Characterizing butt-rot fungi on USA-affiliated islands in the western Pacific

Abstract

Ganoderma and Phellinus are genera that commonly cause tree butt-rot on USA-affiliated islands of the western Pacific. These fungal genera can be quite prevalent, especially in older mangrove stands. Although the majority of infections caused by these fungi lead to severe rotting of the heartwood, they typically do not directly kill the living tissues of the sapwood, cambium, or phloem. In this region, infection by butt-rotting fungi usually causes a loss of structural strength in the bole, but not direct mortality. However, three notable exceptions were found during a recent forest health survey of western Pacific islands. The first includes typhoon damage within a forest, where butt-rot-afflicted trees were exceptionally prone to wind breakage and wind-throw. A second includes the after effects of typhoon-strength winds that cause wounds and breakage in previously healthy trees, consequently allowing ingress of butt-rot fungi that can then subsequently spread via root contact to neighboring trees. A most-notable third exception is when Phellinus noxius, the cause of brown root rot, is the primary pathogen.

Citation

Cannon, Phil; Klopfenstein, Ned B.; Schlub, Robert L.; Kim, Mee-Sook; Ota, Yuko; Sahashi, Norio; Quitugua, Roland J.; Hanna, John W.; Ross-Davis, Amy L.; Ashiglar, Sara M. 2014. Characterizing butt-rot fungi on USA-affiliated islands in the western Pacific. In: Chadwick, K.; Palacios, P., comps. Proceedings of the 61st Annual Western International Forest Disease Work Conference; October 6-11, 2013; Waterton Lakes National Park; AB, Canada. Washington, DC: U.S. Department of Agriculture, Forest Service, Forest Health Protection. p. 107-110.