Section 2: Preserving and Enhancing HabitatAnchor: #i999775
Strive for Diversity
Any vegetated area provides food and cover for at least some wildlife species. If plant diversity is restricted, however, wildlife diversity will also be limited. Different animals require different habitats. Plant diversity is essential to maintaining an abundant and varied wildlife population.
Growth structure is another important factor affecting the quality of wildlife habitats. “Growth structure” simply refers to the height and coverage of the vegetative canopy. Promoting a diverse vegetative growth structure will also encourage wildlife diversity.
Diversity – both in plant variety and growth structure – is the key to preserving and enhancing wildlife habitat. Roadside vegetation management efforts, therefore, should focus on encouraging a diverse native plant population that will provide abundant food and cover for a variety of wildlife.Anchor: #i999796
Intensive Agricultural Areas: In intensive agricultural areas, monocultural row crops dominate. These areas include the Texas panhandle, middle Gulf coast and blackland prairie regions. In these areas, the only suitable nesting habitat for upland birds is within highway rights of way. The timing and frequency of mowing schedules in these areas dramatically affects nesting success. Studies have shown that infrequent mowing (or not mowing at all in some cases) increases the value of the roadsides to nesting wildlife, especially birds and small mammals.
Wetlands: Roadsides prone to inundation or saturation during the spring and summer can serve as valuable habitat when managed properly. Allowing the growth of wetland vegetation in these areas will contribute to the nesting success of waterfowl and also provide feeding habitat and escape cover for shorebirds, wading birds and many reptiles and amphibians.
Rangelands: Roadsides are especially important to wildlife in rangeland areas subjected to continuous livestock grazing. Since boundary fences normally keep domestic livestock off the right of way, the roadsides in these areas usually provide a higher diversity of grasses and forbs than the heavily-grazed adjacent lands.
During late fall and winter, heavily grazed pastures and cultivated farmlands don’t provide suitable food and cover for species of birds and small mammals. However properly maintained rights of way can provide some cover to wildlife species (such as pheasants) that have narrow food and cover requirements.
Bottom Line: Establish non-mow areas and adjust schedules to accommodate wildlife whenever possible.Anchor: #i999826
Use Trees and Shrubs
Incorporating woody shrubs and trees into the roadside environment will provide additional sources of food, escape cover, nesting cover and roosting areas for wildlife. Texas roadsides present many opportunities for habitat enhancement in areas where such vegetation has been cleared or is otherwise lacking.
In the high plains of the Texas panhandle or rolling plains of north Texas, woody species along roadsides will also serve as living snow fences and windbreaks to help prevent drifts across roadways.
In areas with highly erodible soil or blowing sand and dirt, woody plants can also provide superb erosion control.Anchor: #i999846
Over the years in many areas, land use practices have inhibited the growth of specific native plants. One reason this happens is because plants are not allowed to die off naturally and provide seed for the next generation. This process is particularly important in maintaining grass and forb species that depend on seed dispersal.
Roadsides, which have been free of intensive farming, human habitation and domestic livestock grazing, typically harbor more diverse plant communities than adjacent lands. With proper management, roadsides will serve as a source of seeds. These seeds will be windblown or distributed by wildlife into adjacent lands to support natural plant regeneration. In many areas of Texas, roadsides represent the only possible source for natural regeneration.
Roadside vegetation management practices should encourage seed production and proper dispersal by:
- properly selecting native and introduced plants and
- adjusting mowing schedules to allow for seed production and dispersal.
We all know how popular wildflowers have become among the traveling public. Our colorful roadsides have brought on a real public relations success. They’ve generated favorable media coverage and prompted requests from motorists for routes and locations for best viewing.
What may be less understood about our native wildflowers is how beneficial they are to wildlife. Wildflower seeds provide food for many wildlife species, including birds and small mammals. The plants also participate in an intricate food web, supporting many insects and other invertebrates that other wild animals depend upon.
Roadsides typically sustain a greater density and variety of wildflowers than adjacent pastures and fields. So wildflowers represent just one more reason why roadsides are important in our efforts to enhance biological diversity.
Encouraging roadside wildflowers strengthens wildlife diversity.Anchor: #i999903
Roadsides and Endangered Species
Roadsides free from disturbances occurring on adjacent lands can be managed as refuges for the preservation of threatened or endangered plants and sensitive ecosystems. TxDOT and the Texas Parks and Wildlife Department (TPWD) have interagency agreements to identify sensitive plants and develop appropriate management plans. Roadsides can also be managed to enhance habitat for threatened or endangered wildlife. Such roadsides would be particularly valuable in regions where existing potential habitat is scarce.