Author , , , , , , , , , , , ,
Date 2013.
Publication Madrono (In press)
Key Words
AbstractNon-native diseases of dominant tree species have diminished North American forest 33 biodiversity, structure, and ecosystem function over the last 150 years. Since the mid-1990s, 34 coastal California forests have suffered extensive decline of the endemic overstory tree tanoak 35 (Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S.H.Oh (Fagaceae)) following 36 the emergence of the exotic pathogen Phythophthora ramorum and the resulting disease sudden 37 oak death. There are two central challenges to protecting tanoak: 1) the pathogen P. ramorum 38 has multiple pathways of spread and is thus very difficult to eradicate, and 2) the low economic 39 valuation of tanoak obscures the cultural and ecological importance of this species. However, 40 both modeling and field studies have shown that pathogen-centric management and host-centric 41 preventative treatments are effective methods to reduce rates of spread, local pathogen 42 prevalence, and to increase protection of individual trees. These management strategies are not 43 mutually exclusive, but we lack precise understanding of the timing and extent to apply each 44 strategy in order to minimize disease and the subsequent accumulation of fuels, loss of obligate 45 flora and fauna, or destruction of culturally important stands. Recent work identifying heritable 46 disease resistance traits, ameliorative treatments that reduce pathogen populations, and 47 silvicultural treatments that shift stand composition hold promise for increasing the resiliency of 48 tanoak populations. We suggest distinct strategies for pathogen invaded and uninvaded areas, 49 place these in the context of local management goals, and suggest a management strategy and 50 associated research priorities to retain the biodiversity and cultural values associated with tanoak. To combat sudden oak death (SOD), scientists first had to understand the primary host - tanoak, (Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S.Oh (Fagaceae)), so research was conducted on the distribution, genetics, utilization and natural history of tanoak. This Madroño special issue “Tanoak: History, Values and Ecology” presents much of what we have learned, over the past 10 years, about this endemic, broadleaf tree so common throughout coastal California and southwest Oregon. By assembling these papers, our objectives are to synthesize what we have learned about this important SOD host, apply our knowledge to tanoak management and share our appreciation of tanoak.
Full Citation Cobb, R.C.; Rizzo, D.M.; Hayden, K.J.; Garbelotto, M.; Filipe, J.A.N.; Gilligan, C.A.; Dillon, W.W.; Meentemeyer, R.K.; Valachovic, Y.S.; Goheen, E.; Swiecki, T.J.; Hansen, E.M.; and Frankel, S.J. 2013. Biodiversity conservation in the face of dramatic forest disease: an integrated conservation strategy for tanoak (Notholithocarpus densiflorus) threatened by sudden oak death. Madroño. (In press).