Effects ofMicrostegium vimineum(Trin.) A. Camus (Japanese Stiltgrass) on Native Hardwood Survival and Growth: Implications for Restoration

Abstract

Invasive species are an increasing threat to native diversity and ecosystem function. Microstegium vimineum (Trin.) A. Camus (Poaceae) is an annual invasive grass threatening native ecosystems of the eastern United States. While information regarding the invasion, spread, and general ecology of M. vimineum is readily available, few studies exist regarding habitat restoration following M. vimineum invasion. Thus, the objectives of this study were to examine the effects of M. vimineum removal on the growth and survival of native planted hardwood seedlings. Two-year-old hardwood seedlings (Acer saccharum, Quercus rubra, and Liriodendron tulipifera) were planted in a split-plot (open vs. closed forest canopy) block design at Crummies Creek Tree Farm, Calhoun County, West Virginia, in an area that was heavily invaded by M. vimineum. Within each block, three treatments were employed: (1) chemical (Sethoxydim) control, (2) mechanical (hand pulling) control, and (3) no removal (experimental control). The growth (height and basal diameter) and survival of planted seedlings were assessed within each treatment over a two-year period. Hardwood seedling height and diameter differed significantly as a function of forest canopy type and among species; however, no significant treatment effects were detected. There were no differences in survival between M. vimineum removal treatments. These data suggest that restoration of forested habitats invaded by M. vimineum can be achieved by a bottom-up approach that utilizes planted native hardwood seedlings with little additional expenditure of resources for control. Restoring a mid-story tree regeneration layer will likely shade out M. vimineum and erode its dominance in forest stands over time.