Saturday, 31 October 2015

Can putative indicator species predict habitat quality for American ginseng?

Volume 57, 1 September 2015, Article number 2386, Pages 110-117

Department of Biology, Life Science Building, West Virginia University, P.O. Box 6057, Morgantown, WV, United States


Abstract American ginseng, Panax quinquefolius L., is a long-lived medicinal understory herb, which has been heavily harvested since the 1700s. Because of the economic value of the root, and the increasing rarity of this plant, P. quinquefolius is often reintroduced across its range. Land managers and hobby growers recommend using 'associate species' as a way to determine ideal site conditions for reintroduction. However, the accuracy of these putative indicator species in identifying sites that will maximize growth of this rare herb has not been tested. Using a long-term ecological dataset of 26 populations, we evaluated if 20 putative indicators (herbs, shrubs, and trees) could predict P. quinquefolius performance, as measured by the relative growth rate of the leaf area, at the population and microsite level. Of the indicators, only one tree species was able to predict positive performance. If a P. quinquefolius was within 10 m of a Liriodendron tulipifera L., the plant would have increased growth, in terms of leaf area, as compared to plants that were not within 10 m of this tree. Surprisingly, the presence of most putative indicator species was found to be unreliable as a site quality measure. At the population level, four putative indicators, Aralia nudicaulis L., Acer rubrum L., Betula lenta L., and Lindera benzoin (L.) Blume, were actually contra-indicators, as their presence at a site implied lower P. quinquefolius performance. If Podophyllum peltatum L. was absent from a site, but B. lenta present, P. quinquefolius had reduced growth as compared to plants present in other combinations of P. peltatum and B. lenta. The results from this study have important implications for in situ conservation strategies of this rare medicinal plant. Planting P. quinquefolius in sites that increase performance can help ensure that reintroduction projects likely have a greater chance of success, effectively reducing the waste of time, money, and resources spent on projects that have lower levels of success. © 2015 Elsevier Ltd. All rights reserved.

Author keywords

Agroforestry; American ginseng; Medicinal plants; Panax quinquefolius; Rare plant conservation; Reintroduction

Indexed keywords

Engineering controlled terms: Forecasting; Forestry; Population statistics
Agroforestry; American ginseng; Medicinal plants; Panax quinquefolius; Plant conservation; Reintroduction
Engineering main heading: Plants (botany)
GEOBASE Subject Index: agroforestry; bioindicator; biological invasion; data set; economic analysis; environmental indicator; growth; herb; medicinal plant; perennial plant; plant community; prediction; rare species; species conservation
PaperChem Variable: Conservation; Plants
Species Index: Acer rubrum; Aralia nudicaulis; Betula lenta; Lindera benzoin; Liriodendron tulipifera; Panax quinquefolius; Podophyllum peltatum