West Texas Wildlife Management
For long-term benefits to wildlife in West Texas, no habitat management practices are more important than those that restore and/or maintain healthy, native, herbaceous vegetation. Every wildlife species in the Trans-Pecos, whether a game or nongame species, depends upon grasses and forbs to satisfy at least one essential requirement-- whether it's nesting cover, fawning cover, nutritious "greens," seeds, insects, or a source of water. Just as important, grasses and forbs stabilize the soil and conserve precious moisture that comes infrequently. And certainly not least, herbaceous plants provide fuel for prescribed fire, the only "natural" tool and the lowest cost practice for long-term prevention of shrub encroachment.
The emphasis on the restoration and maintenance of herbaceous cover (grasses and forbs) does not diminish the importance of trees, shrubs, and desert succulents. Prior to settlement in the late 1800's, woody plants and succulents were sparsely scattered across the desert grasslands, with increased abundance along wet draws, rocky outcroppings and steep slopes. Their extensive root systems serve the important function of stabilizing soil on these potentially erosive sites (these areas seldom burn and are unable to support protective stands of grass). Woody plants also provide valuable food and cover for many wildlife species and livestock. Woody plants shift from a valuable habitat component to an ecosystem threat only when one or more of the "balancing" processes are removed (e.g., fire or herbaceous vegetation via overgrazing).
Maintenance of healthy grasslands and savannas in West Texas is best accomplished through periodic fire and timely light to moderate grazing, limited to years during and after favorable rainfall. Prescribed fires promote perennial forbs and perennial, warm-season bunchgrasses and prevent detrimental increases in woody shrubs. Repeated prescribed fires during the proper season (late spring or early summer) can inflict mortality on woody species that have already encroached in desert grasslands (restoration will initially require greater fire frequency than that occurring historically for grassland maintenance). Light to moderate grazing during favorable years, using no more than 1/3 of grass production (Holechek et al. 1994), will allow use of excess forage production without weakening root systems and causing plant mortality during drought years. Flexibility with livestock numbers and grazing deferment are critical tools in managing vegetation in the Trans Pecos where weather fluctuations are more dramatic than in any other region of Texas.
Degraded rangelands where soils and water (precipitation) are being lost annually can often be improved through a number of soil and water conservation techniques. Erosion control techniques such as water diversions and sediment traps should be implemented. Header dams, rangeland ripping (Ueckert and Petersen 2002), and berms are water conservation techniques that can partially restore the hydrology on specific sites and initiate seed germination.
Other habitat improvement practices that may apply to specific situations in the Trans Pecos include:
- Mechanical brush management
- Chemical brush management.
- Riparian habitat management (fencing to control time/intensity of grazing; native shrub and tree planting; control invading shrub species)
- Grazing management (light to moderate grazing in favorable years; pasture deferment)
- Water distribution
- Improved water access for birds and small mammals.
- Windmill/trough overflows to create oases of green forbs/grasses, seed and insect production.
- Irrigated food plots.
- Fence modification to allow unimpeded movement of pronghorn antelope and bighorn sheep.
- Reduction of deer in certain areas where numbers are high.
- Reduction of exotic or feral animals that are impacting and/or competing with native species
Understanding Basic Principles
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.