State 1
Grassland

Community 1.1
Native Tall/Midgrass Prairie

This Native Tall/Midgrass Prairie Community (1.1) developed under natural disturbance regimes spanning thousands of years. Composition of tall grasses makes up over 60 percent of annual production, midgrasses approximately 30 percent, and associated grasses, forbs, shrubs, and woody vines make up the remainder. Annual forbs occur in varying amounts in response to grazing intensity, fire, drought, or excessive precipitation. This community is highly productive and can be managed to attain many landowner goals for livestock, wildlife, or recreation. The deep clay soils of this site, when managed in this state, will contain high amounts of organic matter, nutrients, and microbial activity. The soil also has a high available water capacity which can provide moisture to plants for extended amounts of time after rainfall events. These soil properties make this state of the Blackland site one of the most productive in the area. On the Blackland site rainfall can vary from lows on the western side to highs on the eastern side of the range. This difference in rainfall will cause subtle changes in plant community and overall productivity, which is displayed as high and low values in the annual production tables. 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.

Community 1.2
Mid/Shortgrass Priaire

The Mid/Shortgrass Prairie Community (1.2) developed because of continued heavy grazing, an absence of the historic fire regime, and brush management. This community could also be driven by precipitation and may have been more common than the Native Tall/Midgrass Prairie Community (1.1) in drier parts of the MLRA. In comparison to the reference plant community (1.1) the Mid/Shortgrass Prairie Community (1.2) has reduced biomass production and litter accumulation which causes subtle impacts to the water, mineral, and energy cycles. For instance, this plant community has a slight decrease in live herbaceous cover which is replaced with litter and bare ground. The loss of thermal protection will start to negatively affect the available water in the soil. In this situation reduced rainfall and prolonged droughts will begin to have more of an impact of plant production. As tallgrasses decrease, midgrasses such as little bluestem, sideoats grama, plains bristlegrass and silver bluestem increase. Reduced fuel loads result in reduced fire frequency/intensity. Annual and perennial forbs often increase as a result of decreased competition for sunlight and moisture. Introduced grass species such as common bermudagrass (Cynodon dactylon), Kleberg bluestem, and other introduced bluestems may start to invade. For the first time on this site, woody invader seedlings such as mesquite and huisache, attain shrub and then tree status. While the appearance of introduced plants prevents a full restoration to the reference plant 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.

Pathway 1.1A
Community 1.1 to 1.2

The Native Tall/Midgrass Prairie Community (1.1) is the Reference Plant Community that would have dominated the Blackland site for thousands of years. Because of human influence this community is rarely found today. The tall grasses that dominated the landscape 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. The historic fire regime has also been changed so that intermittent fires every 3 to 8 years, which would decrease woody plant encroachment and encourage tall/midgrass dominance, have been prevented to protect livestock and societal interests. These factors cause a shift from a Native Tall/Midgrass Prairie Community (1.1) to a Mid/Shortgrass Prairie Community (1.2).

Pathway 1.2A
Community 1.2 to 1.1

The restoration to the reference plant community (1.1) is relatively simple at this point in time and can be accomplished by installation of 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 encroachment. 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 10 percent canopy of mesquite or huisache. Once initial woody plant management has been achieved, periodic burning, reduced stocking, 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
Tree/Shrubland Complex

Community 2.1
Mesquite/Huisache Grassland

A threshold has been crossed between the Grassland State (1) and the Tree/Shrubland Complex (2). This Mesquite/Huisache Grassland 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 the Mid/Shortgrass Prairie Community (1.2) to the Mesquite/Huisache Grassland Community (2.1) can happen within a period of 5 to 10 years under certain conditions. Mesquite and huisache will be the dominate woody species on this site, but other woody species such as lotebush (Zizyphus obtusifolia), granjeno (Celtis ehrenbergiana), whitebrush (Aloysia gratissima), desert yaupon (Schaefferia cuneifloia), prickly pear (Opuntia engelmannii), and algerita (Mahonia trifoliolata) will occur as part of the plant community. Although there has been an increase in woody plant numbers, the amount of canopy cover they create is the main difference driving the transition. The increased size or number of the woody plants creates more canopy cover and shades out the herbaceous component. This state will have an increased amount of bare ground which will negatively affect the amount of available water for plants in the soil. This will favor the woody species because their root systems can out-compete herbaceous plants for water. In this state forbs will respond quickly to rainfall events and in some cases they will also out-compete grass species for resources, causing an overall decrease in grass production. This community can be quite productive for cattle and wildlife and can be maintained indefinitely with continued management. To do so will require judicious grazing, periodic fire(s), and almost continuous brush management on an individual plant basis or other means that can achieve landowner priorities. The community in this state 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.

Community 2.2
Mesquite/Huisache Shrubland

Over time, with continued heavy grazing, no fire, and no brush management the Blackland site will be transformed into a Mesquite/Huisache Shrubland Community (2.2) with canopies from 50 to 100 percent. Extended droughts will hasten this process. Once the tree canopy reaches approximately 50 percent, the understory composition and production is driven more by shade than competition for moisture. At this point, no amount of deferred grazing will restore the plant community to the Grassland State. The herbaceous production is dominated by threeawn species, Hall’s panicum (Panicum hallii), Texas wintergrass, silver bluestem, and annual forbs and grasses. The same grass species present in the Grassland state 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 giant ragweed (Ambrosia trifida) and annual broomweed, will be able to quickly take advantage of timely rain events. This allows them to dominate the herbaceous plant community at the expense of grass production. The dramatic increase in brush canopy does not necessarily mean an improvement in deer or wildlife habitat. Although there is adequate visual and thermal protection other components of quality habitat, such as an adequate food source, are missing and will affect this areas use. Livestock management also becomes problematic in this plant community because of drastically reduced grass production.

Pathway 2.1A
Community 2.1 to 2.2

Without diligent brush management along with prescribed grazing and other conservation practices this phase will inevitably transition from a Mesquite/Huisache Grassland Community (2.1) to a Mesquite/Huisache Shrubland Community (2.2). This transition can happen within a 5 to 10 year period and is based on an increase of woody canopy cover to more than 50 percent and a severe decrease in herbaceous plant production. Short grasses and forbs will dominate the herbaceous vegetation and while this transition may be desirable for some wildlife, it will be detrimental for a cattle or livestock operation. Cool-season grasses like Texas wintergrass will also become a more dominant part of the plant community.

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/Huisache Grassland Community (2.1). A common practice is the use of aerial applied herbicides to reduce the canopy, allow sunlight to penetrate to the soil surface, and grow enough herbaceous fuel loads for suitable burning. Aerial spraying is followed by the use of prescribed fire to remove some of the woody vegetation and maintain semi-open wooded grassland for several years following treatment. Although these practices kill some of the woody vegetation, plants that are not killed by the herbicide application will re-sprout from the crown and in a relatively short period of time, can attain a 90 to 100 percent canopy again. Often with this community, mechanical means such as root plowing and raking are utilized along with dozing and grubbing. Species like mesquite and huisache will re-sprout if not removed completely from the ground. Chaining and roller chopping are mechanical practices which will be short lived and will typically result in thicker, harder to manage brush stands and will encourage brush seedlings. Follow-up conservation practices such as Individual Plant Treatment (IPT) for woody re-growth and new seedlings 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 re-introduce a seed source for desired native plant species through range planting.

State 3
Converted Land

Community 3.1
Planted Pasture/Cropland

To go from the Mesquite/Huisache Shrubland Community (2.2) to the Converted Land State, (3) mechanical brush management must be applied. Typically rootplowing and raking is utilized to remove the woody vegetation. A seedbed is then prepared and the area is planted into grass or crops. Typical crops planted on this site include small grains like oats or feed grains like sorghum and hay grazer. If introduced species are planted with the addition of moderate to high rates of commercial fertilizer, this site may be more productive than the original plant community. Because these soils are so productive, this site has historically been planted to bermudagrass or introduced bluestems. Inputs such as fertilizer, herbicide, and adequate precipitation or 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 seek to invade as soon as the pasture is established. Not only is there a long-lived seed source of mesquite, huisache, and other woody species, additional seed are brought in by grazing animals and domestic livestock.

Community 3.2
Go Back 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 woody species, very little herbaceous grass production, high amounts of annual forbs and grasses and large areas covered by tree leaf litter or bare ground. 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 2 to 5 years. Typically, pastureland will transition to the Mesquite/Huisache Grassland Community (2.1) and not to Go Back Land (3.2).

Pathway 3.1A
Community 3.1 to 3.2

The transition from Planted Pasture/Cropland (3.1) to Go Back Land (3.2) can occur when crop fields are left to fallow without management. Generally, pastureland will transition to the Tree/Shrubland Complex (2) and not to the Go Back Land plant community.

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 land clearing, 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 Tree/Shrubland Complex (2) can happen within 5 to 10 years. This transition can be driven by persistently dry weather conditions, grazing management, and the lack of fire and brush management practices. Overstocking the site 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

Major inputs, both chemical and mechanical, are often required to restore the Tree/Shrubland Complex State (2) to the Grassland State (1). Often with this community, mechanical means such as rootplowing and raking are utilized along with dozing and grubbing. Species like mesquite and huisache will re-sprout if not removed completely from the ground. Chaining and rollerchopping are mechanical practices which will be short lived and will typically result in thicker, harder to manage brush stands and will encourage brush seedlings. Follow-up conservation practices such as Individual Plant Treatment (IPT) for woody re-growth and new seedlings 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 prepare an appropriate seedbed and, re-introduce a seed source for desired native plant species through range planting.

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 Tree/Shrubland Complex (2) on its own, but usually this timeline is impractical for landowners. Prescribed grazing along with various brush management practices will be necessary to achieve this transition. This phase is very unproductive for herbaceous plants and it could take years for desirable plant species to begin to reestablish.