The Plant Conservation Committee of the Medicinal Plant Working Group, in coordination with the USDA Forest Service, U.S. Fish and Wildlife Service and Garden Club of America combined efforts on September 25 and 26, 2000 to census black cohosh Actaea racemosa L. (Cimicifuga racemosa N.). Twelve enthusiastic "Partners For Plants" volunteers representing six garden clubs from Garden Club of America, botanists Gary Kauffman and Allison Schwarz with the Forest Service, Pat Ford from U. S. Fish and Wildlife Service, and Ed Fletcher from Strategic Sourcing, Inc., representing the Plant Conservation Committee came together in Asheville, North Carolina to collect population data on the occurrence of black cohosh on the Pisgah National Forest. All of the participants found common interest and mutual benefit in the pilot study, and advanced the group's collective objective of quantifying the occurrence of black cohosh in the wild and to begin to assess sustainable harvest levels and conservation for this native medicinal herb.
Black cohosh was selected because of the rapid increase in the commercial demand for this species in the medicinal herb market. In 1998, black cohosh was identified as one of the fastest growing herbal products with an annual increase of over 511 percent from sales in 1997 (Breevort, 1998), of which 98 percent of the black cohosh root supplied for the herbal market is collected from wild populations.
Black cohosh is a long-lived herbaceous
perennial found in eastern deciduous forests in the United States. It has native
occurrences in 25 states and 2 Canadian provinces and is currently ranked as
secure (G4) throughout its range (Natureserve 2000). However, there is little
demographic information on the abundance and distribution of black cohosh throughout
its range, and sustainable harvest levels are unknown. An increase in the harvest
of wild roots may affect native populations and threaten the viability of the
species. An example of over harvest of black cohosh root has occurred in the
state of Illinois, which has resulted in ranking populations in the state as
critically imperiled (Natural Heritage Network, 2000).
Black cohosh occurs in rich habitats identified as cove forest communities. Cove habitat is identified as a mixed mesophytic forest type, and are fairly common throughout southern Appalachian. Black cohosh typically makes up 5 to 10 percent of the understory vegetative cover within the cove. Reproduction is primarily by seed, which, like American ginseng (Panax quinquefolius L.), requires a 1-½ year dormancy period.
The specific objectives of the pilot study were to census a population and to assess the spatial variability within the population in order to calculate the number of permanent plots needed to adequately detect change in a population over time under a harvest regime. Gary Kauffman designed the randomized sampling procedure, which consisted of a series of transects 25 meters apart, for each transect line 2x5 meter plots were randomly placed. Within each plot, all Actaea racemosa plants were counted, individual plant height was measured in the following increments: 0 to 10 cm., 10 to 20 cm., and greater than 20 cm. The presence of inflorescence and or seed set was recorded. The same inventory procedure was used for the second cove, however, the number of plots were increased to more accurately assess the clumping distribution of black cohosh throughout the cove.
The two coves sampled varied slightly in moisture content and total species richness, nevertheless they are considered indicative of the habitat variability found within mesophytic forest communities across western North Carolina. Preliminary data from the inventory indicates that the distribution of Actaea racemosa was sporadic in the two coves, and plants tended to occur in clumps. Of the two coves sampled, Actaea racemosa had a vegetation cover of 5 to 10 percent in the first cove, and a 1 to 5 percent cover in the second cove. Many plants had not produced inflorescence or set seed, and there was little evidence of plants in the 0 to 10 cm. size class.
Further analysis of the data will continue to refine the sampling procedure. The pilot study will continue in 2001, and include the harvest of roots so that we can begin to assess the affects of harvest on the sustainability of these species in the wild. Due to the similarities of Actaea racemosa and A. americana and the potential lack of discrimination between the two species by harvesters, both species will be included in the 2001 study. Actaea racemosa and A. americana roots are known to be wild-collected and sold as black cohosh. Additionally, the spring flowering plant, bloodroot (Sanguinaria canadensis L.) will also be included in the study. Typically, both Actaea's and Sanguinaria canadensis occur within the same cove forest communities.
Nov. 2, 2000.