PARENT SESSION
Oral Session #18: Herbivory: Folivory and rhizovory.
Presiding: A. Stephenson
Monday, August 5. 1:00 PM to 3:45 PM. Apache Meeting Room, TCC.
Browsing effects on growth and reproduction in a natural population of American ginseng.
Furedi, Mary Ann1, Van der Voort, Martha1, Spencer, S. Melinda1, McGraw, James*,1, 1 West Virginia University, Morgantown, WV
ABSTRACT- American ginseng (Panax quinquefolius L) is a long-lived perennial herb found in the deciduous forests of the northeastern United States and southern Canada. Although American ginseng is widely distributed, it is considered rare in much of its range. This rarity may be due to harvest for the herbal market or to browsing by white–tailed deer. Within the last century, deer populations have multiplied in the northeastern U.S. due to effective game management. This study examined the effects of deer on growth and reproduction in a single naturally occurring ginseng population in West Virginia. Data on size, growth, reproduction and browsing were collected during the summers of 1999, 2000, and 2001. We found high but variable rates of browsing in the three years of this study (24.6%, 11.5% and 37.7% in 1999 – 2001, respectively), with most browsing concentrated in the largest adult size classes. The probability of being browsed increased with plant height. Browsing in a given year reduced plant size in the following year. The probability of reproductive success was reduced by browsing for all three years, an effect that was accentuated by early browse. Our study suggests that large deer populations could be having a significant negative effect on ginseng population growth, compounding pressure already exerted by human harvesters. Future work will examine the integrated effects of browsing on ginseng life history using a population projection matrix model.
KEY WORDS: deer, ginseng, conservation, herbivory