Native Grass Restoration in Virginia Old Fields

ABSTRACT Over the past several centuries, upland successional grasslands of Virginia have been invaded by exotic grasses introduced from Europe. We examined three strategies (vegetation removal, nitrogen manipulation, and seeding) for improving the establishment of the native grasses Andropogon gerardii, Sorghastrum nutans, and Schizachyrium scoparium to the northern Shendandoah Valley in Virginia. Experimental plots were subjected to one of four vegetation removal techniques: plowing, glyphosate herbicide, glyphosate plus imazapic herbicide, or no removal. Each plot was divided into two subplots that were either seeded with native grass seeds or not. Within all subplots three levels of soil nitrogen were established (low, ambient, high). The result show that plots subjected to vegetation removal using both herbicides and a reduction in the plant-available soil nitrogen yielded the highest number of native grass seedlings. Native grasses were observed in all plots except for the control which had no vegetation removed. The results from this study inform grassland managers of the importance of vegetation removal prior to restoration attempts.