Natural Resources
Conservation Service
Ecological site R078CY103TX
Loamy Bottomland
23-31" PZ
Last updated: 9/15/2023
Accessed: 08/18/2026
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Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.
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Figure 1. Mapped extent
Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.
MLRA notes
Major Land Resource Area (MLRA): 078C–Central Rolling Red Plains, Eastern Part
MLRA 78C is characterized by moderately dissected, rolling plains with prominent ridges and valleys and numerous terraces adjacent to dissecting streams. Loamy and clayey soils are generally deep, well drained, and developed in calcareous and gypsiferous sediments of Permian age.
LRU notes
NA
Classification relationships
This ecological site is correlated to soil components at the Major Land Resource Area (MLRA) level which is further described in USDA Ag Handbook 296.
Ecological site concept
These sites occur on loamy floodplain soils. The reference vegetation consists of native tallgrasses, forbs, and few woody species. Bottomland hardwood trees will be found along the water courses, but overall canopy averages less than 10% across the landscape. Without brush management or prescribed fire, woody species may encroach and begin to dominate the ecological processes. Continuous abusive grazing may shift the plant community to a midgrass dominated plant community.
Similar sites
R078CY094TX Clayey Bottomland 23-30" PZ
Clayey Bottomland is found on similar physiographic position but with clayey soils and not as productive as loamy bottomland.
R078CY068OK Sandy Bottomland
Sandy Bottomland is found on similar physiographic position, but with sandy soils.
Table 1. Dominant plant species
Tree (1) Populus deltoides
Shrub Not specified
Herbaceous (1) Andropogon gerardii
(2) Sorghastrum nutansPhysiographic features
Soils of the Loamy Bottomland 23-31” PZ ecological site were formed in stratified calcareous silty and loamy alluvium. The site occurs in nearly level bottomlands and flood plains of streams, wide creeks and rivers that carry sediments from Permian and Triassic sandstone and siltstone in the sub-humid and semiarid regions of Texas and Oklahoma, and Kansas. Slopes range from 0 to 2 percent. Some areas have a ground water table within 20 feet. Flooding is usually severe and occurs frequent to rarely, but is of short duration, usually 1 or more times per year to once in 50 years, unless protected. Elevation ranges from 1000 to 2900 feet.
Table 2. Representative physiographic features
Landforms (1) River valley > Flood plain
Runoff class Negligible to medium Flooding duration Very brief (4 to 48 hours) to brief (2 to 7 days) Flooding frequency Rare to frequent Ponding frequency None Elevation 1000 – 2900 ft Slope 0 – 2 % Water table depth 72 in Aspect Aspect is not a significant factor Climatic features
MLRA 78C lies within the subtropical sub-humid climate regime, which typically has dry winters with hot and not as humid summers. MLRA 78C extends north and south from Coldwater, Kansas to just northeast of San Angelo, Texas (Ballinger, Texas), and east to west from Weatherford, Oklahoma to west of Shamrock, Texas. This regime is characterized by rapid changes in temperature; marked extremes, both daily and annual; and rather erratic rainfall. The weather is alternately influenced by cold dry air from the Arctic Circle, and warm moist air from the Gulf of Mexico.
Seasonal changes are gradual. Spring is a season of variable weather and relatively high precipitation with prevailing winds from the southwest. Summers are generally hot with low humidity. Fall has long periods of pleasant weather interspersed with moderate to heavy rains. Winter is open and moderate to cold with winds from the north and infrequent snows.
Wind speeds average more than eleven miles an hour with prevailing southern winds. Rather strong winds can occur in all months of the year. While strong gusty winds occur, severe dust storms are rare.
Approximately 75 percent of the rainfall occurs during the warm season, and much of it comes in storms of high intensity and short duration in May and June. These rains can be particularly erosive on sites where vegetation is sparse. Occasional droughts are to be expected. Lack of rainfall and hot, dry winds often curtail forage production during July and August.Table 3 Representative climatic features
Frost-free period (characteristic range) 160-190 days Freeze-free period (characteristic range) 190-210 days Precipitation total (characteristic range) 30-30 in Frost-free period (actual range) 160-190 days Freeze-free period (actual range) 190-220 days Precipitation total (actual range) 30-30 in Frost-free period (average) 180 days Freeze-free period (average) 200 days Precipitation total (average) 30 in Characteristic rangeActual rangeBarLineFigure 2. Monthly precipitation range
Characteristic rangeActual rangeBarLineFigure 3. Monthly minimum temperature range
Characteristic rangeActual rangeBarLineFigure 4. Monthly maximum temperature range
BarLineFigure 5. Monthly average minimum and maximum temperature
Figure 6. Annual precipitation pattern
Figure 7 Annual average temperature pattern
Climate stations used
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(1) COLDWATER [USC00141704], Coldwater, KS
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(2) MUTUAL [USC00346139], Mutual, OK
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(3) CLINTON SHERMAN AP [USW00003932], Dill City, OK
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(4) VERNON [USC00419346], Vernon, TX
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(5) SEYMOUR 3NW [USC00418221], Seymour, TX
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(6) ABILENE 2 [USC00410013], Abilene, TX
">Influencing water features
These sites are subjected to periodic flooding as well as run-off from adjacent upland site.
Wetland description
NA
Soil features
Soils are mapped for each county within the MLRA. Mapunits are representations of the major soil series component(s) and named accordingly. Each Mapunit is spatially represented on a digital soils map as polygons of different shapes and sizes. Within these Mapunits, there are often minor soil series components included. These minor components are soils that occur within a Mapunit polygon but are of small extent (15% or less of the Mapunit area). However, it is difficult to separate these minor soils spatially due to the scale of soil mapping.
Ecological sites are correlated at the component level of the soil survey. Therefore, a single Mapunit may contain multiple Ecological Sites just as it may contain multiple soil components. This is important to understand when investigating soils and Ecological Sites. A soil survey Mapunit may be correlated to a single Ecological Site based on the major component; however, there may be inclusional areas of additional Ecological Sites which are correlated to the minor components of that particular soil Mapunit.
Representative soil components for this site include:
Clairemont, Colorado, Wheatwood, Cyril, Spur, Port, Westola and Yomont.
The soils in the Loamy Bottomland Ecological Site are very deep and well drained. Permeability is moderate. Runoff is negligible on slopes less than 1 percent and very low on 1 to 3 percent slopes.Table 4. Representative soil features
Parent material (1) Alluvium – sandstone
Surface texture (1) Loam
(2) Silt loam
(3) Silty clay loam
Family particle size (1) Loamy
Drainage class Moderately well drained to well drained Permeability class Very slow to moderate Soil depth 60 – 80 in Surface fragment cover <=3" Not specified Surface fragment cover >3" Not specified Available water capacity
(0-40in)2.8 – 9.3 in Calcium carbonate equivalent
(0-40in)0 – 15 % Electrical conductivity
(0-40in)0 – 2 mmhos/cm Sodium adsorption ratio
(0-40in)0 – 4 Soil reaction (1:1 water)
(0-40in)7.4 – 8.4 Subsurface fragment volume <=3"
(Depth not specified)0 – 2 % Subsurface fragment volume >3"
(Depth not specified)0 – 1 % Ecological dynamics
The information contained in the State and Transition Diagram (STD) and the Ecological Site Description was developed using archeological and historical data, professional experience, and scientific studies. The information presented is representative of a very complex set of plant communities. Not all scenarios or plants are included. Key indicator plants, animals and ecological processes are described to inform land management decisions.
The Loamy Bottomland Ecological Site occurs on nearly level to gently sloping land adjacent to rivers and streams. The historic plant community (Reference) of the Loamy Bottomland Ecological Site developed under the prevailing subtropical, sub-humid climate over time along with the soils defining the site. The topographic position along streams, deep soil and occasional extra runoff water from surrounding uplands encouraged tall grass and woody plant production. The resulting plant community was a Tallgrass Grassland Community (1.1) characterized by tallgrasses plus midgrasses, forbs and scattered woody species . The trees and shrubs occupied locations protected from frequent and intense fires that occurred throughout the region before European settlement (Frost 1994). The endemic woody plants, which historically provided five to ten percent canopy cover, were either resistant to fire or occupied areas where fires were less frequent or intense.
The demise of the Native American Indians, expansion of the livestock industry and cessation of periodic intense fires changed the ecological dynamics of the vegetation on the Loamy Bottomland site. After European settlement in the late 1800’s, the frequency and intensity of fire diminished and continuous overgrazing by cattle and sheep began a transition from the reference plant community towards a woodland plant community. Although recent climatic warming trends and increases in atmospheric carbon dioxide may be enhancing vegetation change, the major forces influencing transition from the historic climax plant community to a woodland state are continuous overgrazing by livestock and the decrease in frequency and intensity of fire (Archer1998).
As livestock and wildlife numbers increase and grazing use exceeds the plants ability to sustain defoliation, the more palatable and generally more productive species decline in the composition, productivity and density. The more palatable and accessible tall grasses and forbs give way to midgrasses, such as sideoats grama , sand dropseed, tobosa, Texas wintergrass, blue grama and vine mesquite. The better quality forbs, such as Illinois bundleflower and Engelmann’s daisy, are replaced by less palatable species. The woody species that had been kept in check by fire and grass competition increase in size and density. The site also becomes open to invasion of species from adjacent sites. The change in density and stature of the woody vegetation brings about a new plant community, the Mixed-grass Community (1.2).
The Mixed-grass Community is characterized by increases in sideoats grama, little bluestem, Arizona cottontop and vine-mesquite and 10 to 20 percent woody plant cover. In the Mixed-grass Community (1.2) ecological processes have changed little and the pathway back to the reference community can be accomplished without major energy inputs. Good grazing management alone will not reverse the trend towards the woodland state, however. Some form of woody plant control, such as prescribed burning and selective, mechanical brush control must accompany it. Due to the watershed location and occasional flooding, chemical brush control should be used with caution on the Loamy Bottomland site.
If the combination of abusive grazing by livestock and wildlife continues, as it did on most areas of this site through the middle of the twentieth century, less palatable grasses, forbs, shrubs and trees become dominant to the detriment of taller and more palatable species. Loss of herbaceous cover and increased bare ground precludes effective burning and encourages accelerated erosion. Soil and litter movement will occur during floods and water infiltration into the soil decreases. When woody plant canopy reaches 20 to 25 percent and the grass component provides less than 50 percent of the herbage production, the transition into a woodland state is complete. The first stage of the woodland state is the Shortgrass/Mixed-brush Community (2.1). Once this threshold is crossed, proper grazing management and prescribed burning alone cannot return the Shortgrass/Mixed-brush Community (2.1) to the Grassland state.
The endemic trees, such as pecan, cottonwood and hackberry, can dominate the overstory in the Shortgrass/Mixed-brush Community (2.1) type. However, mesquite, western soapberry and non-native species such as Chinese elm and salt cedar often invade and form thickets. Once established, the trees and shrubs can become dominant, even without grazing, if they are not controlled. Occasionally saline conditions are produced, resulting in increased amounts of alkali sacaton and inland saltgrass. Salt cedar is particularly invasive where saline conditions develop. Midgrass and forb diversity and production continues to decline while shrubs, shade-tolerant grasses and weedy annuals increase as the canopy becomes denser. The herbaceous component is further reduced through shading and competition from woody vegetation.
Continued abusive grazing by livestock and deer, along with periodic droughts, eventually brings about a plant community in which woody plants are so dominant that only remnants of grassland vegetation remain in the interspaces. This plant community type is identifiable as the Mixed-brush/Annuals Woodland Community (2.2). The understory and interspaces support only remnants of reference vegetation, generally in low vigor and productivity due to shading and competition for water and nutrients. Eventually annual grasses and forbs dominate the herbaceous layer. Summer grazing followed by winter rest frequently encourages dominance of Texas wintergrass. The plant community is so degraded that it cannot reverse retrogression without extensive energy and management inputs.
Restoring the Mixed-brush/Annuals Woodland Community (2.2) to the grassland state requires extensive accelerated management practices, such as mechanical brush control, range planting, prescribed grazing and prescribed burning. The unique characteristics of the Loamy Bottomland Site and the great differences from adjacent sites make special management necessary. It also is important as part of the lands riparian zone and influences downstream water quantity and quality. Often it may be beneficial to fence this site to manage or limit access by grazing animals. Haying of the tallgrasses is an alternative to grazing. With extensive accelerated practices, time and proper management, this plant community can again resemble the reference community in productivity and functioning of ecological processes. The closeness to which the plant community is managed depends upon the goals of management. Generally, the Mixed-grass (1.2) or Shortgrass/Mixed-brush (2.1) Communities will provide adequate habitat for livestock and wildlife.
State and Transition Diagram:
A State and Transition Diagram for the Loamy Bottomland (R078CY103TX) site is depicted below. Thorough descriptions of each state, transition, and pathway follow the model. Experts base this model on available experimental research, field observations, professional consensus, and interpretations. It is likely to change as knowledge increases.
Plant communities will differ across the MLRA because of the natural variability in weather, soils, and aspect. The Reference Plant Community is not necessarily the management goal; other vegetative states may be desired plant communities as long as the Range Health assessments are in the moderate and above category.
The biological processes on this site are complex. Therefore, representative values are presented in a land management context. The species lists are representative and are not botanical descriptions of all species occurring, or potentially occurring, on this site. They are not intended to cover every situation or the full range of conditions, species, and responses for the site.
Composition by dry weight and percent canopy cover are provided to describing the functional groups. Most observers find it easier to visualize or estimate percent canopy for woody species (trees and shrubs).
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
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textEcosystem states
T1A - Absence of disturbance and natural regeneration over time, may be coupled with excessive grazing pressure T1B - Extensive soil disturbance followed by seeding R2A - Adequate rest from defoliation and removal of woody canopy, followed by reintroduction of historic disturbance regimes T2A - Extensive soil disturbance followed by seeding State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 1
Grassland StateThe reference community for the Loamy Bottomland Ecological Site was dominated by tallgrass species. The herbaceous component accounted for 75 to 80 percent of the site’s primary annual production, with tallgrasses such as switchgrass, Indiangrass, big and sand bluestem and little bluestem accounting for 40 to 50 percent of the herbage production. Secondary grasses were sideoats grama, vine mesquite, Arizona cottontop, and plains bristlegrass. Canada wildrye, Texas wintergrass and western wheatgrass were common cool-season grasses. Common forbs included Maximilian sunflower, Illinois bundleflower, heath aster, gaura, prairie clover and Engelmann’s daisy. Woody plants, primarily cottonwood, hackberry, pecan and American elm were widely scattered along the stream course and draws. Shrubs and vines such as bumelia, blackhaw, plum, and pricklyash were present but kept suppressed by periodic fires and grass competition. Annual primary production ranges from 3000 to 8000 pounds annually.
The Mixed-grass Community (1.2) reflects the results of the suppression of fires and the effects of overgrazing on the more palatable species. Indigenous and invading woody plants have increased in density and stature. The endemic hardwoods, particularly plum, western soapberry, sumacs, and elm expand in size and density. Little bluestem, sideoats grama, vine-mesquite, are generally persistent in this phase, but most of the more palatable tall and midgrasses are being replaced by subdominants such as silver bluestem, tobosa, Texas wintergrass and less palatable forbs and annuals. Western ragweed, heath aster and Louisiana sagewort are common weeds. Forage production is not significantly affected but primary production is shifting to the less palatable or more grazing resistant species. Annual primary production ranges from 2500 to 7500 pounds.
Community 1.1
Tallgrass Grassland Community
Figure 8. 1.1 Tallgrass Grassland Community
The reference plant community for the Loamy Bottomland Ecological Site was dominated by tallgrass species when European settlers first arrived. This plant community evolved under the influence of grazing, periodic fire and a dry sub-humid climate. The frequent flooding and an occasional high water table influenced the plant community. Woody plants, primarily cottonwood, hackberry, pecan and American elm were widely scattered along the stream course and draws. Shrubs and vines such as bumelia, blackhaw, plum, pricklyash, hawthorn, redbud, greenbriar, ivy treebine and grape were present but kept suppressed by periodic fires and grass competition. The herbaceous component accounted for 75 to 80 percent of the site’s primary annual production, with tallgrasses such as switchgrass, Indiangrass, big and sand bluestem and little bluestem accounting for 40 to 50 percent of the herbage production. Secondary grasses were sideoats grama, vine mesquite, Arizona cottontop, plains bristlegrass, Canada wildrye and dropseed. Alkali sacaton and inland saltgrass occurred in small amounts where saline conditions occurred. Canada wildrye, Texas wintergrass and western wheatgrass were common cool-season grasses. Common forbs included Maximilian sunflower, Illinois bundleflower, heath aster, gaura, greenthread, verbena, prairie clover and Engelmann’s daisy. (See Plant Community Composition and Annual Production table below).
The Tallgrass Plant Community is highly productive due to deep, fertile soils and water availability. Soil erosion was low due to the abundant plant cover, litter, and slow runoff. Runoff is reduced due to the dense tallgrass cover. The vegetative ground cover helped disperse and slow down runoff thus holding soil in place and enhancing infiltration into the slowly permeable soils. Concentrated water flow patterns were probably rare.
Without proper grazing management that adjusts animal numbers, including deer, to annual forage production and judicious prescribed burning, the Tallgrass Grassland Community will transition (regress) to a Mixed-grass Community (1.2). Generally, the Loamy Bottomland is a preferred habitat for both livestock and wildlife so most areas of this site have received overgrazing by livestock and wildlife and have regressed to a lesser plant community type.Figure 9. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Grass/Grasslike 2400 4000 6400 Forb 300 500 800 Tree 240 400 640 Shrub/Vine 60 100 160 Total 3000 5000 8000 Figure 10. Plant community growth curve (percent production by month). TX2286 , Tallgrass Prairie Community. Tallgrass with warm-season growing season dominated site..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 1 3 3 8 20 18 8 10 17 9 2 1 Community 1.2
Mixed-grass Community
Figure 11. 1.2 Mixed-grass Community
The Mixed-grass Community (1.2) reflects the results of the suppression of fires and the effects of overgrazing on the more palatable species. Indigenous and invading woody plants have increased in density and stature. The endemic hardwoods, particularly plum, western soapberry, sumacs, and elm expand in size and density. Mesquite, redberry juniper, tasajillo, pricklypear wolfberry and lotebush are the more common woody invaders. Little bluestem, sideoats grama, vine-mesquite, are generally persistent in this phase, but most of the more palatable tall and midgrasses are being replaced by subdominants such as silver bluestem, tobosa, bristlegrass, Texas wintergrass and less palatable forbs and annuals. Western ragweed, heath aster and Louisiana sagewort are common weeds. Forage production is not significantly affected but primary production is shifting to the less palatable or more grazing resistant species. Annual primary production ranges from 2500 to 7500 pounds annually with approximately 65 percent being produced by the grassland component. Nutrient cycling and water use is shifting toward the deeper-rooted woody perennials. Soil organic matter and litter are slightly less than were present in the reference community.
The transition of the Mixed-grass Community toward a Woodland State is reversible with prescribed grazing management and prescribed burning practices until the woody canopy exceeds 20 to 25 percent. Once woody plant canopy exceeds 25 percent, the plant community crosses a threshold to the Shortgrass/Mixed-brush Community (2.1). Once the threshold into a Woodland State is crossed the transition is irreversible without considerable energy input in the form of mechanical or chemical brush control.Figure 12. Annual production by plant type (representative values) or group (midpoint values)
Table 6. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Grass/Grasslike 1625 3250 4875 Tree 625 1250 1875 Forb 250 500 750 Total 2500 5000 7500 Figure 13. Plant community growth curve (percent production by month). TX2276 , Mid/Shortgrasses with Forbs. Warm-season mid and shortgrasses, cool-season grasses, and forbs..
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 2 4 8 25 25 14 6 8 5 2 1 Pathway 1.1A
Community 1.1 to 1.2
Tallgrass Grassland Community
Mixed-grass CommunityWithout proper grazing management that adjusts animal numbers, including deer, to annual forage production and judicious prescribed burning, the Tallgrass Grassland Community will transition (regress) to a Mixed-grass Community (1.2).
Pathway 1.2A
Community 1.2 to 1.1
Mixed-grass Community
Tallgrass Grassland CommunityWith the implementation of Prescribed Grazing and Prescribed Burning conservation practices, the Mixed-grass Community can be reverted back to the Tallgrass Grassland Community.
Conservation practices
Prescribed Burning Prescribed Grazing State 2
Woodland StateThe Shortgrass/Mixed-brush Community (2.1) supports a 20 to 35 percent woody plant cover dominated by various bottomland hardwoods plus invading mesquite and mixed-brush with a shortgrass dominated herbaceous layer. The diversity of the grassland component declines while unpalatable woody plants and forbs increase. All, but the more palatable woody species, have increased in size and density. The typical woody plant cover is mesquite dominated with pricklypear, lotebush, and ephedra. Pecan, cottonwood, western soapberry, hackberry and elm persist near the stream edge. Where present, tobosa remains the dominant grass, but as regression progresses under heavy grazing pressure, tobosa gives way to buffalograss and other less palatable shortgrasses and forbs. Gaura, western ragweed, verbena, greenthread and, prairie coneflower are commonly found in this community. Cool-season grasses, such as Texas wintergrass, Canada wildrye and western wheatgrass, are persistent under and around woody plants where shading occurs. Annual herbage production ranges from approximately 2,000 to 7,000 pounds per acre, depending on precipitation events, flooding events and dry cycles.
The Mixed-brush/Annuals Woodland Community (2.2) is the result of continued overgrazing by livestock and no control of woody species. Several woody species may dominate the site. Cottonwood, hackberry and elm were the early dominants. Western soapberry, mesquite and salt cedar have increased tremendously in the past few decades. They often form dense woodlands on the site where grazing has been heavy and continuous and fires have been excluded. Salt cedar, along with baccharis, is particularly problematic where salinity has increased. Common understory shrubs are pricklypear, tasajillo and plum. Shortgrasses, cool-season grasses and low quality annual and perennial forbs occupy the tree interspaces. Characteristic grasses found in this plant community are Texas wintergrass, three-awns, annual panicum, tobosa, silver bluestem and sedges. With continued heavy grazing by livestock and deer, the brush canopy can increase to almost 100 percent cover.
Community 2.1
Shortgrass/Mixed-brush Community
Figure 14. 2.1 Shortgrass/Mixed-brush Community
The Shortgrass/Mixed-brush Community (2.1) supports a 20 to 35 percent woody plant cover dominated by various bottomland hardwoods plus invading mesquite and mixed-brush with a shortgrass dominated herbaceous layer. This community is the result of selective grazing by livestock, suppression of fire and the differential response of plants to defoliation. The diversity of the grassland component declines while unpalatable woody plants and forbs increase. All, but the more palatable woody species, have increased in size and density. The typical woody plant cover is mesquite dominated with pricklypear, wolfberry, lotebush, ephedra and greenbriar as common understory shrubs. Pecan, cottonwood, western soapberry, hackberry and elm persist near the stream edge. Where present, tobosa remains the dominant grass, but as regression progresses under heavy grazing pressure, tobosa gives way to buffalograss and other less palatable shortgrasses and forbs. Gaura, western ragweed, verbena, greenthread and, prairie coneflower are the commonly found forbs in this community. Cool-season grasses, such as Texas wintergrass, Canada wildrye and western wheatgrass, are persistent under and around woody plants where shading occurs. Texas filaree and Japanese brome are often abundant following wet winters. Alkali sacaton is abundant where saline soil conditions occur. Salt cedar may also invade these areas.
Annual herbage production ranges from approximately 2000 to 7000 pounds per acre, depending on precipitation events, flooding events and dry cycles. Annual herbage production is less than in the Shortgrass/Mixed-brush Community (1.2) due to decline in soil structure and organic matter. Herbage production is balanced between the grassland component and woody species.
As the grassland component declines, more soil is exposed to crusting and erosion. During the middle and end of this plant community phase, considerable soil becomes exposed. Water erosion is not a serious problem because of shallow slopes on the site. Higher interception loss of water by the increasing woody canopy combined with evaporation losses reduces the effectiveness of rainfall. Litter, soil organic matter and structure decline in the interspaces reducing water infiltration, but hydrologic conditions improve under the woody plant cover.
When the woody plant cover reaches 35 to 50 percent and the herbaceous component contributes less than 50 percent of the herbage production, the Shortgrass/Mixed-brush Community (2.1) transitions into a Mixed-Brush/Annuals Woodland Community (2.2).
Figure 15. Annual production by plant type (representative values) or group (midpoint values)
Table 7. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Tree 900 2025 3150 Grass/Grasslike 900 2025 3150 Forb 200 450 700 Total 2000 4500 7000 Figure 16. Plant community growth curve (percent production by month). TX2285 , Shortgrass/Mixedbrush Community. Shortgrasses, annual grasses and shrubs dominate the plant community..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 1 3 6 15 24 18 3 5 15 7 2 1 Community 2.2
Mixed-Brush/Annuals Woodland Community
Figure 17. 2.2 Mixed-brush/Annuals Woodland Community
The Mixed-brush/Annuals Woodland Community (2.2) is the result of continued overgrazing by livestock and no control of woody species. Several woody species may dominate the site. Cottonwood, hackberry and elm were the early dominants. Western soapberry, mesquite and salt cedar have increased tremendously in the past few decades. They often form dense woodlands on the site where grazing has been heavy and continuous and fires have been excluded. Salt cedar, along with baccharis, is particularly problematic where salinity has increased. Common understory shrubs are pricklypear, tasajillo and plum. Shortgrasses, cool-season grasses and low quality annual and perennial forbs occupy the tree interspaces. Characteristic grasses found in this plant community are Texas wintergrass, threeawns, annual panicum, tobosa, silver bluestem and sedges. Representative forbs include heath aster, western ragweed, prairie coneflower, annual broomweed and croton. With continued heavy grazing by livestock and deer, the brush canopy can increase to almost 100 percent cover. With dense cover shortgrasses, such as three-awns, Japanese brome, annual panicum and sedges are the dominant grasses. Texas wintergrass persists where mesquite is dominant and can become abundant following above normal rainfall.
The woody species will continue to thicken until the community stabilizes with the climate and soil. The woody overstory can reach 80 to 90 percent ground cover with less than 25 percent of the herbage being produced by a weakened grassland component. With continued livestock grazing, the mature phase of the Mixed-brush/Annuals Woodland Community provides cover for wildlife, but only limited amounts of preferred forage or browse is available for livestock or wildlife.
Returning the Mixed-brush/Annuals Woodland Community back to the Grassland state requires extensive and expensive reclamation practices. Without major brush control and management inputs, this plant community cannot be returned to grassland. Range planting, prescribed grazing and prescribed burning, must follow intensive mechanical brush control. Land use other than livestock production might dictate alternative reclamation approaches to create the plant community that best fits the intended use.
Figure 18. Annual production by plant type (representative values) or group (midpoint values)
Table 8. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Tree 1400 3150 4900 Grass/Grasslike 500 1125 1750 Forb 100 250 350 Total 2000 4525 7000 Figure 19. Plant community growth curve (percent production by month). TX2288 , Mixed-Brush/Annuals/Woodland Community. Spring and summer growth of shortgrasses, cool-season grasses, shrubs, and annual grasses & forbs..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 1 3 6 15 24 18 3 5 15 7 2 1 Pathway 2.1A
Community 2.1 to 2.2
Shortgrass/Mixed-brush Community
Mixed-Brush/Annuals Woodland CommunityWith heavy continuous grazing pressure, no fires, and no brush management practices implemented, the Shortgrass/Mixed-brush Community can be shifted to the Mixed-brush/Annuals Woodland Community.
Pathway 2.2A
Community 2.2 to 2.1
Mixed-Brush/Annuals Woodland Community
Shortgrass/Mixed-brush CommunityWith Brush Management and Prescribed Grazing, the Mixed-brush/Annuals Woodland Community can be shifted back to the Shortgrass/Mixed-brush Communities.
Conservation practices
Brush Management Prescribed Grazing State 3
Converted Land StateThe 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.
Community 3.1
Converted Land CommunityThe Loamy Bottomland Ecological Site is often cultivated and planted to crops. The deep fertile soils and occasional extra runoff make it a productive cropland site. Many acres have been put to plow. Technical advice as to adapted crops, cropping systems, production, and cultivation practices are available from local NRCS or Extension Service offices. When cropping is abandoned the site should be re-vegetated with adapted native plant mixtures, which include reference species. Cultivation and erosion may have reduced soil productivity but near reference forage production may be obtained with a native plant mix that approximates reference species composition. Introduced species 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.
Weedy grasses, forbs and shrubs will be the first species in secondary succession if fields are abandoned and let re-vegetate naturally. They often persist for many years. Even without grazing, woody species will encroach and eventually dominate unless brush management practices and prescribed burning are applied.Figure 20. Plant community growth curve (percent production by month). TX2252 , Small Grains. Cool-season small grain crops..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 5 5 10 10 5 0 0 0 20 25 15 5 Figure 21. Plant community growth curve (percent production by month). TX2264 , Warm-season Pasture Grasses. warm-season pasture grasses having nutrient management, pest management, and prescribed grazing..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 1 2 5 12 25 20 5 5 14 8 2 1 Transition T1A
State 1 to 2Due to heavy continuous grazing, no brush management, and no fires to keep the brush species in check, the Grassland State will transition into the Shrubland State.
Transition T1B
State 1 to 3The transition to the Converted Land 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 1Converting the Woodland State back to the Grassland state requires extensive and expensive reclamation practices. Without major brush control and management inputs, this plant community cannot be returned to grassland. Range planting, prescribed grazing and prescribed burning, must follow intensive mechanical brush control.
Conservation practices
Brush Management Prescribed Burning Prescribed Grazing Range Planting Transition T2A
State 2 to 3The transition to the Converted Land 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 () Foliar cover (%) Grass/Grasslike1 Tallgrasses 1500–4000 Indiangrass SONU2 Sorghastrum nutans 300–800 – eastern gamagrass TRDA3 Tripsacum dactyloides 300–800 – big bluestem ANGE Andropogon gerardii 300–800 – sand bluestem ANHA Andropogon hallii 300–800 – Florida paspalum PAFL4 Paspalum floridanum 300–800 – switchgrass PAVI2 Panicum virgatum 300–800 – little bluestem SCSC Schizachyrium scoparium 200–600 – 2 Midgrasses 450–1200 sideoats grama BOCU Bouteloua curtipendula 45–120 – silver beardgrass BOLAT Bothriochloa laguroides ssp. torreyana 45–120 – Arizona cottontop DICA8 Digitaria californica 45–120 – lovegrass ERAGR Eragrostis 45–120 – vine mesquite PAOB Panicum obtusum 45–120 – tobosagrass PLMU3 Pleuraphis mutica 45–120 – large-spike bristlegrass SEMA5 Setaria macrostachya 45–120 – alkali sacaton SPAI Sporobolus airoides 45–120 – composite dropseed SPCOC2 Sporobolus compositus var. compositus 45–120 – Drummond's dropseed SPCOD3 Sporobolus compositus var. drummondii 45–120 – white tridens TRAL2 Tridens albescens 45–120 – purpletop tridens TRFL2 Tridens flavus 45–120 – 3 Shortgrasses 150–400 purple threeawn ARPU9 Aristida purpurea 15–45 – Wright's threeawn ARPUW Aristida purpurea var. wrightii 15–45 – buffalograss BODA2 Bouteloua dactyloides 15–45 – blue grama BOGR2 Bouteloua gracilis 15–45 – panicgrass PANIC Panicum 15–45 – tumblegrass SCPA Schedonnardus paniculatus 15–45 – sand dropseed SPCR Sporobolus cryptandrus 15–45 – slim tridens TRMU Tridens muticus 15–45 – slim tridens TRMUE Tridens muticus var. elongatus 15–45 – 4 Cool-season Grasses 300–800 sedge CAREX Carex 50–140 – Canada wildrye ELCA4 Elymus canadensis 50–140 – Texas wintergrass NALE3 Nassella leucotricha 50–140 – western wheatgrass PASM Pascopyrum smithii 50–140 – Texas bluegrass POAR Poa arachnifera 50–140 – 5 Cool-season grasses 300–800 sedge CAREX Carex 50–140 – Canada wildrye ELCA4 Elymus canadensis 50–140 – Texas wintergrass NALE3 Nassella leucotricha 50–140 – western wheatgrass PASM Pascopyrum smithii 50–140 – Texas bluegrass POAR Poa arachnifera 50–140 – Forb6 Forbs 300–800 Cuman ragweed AMPS Ambrosia psilostachya 15–50 – anemone ANEMO Anemone 15–50 – white sagebrush ARLUM2 Artemisia ludoviciana ssp. mexicana 15–50 – poppymallow CALLI3 Callirhoe 15–50 – rose heath CHER2 Chaetopappa ericoides 15–50 – smallflower fumewort COMIA2 Corydalis micrantha ssp. australis 15–50 – Illinois bundleflower DEIL Desmanthus illinoensis 15–50 – Engelmann's daisy ENPE4 Engelmannia peristenia 15–50 – beeblossom GAURA Gaura 15–50 – Indian rushpea HOGL2 Hoffmannseggia glauca 15–50 – littleleaf sensitive-briar MIMI22 Mimosa microphylla 15–50 – evening primrose OENOT Oenothera 15–50 – beardtongue PENST Penstemon 15–50 – groundcherry PHYSA Physalis 15–50 – sage SALVI Salvia 15–50 – globemallow SPHAE Sphaeralcea 15–50 – white heath aster SYERE Symphyotrichum ericoides var. ericoides 15–50 – greenthread THELE Thelesperma 15–50 – prairie spiderwort TROC Tradescantia occidentalis 15–50 – vervain VERBE Verbena 15–50 – Tree7 Trees/Shrubs/Vines 300–800 heartleaf peppervine AMCO2 Ampelopsis cordata 0–800 – pecan CAIL2 Carya illinoinensis 0–800 – Texas redbud CECAT Cercis canadensis var. texensis 0–800 – hackberry CELTI Celtis 0–800 – chicory CIIN Cichorium intybus 0–800 – sorrelvine CITR2 Cissus trifoliata 0–800 – Carolina coralbead COCA Cocculus carolinus 0–800 – Christmas cactus CYLE8 Cylindropuntia leptocaulis 0–800 – green ash FRPE Fraxinus pennsylvanica 0–800 – Osage-orange MAPO Maclura pomifera 0–800 – pricklypear OPUNT Opuntia 0–800 – honey mesquite PRGL2 Prosopis glandulosa 0–800 – plum PRUNU Prunus 0–800 – oak QUERC Quercus 0–800 – fragrant sumac RHAR4 Rhus aromatica 0–800 – littleleaf sumac RHMI3 Rhus microphylla 0–800 – western soapberry SASAD Sapindus saponaria var. drummondii 0–800 – greenbrier SMILA2 Smilax 0–800 – elm ULMUS Ulmus 0–800 – rusty blackhaw VIRU Viburnum rufidulum 0–800 – grape VITIS Vitis 0–800 – pricklyash ZANTH Zanthoxylum 0–800 – lotebush ZIOB Ziziphus obtusifolia 0–800 – heartleaf peppervine AMCO2 Ampelopsis cordata 5–30 – Texas redbud CECAT Cercis canadensis var. texensis 5–30 – sorrelvine CITR2 Cissus trifoliata 5–30 – Carolina coralbead COCA Cocculus carolinus 5–30 – Christmas cactus CYLE8 Cylindropuntia leptocaulis 5–30 – pricklypear OPUNT Opuntia 5–30 – plum PRUNU Prunus 5–30 – fragrant sumac RHAR4 Rhus aromatica 5–30 – littleleaf sumac RHMI3 Rhus microphylla 5–30 – bully SIDER2 Sideroxylon 5–30 – greenbrier SMILA2 Smilax 5–30 – rusty blackhaw VIRU Viburnum rufidulum 5–30 – grape VITIS Vitis 5–30 – pricklyash ZANTH Zanthoxylum 5–30 – lotebush ZIOB Ziziphus obtusifolia 5–30 – Table 10. Community 1.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 11. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 12. Community 2.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 13. Community 3.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
Many types of wildlife use Loamy Bottomland Ecological Site. Being associated with flood plains and water courses, it probably received concentrated animal use at times. Bison probably 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 many kinds of 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. Most are still plentiful. Bison and pronghorn antelope, however, are no longer present. White-tailed deer utilize the Loamy Bottomland site in its various states. Deer, turkey and quail particularly favor the habitat provided by the Shortgrass/Mixed-brush (2.1) plant community.
The site in or near reference condition is very suited to primary grass eaters such as cattle. As retrogression occurs and woody plants invade it becomes better habitat for a mixture of cattle, sheep, goats, deer and other wildlife because of the browse and cool season grasses. Sheep and goats are seldom pastured in the MLRA, however. Any 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/Annuals Woodland phase will have little to offer as wildlife habitat except cover.Hydrological functions
The Loamy Bottomland Ecological Site is well-drained, moderately permeable and found on nearly level flood plains. It may receive water from surrounding soils and the site may be covered with by water during flooding events. Soil moisture holding capacity is high and percolation is slow. The deep soils, with moderate to good water holding capacity, are conducive to high herbage production during above average moisture years.
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 Tallgrass Grassland Community (1.1) transitions to the Mixed-grass Community (1.2). These processes continue in the spaces between woody plants in the Shortgrass/Mixed-brush Community (2.1) and the Mixed-brush/Annuals Woodland Community (2.2). Once the woodland matures, the hydrologic and ecological processes, nutrient cycling and energy flow stabilize within the woody plant canopy. Evaporation and interception losses are higher, however, resulting in less moisture reaching the soil.Recreational uses
The Loamy Bottomland site, in conjunction with surrounding sites, is well suited for many outdoor recreational uses including recreational hunting, hiking, camping, equestrian and bird watching. This site along with adjacent upland sites provides diverse scenic beauty and many opportunities for recreation and hunting.
Wood products
Mesquite and Osage-orange are sometimes used for posts and charcoal. Wood from all the trees can be used for furniture or specialty products.
Other products
Jams and jellies are made from fruit bearing species. Seeds are harvested from many HCPC plants for commercial sale. Grasses and forbs may be harvested by the dried-plant industry for sale in dried flower arrangements. Honeybees are utilized to harvest honey from the many flowering plants, such as mesquite.
Other information
None.
Supporting information
Inventory data references
Information presented has been derived from RSDs for Loamy Bottomland PE 36-46 (3-1-74) and PE 32-40 (11-2-71) , an undated NRCS draft Ecological Site Description for Loamy Bottomland PE 31-44, 78C, literature, personal experience, field observations and personal contacts with range-trained personnel. Photos by: J.L. Schuster. Photos 1, 2 and 3 taken on Waggoner Ranch, Baylor County, TX.; Photo 4 location was on sheet # 68 of Jones County Soil Survey Manual. Special thanks to the following for assistance and guidance with development of this ESD: Reggie Quiett and Cody Bauman NRCS Vernon, TX, Mark Moseley NRCS, San Antonio, Texas and Justin Clary NRCS Temple, Texas. Reviewers: Lem Creswell, RMS, NRCS, Weatherford, Texas Steve Glasgow, GLS, NRCS, Stillwater, Oklahoma Greg Scott, RSS, NRCS, Stillwater, Oklahoma
Other references
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 Jones, Knox, Baylor and Haskell Counties, 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.Contributors
Joe McEntire, AC, NRCS, Abilene, Texas
Joseph Schuster, Range & Wildlife Habitat Consultants, Bryan, Texas
PES Edits by Tyson Morley, MLRA Soil Scientist, Altus, OklahomaApproval
Bryan Christensen, 9/15/2023
Acknowledgments
Site Development and Testing Plan Future work, as described in a Project Plan, to validate the information in this Provisional Ecological Site Description is needed. This will include field activities to collect low, medium and high intensity sampling, soil correlations, and analysis of that data. Annual field reviews should be done by soil scientists and vegetation specialists. A final field review, peer review, quality control, and quality assurance reviews of the ESD will be needed to produce the final document. Annual reviews of the Project Plan are to be conducted by the Ecological Site Technical Team.
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
Author(s)/participant(s) Lem Creswell, Zone RMS, NRCS, Weatherford, Texas Contact for lead author 817-596-2865 Date 12/20/2007 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
-
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 when occupied by the natural HCPC. -
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:
Some gullies may be present on side drains into perennial and intermittent streams. Gullies should be vegetated and stable. -
Extent of wind scoured, blowouts and/or depositional areas:
None. -
Amount of litter movement (describe size and distance expected to travel):
This is a flood plain with occasional out of bank flow. Under normal rainfall, little litter movement should be expected, however, litter of all sizes may move long distances depending on obstructions under intense storm events. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface is resistant to erosion. Stability class range is expected to be 5 to 6. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
0-64" thick reddish brown silty loam to silty clay loam that has moderate, medium, coarse blocky structure. SOM is 1-6%. See soil survey for specific soils information. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
The savanna of tallgrasses, shortgrasses and trees and shrubs provides excellent soil protection and infiltration. This should essentially eliminate runoff except during very intense storm events or flooding. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
No evidence of compaction under HCPC. -
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 tallgrasses >>Sub-dominant:
Warm-season midgrasses >Other:
Forbs = Trees/Shrubs/Vines = Cool-season grasses > Warm-season shortgrassesAdditional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
There should be little mortality or decadence for any functional group. -
Average percent litter cover (%) and depth ( in):
Dominant litter is herbaceous. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
3000 - 8000 #/ac -
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:
mesquite, plum, skunkbush sumac, pecan, western soapberry, bumelia, salt cedar -
Perennial plant reproductive capability:
All perennial plants should be capable of reproducing except during periods of prolonged drought conditions, heavy natural herbivory or wildfires.
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