Natural Resources
Conservation Service

Ecological site R087AY008TX

Very Deep Sand

Last updated: 5/16/2025
Accessed: 10/19/2025

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General information

Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.

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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 MLRA is entirely in south-central Texas. It is approximately 10,212 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.
The term “claypan” refers to the heavier clay subsoils underlying the sandy and loamy soils. The vegetation is adapted to fairly droughty conditions due to restricted rooting depth and water transmission. The boundary to the west with the Blackland Prairies is gradual as vegetation transitions from tree to herbaceous species and the amount of precipitation decreases. The boundary to the east with the Southern Coastal Plain is distinct and marked by the tall pine species.
The average annual precipitation in this area is 27 to 45 inches (685 to 1,145 millimeters). Most of the rainfall occurs in spring and fall. The average precipitation during the freeze-free period is about 30 inches (760 millimeters). The average annual temperature is 64 to 70 degrees F (18 to 21 degrees C). The freeze-free period averages about 285 days and ranges from 260 to 310 days.
The dominant soil orders are Alfisols, Vertisols, Mollisols, and Entisols. The soils in the area are very deep to moderately deep and are somewhat excessively drained to somewhat poorly drained. They have a thermic soil temperature regime, an ustic soil moisture regime, and smectitic, siliceous, or mixed mineralogy.
Most of the farmland in this MLRA is used for pasture and livestock grazing. Most of the pastured areas were formerly cultivated. Although significant areas of rangeland have been overgrazed, conservation efforts are improving the rangeland condition. The cropland in the MLRA is used primarily for corn. Other important crops are cotton, peanuts, hay, and truck crops. Urban land is expanding in several areas.

Classification relationships

USDA-Natural Resources Conservation Service, 2006.
-Major Land Resource Area (MLRA) 87A

Ecological site concept

The site is characterized by structureless sands greater than 80 inches in depth. Due to the nature of sandy soils, they are vegetatively unproductive compared to other sites within the other area due to lower water holding capacity. Slopes range from 1 to 8 percent, and the elevation ranges from 260 to 620 feet.

Associated sites

R087AY007TX	Deep Sand Deep Sand, gently sloping to sloping ridges
R087AY009TX	Wet Sandy Draw Wet Sandy Draw, concave drainages
R087AY004TX	Deep Redland Deep Redland, gently sloping upland ridges
R087AY006TX	Sandy Sandy, gently sloping to strongly sloping ridges and stream terraces

Similar sites

R087AY006TX	Sandy Gently sloping to moderately sloping ridges and stream terraces, Drainage class is moderately well drained to well drained, Permeable class is moderate to rapid, Soil depth is 45 - 80 inches, Family particle size is loamy, Slope ranges between 1-8 percent
R087AY007TX	Deep Sand Landforms consist primarily of broad ridges and stream terraces, Drainage class is well drained to somewhat excessively drained, Permeable class is rapid to very rapid, Soil depth is 72 - 80 inches, Family particle size is sandy, Slope ranges from 1-10 percent

R087AY006TX

Sandy

Gently sloping to moderately sloping ridges and stream terraces, Drainage class is moderately well drained to well drained, Permeable class is moderate to rapid, Soil depth is 45 - 80 inches, Family particle size is loamy, Slope ranges between 1-8 percent

R087AY007TX

Deep Sand

Landforms consist primarily of broad ridges and stream terraces, Drainage class is well drained to somewhat excessively drained, Permeable class is rapid to very rapid, Soil depth is 72 - 80 inches, Family particle size is sandy, Slope ranges from 1-10 percent

Table 1. Dominant plant species

Tree	(1) Quercus incana (2) Quercus marilandica
Shrub	(1) Ilex vomitoria (2) Vaccinium arboreum
Herbaceous	(1) Schizachyrium scoparium (2) Sorghastrum elliottii

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Physiographic features

This ecological site occurs on stream terraces and broad ridges of interfluves of broad ridges on inland dissected coastal plains.

Table 2. Representative physiographic features

Landforms	(1) Plains > Stream terrace (2) Plains > Ridge
Runoff class	Negligible to very low
Flooding frequency	None
Ponding frequency	None
Elevation	260 – 620 ft
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)	241 days
Freeze-free period (average)	276 days
Precipitation total (average)	41 in

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Figure 2. Monthly precipitation range

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Figure 3. Monthly average minimum and maximum temperature

Figure 4. Annual precipitation pattern

Figure 5. Annual average temperature pattern

Climate stations used

(1) CROCKETT [USC00412114], Crockett, TX
(2) FAIRFIELD 3W [USC00413047], Fairfield, TX
(3) GONZALES 1N [USC00413622], Gonzales, TX
(4) COLLEGE STN [USW00003904], College Station, TX
(5) BARDWELL DAM [USC00410518], Ennis, TX
(6) ELGIN [USC00412820], Elgin, TX
(7) FRANKLIN [USC00413321], Franklin, TX
(8) SOMERVILLE DAM [USC00418446], Somerville, TX
(9) BELLVILLE 6NNE [USC00410655], Bellville, TX
(10) LA GRANGE [USC00414903], La Grange, TX
(11) MADISONVILLE [USC00415477], Madisonville, TX
(12) SMITHVILLE [USC00418415], Smithville, TX

Influencing water features

This ecological site is influenced by the lower water holding capacity of the very deep sandy soils. Based on the landform position, this site is not influenced by streams or wetlands.

Wetland description

Wetlands are not associated with this site.

Soil features

The soils for this ecological site consist of very deep, somewhat excessively drained, rapidly permeable soils that formed in residuum weathered from Eocene age sandstone of the Claiborne Group. They are loose and structureless to a depth of 80 inches or more. These soils have high permeability and rapid infiltration. The available water- holding capacity and soil fertility are low, making this one of the lowest producing sites in the MLRA. Water erosion on this site is generally not a problem but the site is susceptible to wind erosion. Arenosa is the only soil series correlated to this ecological site. The taxonomic classification is a thermic, uncoated Ustic Quartzipsamment.

Table 4. Representative soil features

Parent material	(1) Residuum – sandstone and shale
Surface texture	(1) Fine sand
Family particle size	(1) Sandy
Drainage class	Somewhat excessively drained
Permeability class	Rapid
Soil depth	80 in
Surface fragment cover <=3"	Not specified
Surface fragment cover >3"	Not specified
Available water capacity (0-40in)	2 in
Calcium carbonate equivalent (0-40in)	Not specified
Electrical conductivity (0-40in)	2 mmhos/cm
Sodium adsorption ratio (0-40in)	Not specified
Soil reaction (1:1 water) (0-40in)	4.5 – 6.5
Subsurface fragment volume <=3" (Depth not specified)	Not specified
Subsurface fragment volume >3" (Depth not specified)	Not specified

Ecological dynamics

The Very Deep Sand ecological site evolved with and maintained by grazing and herding effects of native large ungulates, periodic fires, and extreme climatic fluctuations. Continuous grazing by domestic livestock and the suppression of fire removes little bluestem (Schizachyrium scoparium), slender Indiangrass (Sorghastrum elliottii), switchgrass (Panicum virgatum), and desirable forbs. Less productive perennial and annual grasses and forbs replace these plants.

After years of continuous grazing, communities in this ecological site require periods of prolonged rest for recovery of the perennial herbaceous plant components. Prolonged rest with no fire or brush management lead a community dominated by woody species such as winged elm (Ulmus alata), yaupon (Ilex vomitoria), post oak (Quercus stellata), blackjack oak (Quercus marilandica), and bluejack oak (Quercus incana).

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 text

Ecosystem states

1. Reference

2. Shrubland Dominated

3. Encroached

4. Pastureland

T1A	-	Abandonment, no fire, and grazing management
T1B	-	Brush management, plowed, pasture planting
R2A	-	Prescribed grazing, fire, and/or brush management
T2A	-	Abandonment, no fire, and "inadequate" grazing management
T2B	-	Brush management, plowed, pasture planting
R3A	-	Extensive brush management or herbicide applications
T3A	-	Brush management, plowed, pasture planting
R4A	-	Range planting, prescribed grazing, prescribed burning
T4A	-	Heavy continuous grazing, no brush management, abandonment
T4B	-	Heavy continuous grazing, brush management

State 1
Reference

One community phase exists in the Reference State, the 1.1 Tallgrass/Oak Savannah Community Phase. The State is dominated by warm-season perennial grasses and the overstory canopy cover is less than 30 percent.

Community 1.1
Tallgrass/Oak Savannah

The Reference Plant Community is an open savannah of bluejack, post, and blackjack oak trees that shade up to 30 percent of the ground. Yaupon shrubs are associated with the trees. The herbaceous component is tall and mid-grasses and is dominated by little bluestem, Indiangrass (Sorghastrum nutans), slender Indiangrass, and brownseed paspalum (Paspalum plicatulum). Tall and mid-grasses make up to 50 to 75 percent of the total annual production. A thin stand of purple lovegrass (Eragrostis spectabilis), red lovegrass (Eragrostis secundiflora), woolly sheath threeawn (Aristida lanosa), Hall's panicum (Panicum hallii), and thin paspalum (Paspalum setaceum) occupy the interspaces. Grazing prescriptions that allow for adequate rest periods along with prescribed fire every five to seven years are important in the maintenance of the reference plant community and the savannah landscape structure. Continuous overgrazing or over rest and the absence of fire tend to allow a vegetative shift towards woody species. Without corrective measures, this shift will continue to the Shrubland State.

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	1700	1875	2050
Tree	350	400	450
Shrub/Vine	100	125	150
Forb	100	125	150
Total	2250	2525	2800

State 2
Shrubland Dominated

One community exists in the Shrubland Dominated State, the 2.1 Oak Scrub/Shrubland Community. The herbaceous production is not as great compared to the Reference State, and overstory canopy has increased to 30 and 50 percent.

Community 2.1
Oak Scrub/Shrubland

This plant community phase is a transitional community between the Reference and Encroached States. It develops in the absence of fire, mechanical, or chemical treatments for brush control. It is the result of abandonment or yearly continuous grazing. Trees and shrubs encroach or replace the grassland component of the Reference State. In addition to the naturally occurring bluejack, blackjack, and post oak - yaupon increases in density and canopy coverage (30 to 50 percent). Remnants of little bluestem and Indiangrass may still occur but to a lesser extent than is present in the reference state/current potential state. .The herbaceous component of the community becomes dominated by less desirable herbaceous grasses and forbs. Woollysheath threeawn (Aristida lanosa), sand dropseed (Sporobolus cryptandrus), arrowfeather threeawn (Aristida purpurascens), Scribner's dichanthelium (Dicanthelium oliganthes), thin paspalum (Paspalum setaceum), wild buckwheat (Eriogonum spp.), and Texas croton (Croton texensis) commonly occur.

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)
Grass/Grasslike	1025	1150	1250
Tree	675	750	850
Shrub/Vine	450	475	500
Forb	100	125	150
Total	2250	2500	2750

State 3
Encroached

One community phase exists in the Encroached State, the 3.1 Oak/Yaupon Woodland Community. The ecological site is characterized by a decrease in herbaceous species and an increase in woody species. The overstory canopy cover is greater than 50 percent with significant shrub understory.

Community 3.1
Oak/Yaupon Woodland

This plant community is a closed overstory (50 to 80 percent canopy cover) woodland dominated by bluejack, blackjack, and post oak. Yaupon is the dominant understory shrub. Woody vines also occur and include greenbriar (Smilax spp.), grape (Vitis spp.), and poison ivy (Toxicodendron radicans). Herbaceous understory is almost nonexistent but shade tolerant species including longleaf woodoats (Chasmanthium sessiliflorum) and cedar sedge (Carex planostachys) may occur in small amounts.

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	1475	1625	1775
Grass/Grasslike	450	500	550
Shrub/Vine	225	250	275
Forb	100	125	150
Total	2250	2500	2750

State 4
Pastureland

The Pastureland State contains the 4.1 Pastureland Community. This state is characterized by cultivation and seeding of the land.

Community 4.1
Pastureland

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. The primary means of propagation for these species is by seed distribution via wind, water, and animal vectors. 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.

Transition T1A
State 1 to 2

The Reference State will transition to the Shrubland Dominated State with continued heavy grazing pressure, no brush management, or abandonment occurs. The transition is evident when woody species canopy cover exceeds 30 percent and grasses shift composition to more shade-tolerant species.

Transition T1B
State 1 to 4

The transition to the Pastureland State occurs when the site is plowed for planting pasture. The driver for the transition is the land manager's decision to farm the site.

Restoration pathway R2A
State 2 to 1

Restoration back to the Reference State requires brush management, prescribed grazing or prescribed fire. The woody canopy cover needs to be less than 50 percent and adequate herbaceous fine fuel to carry fire. When the threshold is exceeded, mechanical or chemical brush control becomes necessary to move this transitional community back towards Reference state. Prescribed grazing may require destocking and/or deferment, depending on the condition of the herbaceous understory and seed bank. While these treatment methods may remove the woody species, re-establishment of the herbaceous component is very difficult due to the low water holding capacity and low fertility of the soils.

Transition T2A
State 2 to 3

The Shrubland Dominated State will transition to the Encroached State when continued heavy grazing pressure, no brush management, or abandonment continues. The transition is evident when woody species canopy cover exceeds 50 percent and grasses shift composition to more shade-tolerant species.

Transition T2B
State 2 to 4

The transition to the Pastureland State occurs when the site is cultivated and planted to pasture. The driver for the transition is the land manager's decision to cultivate the site.

Restoration pathway R3A
State 3 to 1

Restoration back to the Reference State requires substantial energy inputs. Brush management/"prescribed fire" and prescribed grazing will be needed to shift the community back. Mechanical or chemical controls can be used to remove the woody overstory species back below 30 percent. Chemical brush control on a large scale is not a viable treatment option due to resistance of yaupon to broadcast herbicide applications. Individual plant treatment with herbicides on a small acreages may be a viable treatment option. Prescribed grazing may require destocking and deferment to manage the understory grasses back to those found in the reference community. Prescribed fire may be a viable option if enough fine fuel still exists in the understory to help carry the fire across the landscape. Increased frequency of burns may be required to initiate a burning schedule. The low water holding capacity and low fertility of these soils make re-establishment of herbaceous species difficult.

Transition T3A
State 3 to 4

The transition to the Pastureland State occurs when the site is cultivated and planted for pasture. The driver for the transition is the land manager's decision to cultivate the site.

Restoration pathway R4A
State 4 to 1

The restoration to Reference State 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 Reference State plant composition. Proper grazing and brush management will be required to ensure success.

Restoration pathway T4A
State 4 to 2

The Converted Land State will transition to the Shrub Dominated State when continued heavy grazing pressure, no brush management, or abandonment continues. The transition is evident when woody species canopy cover exceeds 50 percent and grasses shift composition to more shade-tolerant species.

Transition T4B
State 4 to 3

The Converted Land State will transition to the Encroached State with continued heavy grazing pressure, and brush management is needed to control invasive woody and shrub species.

Additional community tables

Table 8. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Tallgrass			850–1025
	little bluestem	SCSC	Schizachyrium scoparium	850–1025	–
2	Tall/Midgrasses			450–525
	longleaf woodoats	CHSE2	Chasmanthium sessiliflorum	450–525	–
	brownseed paspalum	PAPL3	Paspalum plicatulum	450–525	–
	switchgrass	PAVI2	Panicum virgatum	450–525	–
	slender Indiangrass	SOEL3	Sorghastrum elliottii	450–525	–
	Indiangrass	SONU2	Sorghastrum nutans	450–525	–
	purpletop tridens	TRFL2	Tridens flavus	450–525	–
3	Midgrasses			250–300
	woollysheath threeawn	ARLA6	Aristida lanosa	250–300	–
	red lovegrass	ERSE	Eragrostis secundiflora	250–300	–
	purple lovegrass	ERSP	Eragrostis spectabilis	250–300	–
	sand lovegrass	ERTR3	Eragrostis trichodes	250–300	–
	sand dropseed	SPCR	Sporobolus cryptandrus	250–300	–
4	Midgrasses			150–200
	splitbeard bluestem	ANTE2	Andropogon ternarius	150–200	–
	sedge	CAREX	Carex	150–200	–
	composite dropseed	SPCOC2	Sporobolus compositus var. compositus	150–200	–
Forb
5	Forbs			75–100
	partridge pea	CHFA2	Chamaecrista fasciculata	75–100	–
	Atlantic pigeonwings	CLMA4	Clitoria mariana	75–100	–
	Virginia dayflower	COVI3	Commelina virginica	75–100	–
	ticktrefoil	DESMO	Desmodium	75–100	–
	lespedeza	LESPE	Lespedeza	75–100	–
	snoutbean	RHYNC2	Rhynchosia	75–100	–
	fuzzybean	STROP	Strophostyles	75–100	–
	prairie spiderwort	TROC	Tradescantia occidentalis	75–100	–
6	Forbs			25–50
	Texas bullnettle	CNTE	Cnidoscolus texanus	25–50	–
	hogwort	CRCA6	Croton capitatus	25–50	–
	yankeeweed	EUCO7	Eupatorium compositifolium	25–50	–
	plains snakecotton	FRFL	Froelichia floridana	25–50	–
Shrub/Vine
7	Shrubs/Vines			100–150
	American beautyberry	CAAM2	Callicarpa americana	100–150	–
	parsley hawthorn	CRMA5	Crataegus marshallii	100–150	–
	yaupon	ILVO	Ilex vomitoria	100–150	–
	southern dewberry	RUTR	Rubus trivialis	100–150	–
	cat greenbrier	SMGL	Smilax glauca	100–150	–
	muscadine	VIRO3	Vitis rotundifolia	100–150	–
	Arkansas yucca	YUAR2	Yucca arkansana	100–150	–
	Texas pricklypear	OPENL	Opuntia engelmannii var. lindheimeri	100–150	–
	peppervine	NEAR5	Nekemias arborea	100–150	–
	summer grape	VIAE	Vitis aestivalis	100–150	–
	muscadine	VIRO3	Vitis rotundifolia	100–150	–
	plains yucca	YUCA	Yucca campestris	100–150	–
Tree
8	Trees			350–450
	eastern redcedar	JUVI	Juniperus virginiana	350–450	–
	bluejack oak	QUIN	Quercus incana	350–450	–
	blackjack oak	QUMA3	Quercus marilandica	350–450	–
	post oak	QUST	Quercus stellata	350–450	–

Interpretations

Animal community

The historic savannah provided habitat to bison, deer, turkey, migratory birds and large predators such as wolves, coyotes, mountain lions, and black bear. White-tailed deer, turkey, coyotes, bobcats, and resident and migratory birds find suitable habitat in these savannahs today. Domestic livestock and exotic ungulates are the dominant grazers and browsers of this ecological site. As the savannah transitions through the various vegetative states towards woodlands, the quality of the habitat may improve for some species and decline for others. Management must be applied to maintain a vegetative state in optimum habitat quality for the desired species.

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. Precipitation totals may be high (three to five inches per event) and events may be intense producing high volumes of precipitation over a short period of time. Extended periods of little to no rainfall during the growing season are common. Because of the gently to moderately sloping topography with rapid intake rate of the surface sands and very rapid permeability of the soils, there is usually little to no runoff from this site. Water from these somewhat excessively drained soils provides groundwater recharge. In some places, seeps and springs occur at the base of the site. They provide a continuing flow of high quality water for downstream use and sub-irrigation for vegetation on adjacent sites.

Recreational uses

Hunting, camping, bird watching, and equestrian are common activities.

Wood products

Oaks are used for firewood. Yaupon is used for landscaping.

Other products

Fruit from dewberry and grapes are available for harvest.

Supporting information

Inventory data references

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. Current work for this site is focusing on the verification stage. To accomplish this field verification across the geographical extent of the soils to which it is correlated. Where possible, existing data from partners and NRCS was evaluated. In addition low and medium intensity inventory was completed and analyzed. A final field review, peer review, quality control, and quality assurance review of the will be needed in order to finalize the document and bring it to the characterized stage.

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. USDA-Natural Resources Conservation Service, 2006. - Major Land Resource Area (MLRA)87A.
18. Vines, R.A. 1984. Trees of Central Texas. University of Texas Press, Austin, TX.
19. Vines, R.A. 1977. Trees of Eastern Texas. University of Texas Press, Austin, TX. 538 p.
20. Wright, H.A. and A.W. Bailey. 1982. Fire Ecology: United States and Southern Canada. John Wiley & Sons, Inc.

Contributors

Mike Stellbaur
Tyson Hart
Antonio Argullin

Approval

Dean Stacy, 5/16/2025

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	05/17/2005
Approved by	Dean Stacy
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 uncommon for this site.
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 40 percent bare ground randomly distributed in small patches.
Number of gullies and erosion associated with gullies:
No gullies should be present.
Extent of wind scoured, blowouts and/or depositional areas:
Blowouts or dunes could occur but should be uncommon under reference community.
Amount of litter movement (describe size and distance expected to travel):
This site has very highly permeable soils with very high infiltration rates. Only small-sized litter will move short distances with intense storms.
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.
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Soil surface structure is greater than 80 inches thick with colors from pale brown fine sand to pale brown fine sand and generally single grain structures. SOM is less than one 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 >>

Sub-dominant:
Warm-season midgrasses >

Other:
Trees > Shrubs/Vines > Forbs

Additional:
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 groups.
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):
2,250 pounds per acre for below average moisture years to 2,800 pounds per acre for above average moisture years.
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 post oak, bluejack oak, blackjack oak, yaupon, and elm.
Perennial plant reproductive capability:
All perennial plants should be capable of reproducing, except for periods of prolonged drought conditions, heavy natural herbivory and intense wildfires.

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Ecosystem states

1. Reference

2. Shrubland Dominated

3. Encroached

4. Pastureland

T1A	-	Abandonment, no fire, and grazing management
T1B	-	Brush management, plowed, pasture planting
R2A	-	Prescribed grazing, fire, and/or brush management
T2A	-	Abandonment, no fire, and "inadequate" grazing management
T2B	-	Brush management, plowed, pasture planting
R3A	-	Extensive brush management or herbicide applications
T3A	-	Brush management, plowed, pasture planting
R4A	-	Range planting, prescribed grazing, prescribed burning
T4A	-	Heavy continuous grazing, no brush management, abandonment
T4B	-	Heavy continuous grazing, brush management

State 1 submodel, plant communities

1.1. Tallgrass/Oak Savannah

State 2 submodel, plant communities

2.1. Oak Scrub/Shrubland

State 3 submodel, plant communities

3.1. Oak/Yaupon Woodland

State 4 submodel, plant communities

4.1. Pastureland

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Natural ResourcesConservation Service

Ecological site R087AY008TX

Very Deep Sand

Last updated: 5/16/2025 Accessed: 10/19/2025

General information

Figure 1. Mapped extent

MLRA notes

Classification relationships

Ecological site concept

Associated sites

Similar sites

Table 1. Dominant plant species

Ecosystem states

State 1 submodel, plant communities

State 2 submodel, plant communities

State 3 submodel, plant communities

State 4 submodel, plant communities

Natural Resources
Conservation Service

Last updated: 5/16/2025
Accessed: 10/19/2025