Notes on Economic Plants The Potential for Mahonia nervosa as a Wildcrafted Medicinal Product in the Pacific Northwest 1

Introduction Mahonia nervosa (Pursh) Nutt. (dwarf Oregongrape, low Oregon-grape, dull Oregon-grape) is a common perennial understory shrub in the moist temperate forests of the Pacific Northwest (western Oregon and Washington). Many species of Mahonia (formerly included in the genus Berberis) contain berberine and other alkaloids (Greathouse and Watkins 1938; Suess and Stermitz 1981), and as such are used in herbal medicine for a variety of purposes (Brinker 2005; Drum 2000; Duke 1985). There is an established market for the roots of M. aquifolium (Pursh) Nutt. (tall Oregon-grape), a similar species also native to the region; however, M. nervosa is not widely marketed despite its greater abundance. Furthermore, little to no documentation of M. nervosa’s chemistry could be found, although at least one herbalist (Drum 2000) reports qualitatively on its medicinal uses and preparation. This research sought to characterize the chemical makeup of M. nervosa in comparison to M. aquifolium, and to assess its regeneration potential following various harvest methods. The work was done in collaboration with a small woodland owners’ cooperative in Oregon to assess whether harvesting Oregon-grape could be a viable alternative income source for family forest owners. Herbal supplement sales in the U.S. have increased every year since 2004, reaching $5.2 billion in 2011 (Blumenthal et al. 2012). Data on the importance of Oregon-grape relative to other medicinals grown in the region’s forests is scarce; however, there are several commercial suppliers and buyers in Oregon (Buttolph et al. 2011; Oregon State University 2012). Furthermore, Oregon-grape is considered to be a medicinal substitute for goldenseal (Vance et al. 2001), which has a threatened population and harvest restrictions. There are over 360,000 family forest owners (families owning between 1 and 10,000 acres) in Oregon and Washington, with an average ownership less than 50 acres (Butler 2008). Many owners cite timber production as a management objective that is secondary to recreation, natural preservation, and other amenity uses; however, investment and income production are still primary concerns for landowners. Non-timber forest products provide the potential for a small but continuous revenue source in the interim years between timber harvests. In fact, about 5 % of family forest owners in Oregon and Washington report having collected and sold non-timber forest products from their property (Butler et al. 2012). Oregon-grape regenerates vegetatively from roots and rhizome sprouting as well as from seed. Reestablishment of Oregon-grape cover following harvest depends on residual root or rhizomes left in the soil (Vance et al. 2001). Lonner (2002) studied M. nervosa regeneration following harvest in northern California and found that even partially (25 %) harvested areas did not regenerate to pre-harvest levels of rhizome biomass two years later. In the lower elevation, more productive western Oregon lowland forests, harvested sites might recover more quickly. Besides total biomass produc1 Received 16 October 2012; accepted 1 February 2013; published online 23 February 2013.