Natural Resources
Conservation Service
Ecological site R078AY123TX
Rocky Hill 25-28" PZ
Last updated: 9/12/2023
Accessed: 12/21/2024
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): 078A–Rolling Limestone Prairie
MLRA 78A is characterized by erosional plains with terraces adjacent to perennial and intermittent streams. Loamy and clayey soils range from shallow to deep over limestones and shales of Permian and Pennsylvanian age. Loamy soils are also associated with stream terraces.
LRU notes
NA
Classification relationships
This ecological site is correlated to soil components at the Major Land Resource Area (MLRA) level which is further described in USDA Ag Handbook 296.
Ecological site concept
These sites occur on stony and cobbly clay soils on hills. The reference vegetation consists of tallgrasses and midgrasses with forbs and woody species. Without fire or other brush management, woody species canopy may increase. Abusive grazing practices may lead to a decline in the more palatable plant species and result in an altered plant community.
Associated sites
| R078AY120TX |
Clay Slopes 25-28" PZ Clay Slopes site has less slope, less rock on the soil surface, and is often located adjacent to the Rocky Hill site. |
|---|---|
| R078AY126TX |
Shallow Clay 25-28" PZ Shallow Clay has less slope and occurs downslope of the Rocky Hill site. |
Similar sites
| R078AY126TX |
Shallow Clay 25-28" PZ The Shallow Clay site has slightly less annual production potential because of the lack of more tallgrass species. |
|---|
Table 1. Dominant plant species
| Tree |
(1) Quercus virginiana |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
(1) Schizachyrium scoparium |
Physiographic features
These gently to steep sloping soils in the Rocky Hill ecological site occur on hillslopes, plains, and footslopes of ridges in the Rolling Limestone Prairie. These soils were formed in residuum and slope wash from from claystone and siltstone. Slopes range from 5 to 30 percent. Elevation ranges from 1000 to 2400 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Breaks
> Hillslope
(2) Breaks > Ridge |
|---|---|
| Runoff class | Medium to very high |
| Elevation | 1,000 – 2,400 ft |
| Slope | 5 – 30% |
| Water table depth | 72 in |
| Aspect | Aspect is not a significant factor |
Climatic features
The climate of MLRA 78A is subtropical subhumid, with hot, dry summers and mild, dry winters. The Precipitation is similar north to south throughout the area, but decreases slightly from east to west. Temperature is similar east to west, but warmer from north to south. The area is clear to partly cloudy 80 percent of the time during the summer and 60 percent during the winter. Prevailing winds usually occur from a southerly direction and from north to northwest during passage of fall and winter cool fronts. March and April are the windiest months of the year.
Most precipitation occurs during the warmer months from April to October, in the form of rainfall during thunderstorms, often of short duration and high intensity, with considerable variation in amounts of rain and the area covered. Lightening, strong winds and hail frequently accompany the thunderstorms. Occasional tornadoes are not uncommon. Precipitation distribution is bimodal, with peaks occurring in May-June and September-October. The annual precipitation is about 25 to 28 inches. Timeliness and amount of rainfall are critical to plant growth. Rainfall events of one-fourth inch or less have limited effectiveness. High temperatures and dry winds reduce precipitation effectiveness. Snowfall represents only a small part of the annual precipitation. Snowfall of one inch or more occurs about one in five years, while snowfall of greater than five inches occurs only about one in ten years. Snow cover generally is of short duration (i.e. one to three days). Probability of snowfall is greater in the northern part of MLRA 78A.
Rainfall in the region is highly erratic, usually with more years below than above average. Periodic droughts of both temporary and prolonged duration are common to the area, although not predictable. Some of the more severe droughts of the past century in this region occurred during 1918-1919, early 1930’s, early to mid 1950’s, and mid to late 1990’s. High temperatures and dry winds accentuate the effects of drought. The extremes in climate have greater influence on plant communities than averages. Historic wet and dry cycles of extended duration likely influenced the evolution of drought hardiness and other survival traits in the endemic flora and fauna of the area.
Temperatures range from 31 degrees F in January to 96 degrees F in July, based on the 30-year average from 1971-2000, although considerably lower and higher temperatures for these months, respectively, have been recorded for some years. Periods of excessive heat, exceeding 100 degrees F, are not uncommon during July and August. Temperatures in the winter are generally mild, but abrupt and large drops in temperature can occur when polar air masses plunge southward across the area. The duration of freezing temperatures usually does not last more than three to five days. Temperatures in the spring are mild, both daytime and nighttime. Summer temperatures are hot, with highs generally in the 80’s to mid 90’s during the daytime, cooling down to the upper 70’s during the night. Fall is usually pleasant with mild, sunny days and crisp, cool nights, as cool northers periodically begin moving south this time of year. The area has a frost-free period of approximately 225 to 233 days and a freeze-free period of about 248 to 259 days. The primary growing season for warm-season plants is approximately 233 to 246 days, increasing from north to south. The first frost generally occurs around November 15 and the last frost occurs around March 15. These dates will vary from north to south and from year to year.
The average relative humidity ranges from 35 to 50 percent in mid-afternoon as diurnal air temperature nears maximum. As nighttime air temperature drops, relative humidity rises, averaging 70 to 80 percent by dawn.
Table 3. Representative climatic features
| Frost-free period (characteristic range) | 197-210 days |
|---|---|
| Freeze-free period (characteristic range) | 222-244 days |
| Precipitation total (characteristic range) | 27-29 in |
| Frost-free period (actual range) | 195-216 days |
| Freeze-free period (actual range) | 221-260 days |
| Precipitation total (actual range) | 27-30 in |
| Frost-free period (average) | 204 days |
| Freeze-free period (average) | 235 days |
| Precipitation total (average) | 28 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) CONCHO PK/IVIE RSVR [USC00411934], Millersview, TX
-
(2) COLEMAN [USC00411875], Coleman, TX
-
(3) PUTNAM [USC00417327], Baird, TX
-
(4) ALBANY [USC00410120], Albany, TX
-
(5) THROCKMORTON 7NE [USC00419016], Throckmorton, TX
Influencing water features
NA
Wetland description
NA
Soil features
The soil series in the Rocky Hill ecological site consist of moderately deep to deep, well drained, impermeable to very slowly permeable soils over claystone bedrock or dense clay.
Major Soil Taxonomic Units correlated to this site include: Owens and Throck.
Table 4. Representative soil features
| Parent material |
(1)
Residuum
–
claystone
|
|---|---|
| Surface texture |
(1) Stony clay (2) Cobbly clay loam (3) Very stony clay |
| Family particle size |
(1) Clayey |
| Drainage class | Well drained |
| Permeability class | Slow to very slow |
| Soil depth | 7 – 30 in |
| Surface fragment cover <=3" | Not specified |
| Surface fragment cover >3" | Not specified |
| Available water capacity (0-40in) |
1.2 – 6 in |
| Calcium carbonate equivalent (0-40in) |
1 – 15% |
| Electrical conductivity (0-40in) |
6 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
10 |
| Soil reaction (1:1 water) (0-40in) |
7.4 – 8.4 |
| Subsurface fragment volume <=3" (Depth not specified) |
10 – 15% |
| Subsurface fragment volume >3" (Depth not specified) |
8 – 22% |
Ecological dynamics
The reference plant community for the Rocky Hill ecological site is a mixed tallgrass and midgrass community with a diverse forb component and a significant population of shrubs and trees. Evidence of the historic vegetation can be found in the journals and records of explorers, military expeditions, and boundary survey teams.
Climate is a major factor influencing vegetation on the site. Long-term droughts lasting multiple years or growing seasons are infrequent, but when they do occur, they can have a negative impact on the vegetation. If abusive grazing occurs during or immediately following the drought period, the results can be devastating. The effects of erratic seasonal moisture and short-term dry spells lasting a few months are not as severe as those caused by long-term droughts. However, the lower the ecological status of the site, the greater the negative impact will be during drought periods regardless of duration.
Fire is also an important part of the ecosystem. Most ecosystems in the Rolling Limestone Prairie (MLRA 78A) developed in a 4 to 6 year regime of recurring fires. This site, like other steep, shallow sites probably had a longer recurring fire cycle of 7 to 12 years according to some historians. Many of these fires resulted from lightning strikes during thunderstorms. Native Americans frequently set fires to manipulate the movement of bison and other animals as well as a defensive or offensive technique when dealing with their enemies. These historic fires were usually severe because of the amount and volatility of fuel available to carry the fire. The intensity of fires kept shrubs and sapling trees suppressed and allowed grasses and forbs to flourish. Tallgrass species are fire tolerant and are enhanced by periodic burning. Forbs usually increase for a year or two following these fires before the grasses become dominant again.
Absence of periodic fire allows herbaceous vegetation to become senescent and may eventually lead to the loss of the most desirable species. Seedlings of non-native brush species and invasive weeds may encroach on the site from adjacent sites
Prior to settlement, this site was subject to periodic grazing and browsing by vast herds of bison, wild cattle, wild horses, and deer. Because of the steep, rugged terrain, the Rocky Hill site was probably not grazed as frequently or as severely as other sites in the vicinity. However, at times the site was grazed heavily in conjunction with adjacent sites. These grazing and browsing episodes could be intense and severe, but periods of heavy use were followed by long periods of non-use as the herds migrated to fresh grazing areas before returning to previously grazed areas. The grazed areas had an opportunity to rest, regrow, regain vigor, and reproduce prior to the next grazing event. Intervals between grazing periods were frequently influenced by the amount of time that had elapsed since the last fire on the area.
As the region was settled, fire was reduced or eliminated and grasslands were fenced off to control movement and facilitate grazing by domestic livestock. As a result of abusive grazing or lack of grazing and/or the elimination of fire, in association with extreme climatic events, the tallgrass plant community has been eliminated or severely reduced on most Rocky Hill sites.
Further deterioration leads to the loss of the perennial warm-season midgrass and forb plant community and an increase in short grasses, annuals, and bare ground. This provides the opportunity for less desirable woody species such as mesquite and juniper to encroach from adjacent sites.
Selective individual removal of undesirable trees and shrubs is relatively easy and more practical when brush plants initially appear on the site. The increase of brush can be fairly rapid and the plants per acre will soon become too numerous for individual control to be feasible. Once woody plants become mature or develop into dense stands, control is expensive, uneconomical, impractical, and difficult to achieve. Brush management is most successful using a systems approach. Initial treatment by mechanical methods can be followed by using approved herbicides, and using prescribed fire as a maintenance technique. Prescribed grazing with a reasonable stocking rate can sustain the grass species composition and production at a near historic climax level.
Changes in plant communities and vegetation states on the Rocky Hill site are result of the combined influences of natural events (rainfall, temperature, droughts, etc.) and the accompanying management systems implemented on the area (prescribed fire, grazing management, and brush management).
Rangeland Health Reference Worksheets have been posted for this site on the Texas NRCS website (www.tx.nrcs.usda.gov) in Section II of the eFOTG under (F) Ecological Site Descriptions.
State and Transition Model:
The State and Transition Diagram which follows provides information on some of the most typical pathways that the vegetation on this site can follow as the result of natural events, management inputs, and application of conservation treatments. There may be other plant communities that can exist on this site under certain conditions. Consultation with local experts and professionals is recommended prior to application of practices or management strategies in order to ensure that specific objectives will be met.
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
| T1A | - | Absence of disturbance and natural regeneration over time, may be coupled with excessive grazing pressure |
|---|---|---|
| R2A | - | Adequate rest from defoliation, followed by reintroduction of historic disturbance regimes |
| T2A | - | Absence of disturbance and natural regeneration over time, may be coupled with excessive grazing pressure |
| R3A | - | Adequate rest from defoliation and removal of woody canopy |
State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 1
Tall/Midgrass Savanna State
The reference plant community for the Rocky Hill ecological site is a Tallgrass/Midgrass Savanna Community with a diverse forb component and a significant population of shrubs and trees. This site is dominated by tallgrasses including Indiangrass, big bluestem, and little bluestem. Sideoats grama is the predominant midgrass species. The most common forbs are bushsunflower, Mexican sagewort, Engelmann daisy, gayfeather, basketflower, western ragweed, and gray goldaster. Trees and shrubs are an important of the historic plant community as well. The most common trees include live oak, elm, and hackberry. Shrubs such as flameleaf sumac, skunkbush sumac, bumelia, elbowbush, lotebush, catclaw acacia, and pricklypear are found on the site as well. The Little Bluestem Savanna Community occurs when little bluestem increases on the site, and becomes the dominant species as Indiangrass and big bluestem decrease. A viable population of the original tallgrasses is present. This is still a very productive plant community, but it has less diversity than the tallgrass savanna community. Midgrasses such as sideoats grama, Texas wintergrass, dropseeds, and silver bluestem occupy a significant part of the plant community. Species composition of forbs, shrubs, and trees remains stable in this phase. In the Midgrass Community, tallgrasses decline. They are being replaced by midgrasses such as sideoats grama, Texas cupgrass, dropseeds, and Texas wintergrass. Lower successional forbs begin to replace some of the original perennial forbs. Large rocks and boulders are obvious, but bare ground is minimal. Remaining tallgrasses are usually found adjacent to larger rocks or in protected areas, but some still occur in the open areas. Density and canopy of shrubby species such as lotebush, bumelia, sumacs, pricklypear and yucca begins to increase.
Dominant plant species
-
live oak (Quercus virginiana), tree
-
little bluestem (Schizachyrium scoparium), grass
Community 1.1
Tallgrass/Midgrass Savanna Community
Figure 8. 1.1 Tallgrass/Midgrass Savanna Community
Figure 9. 1.1 Tallgrass/Midgrass Savanna Community (2)
The reference plant community for the Rocky Hill ecological site is a tallgrass/midgrass savanna with a diverse forb component and a significant population of shrubs and trees. This is the reference plant community. In pristine conditions, the site is dominated by tallgrasses including Indiangrass, big bluestem, and little bluestem. Switchgrass and Canada wildrye occur infrequently. Sideoats grama is the predominant midgrass species. Other midgrasses include Texas wintergrass, tall and meadow dropseed, silver bluestem, Texas cupgrass, and vine mesquite. Other midgrasses and shortgrasses found on this site include hairy grama, buffalograss, curlymesquite, slim and rough tridens, sedges, and threeawns. In its pristine state, the rocks and boulders on the soil surface are not generally evident because they are hidden among the tallgrasses. The most common forbs are bushsunflower, Mexican sagewort, Engelmann daisy, heath aster, daleas, gayfeather, basketflower, western ragweed, wild buckwheat, compassplant, eryngo, plains blackfoot, plains tetraneuris, and gray goldaster. Trees and shrubs are an important of the refeence plant community as well. The most common trees include live oak, elm, hackberry, ash, post oak, and Texas oak. Shrubs such as Mexican buckeye, flameleaf sumac, redbud, skunkbush sumac, bumelia, elbowbush, white honeysuckle, lotebush, catclaw acacia, pricklyash, yucca, and pricklypear are found on the site as well.
Figure 10. 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 | 1200 | 2050 | 2800 |
| Forb | 100 | 150 | 200 |
| Shrub/Vine | 200 | 200 | 200 |
| Tree | 100 | 100 | 100 |
| Total | 1600 | 2500 | 3300 |
Figure 11. Plant community growth curve (percent production by month). TX2520, Tall/Midgrass - Liveoak Savanna <10% Canopy. Warm-season perennial tallgrasses dominant with scattered trees and shrubs and a diverse forb community..
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| J | F | M | A | M | J | J | A | S | O | N | D |
| 2 | 2 | 4 | 12 | 23 | 22 | 6 | 4 | 10 | 9 | 4 | 2 |
Community 1.2
Little Bluestem Savanna Community
Figure 12. 1.2 Little Bluestem Savanna Community
Figure 13. 1.2 Little Bluestem Savanna Community (2)
Little bluestem increases on the site, and becomes the dominant species as Indiangrass and big bluestem decrease. Little bluestem may comprise of 50% or more in this plant community. A viable population of the original tallgrasses is present. This is still a very productive plant community, but it has less diversity than the tallgrass savanna community. Midgrasses such as sideoats grama, Texas wintergrass, dropseeds, and silver bluestem occupy a significant part of the plant community. Species composition of forbs, shrubs, and trees remains stable in this phase. Because of the density of the tallgrasses and midgrasses in the Little Bluestem Savanna Community, surface rocks are not generally visible, and bare ground is minimal.
Figure 14. 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 | 1250 | 2150 | 2900 |
| Shrub/Vine | 200 | 200 | 200 |
| Tree | 100 | 100 | 100 |
| Forb | 50 | 50 | 100 |
| Total | 1600 | 2500 | 3300 |
Figure 15. Plant community growth curve (percent production by month). TX2520, Tall/Midgrass - Liveoak Savanna <10% Canopy. Warm-season perennial tallgrasses dominant with scattered trees and shrubs and a diverse forb community..
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| J | F | M | A | M | J | J | A | S | O | N | D |
| 2 | 2 | 4 | 12 | 23 | 22 | 6 | 4 | 10 | 9 | 4 | 2 |
Community 1.3
Midgrass Community
Figure 16. 1.3 Midgrass Community
Figure 17. 1.3 Midgrass Community (2)
A number of temporary and often reversible factors can cause the reference plant community to shift from the original tallgrass dominated site to a midgrass dominant plant community. The shallow, droughty, and steep nature of the soils and topography can accelerate the change if uncontrolled grazing, lack of fire, and/or extended unfavorable climatic conditions exist. These events, by themselves or in combination, eventually cause the plant community to change from a tallgrass dominant to a midgrass dominant. As Indiangrass, big bluestem, and little bluestem decrease, they are replaced by sideoats grama, Texas cupgrass, dropseeds, Texas wintergrass, silver bluestem, and other midgrasses. Lower successional forbs begin to replace some of the original perennial forbs. Large rocks and boulders are obvious, but bare ground is minimal. There is still a sufficient population of Indiangrass, big bluestem, and little bluestem remaining to enable this site to recover to near its historic potential through proper grazing management and prescribed burning. Remaining tallgrasses are usually found adjacent to larger rocks or in protected areas, but some still occur in the open areas. Density and canopy of shrubby species such as lotebush, bumelia, sumacs, pricklypear and yucca begins to increase. Non-native forbs, shrubs and trees begin to encroach from adjacent sites.
Figure 18. 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) |
|---|---|---|---|
| Grass/Grasslike | 700 | 1500 | 2300 |
| Shrub/Vine | 200 | 200 | 200 |
| Tree | 100 | 100 | 100 |
| Forb | 100 | 100 | 100 |
| Total | 1100 | 1900 | 2700 |
Figure 19. Plant community growth curve (percent production by month). TX2521, Midgrass - Oak Savanna <10% woody Canopy. Abundant warm-season midgrasses, with scattered warm-season tallgrasses, scattered trees and shrubs, and a diverse forb community..
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| J | F | M | A | M | J | J | A | S | O | N | D |
| 2 | 2 | 5 | 13 | 21 | 21 | 7 | 5 | 10 | 8 | 4 | 2 |
Pathway 1.1A
Community 1.1 to 1.2
Abusive grazing practices and the elimination of fire from the ecosystem are the two primary factors that cause the reference tallgrass dominant plant community to shift toward a plant community that is totally dominated by little bluestem. Indiangrass and big bluestem are highly preferred forages on this site. As these plants are repeatedly selectively grazed by livestock, little bluestem plants become more and more competitive, and increase noticeably. Elimination or interruption of the natural fire cycle also contributes to an imbalance in the original plant community and tends to favor the more resilient little bluestem plants.
Pathway 1.2A
Community 1.2 to 1.1
Individual Indiangrass and big bluestem plants are still present in remote or protected areas, and a viable seed source exists to enable the original plant community to recover if sound management practices are followed. Implementation of a prescribed grazing management strategy and re-introduction of fire into the ecosystem will reverse the shift away from the original tallgrass plant community. A reasonable and sustainable stocking rate, as well as utilizing a grazing system to control timing, frequency, and duration of livestock grazing can result in the re-establishment of the balanced and diverse tallgrass plant community. A strategically planned and implemented prescribed burning program will assist with the turnaround in the plant community, and is essential in maintaining the balanced and diverse tallgrass savanna plant community.
Conservation practices
| Prescribed Burning | |
|---|---|
| Prescribed Grazing |
Pathway 1.2B
Community 1.2 to 1.3
Continued abusive grazing and lack of fire will eventually result in the little bluestem plant community shifting to a midgrass plant community. If stocking rates are not monitored and adjusted as needed, selective grazing and overgrazing will lead to increased competition from more aggressive grasses and forbs and cause this vegetation change. This change will be accelerated if drought conditions occur.
Pathway 1.3A
Community 1.3 to 1.2
Implementation of a grazing management plan to insure proper stocking rates and to control the timing, frequency, and duration of livestock grazing will enable the midgrass community to revert back to a little bluestem dominated community. Prescribed burning will assist with the recovery and maintenance of the desired plant community. As non-native or undesired shrubs begin to encroach or increase on the site, individual plant treatment can be an effective and economical method of maintaining this plant community and preventing the transition to another vegetation state.
Conservation practices
| Prescribed Burning | |
|---|---|
| Prescribed Grazing |
State 2
Shrubland State
The Midgrass/Shrub Community marks the drastic transition from a productive tallgrass and midgrass plant community to a site that is dominated by lower successional perennial grasses, shortgrasses, forbs, and annual species. Bare ground becomes more evident and begins to appear in the interspaces between the individual grass plants. This makes the site more susceptible to the invasion of undesirable brush and weed species from adjacent sites. Erosion becomes a concern, especially on the steeper slopes. Pricklypear, yucca, catclaw acacia, lotebush, and sumacs increase significantly and the site is invaded by mesquite. Due to the amount of rock on the soil surface, a few tallgrasses still exist between the rocks and in other inaccessible areas.
Dominant plant species
-
honey mesquite (Prosopis glandulosa), shrub
-
catclaw acacia (Acacia greggii var. greggii), shrub
-
curly-mesquite (Hilaria belangeri), grass
-
buffalograss (Bouteloua dactyloides), grass
Community 2.1
Midgrass/Shrub Community
Figure 20. 2.1 Midgrass/Shrub Community (2)
Figure 21. 2.1 Midgrass/Shrub Community
Abusive grazing, extended severe drought conditions, and lack of fire will eventually lead to a drastic transition from a productive tallgrass and midgrass plant community to a site that is dominated by lower successional perennial grasses, shortgrasses, forbs, and annual species. Bare ground becomes more evident and begins to appear in the interspaces between the individual grass plants. This makes the site more susceptible to the invasion of undesirable brush and weed species from adjacent sites. Erosion becomes a concern, especially on the steeper slopes. Pricklypear, yucca, catclaw acacia, lotebush, and sumacs increase significantly and the site is invaded by mesquite. Due to the amount of rock on the soil surface, a few tallgrasses still exist between the rocks and in other inaccessible areas. Because of the amount of tree and shrub canopy, and an insufficient seed source of higher successional grasses, this plant community cannot return to the reference plant community through implementation of management practices alone.
Figure 22. 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 | 350 | 700 | 1150 |
| Shrub/Vine | 300 | 300 | 300 |
| Forb | 150 | 200 | 250 |
| Tree | 100 | 100 | 100 |
| Total | 900 | 1300 | 1800 |
Figure 23. Plant community growth curve (percent production by month). TX2515, Shortgrass/Shrub Dominant Community. Shortgrasses and Shrubs dominate this plant community..
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| J | F | M | A | M | J | J | A | S | O | N | D |
| 3 | 4 | 10 | 10 | 20 | 20 | 5 | 5 | 10 | 8 | 2 | 3 |
State 3
Woodland State
As the site continues to deteriorate to the Woodland State because of mismanagement and/or extreme climatic conditions, tallgrasses, midgrasses, and perennial forbs continue to decline and are replaced by opportunistic species that are more tolerant of grazing and drought. Herbaceous species are primarily limited to early successional perennial grasses and forbs, annual grasses and forbs, and sedges. The density and canopy of trees and shrubs is the dominant vegetation feature of the site. Sparse herbaceous vegetation is scattered among the rocks on the soil surface.
Community 3.1
Tree/Shrub/Vine Community
Figure 24. 3.1 Tree/Shrub/Vine Community
Figure 25. 3.1 Tree/Shrub/Vine Community (2)
As the site continues to deteriorate because of mismanagement and/or extreme climatic conditions such as abusive grazing, extended long-term droughts, and lack of fire, tallgrasses, midgrasses, and perennial forbs continue to decline and are replaced by opportunistic species that are more tolerant of grazing and drought. Herbaceous species are primarily limited to early successional perennial grasses and forbs, annual grasses and forbs, and sedges. The density and canopy of trees and shrubs such as mesquite, lotebush, and Catclaw acacia is the dominant vegetation feature of the site. Sparse herbaceous vegetation is scattered among the rocks on the soil surface. Soil erosion hazard increases because of the amount of bare ground, especially on steeper slopes. Once the site has deteriorated to this point, it is not practical to implement brush management or range seeding on a large scale. However, targeted areas can be treated to enhance wildlife habitat.
Figure 26. 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) |
|---|---|---|---|
| Shrub/Vine | 300 | 300 | 300 |
| Grass/Grasslike | 100 | 200 | 300 |
| Forb | 100 | 200 | 300 |
| Tree | 200 | 200 | 200 |
| Total | 700 | 900 | 1100 |
Figure 27. Plant community growth curve (percent production by month). TX2515, Shortgrass/Shrub Dominant Community. Shortgrasses and Shrubs dominate this plant community..
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| J | F | M | A | M | J | J | A | S | O | N | D |
| 3 | 4 | 10 | 10 | 20 | 20 | 5 | 5 | 10 | 8 | 2 | 3 |
Transition T1A
State 1 to 2
Abusive grazing, resulting from overstocking and continuous grazing, leads to a drastic change in the herbaceous plant community. Higher successional midgrasses such as sideoats grama and Texas cupgrass are replaced by silver bluestem, dropseeds, buffalograss, and lower successional grasses including threeawns, Texas grama, red lovegrass, and annual grasses. Increased bare ground enables opportunistic forbs such as western ragweed, broomweed, and annuals to replace higher successional forbs. Elimination of fire from the ecosystem is a major cause of the significant increase in the frequency, density, and canopy of invasive shrubs such as mesquite, lotebush, pricklyash, catclaw acacia, pricklypear, and yucca.
Restoration pathway R2A
State 2 to 1
Once the site has deteriorated to this state, it is no longer capable of recovering to the reference plant community through the implementation of management practices alone. Brush Management practices are needed to eliminate non-native species, control undesired native species, and reduce overhead canopy to allow understory species to establish and produce. At this stage, there is not a viable population or seed source of the original plant community, so Range Planting is needed to re-establish native grasses and forbs that were components of the original plant community. However, Brush Management and Range Planting are difficult and very expensive on this site because of the rough, rocky, and steep terrain. Labor-intensive hand treatment methods or aerial application may be the only options available for brush management and range planting on this site in some instances. If the original plant community can be restored, Prescribed Grazing and Prescribed Burning are essential to the recovery and maintenance of the desired plant community.
Conservation practices
| Brush Management | |
|---|---|
| Prescribed Burning | |
| Range Planting | |
| Prescribed Grazing |
Transition T2A
State 2 to 3
The combination of long-term overstocking, continuous abusive grazing, and elimination of fire can eventually result in this site being dominated by trees and shrubs. In many cases, overstory and midstory canopies may exceed 40%. The understory plant community is characterized by sparse herbaceous vegetation consisting primarily of low successional grasses and forbs, shade tolerant species, and annuals. Soil erosion hazard is increased by the amount of bare ground, especially on steeper slopes.
Restoration pathway R3A
State 3 to 2
Once the site has reached this stage, it is highly unlikely that the reference plant community can ever be restored in a reasonable time frame with the existing technology and management options. However, selected areas can be treated and managed to open up the canopy, establish beneficial vegetation, and manipulate the plant community to benefit wildlife habitat.
Conservation practices
| Brush Management | |
|---|---|
| Prescribed Burning | |
| Range Planting | |
| Prescribed Grazing |
Additional community tables
Table 10. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Tallgrasses | 700–1600 | ||||
| big bluestem | ANGE | Andropogon gerardii | 100–1600 | – | ||
| Indiangrass | SONU2 | Sorghastrum nutans | 100–1600 | – | ||
| little bluestem | SCSC | Schizachyrium scoparium | 300–1000 | – | ||
| switchgrass | PAVI2 | Panicum virgatum | 0–200 | – | ||
| Canada wildrye | ELCA4 | Elymus canadensis | 0–100 | – | ||
| 2 | Midgrasses | 350–900 | ||||
| sideoats grama | BOCU | Bouteloua curtipendula | 150–300 | – | ||
| Texas wintergrass | NALE3 | Nassella leucotricha | 50–200 | – | ||
| Texas cupgrass | ERSE5 | Eriochloa sericea | 0–150 | – | ||
| composite dropseed | SPCOC2 | Sporobolus compositus var. compositus | 0–150 | – | ||
| Drummond's dropseed | SPCOD3 | Sporobolus compositus var. drummondii | 0–100 | – | ||
| vine mesquite | PAOB | Panicum obtusum | 0–100 | – | ||
| silver beardgrass | BOLAT | Bothriochloa laguroides ssp. torreyana | 0–100 | – | ||
| 3 | Mid/Shortgrasses | 100–300 | ||||
| curly-mesquite | HIBE | Hilaria belangeri | 0–200 | – | ||
| buffalograss | BODA2 | Bouteloua dactyloides | 0–200 | – | ||
| hairy grama | BOHI2 | Bouteloua hirsuta | 0–200 | – | ||
| cedar sedge | CAPL3 | Carex planostachys | 0–100 | – | ||
| tumble windmill grass | CHVE2 | Chloris verticillata | 0–100 | – | ||
| tumblegrass | SCPA | Schedonnardus paniculatus | 0–100 | – | ||
| white tridens | TRAL2 | Tridens albescens | 0–100 | – | ||
| slim tridens | TRMUE | Tridens muticus var. elongatus | 0–100 | – | ||
| slim tridens | TRMUM | Tridens muticus var. muticus | 0–100 | – | ||
| purple threeawn | ARPU9 | Aristida purpurea | 0–50 | – | ||
| Wright's threeawn | ARPUW | Aristida purpurea var. wrightii | 0–50 | – | ||
| red lovegrass | ERSE | Eragrostis secundiflora | 0–50 | – | ||
| Texas grama | BORI | Bouteloua rigidiseta | 0–50 | – | ||
|
Forb
|
||||||
| 4 | Forbs | 100–200 | ||||
| Cuman ragweed | AMPS | Ambrosia psilostachya | 0–50 | – | ||
| awnless bushsunflower | SICA7 | Simsia calva | 0–50 | – | ||
| compassplant | SILA3 | Silphium laciniatum | 0–50 | – | ||
| white heath aster | SYERE | Symphyotrichum ericoides var. ericoides | 0–50 | – | ||
| white sagebrush | ARLUM2 | Artemisia ludoviciana ssp. mexicana | 0–50 | – | ||
| American star-thistle | CEAM2 | Centaurea americana | 0–50 | – | ||
| Engelmann's daisy | ENPE4 | Engelmannia peristenia | 0–50 | – | ||
| buckwheat | ERIOG | Eriogonum | 0–50 | – | ||
| Leavenworth's eryngo | ERLE11 | Eryngium leavenworthii | 0–50 | – | ||
| curlycup gumweed | GRSQ | Grindelia squarrosa | 0–50 | – | ||
| hoary false goldenaster | HECA8 | Heterotheca canescens | 0–50 | – | ||
| plains blackfoot | MELE2 | Melampodium leucanthum | 0–50 | – | ||
| Nuttall's sensitive-briar | MINU6 | Mimosa nuttallii | 0–25 | – | ||
| smartweed leaf-flower | PHPO3 | Phyllanthus polygonoides | 0–25 | – | ||
| Drummond's skullcap | SCDR2 | Scutellaria drummondii | 0–25 | – | ||
| flax | LINUM | Linum | 0–25 | – | ||
| Texas stork's bill | ERTE13 | Erodium texanum | 0–25 | – | ||
| pygmy cudweed | EVAX | Evax | 0–25 | – | ||
| Dakota mock vervain | GLBI2 | Glandularia bipinnatifida | 0–25 | – | ||
| wavyleaf thistle | CIUN | Cirsium undulatum | 0–25 | – | ||
| prairie clover | DALEA | Dalea | 0–25 | – | ||
| stemmy four-nerve daisy | TESC2 | Tetraneuris scaposa | 0–25 | – | ||
| germander | TEUCR | Teucrium | 0–25 | – | ||
| Texas vervain | VEHA | Verbena halei | 0–25 | – | ||
| silverleaf nightshade | SOEL | Solanum elaeagnifolium | 0–25 | – | ||
| queen's-delight | STSY | Stillingia sylvatica | 0–25 | – | ||
| bluestem pricklypoppy | ARAL3 | Argemone albiflora | 0–25 | – | ||
| Texas Indian mallow | ABFR3 | Abutilon fruticosum | 0–25 | – | ||
|
Shrub/Vine
|
||||||
| 5 | Shrubs/Vines | 100–200 | ||||
| plum | PRUNU | Prunus | 0–100 | – | ||
| Mohr oak | QUMO | Quercus mohriana | 0–100 | – | ||
| prairie sumac | RHLA3 | Rhus lanceolata | 0–100 | – | ||
| skunkbush sumac | RHTR | Rhus trilobata | 0–100 | – | ||
| gum bully | SILA20 | Sideroxylon lanuginosum | 0–100 | – | ||
| Mexican buckeye | UNSP | Ungnadia speciosa | 0–100 | – | ||
| Texas Hercules' club | ZAHI2 | Zanthoxylum hirsutum | 0–50 | – | ||
| lotebush | ZIOB | Ziziphus obtusifolia | 0–50 | – | ||
| stretchberry | FOPU2 | Forestiera pubescens | 0–50 | – | ||
| western white honeysuckle | LOAL | Lonicera albiflora | 0–50 | – | ||
| algerita | MATR3 | Mahonia trifoliolata | 0–50 | – | ||
| catclaw acacia | ACGRG3 | Acacia greggii var. greggii | 0–50 | – | ||
| Texas redbud | CECAT | Cercis canadensis var. texensis | 0–25 | – | ||
| Jersey tea | CEHE | Ceanothus herbaceus | 0–25 | – | ||
| Carolina coralbead | COCA | Cocculus carolinus | 0–25 | – | ||
| Christmas cactus | CYLE8 | Cylindropuntia leptocaulis | 0–25 | – | ||
| clapweed | EPAN | Ephedra antisyphilitica | 0–25 | – | ||
| pricklypear | OPUNT | Opuntia | 0–25 | – | ||
| honey mesquite | PRGL2 | Prosopis glandulosa | 0–25 | – | ||
| greenbrier | SMILA2 | Smilax | 0–25 | – | ||
| yucca | YUCCA | Yucca | 0–25 | – | ||
|
Tree
|
||||||
| 6 | Trees | 0–100 | ||||
| live oak | QUVI | Quercus virginiana | 0–100 | – | ||
| cedar elm | ULCR | Ulmus crassifolia | 0–100 | – | ||
| hackberry | CELTI | Celtis | 0–100 | – | ||
| post oak | QUST | Quercus stellata | 0–50 | – | ||
| Nuttall oak | QUTE | Quercus texana | 0–50 | – | ||
| Texas mulberry | MOMI | Morus microphylla | 0–25 | – | ||
Interpretations
Animal community
Historically, the Rocky Hill site was inhabited permanently and intermittently by a wide variety of mammals, reptiles, and birds. Several historical references and journals written in the 18th and 19th century by explorers, survey parties, and military expeditions refer to herds of bison, wild cattle, wild horses, deer, and antelope roaming freely across the Rolling Limestone Prairie and adjacent regions.
The Rocky Hill site provides excellent habitat for many species of wildlife due to the rough, steep terrain and the diversity of plant species, growth forms, distribution, and structure of the vegetation that occurs. The site provides shelter, escape cover, and nesting habitat, as well as a variety of browse, mast, seeds, and fruit that are important to the diets of various wildlife species. Currently, the site is utilized by deer, wild turkey, numerous species of birds, and a variety of small fur-bearing mammals. Animal species and populations fluctuate as the vegetation cycles through temporary phases and different ecological
Because of the tree and shrub component and the topography, the Rocky Hill site is well suited for grazing and browsing by goats. Grazing by cattle is most common on the lower slopes and benches of this site. Most European breeds of cattle and small statured cattle are not well suited to the steeper slopes on this site. Some of the hardier breeds of cattle are better suited to the slopes, but are still not well adapted for the steepest terrain and lack of water sources on the site. Livestock grazing and distribution can be improved by providing water sources, providing supplemental feed in strategic locations, and by implementing grazing management systems that incorporate frequent and timely deferment periods.
Hydrological functions
The Rocky Hill site has a good soil-water-air-plant relationship because of the amount of rock on the soil surface and in the upper portions of the soil profile. Showers and light rains can be very effective on this site. Surface rocks retain moisture and release it slowly to the soil and vegetation following showers and light rainfall. Rocks and fragments in the soil provide pockets for oxygen, moisture, and plant roots.
When herbaceous vegetation and ground cover are maintained in a healthy and vigorous status, water infiltration into the soil profile is increased significantly, resulting in less runoff. A healthy grass cover results in improved water quality because it serves as a filter or trap to reduce sediments and pollutants before the water flows offsite. Surface runoff is rapid during heavy rainfall events due to the rough, steep topography, slowly permeable soils, and numerous limestone outcrops.
Recreational uses
These scenic areas offer outdoor activities including photography, shaded picnic areas, bird watching, hiking, camping, horseback riding, and off-road vehicle use. The Rocky Hill site is a prime site for wildlife habitat. Where it is managed properly, it provides outstanding opportunities for hunting deer and turkey. The tree foliage of this site produces outstanding fall colors.
Wood products
Oaks and some of the other hardwood trees can be used for firewood. Some of the woody species may be used for specialty products and crafts.
Other products
Plums, agarito berries and pricklypear tunas can be eaten or used to make jelly.
Other information
None.
Supporting information
Inventory data references
Vegetation data for this site was obtained from existing Range Site Descriptions, SCS-RANGE -417 Production and Composition Records for Native Grazing Lands, and on-site inventories by the author and local experts including ranchers, natural resource specialists from federal and state agencies, and personnel from cooperating agencies and organizations. A total of 15 SCS-RANGE-417’s containing data collected from 4 counties during the period 10/30/1979 to 12/12/1986 were reviewed for this site.
Other references
Ajilvsgi, Geyata. Wildflowers of Texas. Sharer Publishing, Bryan, TX. 1984.
Bachand, Richard. The American Prairie: Going, Going, Gone? National Wildlife Federation. Rocky Mountain Natural Resource Center. Boulder, CO. 2001.
Coffey, Chuck R., and Russell Stevens. Grasses of Southern Oklahoma and North Texas: A Pictorial Guide. The Samuel Roberts Noble Foundation, Ardmore, OK. 2004
Diggs, George M., Jr., Barney L. Lipscomb, and Robert J. O’Kennon. Illustrated Flora of North Central Texas. Botanical Research Institute of Texas. Fort Worth, TX 1999.
Egan, Dave and Evelyn A. Howell. The Historical Ecology Handbook…A Restorationist’s Guide to Reference Ecosystems. Island Press, Washington, DC. 2001.
Flores, Dan. “Indian Use of Range Resources” presented at 20th Annual Ranch Management Conference. Lubbock, TX, September 30, 1983.
Frost, Cecil C. Presettlement Fire Frequency Regimes of the United States: A First Approximation. Tall Timber Fire Ecology Conference Proceedings, No. 20. Tall Timbers Research Station. Tallahassee, FL. 1998.
Gleason, Jerry. Personal communication. 2008 and 2009.
Hatch, Stephan L., Kancheepuram N. Gandhi, and Larry E. Brown. Checklist of the Vascular Plants of Texas. Texas Agricultural Experiment Station MP-1655. College Station, TX. 1990
Hatch, Stephan L., Jennifer Pluhar. Texas Range Plants. Texas A&M University Press, College Station, TX. 1993.
Kelton, Elmer. “History of Rancher Use of Range Resources” presented at 20th Annual Ranch Management Conference. Lubbock, TX, September 30, 1983.
Kirkpatrick, Zoe Merriman. Wildflowers of the Western Plains. University of Texas Press. Austin, TX. 1992.
Larrabee, Aimee and John Altman. Last Stand of the Tallgrass Prairie. Sterling Publishing Co., New York, NY. 2001.
North Rolling Plains Resource Conservation and Development. Common Rangeland Plants of the Texas Panhandle. Pampa, TX. 2008.
Packard, Stephen and Cornelia F. Mutel. The Tallgrass Restoration Handbook for Prairies, Savannas, and Woodlands. Island Press, Washington, DC. 1997.
Parker, W.B. Through Unexplored Texas In The Summer and Fall of 1854. The Texas State Historical Commission. Austin, TX 1984
Shiflet, Thomas N. et. Al. Rangeland Cover Types of the United States. Society for Range Management. Denver, CO. 1994.
Smith, Jared G. Grazing Problems in the Southwest and How to Meet Them. United States Department of Agriculture Division of Agrostology. Washington, DC. 1899.
Texas Almanac 2008-2009. Dallas Morning News. Dallas, TX. 2008.
Tyrl, Ronald J., Terrence G. Bidwell, and Ronald E. Masters. Field Guide to Oklahoma Plants. Oklahoma State University, Stillwater, OK. 2002.
United States Department of Agriculture Natural Resources Conservation Service, National Plant Data Center, Baton Rouge, LA. The PLANTS Database. http://plants.usda.gov 2007.
United States Department of Agriculture Natural Resources Conservation Service, Ag Handbook 296. Land Resource Regions and Major Land Resource Areas of the United States, the Caribbean, and the Pacific Basin. 2006.
United States Department of Agriculture Natural Resources Conservation Service, Temple, TX. Rocky Hill Ecological Site Description R080BY156TX. 2008.
United States Department of Agriculture Soil Conservation Service, Temple, TX. Production and Composition Record for Native Grazing Lands. SCS-RANGE 417 data from Throckmorton, Shackelford, Callahan, and Coleman Counties. 1981-1986.
United States Department of Agriculture Soil Conservation Service, Washington, DC. Web Soil Survey http://websoilsurvey.nrcs.usda.gov/app/. 2007
United States Department of Agriculture Soil Conservation Service, Temple, TX. Published Soil Surveys: Throckmorton, Shackelford, Callahan, Coleman, and Concho Counties. Various publication dates.
United States Department of Agriculture Soil Conservation Service, Temple, TX. Range Site Descriptions for the Rolling Limestone Prairie. Various publication dates.
Vines, Robert A. Trees of North Texas. University of Texas Press, Austin, TX. 1982
Weniger, Del. The Explorers’ Texas. Eakin Publications. Austin, TX. 1984.
Weniger, Del. Cacti of the Southwest. University of Texas Press, Austin, TX. 1978.
Williams, Gerald W. References On The American Indian Use Of Fire in Ecosystems. United States Department of Agriculture – Forest Service, Washington, DC. 2005.
ACKNOWLEDGEMENTS:
I would like to express my thanks and appreciation to the following for their cooperation, assistance, and support in the development of this Ecological Site Description:
Kimberly Burr, USDA Natural Resources Conservation Service, Albany, TX
Jerry Gleason, USDA Natural Resources Conservation Service, Throckmorton, TX
Reviewers and Technical Contributors:
Lem Creswell, RMS, NRCS, Weatherford, Texas
Nathan Haile, RSS, NRCS, Weatherford, Texas
Mark Moseley, RMS, NRCS, San Antonio, Texas
Justin Clary, RMS, NRCS, Temple, Texas
Contributors
Dan Caudle, DMC Natural Resources Management, Weatherford, Texas
PES Edits by Tyson Morley, MLRA Soil Scientist, Altus, Oklahoma
Approval
Bryan Christensen, 9/12/2023
Acknowledgments
Site Development and Testing Plan:
Future work, as described in a Project Plan, to validate the information in this Provisional
Ecological Site Description is needed. This will include field activities to collect low,
medium and high intensity sampling, soil correlations, and analysis of that data. Annual
field reviews should be done by soil scientists and vegetation specialists. A final field review, peer review, quality control, and quality assurance reviews of the ESD will be needed to produce the final document.
Annual reviews of the Project Plan are to be conducted by the Ecological Site Technical
Team.
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
| Author(s)/participant(s) | Lem Creswell, RMS, NRCS, Weatherford, Texas |
|---|---|
| Contact for lead author | 817-596-2865 |
| Date | 10/28/2008 |
| 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:
Deposition or erosion is uncommon during normal rainfall events, but may occur in limited areas during intense rainfall events. -
Number and height of erosional pedestals or terracettes:
None. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Expect no more than 20% bare ground scattered randomly throughout the site. -
Number of gullies and erosion associated with gullies:
Few rills and no gullies should occur. -
Extent of wind scoured, blowouts and/or depositional areas:
None. -
Amount of litter movement (describe size and distance expected to travel):
Little or no litter movement or deposition during normal rainfall events. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface in HCPC is resistant to wind erosion. Stability range is expected to be 5-6. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
0-4 inches of brown stony clay. Limestone, ironstone, and sandstone rock covers as much as 45% of the soil surface. Rocks greater than 48 inches across are scattered across the site. SOM is 1-4%. See soil survey for more information. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
The tallgrass/midgrass savanna with abundant forbs, adequate litter, and little bare ground provides for maximum infiltration and negligible runoff. -
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 > Perennial forbs >Other:
Shrubs/Vines > Trees > Warm-season shortgrasses > Cool-season grassesAdditional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Perennial grasses will naturally exhibit a minor amount (less than 5%) of senescence and some mortality every year. -
Average percent litter cover (%) and depth ( in):
Litter is primarily herbaceous. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
1600 to 3300 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, pricklypear, yucca, pricklyash, catclaw acacia, lotebush, King Ranch bluestem, annual broomweed. -
Perennial plant reproductive capability:
All perennial species should be capable of reproducing every year unless disrupted by extended drought, overgrazing, wildfire, insect damage, or other events occuring immediately prior to, or during the reproductive phase.
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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.
| T1A | - | Absence of disturbance and natural regeneration over time, may be coupled with excessive grazing pressure |
|---|---|---|
| R2A | - | Adequate rest from defoliation, followed by reintroduction of historic disturbance regimes |
| T2A | - | Absence of disturbance and natural regeneration over time, may be coupled with excessive grazing pressure |
| R3A | - | Adequate rest from defoliation and removal of woody canopy |