Roadsides may contain unique plant communities and rare plants that may need protection. These areas are identified in the planning process but are managed during the operations and maintenance phase of the project. Many states have programs to protect listed species, species of interest, or remnant plant communities (AASHTO 2013a) on roadsides. They are called by a variety of names, including Special Management Areas (SMAs), natural heritage remnants, wildflower research areas, and Biological Management Areas (BMAs). These areas have some or all of the following features in common (adapted from AASHTO 2013a):
- Collaboration—Most states with established management areas in right-of-way have accomplished this through collaboration with maintenance staff; conservation groups; and federal, state, and local agencies.
- GIS—Many states use GIS to identify rare plant populations and remnant habitats. Known locations of rare species are obtained from state departments of natural resources, the U.S. Fish and Wildlife Service, the U.S. Forest Service, the Bureau of Land Management, counties, local environmental groups, and individuals.
- Management plans and BMPs—Most special management areas have plans or BMPs for how to preserve remnant sites or species of interest. These practices include how vegetation control treatments, such as mowing, herbicides, prescribed burns, and grazing, will be used to preserve and enhance remnant areas or species of interest. Maintenance treatments that support species of interest, such as minimizing shading from trees or competition from surrounding vegetation, can be a part of the BMPs. In areas where species of interest require full sunlight for survival, trees and shrubs around these plants may be removed. Where competing vegetation or noxious plant species threaten species of interest, herbicide may be applied or manual removal of vegetation around these species may occur. In areas where potential soil erosion and landsides threaten species of interest or remnant areas, soil stabilization measures may be taken. Public access may be curtailed if it affects plant survival.
- Signage—Some states place special signs along the boundaries of the management areas and have instructions on the signs indicating what maintenance activities are allowed.
- Training—Some states have developed training programs for maintenance staff specific to managing rare species. This training covers the identification of species of interest, habitat, and preferred management options.