development and use of state-and-transition models for rangelands. J. Range Management. 56(2): 114-126.
9. Hamilton W. and Darrell Ueckert. 2005. Rangeland Woody Plant Control--Past, Present, and Future.Ch 1 in: Brush Management-Past, Present, and Future. Texas A & M University Press. Pp.3-16.
Justin Clary, RMS, NRCS, Temple, Texas
Nathan Haile, RSS, NRCS, Weatherford, Texas
Lem Creswell, RMS, NRCS, Weatherford, Texas
Mark Moseley, RMS, NRCS, Boerne, Texas
Dr. Joe Schuster, Range & Wildlife Habitat Consultants, LLC, Bryan, TX
David Kraft, 10/10/2018
Site Development and Testing Plan:
Future work, as described in a Project Plan, to validate the information in this Provisional Ecological Site Description is needed. This will include field activities to collect low, medium and high intensity sampling, soil correlations, and analysis of that data. Annual field reviews should be done by soil scientists and vegetation specialists. A final field review, peer review, quality control, and quality assurance reviews of the ESD will be needed to produce the final document. Annual reviews of the Project Plan are to be conducted by the Ecological Site Technical Team.
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
|Author(s)/participant(s)||Lem Creswell, Zone RMS, NRCS, Weatherford, Texas|
|Contact for lead author||817-596-2865|
|Approved by||Mark Moseley, RMS, NRCS, Boerne, Texas|
|Composition (Indicators 10 and 12) based on||Annual Production|
Number and extent of rills:None.
Presence of water flow patterns:Water flow patterns are common and follow old stream meanders. Deposition or erosion is uncommon for normal rainfall but may occur during intense rainfall events.
Number and height of erosional pedestals or terracettes:Pedestals or terracettes would have been uncommon for this site.
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):Expect no more than 20% bare ground randomly distributed throughout.
Number of gullies and erosion associated with gullies:Any gullies should be stable and vegetated.
Extent of wind scoured, blowouts and/or depositional areas:None to slight.
Amount of litter movement (describe size and distance expected to travel):Little or no litter movement or deposition during normal rainfall events; however, litter of all sizes may move long distances depending on obstructions under intense storm events. This is a flood plain with occasional out of bank flow.
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):Soil surface in HCPC is resistant to erosion. Stability range is expected to be 5-6.
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):0-44 inches thick with colors from brown to dark brown clay with generally moderate medium, granular structure and moderate fine angular blocky structure. SOM is approximately 1-6%. See soil survey for more information.
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:Under HCPC, the bottomland of tallgrasses, midgrasses, forbs, and trees having adequate litter and little bare ground can provide for maximum infiltration and little runoff under normal rainfall events.
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 midgrasses >
Sub-dominant:Cool-season grasses >
Other:Warm-season tallgrasses = Warm-season shortgrasses > Shrubs/Vines > Trees
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):Perennial grasses will naturally exhibit a minor amount (less than 5%) of senescence and some mortality every year.
Average percent litter cover (%) and depth ( in):Litter is primarily herbaceous.
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):3000-6000 pounds per acre
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:Honey mesquite, Prickly pear, Bermudagrass, Johnsongrass and King Ranch bluestem.
Perennial plant reproductive capability:All perennial species should be capable of reproducing every year unless disrupted by extended drought, overgrazing, wildfire, insect damage, or other events occuring immediately prior to, or during the reproductive phase.
The Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
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