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Abstract
In late August 2009, a 20.3 cm (8 in) diameter tanoak (
Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S.H. Oh) adjacent to a popular hiking trail on the Rogue River-Siskiyou National Forest was found infected with
Phytophthora ramorum. The trail was immediately closed to the public. An eradication treatment consisting of injecting herbicide and cutting, piling, and burning tanoaks and other selected hosts in a 91.4 m (300 ft) radius around the infected tanoak was prescribed and completed by early winter. Close to 487.7 m (1600 ft) of trail lies within or on the boundary of the treatment area while approximately 61 m (200 ft) of trail pass through the heart of the infested zone. Knowing the potential for
P. ramorum to persist in soils after treatment, options to reduce the risk of human-assisted spread of the pathogen via infested trail soil were discussed. Closing the trail permanently was not considered a viable option. A previous study suggested that, due to their antimicrobial activity, western red cedar (
Thuja plicata Donn ex D. Don) heartwood chips placed on trails could help limit the number of
P. ramorum spores in soils and the potential for new infections from splash dispersal. As a result, a 10.2 cm (4 in) thick layer of western redcedar heartwood chips was placed on the trailhead and through the center of the treated area. The trail was reopened to public use after the chip treatment was completed.
Parent Publication
Citation
Goheen, Ellen Michaels. 2013. Reducing the spread of
Phytophthora ramorum on the Redwood Nature Trail, Rogue River-Siskiyou National Forest, Curry County, Oregon: A Case Study. In: Frankel, S.J.; Kliejunas, J.T.; Palmieri, K.M.; Alexander, J.M. tech. coords. Proceedings of the sudden oak death fifth science symposium. Gen. Tech. Rep. PSW-GTR-243. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: p. 141.
