Natural Resources
Conservation Service
Ecological site R087AY012TX
Clayey Bottomland
Last updated: 9/21/2023
Accessed: 08/30/2026
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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): 087A–Texas Claypan Area, Southern Part
This area is entirely in south-central Texas. It makes up about 10,535 square miles (27,295 square kilometers). The towns of Bastrop, Bryan, Centerville, College Station, Ennis, Fairfield, Franklin, Giddings, Gonzales, Groesbeck, La Grange, Madisonville, and Rockdale are in this MLRA. Interstate 45 crosses the northern part of the area, and Interstate 10 crosses the southern part. A number of State Parks are located throughout this area. The parks are commonly associated with reservoirs.
Classification relationships
USDA-Natural Resources Conservation Service, 2006.
-Major Land Resource Area (MLRA) 87AEcological site concept
The Clayey Bottomland has soils that are very deep clays and are associated with flooding regimes. Their heavy-textured soils cause water to drain slowly and may potentially pond for many days.
Associated sites
R087AY003TX Claypan Savannah
Claypan Savannah
R087AY005TX Sandy Loam
Sandy Loam
R087AY006TX Sandy
Sandy
R087AY010TX Sandy Bottomland
Sandy Bottomland
R087AY011TX Loamy Bottomland
Loamy Bottomland
Similar sites
R087AY011TX Loamy Bottomland
Loamy Bottomland
Table 1. Dominant plant species
Tree (1) Fraxinus pennsylvanica
(2) Ulmus crassifoliaShrub (1) Ilex decidua
(2) Crataegus marshalliiHerbaceous (1) Elymus virginicus
(2) CarexPhysiographic features
This site is nearly level and occurs along major rivers and their tributaries. The sites flood throughout the year, especially during late fall to early spring. Sites can pond water as well.
Table 2. Representative physiographic features
Landforms (1) Plains > Flood plain
Runoff class High Flooding duration Brief (2 to 7 days) to very long (more than 30 days) Flooding frequency Rare to frequent Ponding duration Brief (2 to 7 days) to long (7 to 30 days) Ponding frequency Rare to occasional Elevation 200 – 750 ft Slope 0 – 2 % Ponding depth 0 – 6 in Water table depth 24 – 80 in Aspect Aspect is not a significant factor Climatic features
The climate for MLRA 87A is humid subtropical and is characterized by hot summers, especially in July and August, and relatively mild winters. The summer months have little variation in day-to-day weather except for occasional thunderstorms that dissipate the afternoon heat. The moderate temperatures in spring and fall are characterized by long periods of mild days and cool nights. The average annual precipitation in this area is 41 inches. Most of the rainfall occurs in spring and fall. The freeze-free period averages about 276 days and the frost-free period 241 days.
Table 3 Representative climatic features
Frost-free period (average) 240 days Freeze-free period (average) 280 days Precipitation total (average) 40 in BarLineFigure 2. Monthly precipitation range
BarLineFigure 3. Monthly average minimum and maximum temperature
Figure 4. Annual precipitation pattern
Figure 5 Annual average temperature pattern
Climate stations used
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(1) BELLVILLE 6NNE [USC00410655], Bellville, TX
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(2) GONZALES 1N [USC00413622], Gonzales, TX
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(3) LA GRANGE [USC00414903], La Grange, TX
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(4) MADISONVILLE [USC00415477], Madisonville, TX
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(5) SMITHVILLE [USC00418415], Smithville, TX
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(6) FRANKLIN [USC00413321], Franklin, TX
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(7) FAIRFIELD 3W [USC00413047], Fairfield, TX
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(8) COLLEGE STN [USW00003904], College Station, TX
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(9) BARDWELL DAM [USC00410518], Ennis, TX
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(10) CROCKETT [USC00412114], Crockett, TX
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(11) ELGIN [USC00412820], Elgin, TX
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(12) SOMERVILLE DAM [USC00418446], Somerville, TX
">Influencing water features
This site is adjacent to rivers and streams. It receives overflow from watercourses and runoff from higher adjacent sites.
Wetland description
All soils in this site are hydric and may be wetlands, but onsite delineations are required to make certain.
Soil features
The soils of this site are deep clays. They receive extra water as overflow from watercourses or as runoff from adjacent higher sites. Having high shrink-swell characteristics, the soils crack when dry. In this condition, they take in water rapidly. When the soil becomes wet and the cracks close, permeability becomes very slow. The soils are very fertile and hold large amounts of water for plant use. They have a high wilting point which reduces forage yields in extremely dry years. Soils correlated include: Navaca, Navasota, Oletha, Roetex, Texark, and Zilaboy.
Table 4. Representative soil features
Parent material (1) Alluvium – mudstone
Surface texture (1) Clay
Family particle size (1) Clayey
Drainage class Somewhat poorly drained to moderately well drained Permeability class Very slow Soil depth 80 in Surface fragment cover <=3" Not specified Surface fragment cover >3" Not specified Available water capacity
(0-40in)5 – 7 in Calcium carbonate equivalent
(0-40in)0 – 15 % Electrical conductivity
(0-40in)0 – 16 mmhos/cm Sodium adsorption ratio
(0-40in)0 – 15 Soil reaction (1:1 water)
(0-40in)5.1 – 8.4 Subsurface fragment volume <=3"
(Depth not specified)0 – 3 % Subsurface fragment volume >3"
(Depth not specified)Not specified Ecological dynamics
Natural fertility, presence of shade, proximity to water, and nutritious forage make this site a preferred grazing area. The wet nature of the site protects it from grazing at times, but during dry conditions it is often the first site to be overused. Virginia wildrye (Elymus virginicus), eastern gamagrass (Tripsacum dactyloides), switchcane (Arundinaria gigantea), switchgrass (Panicum virgatum), and sedges (Carex spp.) decrease in abundance and are replaced by dallisgrass (Paspalum dilatatum), common Bermudagrass (Cynodon dactylon), and carpetgrass (Axonopus fissifolius) as abusive grazing continues. Shrubs and hardwood saplings invade the site in the absence of proper grazing management and brush management. Prolonged mismanagement or abandonment allows the site to become a hardwood forest dominated by water oak (Quercus nigra), willow oak (Quercus phellos), overcup oak (Quercus lyrata), and cedar elm (Ulmus crassifolia) on non-calcareous sites or green ash (Fraxinus pennsylvanica), eastern cottonwood (Populus deltoides), pecan (Carya illinoinensis), cedar elm, and sugarberry (Celtis laevigata) on calcareous sites.
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 - Heavy continuous grazing, no brush management, no fire T1B - Invasion by invasive introduced species T1C - Brush management, crop cultivation, pasture planting R2A - Brush management, prescribed grazing, fire T2A - Invasion by invasive introduced species T2B - Brush management, crop cultivation, pasture planting R3A - Brush management, invasive species control, range planting, prescribed grazing T3A - Brush management, crop cultivation, pasture planting R4A - Brush management, invasive species control, range planting, prescribed grazing T4A - Invasion by invasive introduced species State 1 submodel, plant communities
1.1A - Heavy continuous grazing, no brush management, no fire 1.2A - Brush management, prescribed grazing, fire State 2 submodel, plant communities
State 3 submodel, plant communities
State 4 submodel, plant communities
State 1
SavannahTwo communities exist in the Savannah State: the 1.1 Wildrye/Sedge Savannah Community and the 1.2 Shrub Community. Community 1.1 is characterized by tall and midgrass dominating the understory, with 20 percent woody cover by ash and elm. Community 1.2 is characterized by a an increase in shade tolerant grasses and 20 to 40 percent canopy cover of woody species.
Community 1.1
Wildrye/Sedge Savannah
The reference plant community of this site is a savannah. Oak, elm, hackberry (Celtis spp.), cottonwood, ash, black willow (Salix nigra), pecan, and other large trees provide about a 20 percent canopy. The overstory canopy is denser immediately adjacent to the watercourse. The understory includes hawthorn (Crataegus spp.), greenbriar (Smilax spp.), rattan (Calamus spp.), peppervine (Ampelopsis arborea), grape (Vitis spp.), and trumpet creeper (Campsis radicans). Sedges, Virginia wildrye, switchcane, broadleaf woodoats (Chasmanthium latifolium), and rustyseed paspalum (Paspalum langei) are in shaded and wet areas and dominate the herbaceous plant community. Various combinations of beaked panicum (Panicum anceps), switchgrass, Indiangrass, big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium), eastern gamagrass, vinemesquite (Panicum obtusum), and Florida paspalum (Paspalum floridanum) may dominate drier, open areas.
Continuous yearlong grazing grazing with no weed or brush management or abandoning the site for several years will tend to move towards a shrub-sapling community. Once woody shrubs and saplings invade the site, brush management in some form must be used to move back toward the savannah state. Prescribed burning is not a viable management tool on this site.Figure 6. 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 2800 4500 4900 Tree 800 1000 1400 Shrub/Vine 200 275 350 Forb 200 275 350 Total 4000 6050 7000 Community 1.2
ShrubThis plant community is a transitional community between the Savannah and Woodland State. It develops in the absence of proper grazing management and mechanical or chemical brush control treatments. It is usually the result of abandonment following cropping or yearly continuous grazing. Trees and shrubs begin to replace the grassland component of the savannah community. In addition to the naturally occurring cedar elm, water oak, hackberry, pecan, cottonwood, and green ash - honey locust (Gleditsia triacanthos), Chinese tallow (Triadica sebifera), and eastern persimmon (Diospyros virginiana) increase in density and canopy coverage (20 to 40 percent). Species whose seeds are windblown (elm, cottonwood, ash) or animal dispersed (persimmon, pecan, Chinese tallow) are the first to colonize and dominate the site.
Remnants of Virginia wildrye and eastern gamagrass may still occur but the herbaceous component of the community becomes dominated by lesser producing grasses and forbs. Shade-tolerant species such as broadleaf woodoats, longleaf woodoats (Chasmanthium sessiliflorum), Cherokee sedge (Carex cherokeensis), ironweed (Veronia baldwinii), buttercup (Ranunculus spp.), and goldenrod (Solidago spp.) are the most abundant species as canopy cover increases. Prescribed burning is not a viable option for returning this community to a savannah due to the moisture content in and lack of quantity of herbaceous fine fuels. Mechanical or chemical brush control as well as prescribed grazing must be applied to move this vegetative state back towards the reference plant community.Figure 7. 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)Tree 1300 1750 2200 Grass/Grasslike 1150 1700 1950 Shrub/Vine 300 500 600 Forb 250 450 550 Total 3000 4400 5300 Pathway 1.1A
Community 1.1 to 1.2The Wildrye/Sedge Savannah will transition to the Shrubland Community when continued heavy grazing pressure, no brush management, and/or field abandonment continues. The transition is evident when woody species canopy cover exceeds 20 percent and grasses shift composition to more shade-tolerant species.
Pathway 1.2A
Community 1.2 to 1.1Restoration back to the Wildrye/Sedge Community requires brush management and prescribed grazing. Mechanical or chemical controls can be used to remove the woody species and shrubs. Prescribed grazing may require destocking and/or deferment.
State 2
WoodlandOne community exists in the Woodland State, the Ash/Elm Woodland Community. It is characterized by shade tolerant grasses and an overstory canopy of 40 to 80 percent.
Community 2.1
Ash/Elm WoodlandThis plant community is a closed overstory (40 to 80 percent) woodland dominated by green ash, cedar elm, overcup oak, water oak, willow oak, pecan, cottonwood, sycamore (Plantanus occidentalis), and black willow. Understory shrubs and sub-shrubs include yaupon, farkleberry (Vaccinium arboreum), possumhaw (Ilex decidua), American beautyberry (Callicarpa americana), and hawthorn. Woody vines also occur and include Alabama supplejack (Berchemia scandens), poison ivy (Toxicodendron radicans), grape, greenbrier, trumpet creeper, Virginia creeper (Parthenocissus quinquefolia), and peppervine.
A herbaceous understory is almost nonexistent but shade tolerant species including longleaf uniola, broadleaf woodoats, sedges, ironweed, ice plant (Verbesina lindheimeri), switchcane, eastern gamagrass, and goldenrod may occur in small amounts. Prescribed fire is not a viable treatment option for conversion of this site back to a semblance of the Wildrye/Sedge Savannah. Broadcast chemical brush control is not a treatment option either, however, individual plant treatment with herbicides on small acreages may be a viable option. Mechanical treatment of this site, along with seeding, is the most viable treatment option although probably not economical.Figure 8. 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 2800 3850 4900 Shrub/Vine 650 900 1150 Grass/Grasslike 300 400 500 Forb 100 150 200 Total 3850 5300 6750 State 3
InvasionOne community exists in the Invasion State, the Bermudagrass/Dallisgrass Community. It is characterized by an invasion by tame pasture grasses. The invasive species may have been planted for agriculture purposes or they may have invaded from nearby pastures.
Community 3.1
Bermudagrass/DallisgrassThe herbaceous community is dominated by common Bermudagrass, dallisgrass, carpetgrass, giant ragweed, and annual sumpweed. White clover (Trifloium repens), vetch (Vicia sativa), and annual ryegrass (Lolium multiflorum) may also occur. This community develops from years of heavy continuous grazing. Prescribed grazing may shift this community back towards the Wildrye/Sedge Savannah Community, but total restoration may not be possible as invasive species are hard to control.
Figure 9. 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)Grass/Grasslike 2000 2500 3000 Forb 1000 1250 1500 Tree 800 1100 1400 Shrub/Vine 200 275 350 Total 4000 5125 6250 State 4
Converted LandThe Converted Land State contains one community, the 4.1 Converted Land Community. The state is characterized by the land manager farming crops or planted grasses.
Community 4.1
Converted LandConversion of this site to cropland (primarily cotton) occurred from the middle 1800's to the early 1900's. Some remains in cropland today, typically cotton (Gossypium spp.), corn (Zea mays), sorghum (Sorghum spp.), and soybeans (Glycine max). Ditching, land leveling, and levee construction has significantly changed the topography and hydrology on many acres of this site. While restoration of this site to a semblance of the reference plant community is possible with seeding and prescribed grazing, complete restoration of the reference community in a reasonable time is very unlikely.
Following crop production, this site is often planted to native or introduced grasses and legumes for livestock grazing or hay production. Typical species planted include improved Bermudagrass varieties, bahiagrass, switchgrass, dallisgrass, eastern gamagrass, annual ryegrass (Lolium multiflorum), and white clover. Many of the introduced species (bahiagrass, Bermudagrass, and dallisgrass) are invasive - moving by wind, water, and animals. Once established, they are extremely difficult to remove and will hinder the reestablishment of native species. The establishment and maintenance of these species requires cultivation, fertilization, weed control, and prescribed grazing management.Figure 10. Annual production by plant type (representative values) or group (midpoint values)
Table 9. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Grass/Grasslike 5000 6300 7600 Forb 2000 2750 3500 Total 7000 9050 11100 Transition T1A
State 1 to 2The Savannah State will transition to the Woodland State when continued heavy grazing pressure, no brush management, and/or field abandonment continues. The transition is evident when woody species canopy cover exceeds 40 percent and grasses shift composition to more shade-tolerant species.
Transition T1B
State 1 to 3The Savannah State will transition to the Invasion State when continuous, yearlong heavy grazing occurs, coupled with the invasion of species like Bermudagrass and Dallisgrass.
Transition T1C
State 1 to 4The transition to the Converted State occurs when the site is plowed for planting crops or pasture. The driver for the transition is the land manager's decision to farm the site.
Restoration pathway R2A
State 2 to 1Restoration back to the Savannah State requires substantial energy inputs. Brush management and prescribed grazing will be needed to shift the community back to the reference state. Mechanical or chemical controls can be used to remove the woody overstory species back below 20 percent. Prescribed grazing may require destocking and/or deferment to manage the understory grasses back to those found in the reference community.
Transition T2A
State 2 to 3The Woodland State will transition to the Invasion State when invasion by species like Bermudagrass and Dallisgrass occur. These species will invade from nearby pastures and compete with native vegetation.
Transition T2B
State 2 to 4The transition to the Converted State occurs when the site is plowed for planting crops or pasture. The driver for the transition is the land manager's decision to farm the site.
Restoration pathway R3A
State 3 to 1Restoration back to the Savannah State requires substantial energy inputs. If woody species are present, chemical or mechanical brush management will be required. Range planting may be required if invasive species have taken over completely. Total restoration back to the reference community may not be possible due to the challenge of completely removing invasive species from the community.
Transition T3A
State 3 to 4The transition to the Converted State occurs when the site is plowed for planting crops or pasture. The driver for the transition is the land manager's decision to farm the site.
Restoration pathway R4A
State 4 to 1The restoration to State 1 can occur when the land manager ceases agronomic practices. Range planting of native species found in the reference community will be required to bring back a similar community as the State 1 plant composition. The extent of previous soil disturbances will determine how much seedbed preparation will be needed, as well as the ability to be restored. Proper grazing and brush management will be required to ensure success.
Transition T4A
State 4 to 3The Converted Land State will transition to the Invasion State when continued heavy grazing pressure, no brush management, and/or field abandonment occurs. The transition is evident when forbs, shrubs, and woody species begin to limit the production of planted crops or pasture grasses.
Additional community tables
Table 10. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Cool-season grasses 1435–2450 sedge CAREX Carex 1435–2450 – Virginia wildrye ELVI3 Elymus virginicus 1435–2450 – 2 Tallgrasses 1005–1715 beaked panicgrass PAAN Panicum anceps 1005–1715 – rustyseed paspalum PALA11 Paspalum langei 1005–1715 – switchgrass PAVI2 Panicum virgatum 1005–1715 – eastern gamagrass TRDA3 Tripsacum dactyloides 1005–1715 – 3 Warm-season grasses 430–735 big bluestem ANGE Andropogon gerardii 430–735 – buffalograss BODA2 Bouteloua dactyloides 430–735 – Indian woodoats CHLA5 Chasmanthium latifolium 430–735 – longleaf woodoats CHSE2 Chasmanthium sessiliflorum 430–735 – cylinder jointtail grass COCY Coelorachis cylindrica 430–735 – deertongue DICL Dichanthelium clandestinum 430–735 – twoflower melicgrass MEMU Melica mutica 430–735 – nimblewill MUSC Muhlenbergia schreberi 430–735 – Florida paspalum PAFL4 Paspalum floridanum 430–735 – vine mesquite PAOB Panicum obtusum 430–735 – redtop panicgrass PARI4 Panicum rigidulum 430–735 – little bluestem SCSC Schizachyrium scoparium 430–735 – marsh bristlegrass SEPA10 Setaria parviflora 430–735 – Indiangrass SONU2 Sorghastrum nutans 430–735 – gaping grass STHI3 Steinchisma hians 430–735 – purpletop tridens TRFL2 Tridens flavus 430–735 – longspike tridens TRST2 Tridens strictus 430–735 – Forb4 Forbs 175–350 great ragweed AMTR Ambrosia trifida 175–350 – annual marsh elder IVAN2 Iva annua 175–350 – giant goldenrod SOGI Solidago gigantea 175–350 – Baldwin's ironweed VEBA Vernonia baldwinii 25–350 – white crownbeard VEVI3 Verbesina virginica 25–350 – fuzzybean STROP Strophostyles 175–300 – lespedeza LESPE Lespedeza 175–300 – prairie snoutbean RHLA5 Rhynchosia latifolia 175–300 – ticktrefoil DESMO Desmodium 175–300 – Shrub/Vine5 Shrubs/Vines 200–350 Alabama supplejack BESC Berchemia scandens 200–350 – parsley hawthorn CRMA5 Crataegus marshallii 200–350 – possumhaw ILDE Ilex decidua 200–350 – yaupon ILVO Ilex vomitoria 200–350 – oakwoods dewberry RULA5 Rubus largus 200–350 – saw greenbrier SMBO2 Smilax bona-nox 200–350 – cat greenbrier SMGL Smilax glauca 200–350 – grape VITIS Vitis 200–350 – Tree6 Trees 800–1400 bitternut hickory CACO15 Carya cordiformis 800–1400 – pecan CAIL2 Carya illinoinensis 800–1400 – sugarberry CELAL Celtis laevigata var. laevigata 800–1400 – green ash FRPE Fraxinus pennsylvanica 800–1400 – overcup oak QULY Quercus lyrata 800–1400 – water oak QUNI Quercus nigra 800–1400 – willow oak QUPH Quercus phellos 800–1400 – black willow SANI Salix nigra 800–1400 – western soapberry SASAD Sapindus saponaria var. drummondii 800–1400 – bald cypress TADI2 Taxodium distichum 800–1400 – cedar elm ULCR Ulmus crassifolia 800–1400 – Table 11. Community 1.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 12. Community 2.1 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 (%) Table 14. Community 4.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
Historically, the Clayey Bottomland site provided habitat to bison, deer, turkey, migratory birds and large predators such as wolves, coyotes, mountain lions, and black bear. White-tailed deer, turkey, fox and gray squirrels, coyotes, bobcats, and migratory birds find suitable habitat in these savannahs today. The favorable moisture regime of this site attracts many species of wildlife during the hot dry summer months when the quality and quantity of forages on upland sites may be lacking. Where old mast producing oaks and pecan trees are present, this site provides habitat for deer, turkey, squirrels, and ducks - especially during the winter. If the site transitions from the Savannah State towards the Woodland State, the quality of the habitat for deer, turkey, squirrels, and migratory birds declines.
Hydrological functions
Peak rainfall periods occur in May and June from frontal passage thunderstorms and in September and October from tropical systems as well as frontal passages. Rainfall amounts may be high (three to five inches per event) and events may be intense. The site is subject to erosion along adjacent stream banks where adequate herbaceous cover is not maintained and on heavy use areas such as roads and livestock trails. Extended periods (60 days) of little to no rainfall during the growing season are common. The site may be periodically inundated from overflow water from adjacent watercourses and may be ponded or saturated for long periods. This site may be a wetland or contain wetland inclusions as oxbows or stream meanders.
Recreational uses
Hunting, camping, bird watching, and equestrian activities are common.
Wood products
Water oak and willow oak provides material for hardwood flooring, plywood, veneer, and crossties. Green ash is used for bats, tool handles, and furniture. Post oak and water oak are used for firewood.
Other products
Fruit from blackberries, grapes, and plums and nuts from pecans are harvested.
Supporting information
Inventory data references
These site descriptions were developed as part a Provisional Ecological Site project using historic soil survey manuscripts, available site descriptions, and low intensity field traverse sampling. Future work to validate the information is needed. This will include field activities to collect low, medium, and high-intensity sampling, soil correlations, and analysis of that data. A final field review, peer review, quality control, and quality assurance review of the will be needed to produce the final document.
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. Archer, S. and F.E. Smeins. 1991. Ecosystem-level Processes. Chapter 5 in: Grazing Management: An Ecological Perspective. Edited by R.K. Heitschmidt and J.W. Stuth. Timber Press, Portland, OR.
3. Bestelmeyer, B.T., J.R. Brown, K.M. Havstad, R. Alexander, G. Chavez, and J.E. Herrick. 2003. Development and use of state-and-transition models for rangelands. J. Range Manage. 56(2): 114-126.
4. Brown, J.R. and S. Archer. 1999. Shrub invasion of grassland: recruitment is continuous and not regulated by herbaceous biomass or density. Ecology 80(7): 2385-2396.
5. Foster, J.H. 1917. Pre-settlement fire frequency regions of the United States: a first approximation. Tall Timbers Fire Ecology Conference Proceedings No. 20.
6. Gould, F.W. 1975. The Grasses of Texas. Texas A&M University Press, College Station, TX. 653p.
7. Hamilton, W. and D. Ueckert. 2005. Rangeland Woody Plant Control: Past, Present, and Future. Chapter 1 in: Brush Management: Past, Present, and Future. pp. 3-16. Texas A&M University Press.
8. Scifres, C.J. and W.T. Hamilton. 1993. Prescribed Burning for Brush Management: The South Texas Example. Texas A&M University Press, College Station, TX. 245 p.
9. Smeins, F., S. Fuhlendorf, and C. Taylor, Jr. 1997. Environmental and Land Use Changes: A Long Term Perspective. Chapter 1 in: Juniper Symposium 1997, pp. 1-21. Texas Agricultural Experiment Station.
10. Stringham, T.K., W.C. Krueger, and P.L. Shaver. 2001. State and transition modeling: and ecological process approach. J. Range Manage. 56(2):106-113.
11. Texas Agriculture Experiment Station. 2007. Benny Simpson’s Texas Native Trees (http://aggie-horticulture.tamu.edu/ornamentals/natives/).
12. Texas A&M Research and Extension Center. 2000. Native Plants of South Texas (http://uvalde.tamu.edu/herbarium/index.html).
13. 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, OR.
14. USDA/NRCS Soil Survey Manuals counties within MLRA 87A.
15. USDA, NRCS. 1997. National Range and Pasture Handbook.
16. USDA, NRCS. 2007. The PLANTS Database (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
17. Vines, R.A. 1984. Trees of Central Texas. University of Texas Press, Austin, TX.
18. Vines, R.A. 1977. Trees of Eastern Texas. University of Texas Press, Austin, TX. 538 p.
19. Wright, H.A. and A.W. Bailey. 1982. Fire Ecology: United States and Southern Canada. John Wiley & Sons, Inc.Contributors
Mike Stellbaur
Tyson HartApproval
Bryan Christensen, 9/21/2023
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) Mike Stellbauer, David Polk and Bill Deauman Contact for lead author Mike Stellbauer, Zone RMS, NRCS, Bryan, Texas Date 06/08/2004 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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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 are uncommon for this site when occupied by the reference community. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Expect no more than 20 percent 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):
The soil structure is 0 to 48 inches thick with colors from dark reddish brown clay to very dark gray clay with generally subangular blocky structure. SOM is approximately 1 to 6 percent. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
The savannah of trees, shrubs, vines, grasses, and forbs, along with adequate litter and little bare ground, provides 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 tallgrasses > Cool-season midgrasses >>Sub-dominant:
Other:
Trees > Shrubs/Vines > ForbsAdditional:
-
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):
Litter is primarily herbaceous with small to large woody litter common. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
4,000 pounds per acre for below average moisture years to 7,000 pounds per acre for above average moisture year. -
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:
Potential invasive species include Chinese tallow, huisache, honey locust, bois d''arc, elm, ash, McCartney rose, dallisgrass, Bermudagrass, Johnsongrass, annual sumpweed, and giant ragweed. -
Perennial plant reproductive capability:
All perennial plants should be capable of reproducing, except for prolonged drought conditions, heavy natural herbivory and intense wildfires.
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PrintThe 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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