EFFECTS OF FERTILIZATION AND DISTURBANCE ON NATIVE SPECIES ESTABLISHMENT ON HIGHWAY CORRIDORS IN WEST VIRGINIA

摘要

Introduced and invasive species have been recognized as potential threats to natural plant communities. Many such plant species are introduced along roadways, which then can spread to adjacent fields and forests. The West Virginia Division of Highways is required to develop seeding mixtures comprised of native plants for revegetating highway corridors and thereby reducing the potential for introduction of non-native species along roads. Therefore, the objectives of this project were to identify native plants that are suitable for seeding on highway sites and to document the establishment of these species after seeding on highway cut and fill areas. Phase 1 of the project began in April 2002, when three sites (Baker, Hazelton, and Parkersburg) were seeded with five seed mixes (Control, Native, DOH, DOH-Native, and DOH(1/2)-Native) into fertilized and unfertilized plots. Plots were 2m by 2m and each treatment (seed mix and fertilizer) was replicated four times (40 plots per site). Phase 2 of the project began in March 2003 when a native seed mix was sown on three sites (Weston, Buckhannon, and Elkins) into five different surface treatments and two fertilizer rates. After 2 years, Phase 1 results show that fertilizer and seeding mixture have a significant affect on plant growth and ground cover. The fertilized DOH and DOH-Native plots had the highest ground covers while the unfertilized Control and Native plots had the lowest. Unseeded, unfertilized plots generally had more weedy species than other plots. Native species establishment was poor and plots seeded to native species were mostly colonized by non-native and non-seeded species from adjacent areas. Native species were seen minimally by the second year. Phase 2 first year results also show that fertilizer and surface treatment had a significant affect on plant growth and ground cover. Tilled and herbicided plots tended to promote the establishment of native species best. In subsequent years, it is anticipated that the native species will emerge and become a more prominent contributor to the ground cover.