Black Cohosh (Cimcifuga racemosa) Harvest monitoring 2002
The third annual census of black cohosh in western North Carolina took place in 2002 on September 9th and 10th. As in previous years a diverse group of individuals including members of the Plant Conservation Committee of the Medicinal Plant Working Group helped to make this a successful project. Twenty-seven "Partners for Plants" volunteers representing nine separate clubs from the Gardens Clubs of America provided the backbone of the support. Other continuing participants included Edward Fletcher, representing the herbal industry, Pat Ford, botanist with the U.S. Fish and Wildlife Service (FWS), and Gary Kauffman, botanist with the National Forests in North Carolina (USFS). New participants included Jim Chamberlain, research scientist at the Southern Research Station (USFS), Rebecca Wood, Hocking Technical College professor and one of her students, Rina Caudwell.
The group's focus for 2002 was to continue the assessment of sustainable harvest levels of black cohosh (Cimcifuga racemosa). In order to further assess the range of black cohosh abundance and harvest potential across western North Carolina, the Nantahala National Forest was selected for the study site in 2002. Twenty-five 10 by 10 meter permanent plots were established in 4 separate rich cove forests, all easily accessible along Moses Creek Road in rural Jackson County. Black cohosh was harvested (either lightly or heavily) from 16 plots replicating the harvesting intensity initiated in 2001 in the Pisgah National Forest. Nine plots were established as controls. Quantitative data was also collected for bloodroot (Sanguinaria canadensis). While the root has been used during the mid 90's as a dental antiplaque agent, there has been more recent interest in its antibiotic properties. Bloodroot is currently being harvested primarily as a cattle feed supplement (antibiotic) to prevent scours. It is principally being exported to Germany, where the industry is projecting annual harvest totals exceeding 25 metric tons.
Bloodroot occurs in similar habitat, mesic deciduous hardwood forest, to black and yellow cohosh throughout its very broad range. Like black cohosh, the species has been found to be an excellent indicator for ginseng (Panax quinquefolius) since it also occurs in greater numbers in calcium rich habitats. Bloodroot is most conspicuous in the early spring when its bright white petals emerge, even before the leaves. While the undulate orbiculate leaves are also distinctive, they are not as conspicuous since numerous other taller herbs typically overshadow them. As with the 2 cohosh species, the desirable medicinal portion of the plant is the narrow fingerlike rhizome. These rhizomes have a distinctive orange-red color, exuding a red latex when cut. Like many other mixed mesophytic forest herbs, Sanguinaria canadensis occurs across a large portion of the eastern United States. Bloodroot has a distribution broader than black cohosh with occurrences in 5 Canadian provinces and thirty-eight states (Natureserve Explorer 2003). The range extends from Nova Scotia west to Manitoba and Minnesota, south to northern Florida and eastern Texas. The species is currently ranked as demonstrably secure (G5) throughout their ranges (Natureserve Explorer 2003).
While bloodroot is not threatened at this time, there is scant demographic information on the abundance and distribution of this species throughout its range, and sustainable harvest levels are unknown. Harvest levels of 25 metric tons or greater could rapidly deplete its numbers throughout its range. The data collected now before the demand greatly increases will be valuable in making management decisions on harvest levels for this species.
During the last 25 years abundance data on the distribution of species across numerous forested communities forest has been gathered both on public and private lands within the southern Appalachians. The preliminary data suggest indicate that bloodroot is neither as abundant (occurring in 191 plots versus 343 plots) nor as dense (average density of less than 1% cover compared to an average of 4.9%) as black cohosh. Only 5 of the 191 sampled plots had greater than 2% bloodroot cover. Harvest levels of 25 metric tons or greater could rapidly deplete its numbers throughout the southern Appalachians as well as across significant portions of its range. The data collected now before the demand greatly increases will be valuable in making informed management decisions on harvest levels for this species.
Preliminary Results of the monitoring study.
One thousand three hundred seventy black cohosh (Cimcifuga racemosa) plants were counted in 2002. The 25 plots averaged 54.8 individuals. Only one Cimcifuga americana was counted within the 25 plots in comparison to the numerous C. americana individuals counted last year. This further demonstrates the variation on the abundance of these 2 species across the southern Appalachians.
One Hundred Sixty-six (166) plants of black cohosh were harvested within the nine lightly harvested plots. The seven heavily harvested plots yielded 243 black cohosh roots. As last year individual root weight varied considerably (standard deviation = 41 grams) from 4 grams to 301 grams; the average was 61 grams. Due to the variation in the age of the harvested plants, we estimate approximately 15 to 20 plants equal one pound of dried roots/rhizomes. These estimates were derived with the assumption it takes approximately 4 lbs of wet roots to yield 1 dried pound and most collectors harvest older larger plants (those at least in the 50 percentile of the largest roots harvested). Fifty percent of the roots weighed at least 90 grams.
For bloodroot (Sanguinaria canadensis) 953 individuals were counted. Individual plots were highly variable in the number of bloodroot individuals, varying from 1 to 134. The average per plot was 38.1 individuals.
Ed Fletcher of Strategic Sourcing planted the harvested roots/rhizomes. Ed has been an integral member of the cohosh project here in North Carolina since its inception 3 years ago. The roots/rhizomes were planted on his property and will be monitored yearly for regrowth. This data will provide valuable information on the potential for black cohosh as a cultivated medicinal crop in the southern Appalachians.
We will continue to census and appraise sustainable harvest levels for wild-collected rhizomes of black cohosh and bloodroot in 2003, possibly both in the spring (bloodroot) and fall (black Cohosh). One of the objectives next year is to assess and recount the black and yellow cohosh plots harvested in 2001 on the Pisgah National Forests. Another goal is to harvest some bloodroot.
USFS Botanist, National Forests in NC