State 1
Mid/Tallgrass State

The Midgrass/Tallgrass Community is the reference plant community. In pristine conditions it is an open prairie dominated by midgrasses, scattered tallgrasses, some perennial forbs, and a few widely scattered shrubs. Sideoats grama and vine mesquite are the most abundant grasses. Tallgrasses such as big bluestem and Indiangrass may be found on the upslopes of the site or in areas with more open soil profiles. Woody canopy is less than 5%. Widely scattered shrubs and small trees include skunkbush sumac, catclaw acacia, lotebush, and hackberry. The Midgrass Community is totally dominated by midgrasses. A viable population of primary midgrasses still persists, but other midgrasses such as silver bluestem, Texas wintergrass, and dropseeds increase significantly. Early successional forbs and shortgrasses such as curlymesquite, buffalograss, and western ragweed begin to increase. The canopy of shrubs and trees begins to gradually increase as mesquite, pricklypear, lotebush, and similar species encroach from adjacent areas. Little bluestem and other tallgrasses are eliminated or severely reduced but may still be found in remote or protected areas. Woody canopy of shrubs and trees is less than 10%.

Community 1.1
Mid/Tallgrass Prairie Community

Figure 8. 1.1 Mid/Tallgrass Prairie Community

Figure 9. 1.1 Mid/Tallgrass Prairie Community (2)

The reference plant community for the Clay Slopes ecological site in the Rolling Limestone Prairie is a midgrass/tallgrass prairie. It is an open prairie dominated by midgrasses, scattered tallgrasses, some perennial forbs, and a few widely scattered shrubs. Sideoats grama and vine mesquite are the most abundant grasses. Little bluestem is a significant component of the plant community. Tallgrasses such as big bluestem and Indiangrass may be found on the upslopes of the site where it transitions into steeper sites such as the Rocky Hill ecological site, on areas with more open soil profiles, and during growing seasons with above average rainfall. Woody canopy is less than 5%. Widely scattered shrubs and small trees include skunkbush sumac, catclaw acacia, lotebush, and hackberry.

Community 1.2
Midgrass Prairie Community

Figure 12. 1.2 Midgrass Prairie Community

Figure 13. 1.2 Midgrass Prairie Community (2)

Figure 14. 1.2 Midgrass Prairie Community (3)

Uncontrolled grazing, elimination of fire from the ecosystem, and severe drought conditions result in the shift from a midgrass/tallgrass plant community to a midgrass plant community totally dominated by midgrasses. A viable population of primary midgrasses still persists, but other midgrasses such as silver bluestem, Texas wintergrass, and dropseeds increase significantly. Early successional forbs and shortgrasses such as curlymesquite, buffalograss, and western ragweed begin to increase. The canopy of shrubs and trees begins to gradually increase as mesquite, pricklypear, lotebush, and similar species encroach from adjacent areas. Little bluestem and other tallgrasses are eliminated or severely reduced but may still be found in remote or protected areas. Woody canopy of shrubs and trees is less than 10%.

Pathway 1.1A
Community 1.1 to 1.2

Mid/Tallgrass Prairie Community

Midgrass Prairie Community

Uncontrolled or mismanaged grazing for an extended period of time, elimination of fire from the ecosystem, and/or the effects of extended drought are the primary factors that cause the reference plant community to shift from an open midgrass/tallgrass prairie to an open prairie that is almost exclusively midgrasses, with only remnants of tallgrasses remaining. As little bluestem and other tallgrasses decline, they are initially replaced by midgrasses such as sideoats grama, vine mesquite, and Arizona cottontop. Another community of competitive midgrasses including silver bluestem, meadow dropseed, white tridens, and Texas wintergrass, begins to 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 competitive and aggressive midgrasses and perennial forbs. Shortgrasses and more aggressive perennial forbs gradually begin to increase at this stage. Woody canopy may increase slightly.

Pathway 1.2A
Community 1.2 to 1.1

Midgrass Prairie Community

Mid/Tallgrass Prairie Community

A viable population of little bluestem, sideoats grama, Arizona cottontop, and vine mesquite, as well as sufficient individual plants of big bluestem and Indiangrass still exists on this site. At this stage, implementation of a prescribed grazing management strategy and re-introduction of periodic fire into the ecosystem will reverse the shift away from the original plant community. A reasonable and sustainable stocking rate in combination with a grazing system to control the timing, frequency, duration, and degree of grazing can result in the re-establishment of the balanced and diverse midgrass/tallgrass prairie. A strategically planned and implemented prescribed burning program will accelerate the recovery process. Tree and shrub canopy may have increased slightly, but does not require extensive treatment. However, individual treatment of trees and shrubs that have increased or invaded can be an effective and economical method of maintaining the plant community at this stage.

State 2
Mixedgrass State

In the Midgrass/Shortgrass Community, primary midgrasses including sideoats grama, vine mesquite, and Arizona cottontop decline drastically and little bluestem and other tallgrasses are almost completely eliminated from the site. Midgrasses such as silver bluestem, dropseeds, and white tridens increase significantly. Shortgrasses such as curlymesquite, buffalograss, hairy grama, and slim tridens increase and become co-dominant with midgrasses. Woody canopy increases to as much as 15%. Texas wintergrass increases as the woody canopy increases. The Shortgrass/Annuals Community is experiencing continued deterioration of the plant community which eventually results in a plant community characterized by shortgrasses such as buffalograss, curlymesquite, threeawns and Texas grama, encroachment of annual grasses and forbs, an increase in shrubs, and an increase in bare ground. Western ragweed and broomweed are the dominant forbs. Mesquite, catclaw acacia, lotebush, pricklypear, and other shrubs increase in density or invade from adjacent sites. Woody canopy increases to approximately 20%. Texas wintergrass becomes the dominant midgrass as the density and canopy of shrubs continues to increase.

Community 2.1
Midgrass/Shortgrass Community

Figure 17. 2.1 Midgrass/Shortgrass Community

Figure 18. 2.1 Midgrass/Shortgrass Community (2)

Figure 19. 2.1 Midgrass/Shortgrass Community (3)

Primary midgrasses including sideoats grama, vine mesquite, and Arizona cottontop decline drastically and little bluestem and other tallgrasses are almost completely eliminated from the site. Midgrasses such as silver bluestem, dropseeds, and white tridens increase significantly. Shortgrasses such as curlymesquite, buffalograss, hairy grama, and slim tridens increase and become co-dominant with midgrasses. Woody canopy increases to as much as 15% as shrubs and woody plants increase in density and begin to encroach from adjacent areas. Texas wintergrass increases as the woody canopy increases.

Community 2.2
Shortgrass/Annuals Community

Figure 22. 2.2 Shortgrass/Annuals Community

Figure 23. 2.2 Shortgrass/Annuals Community (2)

Severe disturbances such as abusive grazing, persistent drought conditions, or combinations of abusive grazing, extreme climatic conditions, and other factors, cause the plant community to change dramatically. Continued deterioration of the plant community eventually results in a plant community characterized by shortgrasses such as buffalograss, curlymesquite, threeawns and Texas grama, encroachment of annual grasses and forbs, an increase in shrubs, and an increase in bare ground. Western ragweed and broomweed are the dominant forbs. Mesquite, catclaw acacia, lotebush, pricklypear, and other shrubs increase in density or invade from adjacent sites. Woody canopy increases to approximately 20%. Texas wintergrass becomes the dominant midgrass as the density and canopy of shrubs continues to increase. Bare ground begins to appear in some areas and can become a serious problem in the most deteriorated state.

Pathway 2.1A
Community 2.1 to 2.2

Midgrass/Shortgrass Community

Shortgrass/Annuals Community

At this stage, the site is characterized by shortgrasses, encroachment of annual grasses and forbs, an increase in shrubs, and an increase in bare ground as the result of continuous heavy grazing, extended drought, and lack of fire. Curlymesquite, buffalograss, hairy grama, slim tridens, Texas grama, and threeawns become the dominant perennial grasses. Annual forbs and grasses increase significantly as bare ground increases. Texas wintergrass becomes the dominant midgrass as the density and canopy of shrubs continues to increase. Silver bluestem, meadow dropseed, white tridens and remnant individual plants of sideoats grama and vine mesquite still persist.

Pathway 2.2A
Community 2.2 to 2.1

Shortgrass/Annuals Community

Midgrass/Shortgrass Community

Implementation of a grazing management plan to is necessary to allow midgrasses to be competitive with the shortgrasses and annuals, and re-establish themselves. Prescribed burning will assist with the recovery and maintenance of the desired plant community.

State 3
Shrubland State

The Shrubland Community is dominated by non-native and invasive native shrubs such as mesquite, catclaw acacia, lotebush, pricklypear, and tasajillo with a canopy of 25% or more. The woody canopy has a noticeable detrimental effect on the understory vegetation. Extensive areas of bare ground may occur. Shortgrasses as well as annual grasses and forbs, and early successional midgrasses increase dramatically and invade from adjacent sites. Texas wintergrass and other shade tolerant species will also increase. If fields are abandoned and left to re-vegetate naturally, weedy grasses, forbs and shrubs will become established.

Community 3.1
Shrubland Community

Figure 26. 3.1 Shrubland Community

Figure 27. 3.1 Shrubland Community (2)

Continuous abusive grazing, lack of fire, and extended drought can all be major factors in the deterioration of the plant community from an open prairie to a shrub dominated site. The site is dominated by non-native and invasive native shrubs such as mesquite, catclaw acacia, lotebush, pricklypear, and tasajillo with a canopy of 25% or more. The woody canopy has a noticeable detrimental effect on the understory vegetation. Extensive areas of bare ground may occur. Opportunistic annual forbs and grasses become established on the exposed soil surface. Shortgrasses as well as annual grasses and forbs, and early successional midgrasses increase dramatically and invade from adjacent sites. Texas wintergrass and other shade tolerant species will also increase. If fields are abandoned and left to re-vegetate naturally, weedy grasses, forbs and shrubs will become established.

State 4
Converted Land State

Since the site generally occurs as small irregularly shaped areas, the Converted Land State Community is usually treated and managed in conjunction with surrounding sites. Kleingrass, Old World bluestem, and King Ranch bluestem are the most commonly seeded introduced grasses, but some areas have been planted to Bermudagrass. The areas that have been converted to cropland are primarily planted to wheat, oats, or forage sorghum. After conversion to other land uses, these areas must be intensively managed in order to maintain production and quality. Production potential for seeded species and crops is moderately high. The Abandoned Community occurs when over time, many of these cultivated and intensively managed areas have been abandoned because of adverse economic conditions. Adverse economic conditions, drought, and other outside factors may result in these areas being abandoned or neglected. If fertility is not maintained, and weed control is not routinely carried out, the land will tend to revert to early successional plants such as annual forbs and grasses. These abandoned lands have deteriorated to the point that they will never return to historical vegetation because of soil degradation and lack of natural seed source.

Community 4.1
Converted Land Community

Since the site generally occurs as small irregularly shaped areas, it is usually treated and managed in conjunction with surrounding sites. Kleingrass, Old World bluestem, and King Ranch bluestem are the most commonly seeded introduced grasses, but some areas have been planted to Bermudagrass. The areas that have been converted to cropland are primarily planted to wheat, oats, or forage sorghum. After conversion to other land uses, these areas must be intensively managed in order to maintain production and quality. Production potential for seeded species and crops is moderately high. Refer to Forage Suitability Group Descriptions for specific recommendations, production potentials, species adaptation, etc. In the highest state of production following conversion, the trees, shrubs and forbs have been severely reduced or eliminated from the site. The more shrubs, trees, and forbs that occur on a converted site, the lower the overall forage production would be. The annual production figures below reflect this change.

Community 4.2
Abandoned Land Community

In time, many of these cultivated and intensively managed areas have been abandoned because of adverse economic conditions. Adverse economic conditions, drought, and other outside factors may result in these areas being abandoned or neglected. If fertility is not maintained, and weed control is not routinely carried out, the land will tend to revert to early successional plants such as annual forbs and grasses. These abandoned lands have deteriorated to the point that they will never return to historical vegetation because of soil degradation and lack of natural seed source. Abandoned croplands and reseeded areas tend to revert back to a more natural state through the process of secondary succession. This is a very slow process that takes decades or centuries to evolve, dependent on the status of the area at the time it is abandoned. The first plants to establish are “pioneer plants” (annual forbs and grasses followed by early successional shortgrasses and midgrasses). If managed properly, some of these abandoned areas may eventually begin to approximate the diversity and complexity of the native Clay Slopes ecosystem. Midgrasses, perennial forbs, and tallgrasses may begin to establish if the area is carefully managed. However, it is highly unlikely that abandoned lands can ever return to climax vegetation within a reasonable period of time.

Pathway 4.1A
Community 4.1 to 4.2

After conversion to other land uses, these areas must be intensively managed in order to maintain production and quality. Economics, drought, and other outside factors may result in these areas being abandoned or neglected. If fertility is not maintained, and weed control is not routinely carried out, the land will tend to revert to “pioneer” plants such as annual forbs and grasses.

Pathway 4.2A
Community 4.2 to 4.1

Abandoned lands can be re-established to cropland, introduced pasture, or seeded monocultures by cultivation to control unwanted vegetation, seedbed preparation, and seeding or planting desired vegetation with normal with seedbed preparation.

Transition T1A
State 1 to 2

Continued abusive grazing practices and a lack of fire will eventually result in further deterioration of the midgrass plant community. This decline may be intensified or accelerated by drought conditions and/or failure to carry out maintenance brush management practices. As a result of this level of mismanagement, little bluestem and other tallgrasses are eliminated from the site except for remnant plants that are protected. Sideoats grama, vine mesquite, and Arizona cottontop are drastically reduced. Silver bluestem, meadow dropseed, and white tridens become the dominant midgrasses. Shortgrasses including curlymesquite, buffalograss, hairy grama, and slim tridens increase significantly and become co-dominants. Non-native and invasive native shrubs begin to increase on the site and invade from adjacent sites. The increase in density and woody canopy of shrubs begins to have an adverse effect on the understory herbaceous vegetation because of increased shading and competition for space and soil moisture. Texas wintergrass begins to increase significantly as the woody canopy increases.

Transition T1B
State 1 to 4

This plant community can be converted to cropland or seeded introduced grasses or commercially available native grasses. Because the site usually occurs as small irregularly shaped areas, it is usually treated and managed in conjunction with surrounding sites. Kleingrass, Old World bluestem, and King Ranch bluestem are the most commonly seeded introduced grasses, but some areas have been planted to bermudagrass. The areas that have been converted to cropland are primarily planted to wheat, oats, or forage sorghum. Seedbed preparation can be accomplished with normal cultivation equipment and desired vegetation can be seeded or planted. This is a terminal state because the soil has been altered and the historic plant species no longer exist on the site.

Constraints to recovery. Extensive soil disturbance followed by seeding

Restoration pathway R2A
State 2 to 1

At this stage, there is no longer a viable population of the original primary midgrasses and tallgrasses to reproduce sufficient seed to enable the plant community to recover through management practices alone. Range planting is needed to re-introduce the desired midgrass and tallgrass species back into the plant community. Implementation of a grazing management plan is necessary to allow establishment of seeded vegetation and control the timing, frequency, duration, and degree of grazing following establishment. Brush management is needed when the density and canopy of shrubs and trees begins to have an adverse effect on the desired grasses and forbs. Periodic prescribed burning is needed to keep woody species under control, encourage diversity in the grass and forb plant community, and assist with the recovery and maintenance of the desired plant community.

Transition T2A
State 2 to 3

Continuous abusive grazing, lack of fire, and extended drought can all be major factors in the deterioration of the plant community from an open prairie to a shrub dominated site. The site is dominated by non-native and invasive native shrubs with a canopy of 25% or more. The woody canopy has a noticeable detrimental effect on the understory vegetation. Extensive areas of bare ground may occur. Shortgrasses as well as annual grasses and forbs, and early successional midgrasses increase dramatically and invade from adjacent sites. Texas wintergrass and other shade tolerant species increase. The site is highly susceptible to water erosion. Once the site has declined to this stage, it will not return to a higher state of vegetation through management practices alone.

Transition T2B
State 2 to 4

This plant community can be converted to cropland or seeded introduced grasses or commercially available native grasses, but it may require mechanical brush management to remove unwanted shrubs and trees if they are dense enough to interfere with seedbed preparation, seeding or planting operations, or management following establishment. Seedbed preparation methods may require heavier equipment, and seeding or planting methods may have to be modified to overcome more intensive land preparation treatments. Because the site usually occurs as small irregularly shaped areas, it is usually treated and managed in conjunction with surrounding sites. Kleingrass, Old World bluestem, and King Ranch bluestem are the most commonly seeded introduced grasses, but some areas have been planted to Bermudagrass. The areas that have been converted to cropland are primarily planted to wheat, oats, or forage sorghum. Seedbed preparation can be accomplished with normal cultivation equipment and desired vegetation can be seeded or planted. This is a terminal state because the soil has been altered and the historic plant species no longer exist on the site.

Restoration pathway R3A
State 3 to 2

It is probably not practical or economically feasible to attempt to restore the reference plant community through brush management and revegetation. In order to have any possibility of recovery from this state, a carefully planned and implemented prescribed grazing management strategy must be implemented, extensive brush management is required, and range planting is necessary to re-introduce perennial grasses and forbs to the plant community. These treatments may result in the re-establishment of establish a perennial grass plant community with most of the primary grasses, but lacking the diversity of forbs and minor grasses found in the reference plant community. This is a difficult, risky, and expensive consideration. If the reseeded areas become established, a prescribed burning management program is needed to maintain balance, diversity, and vigor in the plant community.

Transition T3A
State 3 to 4

This plant community can be converted to cropland or seeded introduced grasses or commercially available native grasses, but extensive brush management is required to clear the land. Seedbed preparation techniques with heavy equipment are required and seeding or planting methods may have to be modified to overcome more intensive land preparation treatments. These treatments are radical, expensive, and generally not recommended. Because the site usually occurs as small irregularly shaped areas, it is usually treated and managed in conjunction with surrounding sites. Kleingrass, Old World bluestem, and King Ranch bluestem are the most commonly seeded introduced grasses, but some areas have been planted to Bermudagrass. The areas that have been converted to cropland are primarily planted to wheat, oats, or forage sorghum. Seedbed preparation can be accomplished with normal cultivation equipment and desired vegetation can be seeded or planted. This is a terminal state because the soil has been altered and the historic plant species no longer exist on the site.

Restoration pathway R4A
State 4 to 2

Abusive grazing, lack of fire, lack of brush management, and abandonment are factors that result in these previously treated areas reverting to areas that are dominated by bare ground, annual grasses and forbs, low successional perennial grasses and forbs, and stunted shrubs. The site is highly susceptible to water erosion. In this scenario, this is a terminal state because the soil has been altered and the historic plant species no longer exist on the site.