Effects of Weed Removal and Reseeding in a Forest Understory Invaded by Pale Swallow-wort

Following the removal of invasive weeds, active revegetation can be used to facilitate the recovery of native plants and provide biotic resistance against the recurrence of invasive species. We conducted a weed removal and reseeding experiment in a forest understory infested with pale swallow-wort, Vincetoxicum rossicum Kleopow Barbar. (Apocynaceae). Thirty 1.81 m by 1.81 m plots were divided into three V. rossicum removal treatments (1. no treatment, 2. cut and spray with glyphosate, and 3. cut and spray with glyphosate followed by root removal). Half of the plots from each treatment were then seeded with a native seed mix containing 18 species. Three years after plot treatments, vegetation surveys were conducted to assess their impacts on V. rossicum percentage cover and stem density, and native plant recovery. Plots from which V. rossicum was removed by digging had the lowest V. rossicum cover, and the highest Floristic Quality Index (FQI). Reseeding treatments did not affect V. rossicum coverage, stem density, or FQI. Vincetoxicum rossicum removal by digging can be effective for controlling small understory populations. Despite the underwhelming results of reseeding, Elymus hystrix L. (Poaceae) has emerged as a promising species for providing biotic resistance against V. rossicum reinvasion.