Recovery of Populations of Goldenseal (Hydrastis canadensis L.) and American Ginseng (Panax quinquefolius L.) Following Harvest

Abstract

Goldenseal (Hydrastis canadensis L.) and American ginseng(Panax quinquefolius L.) have been harvested commercially for the past few centuries. Harvested populations can recover if vegetative propagules remain in the soil. Experiment I tested the efficacy of vegetative reproduction in goldenseal and ginseng. Partial and intact rhizomes and roots were planted in garden experiments in West Virginia and monitored for 1 y (goldenseal), and for 4 y (ginseng). During the experiment more than 40% of the propagule types of goldenseal (n = 5) and ginseng (n = 7) sprouted. Sprouting varied from year to year in ginseng, and dormancy and/or death occurred in both species. Of the ginseng propagules that sprouted, 77% were dormant for at least 1 y and half of those were not present in the final year of the experiment. Sprouting and reproductive status were dependent on propagule type for both species. In Experiment II we monitored recovery of wild populations of goldenseal and ginseng following natural and simulated harvests. After a harvest event leaving only 4 visible plants at the site, a goldenseal population recovered to 932 stems in the first growing season. In the subsequent 3 y, the population declined numerically, but the size of individuals increased significantly. In a harvested ginseng population, less than half the original number of ginseng plants were present 1 y after harvest. By the second year, stem number exceeded the preharvest count, but the demographic structure of the population had changed dramatically: 78% of the population was reproductive before harvest, while 0%, 4%, 7%, 18% and 26%, respectively, were reproductive in the 5 y following harvest. Both rhizomes and roots of goldenseal and ginseng are capable of regenerating plants, conferring a degree of short term resiliency following harvest.