Recovery of Black Cohosh (Actaea racemosa L.) Following Experimental Harvests

Abstract

Since European colonization and subsequent commercialization of Appalachian medicinal and edible plants, millions of kilograms of plant material have been extracted from our forests, with little effort to manage these species as natural resources. Roots and rhizomes of black cohosh, a native Appalachian forest herb, are extensively harvested for treatment of menopausal symptoms. As nearly all cohosh sold commercially is collected from natural populations, the potential for harvest impacts is considerable. To better understand wild-harvest impacts and the likelihood of post-harvest recovery, we studied the effects of 2 to 4 y of experimental harvest on natural black cohosh populations in the George Washington-Jefferson National Forest in southwest Virginia. After 2 to 3 y of intense harvest (66% plant removal), we found significant reductions in foliage area, stem production, and mean and maximum plant height. The effects of moderately intense harvest (33%) were less clear, producing growth measures between, yet not significantly different from, control (non-harvest) and intensively harvested plots. After three successive years of experimental harvest, harvest treatments were terminated to assess population regrowth. Populations experiencing intensive harvest showed no evidence of recovery after 1 y. Results suggest that black cohosh is highly responsive to harvest intensity and that low to moderate harvest intensities and/or longer recovery periods will be necessary for prolonged and sustainable harvests at our study site. While this study has increased our understanding of harvest impacts on black cohosh, continued assessment is needed to determine the sustainability of low to moderate harvest levels and minimum recovery periods necessary for population reestablishment.