ARS | Publication request: Japanese Raspberry (Rubus parvifolius L.): An Invasive Species Threat in Savanna and Prairie

Submitted to: North American Prairie Conference
Publication Type: Abstract Only
Publication Acceptance Date: July 1, 2010
Publication Date: August 4, 2010
Citation: Drobney, P.M., Widrlechner, M.P. 2010. Japanese Raspberry (Rubus parvifolius L.): An Invasive Species Threat in Savanna and Prairie [abstract]. 22nd North American Prairie Conference Program. p. 73.

Technical Abstract: Japanese raspberry, (Rubus parvifolius L.) is native to eastern Asia and Australia and has naturalized in several locations in Illinois, Iowa, Massachusetts, Missouri, and Virginia. This species was introduced in North America for food and erosion control, but the authors are concerned that it is a serious invasive species threat in savannas and prairies. It was found in a former commercial game hunting farm on Walnut Creek National Wildlife Refuge (NWR), (now Neal Smith NWR) in 1991, and was identified as Japanese raspberry in 1995. It thrives in dense shade in a remnant savanna on the refuge forming rapidly expanding near-monocultural populations. Efforts to control it with herbicide treatment since its discovery have been unsuccessful, but also somewhat sporadic. A second population within a mile of the refuge in a roadside demonstrates its ability to thrive in full sun. County dredging of ditches for drainage improvement may be serving as a vector for its expansion. Japanese raspberry grows vigorously and spreads via rooting from low-arching to prostrate canes that are up to 300 cm long, and seeds are dispersed by birds. In summer, primocanes are green to purplish-green, though they turn reddish brown in winter. It has pink flowers and bright red fruit.