Student West Chester University of Pennsylvania, United States
Abstract: American ginseng is North America’s leading wild-harvested herb, and provides millions of dollars of yearly supplement income to individuals throughout Appalachia. Ginseng’s viability, however, is currently being threatened by overharvest. The current enforceable harvest regulation is the “5-year rule,” which sets a 5-year age minimum for harvest. The 5-year rule is not sufficient to prevent population decrease and potential extirpation, because this age-based regulation does not consider the high variability of ginseng developmental rates across heterogeneous habitats where ginseng grows. By five years, most plants have not replaced themselves in a population. Leaf area, a measure of plant size, best predicts reproductive success, growth, and survival in American ginseng along with the probability of self-replacement. However, leaf area is difficult to measure in the field, requiring expensive equipment or mathematical training, and is not verifiable at the point of sale. The purpose of this work was to identify easily-measured morphological traits that accurately predict leaf area and that remain verifiable when ginseng is sold. We collected age, leaf area, seed count, and morphological data on the stems and roots of fresh plants (n=90) and a subsample of dry plants (n=30). Dry measurements were necessary to account for changes in morphology during the drying process since most ginseng is sold to dealers dry. We performed regressions to determine the best predictors of leaf area, which serves as our best size-based estimate of survival and reproduction. We regressed leaf area on age and confirmed that age is not a good predictor of plant size. Among the numerous shoot and root traits measured, stalk height is the best simple predictor of leaf area and replacement probability, and is verifiable at sale since stalk height did not change significantly when dried. Prior studies clearly indicate that the continued use of age-based harvest protocol will further damage ginseng populations across its range. The development of impactful, size-based harvest regulations is vital in the protection of this ecologically, economically, and culturally-valuable medicinal herb. We propose that an easily-measured, verifiable size-based morphological trait like stalk height be considered when developing conservation-oriented, size-based harvest regulations. Such a trait will allow harvesters and ginseng dealers to quickly evaluate if a plant is harvestable and sellable and will go far in moving the needle toward conservation. A similar size-based approach has been utilized successfully in fisheries science and is likely to provide similar levels of protection in wild-harvested ginseng.
