Section 2: Preserving and Enhancing Habitat
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.Mow Wisely
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.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.
Nurture Seeds
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.
Encourage Wildflowers
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.
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.