The Vascular Flora of Roadside Habitats in West Virginia, USA

ABSTRACT In order to provide vegetation managers with information on roadside habitats in West Virginia, a statewide roadside vegetation study was conducted in 2000. The vegetation along nearly 1,500 km of four-lane highways was sampled in 339 randomly selected 20 m wide strip plots. An index of occurrence class (IOC) for each species was calculated using the product of the percent frequency of occurrence and relative abundance. A total of 467 species were documented, 325 of which were native. Seven families accounted for more than 50% of all species. When ranked on the basis of total IOC values, 15 of the top 25 species were introduced. Mean IOC values for introduced species (6.0) were significantly greater than native species (4.3, p¼0.0013). We propose that despite initial variability of landform, parent material, forest cover types, and climate, the relative similarity of species composition along the highways we sampled was the result of the physical and biological disturbances associated with initial construction (cuts and fills), and postconstruction seeding and vegetation management efforts.