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    Oak Prairie Habitat Management

    Oak-Prairie Wildlife Management
    Historical Perspective

    The Oak-Prairie wildlife district, as the name implies, spans parts of 2 different ecoregions. The northern third of the district consists of what is typically considered Post Oak Savannah, whereas the remainder of the district lies in the Coastal Prairies. This is an ecologically diverse part of Texas, and pockets of habitat more characteristic of South Texas brush country and the Pineywoods can even be found in the western and eastern reaches of the Oak-Prairie district, respectively.

    The original savannahs in the northern part of the Oak-Prairie region were characterized by native grasses such as little bluestem, silver bluestem, and brownseed paspalum with scattered clumps of trees. Post oak trees dominated, but other species included blackjack oak, water oak, winged elm, hackberry, and yaupon. Fire working in concert with other factors such as drought, herbivory, and competition from grasses restricted shrub and tree growth and maintained the savannah. The natural fire frequency on level to rolling topography appears to have ranged from 5 to 10 years and on topography dissected with breaks and rivers the fire frequency may have been 20 to 30 years. Since the early 1800s, the suppression of fire, and soil disturbance and land clearing practices by farmers and ranchers have resulted in a higher density of smaller trees and more thick undergrowth of vegetation, especially yaupon. Bottomlands in the early 1800s were typically composed of large hardwoods with very little understory vegetation. Many bottomlands have now been cut over and cleared. Others have thick understories resulting from timber cutting or various soil disturbances, or are relatively open due to continuous grazing. According to written accounts from early explorers and settlers in 1800s, white-tailed deer, wild turkey, bison, black bear, squirrel, mountain lion, and red wolf were once common in the Post Oak Savannah.

    The most striking change to the savannah has been the degradation or loss of the native range grasses from overgrazing and the clearing of the native range to plant monocultures of improved grasses, such as coastal Bermudagrass, for cattle. The rich diversity of grasses and weeds in the native savannah provided food and cover for many wildlife species and the conversion to "improved pastures" is responsible for the decline and even disappearance of species such as the bobwhite quail in much of the area.

    The Coastal Prairie of Texas is a tallgrass prairie similar in many ways to the tallgrass prairie of the Great Plains. It is estimated that, in pre-settlement times, there were nine million acres of Coastal Prairie, of which 6.5 million acres were in Texas. Today less than one percent of the Coastal Prairie remains.

    Nearly 1,000 plant species have been identified in the Costal Prairie, but no one knows how many species have followed the prairie vole and the Louisiana Indian paintbrush to extinction. The Coastal Prairie historically was home to herds of bison and pronghorn antelope, and red wolves roamed among the riverine forests that crisscrossed the area. Coastal Prairie and its adjacent marsh habitat provide immense space for waterfowl and thousands of other forms of wildlife. Even in its altered state, Coastal Prairies routinely host more red-tailed hawk, northern harriers, white ibis, and white-faced ibis than any other region in the United States. The Coastal Prairie is home to the federally endangered Attwater's prairie chicken (North America's most endangered bird) and is the exclusive wintering ground of the whooping crane.

    Whereas factors such as soil type and rainfall contribute to the formation of a prairie, fire is the natural mechanism by which prairie renews itself. Fire prevents woody plants from establishing, stimulates seed germination, replenishes nutrients, and allows light to reach young leaves. Historically, prairie fires occurred in the summer as a result of lightning strikes, and the fires, along with drought and competition from herbaceous plants, prevented the establishment of woody plants to maintain a grass-dominated ecosystem.

    Although much of the prairie has been converted to improved pasture for cattle grazing, the majority has been altered for growing rice, sugarcane, forage, and grain crops. Much of the Coastal Prairie that remains in Texas is because it was used for cattle production and never plowed. Many species, however, have been lost through overgrazing. Continued threats to what remains of the Coast Prairie include conversion to other kinds of agriculture and development. Most remnants are privately owned with only a small percentage preserved on government land. The prairie remnants that escape conversion or paving face overgrazing or becoming overgrown with shrubs due to the suppression of fire.

    Like most of Texas, the future of the Post-oak Savannah and Coastal Prairies is in the hands of the private landowners. The good news is that landowners are becoming increasingly interested in wildlife and habitat management. More landowners earn income from other professions and depend less on the land for making a living. The major challenge is that land ownership is becoming increasingly fragmented. With each generation of our growing population, ranches and farms get smaller. Most landowners no longer own enough acreage to effectively manage for wildlife without cooperating with their neighbors. The solution is Wildlife Management Associations, also known as Wildlife Co-ops, which are groups of local landowners working together for their common wildlife interests. The Oak-Prairie Wildlife District leads the state in Wildlife Co-ops and the future of wildlife in this region of Texas depends largely of their success.




    Oak-Prairie Wildlife Management
    Habitat Management


    Leopold's Tools (Axe, Cow, Plow, Fire, and Gun)

    The border above illustrates 5 basic tools (axe, cow, plow, fire, and gun) used for managing wildlife communities. The key to managing natural resources is to use a holistic approach, where all of these Tools are applied to develop and maintain healthy ecosystems. Single species deserve less attention, while the system in which they thrive requires more. Knowing how that system functions, and applying the techniques with which that system developed (e.g., moderate cattle grazing, prescribed burning, hunting) is imperative for its continued existence.

    Axe

    As discussed in Historical Perspective, changes in land use patterns (such as the suppression of fire) have resulted in brush encroachment in many areas, causing a decrease in plant species diversity. Brush control is often viewed as a tool for livestock management rather than wildlife. But when practiced properly, the management of brush improves the habitat for wildlife as well as for cattle. The idea of brush management is to create a mixture of habitat to provide the most benefit. The patterns in which brush is managed determine the amount of "edge" produced.

    Many wildlife species, are considered edge animals. This means that the edge of some woods or brush is their preferred habitat. These areas usually provide the most food as well as being close to escape cover.

    Key points in the management of brush for wildlife include:

    * Brush control patterns will depend on the terrain.
    * Shallow or thinner soils do not respond as well to brush control practices.
    * Brush cover must be left along water courses.
    * The width of wooded strips left should be wide enough to prevent seeing through them during the winter.
    * Natural wildlife travel corridors and high quality food plants should be preserved.
    * On flat terrain, alternate strips of cleared and wooded areas produce good results. Establish strips at a 1:1 ratio (300 feet cleared and 300 feet wooded).
    * Irregular patterns produce a greater amount of "edge." Small clearings (2-3 acres) randomly scattered are a good alternative to strip clearing.


    Cow

    As Aldo Leopold wrote in his 1933 textbook titled Game Management, "...game can be restored by the creative use of the same tools which have heretofore destroyed it - ax, plow, cow, fire, and gun." Leopold often referred to the "cow" as an effective wildlife management tool. Cattle can be used as a tool to manipulate and enhance wildlife habitat and plant diversity (as bison did). The main role of grazing in a wildlife management program is to reduce the quantity of grass, allowing sunlight to reach the lower growing forbs, which are important wildlife foods. Furthermore, this process creates more structural diversity, which is more conducive to nesting, brood rearing, and hiding.

    However, like any tool, grazing can also be misused and cause more damage than good. Overgrazing is 1 of the most common habitat problems in the Oak-Prairies district. Too many cattle on a pasture for too long begin to eat more and more browse once the grass is depleted, thereby competing with deer. Heavily grazed pastures also lack nesting cover for quail, turkey, and songbirds as well as fawning cover for deer. Range improvement can be attained through proper grazing rates and by scheduled rest periods to allow pastures to be free of grazing by domestic livestock. Rotational grazing systems should allow pastures to be rested (deferred) during a specified time of the year. Some examples of grazing options in order of preference are: a short duration or "time control" system; a high intensity - low frequency system (HILF); a 3 pasture-1 herd system, and the 4 pasture-3 herd rotational grazing system. Each requires different degrees of involvement and fencing. Professionals from the Natural Resources Conservation Service (NRCS), Texas Agricultural Extension Service, and/or Texas Parks and Wildlife can discuss the advantages and disadvantages of each system.

    Plow

    Disking is a method of soil disturbance that encourages the growth of forbs (commonly called weeds or wildflowers) and other annual plants. Common seed producing forbs enhanced through disking include croton (doveweed), sunflower, and ragweed. Many forb seeds are present in the soil and only require shallow disking to germinate.

    The best method of disking for wildlife is long strips 15 to 30 feet in width. These strips should be adjacent to wooded areas or meander through natural cover. The second year in a disking program a new strip adjacent to the first year's disked area should be selected. Thereafter, the strips should be disked in alternate years. This creates a more diverse plant community by maintaining different stages of regrowth.

    The optimum time for disking is October through February. It is important to disk before spring green-up or forb growth may not be promoted.

    Fire

    Fires, natural and man-made, played an integral role in maintaining the post oak savannah and coastal prairie ecosystems. Since the 1850s, man has suppressed fire. Once semi-open post oak savannahs now have thick understories of yaupon, and much of the remaining coastal prairies have been invaded by brush.

    A prescribed burn program that is used properly with a grazing deferment program, is an effective tool for managing wildlife habitat. Burning increases plant quantity and quality, and enhances habitat diversity. Many plant species are tolerant of fire. Others require fire for adequate germination. Europeans suppressed fire to prevent damage to wooden structures, farmlands, fences, and grazing lands. That eliminated or reduced the role that fire played in maintaining the ecosystem.

    Burned pastures can be grazed immediately to reduce grasses that compete with forbs, then deferred to allow the pasture to rest. Portions of the property should be left in permanently unburned cover to insure that plants intolerant of fire are part of the ecosystem diversity. A burning schedule should be maintained to give priority to burning in the winter and early spring before green-up. Even with the best planning, burning "windows of opportunity" always depend on humidity, wind, and fuel moisture. The inexperienced manager should ask for assistance and/or advice from agencies such as TPW or the NRCS. While instructional materials are available, it is suggested that the novice assist on a burn conducted by an experienced person before attempting the first controlled burn.

    For more information on prescribed burning, please see Prescribed Range Burning in Texas.

    Gun

    Data from 1984-93 revealed that the post oak savannah and coastal prairies have higher concentrations of hunters than any other region of the state, with 1 hunter for every 77 and 83 acres, respectively. This is a symptom of the trend of smaller and smaller land parcels as large ranches are sold off in pieces or divided as they are passed from generation to generation. With such high densities of hunters, harvest management plays a key role in the health of a deer herd. You simply cannot harvest a buck for every 100 acres and expect to have any bucks reach 5 or 6 years of age and their full potential; cooperation among landowners through Wildlife Management Associations is often necessary.

    In addition to the need to restrict the buck harvest, many parts of the Oak-Prairie region have deer densities that are too high, and warrant the harvest of some does. Good habitat will only support so many deer, and to have healthy deer it is important that the population be maintained within the carrying capacity of the habitat. Although much of the Oak-Prairie district consists of 1-buck counties, does can be harvest through the Managed Lands Deer Permit Program. This program has an advantage over blanket regulations because it allows doe permits to be issued at the rate needed for a particular ranch.

    Because of the wide range of deer densities that occur in the Oak-Prairie region, you should contact your local biologist to receive a harvest recommendation.
    Summary

    Today, it is very important that land managers understand basic ecological principles of plant succession, plant growth, food chains, and water, mineral and soil nutritive cycles as they affect range, wildlife, and grazing management. In addition we should know and recognize the basic needs and preferences of the livestock and wildlife species for which we are trying to manage. It is equally important to manage for a high level of plant succession and quality wildlife habitat using the basic tools of grazing, rest, fire, hunting, animal impact, disturbance, and technology. This not only produces high quality habitat and animals, but also can lead to more stable conditions during stress periods such as droughts and winter.

    #2
    [ATTACH]149332[/ATTACH]

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      #3
      good read. Thanks for sharing

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