Solutions from the sunbelt: the southeastern States share strategies to protect wildlife and fragile habitats

Public Roads, July-August, 2003 by Alex Levy

The southeastern United States is one of the fastest-growing regions in the country. According to a study conducted by the Southern Rural Development Center at Mississippi State University, population growth in the region averaged 20 percent over the decade from 1990 and 2000. Combining a temperate climate, relatively low living costs, a highly developed network of modern interstates and other highways, and freight rail lines that historically moved cotton and produce from farm to market, the South continues its legacy of growth; however, today the Southeast also is sprouting urban sprawl.

Providing the foundation for the remarkable growth in the eastern Sunbelt are some of the most resilient and fragile associations of living organisms on the planet. The plants and animals in these ecosystems represent some of the most biologically diverse species on Earth. Ample streams, rivers, wetlands, and terrestrial habitats support this biodiversity.

According to classifications by the U.S. Department of Interior's U.S. Geological Survey, the ecosystems in the South range from the spruce-fir forests of the highest points of the southern Appalachian Mountains to the tropical hardwood hammocks of southernmost Florida. In between these extremes lies a diversity of indigenous habitats: the old-growth deciduous and hemlock forests, cliffs, rocky stream gorges, and grassy and heath balds of the Appalachians; the sawgrass marshes, mangrove forests, and pine rocklands of south Florida; the carnivorous plant wetlands, baldcypress swamps, live oak maritime forests, longleaf pine savannas, and dunes of the coastal plain; the oak-hickory forests, bottomland forests, prairies, glades, and barrens of the piedmont and continental interior; and the springs and extensive cave systems of limestone areas.

The most saturated of these habitats represent nearly 80 percent of the Nation's dwindling wetlands. Such biodiversity may be nature's way of ensuring species survival through genetic variability, but in human nature lies the capacity to sustain--or subdue--millions of years of natural history with relatively minor actions.

With the blossoming human population, a growing network of transportation corridors is emerging on the Southeast's sand, peat, limestone, and red clay soils. Along with this growth, State departments of transportation (DOTs) are demonstrating the valuable role that they can play in protecting and enhancing wildlife habitats throughout the region. The southeastern States are planning, building, and retrofitting roads with measures to improve landscape connectivity, reduce roadkills, and protect human lives and property from animal-vehicle collisions.

Florida

In 1993, responding to the need for at] interstate-level upgrade of Alligator Alley, a major east-west corridor across the Everglades, the Florida Department of Transportation (FDOT) and the Federal Highway Administration (FHWA) wrestled with finding a safe, effective, and economical solution to address significant highway mortality rates for the federally listed endangered Florida panther.

Populations of this close cousin of the western mountain lion have dwindled to a staggeringly low number. Perhaps the largest native predator in the eastern United States, the Florida panther is a subspecies that is commonly thought to represent the only known remnant of the eastern cougar that once inhabited much of the Southeast.

For the Alligator Alley highway, FDOT's solution was a series of constructed highway underpasses, coupled with extensive right-of-way fencing. The fences direct the big cats away from the roadside while still accommodating their need to move throughout large territories to hunt. FDOT also is making wildlife underpasses a more routine part of the State's highway and tollway systems.

Since installation of the underpasses, no Florida panthers have been killed on Alligator Alley. For additional information about wildlife underpasses, see the proceedings from the International Conference on Ecology and Transportation at www.itre.ncsu.edu/cte/icoet.

Not only does Florida stand out as a southeastern pioneer of habitat connectivity, but also the State was the host for the first International Conference on Wildlife Ecology and Transportation. Now in its 8th year, the biennial event has broadened its mission to become the International Conference on Ecology and Transportation--the only international, interagency event addressing the broad range of ecological issues related to surface transportation.

More recently, FDOT and 22 other agencies representing Florida and the Federal government signed a memorandum of understanding to make transportation decisions more efficient while protecting the human and natural environment. The new process streamlines planning by engaging all stakeholders earlier in a project, establishing interagency teams to coordinate reviews and ensure agency interaction throughout the life of a project, and identifying critical issues earlier to result in better transportation decisions for the environment and the public.