Natural Resources
Conservation Service
Ecological site R083DY024TX
Tight Sandy Loam
Last updated: 9/21/2023
Accessed: 11/13/2024
General information
Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.
Figure 1. Mapped extent
Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.
MLRA notes
Major Land Resource Area (MLRA): 083D–Lower Rio Grande Plain
Major Land Resource Area (MLRA) 83D makes up about2,500 square miles (6,475 square kilometers). The towns of Brownsville, Edinburg, Harlingen, McAllen, and Raymondville are in this area. U.S. Highways 77 and 281 terminate in Brownsville and McAllen, respectively. The Santa Ana National Wildlife Area is along the Rio Grande in this area.
Classification relationships
USDA-Natural Resources Conservation Service, 2006.
-Major Land Resource Area (MLRA) 83D
Ecological site concept
For the Sandy Loam site, fine sandy loam surface textures are underlain by a dense argillic horizon at 10 to 15 inches. These contrasting soil textures perch water during rainfall events but become droughty during times of dry weather.
Associated sites
R083DY006TX |
Fresh Marsh |
---|---|
R083DY007TX |
Lakebed |
R083DY023TX |
Sandy Loam |
R083DY025TX |
Clay Loam |
Similar sites
R083AY024TX |
Tight Sandy Loam |
---|---|
R083CY024TX |
Tight Sandy Loam |
R083EY024TX |
Tight Sandy Loam |
Table 1. Dominant plant species
Tree |
Not specified |
---|---|
Shrub |
(1) Celtis ehrenbergiana |
Herbaceous |
(1) Schizachyrium scoparium |
Physiographic features
These sites are on nearly level to gently sloping terraces on the Rio Grande delta plain. Slopes range from 0 to about 3 percent.
Table 2. Representative physiographic features
Landforms |
(1)
Delta plain
> Terrace
|
---|---|
Runoff class | Low |
Flooding frequency | None |
Ponding frequency | None |
Elevation | 10 – 220 ft |
Slope | 3% |
Water table depth | 30 – 80 in |
Aspect | Aspect is not a significant factor |
Climatic features
MLRA 83 has a subtropical, subhumid climate. Winters are dry and warm, and the summers are hot and humid. Tropical maritime air masses predominate throughout spring, summer and fall. Modified polar air masses exert considerable influence during winter, creating a continental climate characterized by large variations in temperature. Peak rainfall occurs late in spring and a secondary peak occurs early in fall. Heavy thunderstorm activities increase in April, May, and June. July is hot and dry with little weather variations. Rainfall increases again in late August and September as tropical disturbances increase and become more frequent. Tropical air masses from the Gulf of Mexico dominate during the spring, summer and fall. Prevailing winds are southerly to southeasterly throughout the year except in December when winds are predominately northerly.
Table 3. Representative climatic features
Frost-free period (characteristic range) | 365 days |
---|---|
Freeze-free period (characteristic range) | 365 days |
Precipitation total (characteristic range) | 22-26 in |
Frost-free period (actual range) | 271-365 days |
Freeze-free period (actual range) | 365 days |
Precipitation total (actual range) | 21-27 in |
Frost-free period (average) | 348 days |
Freeze-free period (average) | 365 days |
Precipitation total (average) | 24 in |
Figure 2. Monthly precipitation range
Figure 3. Monthly minimum temperature range
Figure 4. Monthly maximum temperature range
Figure 5. Monthly average minimum and maximum temperature
Figure 6. Annual precipitation pattern
Figure 7. Annual average temperature pattern
Climate stations used
-
(1) RAYMONDVILLE [USC00417458], Raymondville, TX
-
(2) SANTA ROSA 3 WNW [USC00418059], Edcouch, TX
-
(3) WESLACO [USC00419588], Weslaco, TX
-
(4) MCALLEN [USC00415701], McAllen, TX
-
(5) MERCEDES 6 SSE [USC00415836], Mercedes, TX
-
(6) MCALLEN MILLER INTL AP [USW00012959], McAllen, TX
-
(7) HARLINGEN [USC00413943], Harlingen, TX
-
(8) MISSION 4 W [USC00415972], Mission, TX
-
(9) BROWNSVILLE [USW00012919], Brownsville, TX
-
(10) LA JOYA [USC00414911], Mission, TX
-
(11) RIO GRANDE CITY [USC00417622], Rio Grande City, TX
Influencing water features
The abrupt textural change causes water to perch after heavy rainfall events. Also, a seasonally high water table exists as high as 30 to 80 inches below the surface, particularly a few weeks after heavy rainfall in the area.
Wetland description
N/A.
Soil features
The soils are very deep, moderately well to somewhat poorly drained, and have slow permeability. The argillic horizon abruptly changes from fine sandy loam to sandy clay loam below the A-horizon. Soil series correlated to this site include: Delfina and Lozano.
Table 4. Representative soil features
Parent material |
(1)
Alluvium
–
sedimentary rock
(2) Eolian deposits – sedimentary rock |
---|---|
Surface texture |
(1) Fine sandy loam |
Family particle size |
(1) Fine-loamy |
Drainage class | Somewhat poorly drained to moderately well drained |
Permeability class | Slow |
Soil depth | 80 in |
Surface fragment cover <=3" | Not specified |
Surface fragment cover >3" | Not specified |
Available water capacity (0-40in) |
5 – 6 in |
Calcium carbonate equivalent (0-40in) |
15% |
Electrical conductivity (0-40in) |
8 mmhos/cm |
Sodium adsorption ratio (0-40in) |
10 |
Soil reaction (1:1 water) (0-40in) |
6.1 – 8.4 |
Subsurface fragment volume <=3" (Depth not specified) |
3% |
Subsurface fragment volume >3" (Depth not specified) |
Not specified |
Ecological dynamics
The Lower Rio Grande (MLRA 83D) was a disturbance-maintained system. Prior to European settlement (pre-1825), fire and grazing were the two primary forms of disturbance. Grazing by large herbivores included antelope, deer, and small herds of bison. The infrequent but intense, short-duration grazing by these species suppressed woody species and invigorated herbaceous species. The herbaceous savannah species adapted to fire and grazing disturbances by maintaining belowground tissues. Wright and Bailey (1982) report that there are no reliable records of fire frequency for the Rio Grande Plains because there are no trees to carry fire scars from which to estimate fire frequency. Because savannah grassland is typically of level or rolling topography, a natural fire frequency of three to seven years seems reasonable for this area.
Historical accounts prior to 1800 identify grazing by herds of wild horses, followed by heavy grazing by sheep and cattle as settlement progressed. Grazing on early ranches changed natural graze-rest cycles to continuous grazing and stocking rates exceeded the carrying capacity. These shifts in grazing intensity and the removal of rest from the system reduced plant vigor for the most palatable species, which on this site were midgrasses and palatable forbs. Shortgrasses and less palatable forbs began to dominate the site. This shift resulted in lower fuel loads, which reduced fire frequency and intensity. The reduction in fires resulted in an increase in size and density of woody species.
The open grassland in this area supports mid prairie grasses with scattered woody plants, perennial forbs, and legumes on soils in the uplands. Twoflower and fourflower trichloris, plains bristlegrass, and lovegrass tridens are among the dominant grasses on these soils. Desert yaupon, spiny hackberry, and blackbrush are the major woody plants. In bottomland areas, tallgrasses and midgrasses, such as switchgrass, giant sacaton, fourflower trichloris, big sandbur, little bluestem, and southwestern bristlegrass, are dominant. Hackberry, mesquite, elm, and palm trees are the major woody plants. Forbs are important but minor components of all plant communities.
Most of this area is cropland or improved pasture that is extensively irrigated. Large acreages of rangeland are grazed mainly by beef cattle and wildlife. The major crops are cotton, grain sorghum, citrus, onions, cabbage, and other truck crops. Almost all the crops are grown under irrigation. Hunting leases for white-tailed deer, quail, white-winged dove, and mourning dove are an important source of income in the area. Some of the major wildlife species in this area are white-tailed deer, javelina, coyote, fox, bobcat, raccoon, skunk, opossum, jackrabbit, cottontail, turkey, bobwhite quail, scaled quail, white-winged dove, and mourning dove.
State and transition model
Figure 8. STM
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Click on state and transition labels to scroll to the respective text
Ecosystem states
T1A | - | Absence of disturbance and natural regeneration over time, coupled with excessive grazing pressure |
---|---|---|
T1B | - | Extensive soil disturbance followed by seeding with improved forage species |
R2A | - | Reintroduction of historic disturbance return intervals |
T2A | - | Extensive soil disturbance followed by seeding improved forage species |
T3A | - | Absence of disturbance and natural regeneration over time, coupled with excessive grazing pressure |
State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 1
Grassland
Dominant plant species
-
spiny hackberry (Celtis ehrenbergiana), shrub
-
lime pricklyash (Zanthoxylum fagara), shrub
-
little bluestem (Schizachyrium scoparium), grass
-
pink pappusgrass (Pappophorum bicolor), grass
Community 1.1
Midgrass
The Midgrass Community (1.1) developed under natural disturbance regimes spanning thousands of years. Composition of grasses makes up over 90 percent by weight of annual production while forbs, shrubs, and woody species make up the remainder. Shrubs and trees may be found scattered throughout, and without disturbance will grow very large, but will not create a significant canopy cover. Annual forbs occur in varying amounts in response to grazing intensity, fire, drought, or excessive precipitation. This community is greatly affected by variations in plant available water in the soil. This sometimes extreme fluctuation is reflected in the herbaceous plant community and along with grazing may be the most important factor driving species composition within the Grassland State (1). Tall and midgrasses dominate this site under favorable growing conditions and bare ground is limited due to the multi-layered structure of the grass and forb community. The herbaceous cover produces a thermal insulation which reduces evaporation of soil water and greatly reduces ground temperatures. These factors promote the midgrass and forb community. During drought conditions shortgrasses will increase and become larger components of the herbaceous community and bare ground will slightly increase. Differences in rainfall across the region will cause subtle changes in plant community and overall productivity. Although the values provided in this report are representative, doing an onsite inventory of plant community and production when planning management decisions will help land managers make sound decisions based on actual conditions on the ground.
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 | 1400 | 2500 | 3600 |
Shrub/Vine | 75 | 140 | 200 |
Forb | 75 | 140 | 200 |
Tree | 0 | 25 | 50 |
Total | 1550 | 2805 | 4050 |
Table 6. Ground cover
Tree foliar cover | 0-1% |
---|---|
Shrub/vine/liana foliar cover | 0-1% |
Grass/grasslike foliar cover | 70-90% |
Forb foliar cover | 5-10% |
Non-vascular plants | 0% |
Biological crusts | 0% |
Litter | 5-25% |
Surface fragments >0.25" and <=3" | 0% |
Surface fragments >3" | 0% |
Bedrock | 0% |
Water | 0% |
Bare ground | 0-5% |
Table 7. Canopy structure (% cover)
Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
---|---|---|---|---|
<0.5 | 0-1% | 0-1% | 10-40% | 5-10% |
>0.5 <= 1 | 0-1% | 0-1% | 20-40% | 5-10% |
>1 <= 2 | 0-1% | 0-1% | 40-100% | 5-10% |
>2 <= 4.5 | 0-1% | – | 30-70% | – |
>4.5 <= 13 | 0-1% | – | – | – |
>13 <= 40 | 0-1% | – | – | – |
>40 <= 80 | – | – | – | – |
>80 <= 120 | – | – | – | – |
>120 | – | – | – | – |
Figure 10. Plant community growth curve (percent production by month). TX8513, Mid/Tallgrass Community. Mid and tallgrasses dominate the site with few forbs and shrubs..
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
---|---|---|---|---|---|---|---|---|---|---|---|
J | F | M | A | M | J | J | A | S | O | N | D |
0 | 0 | 5 | 10 | 20 | 15 | 5 | 10 | 15 | 10 | 5 | 5 |
Community 1.2
Shortgrass
The Shortgrass Community (1.2) develops because of continued heavy grazing, an absence of the historic fire regime, and lack of brush management. This community could also be driven by precipitation and may have been more common than the reference plant community (1.1) in drier parts of the region. The Shortgrass Prairie Community (1.2) has reduced biomass production and litter accumulation which causes subtle impacts to the water, mineral, and energy cycles. In this phase reduced rainfall and prolonged droughts will begin to have more of an impact on plant production. As midgrasses decrease shortgrasses such as red grama, brownseed paspalum, plains bristlegrass, and perennial three awns increase. Reduced fuel loads result in reduced fire frequency and intensity. Annual and perennial forbs often increase as a result of decreased competition for sunlight and moisture. Introduced grass species such as Kleberg bluestem (Dicanthium annulatum) and other introduced bluestems may start to invade. For the first time on this site, woody invader seedlings, such as mesquite and huisache, gain considerable height and density. This phase will quickly transition to the Shrubland State (2) if herbaceous plant production does not increase and shrub density grows. While the appearance of introduced plants may prevent a full restoration to the reference community, some of these plants do perform the same functions as native species. Management activities can slow down the increase of introduced plants if this is the management goal.
Figure 11. 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 | 975 | 1725 | 2500 |
Shrub/Vine | 300 | 500 | 700 |
Forb | 225 | 410 | 600 |
Tree | 50 | 125 | 200 |
Total | 1550 | 2760 | 4000 |
Figure 12. Plant community growth curve (percent production by month). TX8514, Mid/Shortgrass Parkland Community. Mid and shortgrasses dominate while oak mottes and density of mesquite are expanded..
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
---|---|---|---|---|---|---|---|---|---|---|---|
J | F | M | A | M | J | J | A | S | O | N | D |
0 | 0 | 5 | 10 | 20 | 15 | 5 | 10 | 15 | 10 | 5 | 5 |
Pathway 1.1A
Community 1.1 to 1.2
The midgrasses are highly preferred by livestock and are easily eliminated from the plant community with heavy continuous grazing. This is because less palatable plants are left ungrazed and will eventually be able to out-compete the dominant grasses for resources and space. Rainfall patterns and subsoil moisture variations drive the diversity of the herbaceous component on this site, but prolonged drought and continuous grazing will create conditions that increase bare ground and shortgrass dominance. Invasive shrub species, like mesquite, will begin to encroach. The historic fire regime has also been changed so that intermittent fires every three to eight years, which would decrease woody plant encroachment and encourage midgrass dominance, have been prevented to protect livestock and societal interests. These factors cause a shift from a Midgrass Community (1.1) to a Shortgrass Community (1.2).
Pathway 1.2A
Community 1.2 to 1.1
The restoration to the reference plant community (1.1) can be accomplished by prescribed grazing with appropriate stocking rates. If the herbaceous component of this community remains healthy and maintains at least 85 to 90 percent ground cover, including live plants and litter, the woody component of this site will remain stable and new seedling growth will be inhibited. Individual Plant Treatment (IPT) and prescribed burning will be the most efficient and economical ways to manage brush species. The use of prescribed fire in conjunction with prescribed grazing enhances the recovery process. Mechanical or chemical brush management is also feasible and relatively economical because this community has less than a 20 percent shrub canopy. Once initial woody plant management has been achieved, periodic burning, reduced stocking rates, and prescribed grazing will cause a transition towards the reference plant community over time. If the landowner wants to speed this transition, some range planting can be done to increase the number of desired species.
State 2
Shrubland
Dominant plant species
-
lime pricklyash (Zanthoxylum fagara), shrub
-
spiny hackberry (Celtis ehrenbergiana), shrub
-
honey mesquite (Prosopis glandulosa), shrub
Community 2.1
Midgrass/Shrubland
A threshold has been crossed between the Grassland State (1) and the Shrubland State (2). This Midgrass/Shrubland Community (2.1) has developed because of continuous heavy grazing, loss of fire as a management tool, greatly altered water and energy cycles, and invasion of woody plants. Episodic droughts will also hasten this process. The shift from can happen within a period of 5 to 10 years under certain conditions. Mesquite will be the dominate woody species on this site, but other woody species such as lime pricklyash, granjeno, desert yaupon (Schaefferia cuneifloia), prickly pear (Opuntia engelmannii), and algerita (Mahonia trifoliolata) will begin to increase as part of the plant community. Herbaceous production in this state is lower than in the Grassland State (1) and because of an increase in bare ground and shrub canopy cover, the resilience of the grass community is negatively affected. The more productive midgrasses will begin to fade from the plant community while less palatable shortgrasses increase. Plants that will increase in this state include red grama (Bouteloua trifida), three awn species (Aristida spp.), brownseed paspalum, and forbs like false broomweed (Haploesthes greggii) and dogweed. Grazing management on this site plays an important role in maintaining healthy grass communities that can take advantage of rainfall events and are more capable of withstanding drought conditions. In this state, forbs will respond quickly to rainfall events and can also out-compete grasses for resources, causing an overall decrease in grass production.
Figure 13. 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 | 650 | 1150 | 1650 |
Shrub/Vine | 400 | 875 | 1350 |
Tree | 200 | 350 | 500 |
Forb | 300 | 400 | 500 |
Total | 1550 | 2775 | 4000 |
Figure 14. Plant community growth curve (percent production by month). TX8507, Woodland Community, 30+% canopy. Woody canopy is greater than 30%..
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
---|---|---|---|---|---|---|---|---|---|---|---|
J | F | M | A | M | J | J | A | S | O | N | D |
2 | 2 | 5 | 10 | 18 | 15 | 5 | 9 | 15 | 9 | 5 | 5 |
Community 2.2
Shrubland
Over time, with continued heavy grazing, no fire, and no brush management the Tight Sandy Loam ecological site will be transformed into a Shrubland Community (2.2) with canopies from 50 to 100 percent. Average shrub canopy heights can vary from 10 to 20 feet depending on the age of the plants and local rainfall history. Extended droughts will hasten this transition process. Once the mesquite community begins to mature, mixed shrubs will begin to increase underneath the canopy creating mottes that will increase in size and density. Shrub species like desert yaupon (Schaefferia cuneifloia), catclaw acacia (Acacia gregii), elbowbush (Forestiera pubescens), and the other species already mentioned, will increase in density. At this point, no amount of deferred grazing will restore the plant community to the Grassland State (1). The herbaceous production is dominated by threeawn species, red grama, annual grasses, and annual forbs. The same grass species present in the Grassland State (1) can be found in this community phase, but they will be much less productive and more infrequent. Because of the higher amounts of bare ground, opportunistic forbs like western ragweed (Ambrosia psilostachya), annual broomweed (Amphiachyris amoena), and dogweed will be able to quickly take advantage of timely rain events. Livestock management becomes problematic in this plant community because of drastically reduced grass production. The community may be much better wildlife habitat than the previous state because of the increased amount of woody cover and the increased production of both perennial and annual forbs. With increased emphasis on white-tailed deer and bobwhite quail, many landowners choose to manage their land in this condition to enhance wildlife populations.
Figure 15. Annual production by plant type (representative values) or group (midpoint values)
Table 10. Annual production by plant type
Plant type | Low (lb/acre) |
Representative value (lb/acre) |
High (lb/acre) |
---|---|---|---|
Shrub/Vine | 700 | 1225 | 1750 |
Grass/Grasslike | 450 | 825 | 1200 |
Tree | 300 | 525 | 750 |
Forb | 50 | 175 | 300 |
Total | 1500 | 2750 | 4000 |
Figure 16. Plant community growth curve (percent production by month). TX8507, Woodland Community, 30+% canopy. Woody canopy is greater than 30%..
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
---|---|---|---|---|---|---|---|---|---|---|---|
J | F | M | A | M | J | J | A | S | O | N | D |
2 | 2 | 5 | 10 | 18 | 15 | 5 | 9 | 15 | 9 | 5 | 5 |
Pathway 2.1A
Community 2.1 to 2.2
Without diligent brush management, prescribed grazing, and other conservation practices, this phase will inevitably transition to a Shrubland Community (2.2). This transition is relatively long-term, but can begin within 5 to 10 years. This transition is based on an increase of woody canopy cover and a severe decrease in herbaceous plant production. Shortgrasses and forbs will dominate the herbaceous vegetation. This transition may be desirable for some wildlife, but it will be detrimental for a cattle operation.
Pathway 2.2A
Community 2.2 to 2.1
Major inputs, both chemical and mechanical, are often required to restore this community to the Mesquite Prairie Community (2.1). Prescribed burning is an effective tool to control the mixed brush community if weather conditions are good and the plant community can produce enough fine fuel to carry a burn. Often with this community, mechanical means such as root plowing and raking are utilized along with dozing and grubbing. Species like mesquite will re-sprout if not removed completely from the ground. Chaining and roller chopping are short-lived mechanical practices typically resulting in thicker, harder to manage brush stands that encourage brush seedlings. Follow-up conservation practices such as Individual Plant Treatment (IPT) for woody re-growth and prescribed grazing will be necessary for several years after the initial brush management to maintain an improved plant community. Depending on local conditions it may also be necessary to replant seeds for desired native plants.
Community 3.1
Converted Land
Typically, rootplowing and raking are utilized to remove the woody vegetation. A seedbed is then prepared, and the area is planted into grass or crops. Crops planted on this site include small grains like oats or feed grains. Inputs such as fertilizer, herbicide, and adequate irrigation may be necessary to maintain high productivity. Now, because of the availability of seed, landowners can also replant with native species. To maintain this seeded state, herbicides must be used to control woody seedlings that invade. Not only is there a long-lived seed source of mesquite and other woody species, additional seeds are brought in by grazing animals and domestic livestock.
Figure 17. Annual production by plant type (representative values) or group (midpoint values)
Table 11. Annual production by plant type
Plant type | Low (lb/acre) |
Representative value (lb/acre) |
High (lb/acre) |
---|---|---|---|
Grass/Grasslike | 1500 | 2750 | 4000 |
Total | 1500 | 2750 | 4000 |
Figure 18. Plant community growth curve (percent production by month). TX8513, Mid/Tallgrass Community. Mid and tallgrasses dominate the site with few forbs and shrubs..
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
---|---|---|---|---|---|---|---|---|---|---|---|
J | F | M | A | M | J | J | A | S | O | N | D |
0 | 0 | 5 | 10 | 20 | 15 | 5 | 10 | 15 | 10 | 5 | 5 |
Community 3.2
Abandoned Land
This community develops after land has been cropped and left to fallow without management inputs. It can also develop after a mechanical brush management practice has been applied but not followed up with appropriate management practices. It is typified by the dominance of mesquite, very little herbaceous grass production, high amounts of annual forbs and grasses, large areas covered by tree leaf litter, and/or bare ground. This phase does not have a diverse plant community and the shrub canopy cover can be up to 100 percent mesquite. Because of the seed bank present in the soil and the constant addition of new seed from grazing/browsing animals and seed eating birds, re-infestation of woody seedlings happens in a relatively short time period of two to five years. Typically, planted pasture will transition directly to the Shrubland State (2).
Figure 19. Plant community growth curve (percent production by month). TX5136, Converted Land Community - Woody Seedling Encroachment. Converted Land Community that has been encroached by woody seedlings due to abandonment of crop and pastureland..
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
---|---|---|---|---|---|---|---|---|---|---|---|
J | F | M | A | M | J | J | A | S | O | N | D |
2 | 2 | 5 | 10 | 18 | 15 | 5 | 9 | 15 | 9 | 5 | 5 |
Pathway 3.1A
Community 3.1 to 3.2
The transition from the Converted Land Community (3.1) to the Abandoned Land Community (3.2) can occur when crop fields are left to fallow without management. Shrub species, like mesquite, will begin to grow and dominate the plant community. Generally, planted pasture will transition to the Shrubland State (2).
Pathway 3.2A
Community 3.2 to 3.1
Many land managers may want to utilize this site as cropland or pastureland. To achieve this transition land clearing practices such as dozing and raking will be necessary. After the land has been cleared and an appropriate seedbed prepared, the crop or pasture can be planted.
Transition T1A
State 1 to 2
The transition from the Grassland State (1) to the Shrubland State (2) can happen within 5 to 10 years. This transition is driven by persistently dry weather conditions, grazing management, and the lack of fire and brush management practices. Overstocking with grazing animals will put pressure on the herbaceous plant component of the community. This will create a more favorable environment with bare ground and open spaces for woody plants to germinate and grow. If the woody component is not managed it will begin to dominate the landscape and out-compete grasses and forbs for water, sunlight, and other resources.
Transition T1B
State 1 to 3
Land managers may want to utilize this site as cropland or pastureland. To achieve this transition from the Grassland State (1), brush management and heavy disking with a Rhome disk, or other heavy implement, will be necessary to incorporate the vegetation into the soil. Prescribed burning can also be used prior to the disking operation to eliminate excessive vegetation. After the land has been cleared and an appropriate seedbed prepared, the crop or pasture can be planted.
Restoration pathway R2A
State 2 to 1
Brush management, either mechanical or chemical, is necessary to restore the site to the Grassland State. Removal of woody species to reduce canopy cover will allow light to the herbaceous species. Prescribed grazing and fire will also help.
Transition T2A
State 2 to 3
Land managers may want to utilize this site as cropland or pastureland. To achieve this transition, practices such as dozing and raking will be necessary. After the land has been cleared and an appropriate seedbed prepared, the crop or pasture can be planted.
Transition T3A
State 3 to 2
In time, this site will revert to the Shrubland State (2) on its own. If no brush management occurs, woody species will occupy the overstory canopy and shade out herbaceous species.
Additional community tables
Table 12. Community 1.1 plant community composition
Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
---|---|---|---|---|---|---|
Grass/Grasslike
|
||||||
1 | Tall/Midgrasses | 800–2000 | ||||
little bluestem | SCSC | Schizachyrium scoparium | 550–1500 | – | ||
false Rhodes grass | TRCR9 | Trichloris crinita | 550–1500 | – | ||
multiflower false Rhodes grass | TRPL3 | Trichloris pluriflora | 550–1500 | – | ||
2 | Midgrasses | 400–1200 | ||||
sideoats grama | BOCU | Bouteloua curtipendula | 250–800 | – | ||
silver beardgrass | BOLA2 | Bothriochloa laguroides | 250–800 | – | ||
Arizona cottontop | DICA8 | Digitaria californica | 250–800 | – | ||
plains lovegrass | ERIN | Eragrostis intermedia | 250–800 | – | ||
tanglehead | HECO10 | Heteropogon contortus | 250–800 | – | ||
pink pappusgrass | PABI2 | Pappophorum bicolor | 300–800 | – | ||
plains bristlegrass | SEVU2 | Setaria vulpiseta | 300–800 | – | ||
3 | Shortgrasses | 200–400 | ||||
threeawn | ARIST | Aristida | 75–250 | – | ||
buffalograss | BODA2 | Bouteloua dactyloides | 75–250 | – | ||
slender grama | BORE2 | Bouteloua repens | 75–250 | – | ||
red grama | BOTR2 | Bouteloua trifida | 75–250 | – | ||
coastal sandbur | CESP4 | Cenchrus spinifex | 75–250 | – | ||
hooded windmill grass | CHCU2 | Chloris cucullata | 75–250 | – | ||
fall witchgrass | DICO6 | Digitaria cognata | 75–250 | – | ||
curly-mesquite | HIBE | Hilaria belangeri | 75–250 | – | ||
brownseed paspalum | PAPL3 | Paspalum plicatulum | 75–250 | – | ||
Forb
|
||||||
4 | Forbs | 75–200 | ||||
Forb, annual | 2FA | Forb, annual | 60–160 | – | ||
Cuman ragweed | AMPS | Ambrosia psilostachya | 60–160 | – | ||
Illinois bundleflower | DEIL | Desmanthus illinoensis | 60–160 | – | ||
Engelmann's daisy | ENPE4 | Engelmannia peristenia | 60–160 | – | ||
coastal indigo | INMI | Indigofera miniata | 60–160 | – | ||
yellow puff | NELU2 | Neptunia lutea | 60–160 | – | ||
rosy palafox | PARO | Palafoxia rosea | 60–160 | – | ||
Virginia plantain | PLVI | Plantago virginica | 60–160 | – | ||
American snoutbean | RHAM | Rhynchosia americana | 60–160 | – | ||
awnless bushsunflower | SICA7 | Simsia calva | 60–160 | – | ||
silverleaf nightshade | SOEL | Solanum elaeagnifolium | 60–160 | – | ||
fiveneedle pricklyleaf | THPEP | Thymophylla pentachaeta var. pentachaeta | 60–160 | – | ||
Shrub/Vine
|
||||||
5 | Shrubs | 75–200 | ||||
spiny hackberry | CEEH | Celtis ehrenbergiana | 25–100 | – | ||
Brazilian bluewood | COHO | Condalia hookeri | 25–100 | – | ||
lime pricklyash | ZAFA | Zanthoxylum fagara | 25–100 | – | ||
Tree
|
||||||
6 | Tree | 0–50 | ||||
honey mesquite | PRGLG | Prosopis glandulosa var. glandulosa | 0–50 | – |
Interpretations
Animal community
As a historic tall/midgrass prairie, this site was occupied by bison, antelope, deer, quail, turkey, and dove. This site was also used by many species of grassland songbirds, migratory waterfowl, and coyotes. This site now provides forage for livestock and is still used by quail, dove, migratory waterfowl, grassland birds, coyotes, and deer.
Feral hogs (Sus scrofa) can be found on most ecological sites in Texas. Damage caused by feral hogs each year includes, crop damage by rutting up crops, destroyed fences, livestock watering areas, and predation on native wildlife, and ground-nesting birds. Feral hogs have few natural predators, thus allowing their population to grow to high numbers.
Wildlife habitat is a complex of many different plant communities and ecological sites across the landscape. Most animals use the landscape differently to find food, shelter, protection, and mates. Working on a conservation plan for the whole property, with a local professional, will help managers make the decisions that allow them to realize their goals for wildlife and livestock.
Grassland State (1): This state provides the maximum amount of forage for livestock such as cattle. It is also utilized by deer, quail and other birds as a source of food. When a site is in the reference plant community phase (1.1) it will also be used by some birds for nesting, if other habitat requirements like thermal and escape cover are near.
Shrubland State (2): This state can be maintained to meet the habitat requirements of cattle and wildlife. Land managers can find a balance that meets their goals and allows them flexibility to manage for livestock and wildlife. Forbs for deer and birds like quail will be more plentiful in this state. There will also be more trees and shrubs to provide thermal and escape cover for birds as well as cover for deer.
Converted Land State (3): The quality of wildlife habitat this site will produce is extremely variable and is influenced greatly by the timing of rain events. This state is often manipulated to meet landowner goals. If livestock production is the main goal, it can be converted to pastureland. It can also be planted to a mix of grasses and forbs that will benefit both livestock and wildlife. A mix of forbs in the pasture could attract pollinators, birds and other types of wildlife. Food plots can also be planted to provide extra nutrition for deer.
This rating system provides general guidance as to animal preference for plant species. It also indicates possible competition between kinds of herbivores for various plants. Grazing preference changes from time to time, especially between seasons, and between animal kinds and classes. Grazing preference does not necessarily reflect the ecological status of the plant within the plant community. For wildlife, plant preferences for food and plant suitability for cover are rated. Refer to habitat guides for a more complete description of a species habitat needs.
Hydrological functions
Peak rainfall periods occur in May and June from thunderstorms and in September and October from tropical systems. Rainfall events may be high (three to five inches per event) and intense. Extended periods (45 to 60 days) of little to no rainfall during the growing season are common. Because of the flat topography of this site, water erosion is minimal.
Recreational uses
Hunting and photography are common activities.
Wood products
In the Grassland State, no wood products are available. In a Shrubland State, the site may produce many large mesquite trees and these are often cut for firewood and barbecue.
Supporting information
Inventory data references
Information presented was derived from the revised Range Site, literature, limited NRCS clipping data (417s), field observations, and personal contacts with range-trained personnel.
Other references
AgriLife. 2009. Managing Feral Hogs Not a One-shot Endeavor. AgNews, April 23, 2009. http://agnews.tamu.edu/showstory.php?id=903.
Baen, J. S. 1997. The growing importance and value implications of recreational hunting leases to agricultural land investors. Journal of Real Estate Research, 14:399-414.
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. Journal of Range Management, 56(2):114-126.
Briske, B B, B. T. Bestelmeyer, T. K. Stringham, and P. L. Shaver. 2008. Recommendations for development of resilience-based State-and-Transition Models. Rangeland Ecology and Management, 61:359-367.
Diamond, D. D. and T. E. Fulbright. 1990. Contemporary plant communities of upland grasslands of the Coastal Sand Plain, Texas. Southwestern Naturalist, 35:385-392.
Dillehay T. 1974. Late quaternary bison population changes on the Southern Plains. Plains Anthropologist, 19:180-96.
Foster, J. H. 1917. Pre-settlement fire frequency regions of the United States: a first approximation. Tall Timbers Fire Ecology Conference Proceedings No. 20.
Frost, C. C. 1995. Presettlement fire regimes in southeastern marshes, peatlands, and swamps. In: Prodeedings, 19th Tall Timbers fire ecology conference, 39-60. Tall Timbers Research Station, Tallahassee, FL.
Fulbright, T. E. and S. L. Beasom. 1987. Long-term effects of mechanical treatment on white-tailed deer browse. Wildlife Society Bulletin, 15:560-564.
Hamilton, W. and D. Ueckert. 2005. Rangeland Woody Plant Control: Past, Present, and Future. In: Brush Management: Past, Present, and Future, 3-16. Texas A&M University Press. College Station, TX.
Kneuper, C. L., C. B. Scott, and W. E. Pinchak. 2003. Consumption and dispersion of mesquite seeds by ruminants. Journal of Range Management, 56:255-259.
Lehman, V. W. 1969. Forgotten Legions: Sheep in the Rio Grande Plain of Texas. Texas Western Press, El Paso, TX.
McClendon, T. 1991. Preliminary description of the vegetation of South Texas exclusive of the Coastal Saline Zones. Texas Journal of Science, 43:13-32.
Norwine, J. and R. Bingham. 1986. Frequency and severity of droughts in South Texas: 1900-1983, 1-17. In Livestock and wildlife management during drought. Edited by R. D. Brown. Caesar Kleberg Wildlife Research Institute, Kingsville, TX.
Rhyne, M. Z. 1998. Optimization of wildlife and recreation earnings for private landowners. M. S. Thesis, Texas A&M University-Kingsville, Kingsville, TX.
Scifres C. J., W. T. Hamilton, J. R. Conner, J. M. Inglis, and G. A. Rasmussen. 1985. Integrated Brush Management Systems for South Texas: Development and Implementation. Texas Agricultural Experiment Station, College Station, TX.
Scifres, C. J. and W. T. Hamilton. 1993. Prescribed burning for brushland management: the South Texas example. Texas A&M Press, College Station, TX.
Smeins, F. E., D. D. Diamond, and W. Hanselka. 1991. Coastal prairie, 269-290. In Ecosystems of the World: Natural Grasslands. Edited by R. T. Coupland. Elsevier Press, Amsterdam, Netherlands.
Snyder, R. A. and C. L. Boss. 2002. Recovery and stability in barrier island plant communities. Journal of Coastal Research, 18:530-536.
Texas Parks and Wildlife Department. 2007. List of White-tailed Deer Browse and Ratings. District 8.
Urbatsch, L. 2000. Chinese tallow tree (Triadica sebifera (L.) Small. USDA-NRCS Plant Guide.
Wright, B. D., R. K. Lyons, J. C. Cathey, and S. Cooper. 2002. White-tailed deer browse preferences for South Texas and the Edwards Plateau. Texas Cooperative Extension Bulletin B-6130.
Wright, H.A. and A.W. Bailey. 1982. Fire Ecology: United States and Southern Canada. John Wiley & Sons, Inc., Hoboken, NJ.
Contributors
Gary Harris, MSSL, NRCS, Robstown, Texas
Approval
Bryan Christensen, 9/21/2023
Acknowledgments
Technical reviewers and contributors include:
Clark Harshbarger, RSS, NRCS, Robstown, Texas
Vivian Garcia, RMS, NRCS, Corpus Christi, Texas
Shanna Dunn, RSS, NRCS, Corpus Christi, Texas
Jason Hohlt, RMS, NRCS, Kingsville, Texas
Tyson Hart, RMS, NRCS, Nacogdoches, Texas
Michael Margo, RMS, NRCS, Marfa, Texas
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) |
David Hinojosa, RMS, NRCS, Robstown, Texas Jason Hohlt, RMS, NRCS, Kingsville, Texas |
---|---|
Contact for lead author | 361-241-0609 |
Date | 09/17/2012 |
Approved by | Bryan Christensen |
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 pattens are rare for this site due to landscape position and slopes. -
Number and height of erosional pedestals or terracettes:
Pedestals are uncommon. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Less than 10 percent bare ground. -
Number of gullies and erosion associated with gullies:
None. -
Extent of wind scoured, blowouts and/or depositional areas:
None. -
Amount of litter movement (describe size and distance expected to travel):
Small-to-medium sized litter may move short distances during 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 stability class range is expected to be 4 to 6. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Soil surface struture is 10 to 15 inches thick with brown colors and with subangular blocky structure. Soil organic matter is less than three percent. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Herbaceous production of bunch, rhizomatous, and stoliniferous grasses will help minimize runoff and maximize infiltration. Grasses should comprise approximately 90 percent of total annual production by weight. Shrubs will comprise about five percent by weight. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
A strong, naturally occuring argillic horizon is commonly found within 9 to 14 inches of the soil surface. -
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:
Perennial Midgrasses = Perennial Shortgrasses > Perennial Tall/Midgrasses >Sub-dominant:
Forbs > Shrubs >> TreesOther:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Potential for 5 to 15 percent plant mortality of perennial bunchgrasses during extreme drought. -
Average percent litter cover (%) and depth ( in):
5 to 15 percent litter cover. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
1,500 to 4,050 pounds per acre. -
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
Mesquite, Old World bluestems, buffelgrass, guineagrass, false broomweed, goldenweed, and tanglehead. -
Perennial plant reproductive capability:
All species should be capable of reproducing.
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The Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
Click on box and path labels to scroll to the respective text.
Ecosystem states
T1A | - | Absence of disturbance and natural regeneration over time, coupled with excessive grazing pressure |
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T1B | - | Extensive soil disturbance followed by seeding with improved forage species |
R2A | - | Reintroduction of historic disturbance return intervals |
T2A | - | Extensive soil disturbance followed by seeding improved forage species |
T3A | - | Absence of disturbance and natural regeneration over time, coupled with excessive grazing pressure |