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Everett M. HansenProfessor,
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Forest pathology, the biology and management of forest tree diseases; population biology of forest fungi; ecology, taxonomy and phylogenetics of Phytophthora.
My research interests are diverse, addressing both immediate forest management issues and fundamental questions of pathogen biology.
· Work with laminated root rot caused by Phellinus weirii, includes long-term studies of silvicultural strategies to lessen economic impacts of this widespread native disease of Douglas-fir, as well as ecological investigations of the roles the pathogen plays in determining forest structure and function in wild forests.
· Root rot of Port Orford cedar (Phytophthora lateralis) is an introduced disease, spread in water and by human activity. We support an intensive management effort by Federal land management agencies to limit the further spread of the pathogen and restore cedar on affected sites. Much of our effort is focused on breeding for resistance, and developing the biological basis for deployment strategies to use the resistant stock that is increasingly available from the program.
· Sudden Oak Death (Phytophthora ramorum) is new in the west, devastating in California and threatening in Oregon. This state has responded with an eradication effort that so far, is keeping the disease in check. We support the eradication program by providing diagnostic and survey methods including molecular probes for the pathogen. Our research aims to clarify epidemiology in Oregon forests using molecular population genetics, spore trapping, and host range studies. Intriguingly, P. ramorum and P. lateralis are very closely related. Another avenue of research explores the evolutionary biology of Phytophthora species, especially the many new species we are discovering in forests around the world.
Wendy Sutton
Paul Reeser
Jen Britt
Carolyn Choquette
Molly Botts (MS expected 2009)
Robin Mulvey (MS expected 2010)
Ebba Peterson (PhD expected 2011)
Eunsung Oh, PhD, 2005, Mechanisms of Resistance to Phytophthora lateralis.
Angel Saavedra, MS, 2006, A new disease of golden Chinquapin caused by Phytophthora cambivora.
Aaron Smith, MS 2007, Biology of Chlamydospores of Phytophthora ramorum
BOT 415/515 Forest Insect and Disease Management
BOT 616 Forest Pathology
Oh, E. and E.M. Hansen. 2007. Histopathology of infection and colonization of Port-Orford-cedar by Phytophthora lateralis . Phytopathology 97: 684-693.
Greslebin, A., E.M. Hansen and W. Sutton. 2007. Phytophthora austrocedrae sp. nov., a new species associated with Austrocedrus chilensis mortality in Patagonia ( Argentina ). Mycol. Res. 111:308-316.
Saavedra, A., Goheen, D.G., and E.M. Hansen. 2007. Phytophthora cambivora in Oregon forests and causing lethal crown rot of golden chinquapin. Forest Pathology (In Press).
Prospero, S., E.M. Hansen , N.J. Grunwald, and L.M. Winton. 2007. Population dynamics of the sudden oak death pathogen Phytophthora ramorum in Oregon from 2001 to 2004. Molecular Ecology. doi: 10.1111/j.1365-294X.2007.03343.x
Winton, L.M., J.K. Stone, and E.M. Hansen. 2007. Polymorphic microsatellite markers for the Douglas-fir pathogen Phaeocryptopus gaeumannii , causal agent of Swiss needle cast disease. Molecular Ecology Notes. doi: 10.1111/j.1471-8286.2007.01802.x
Parke, J. L. Oh, E. Voelker, S. Hansen, E. M. Buckles, G., and Lachenbruch. B. 2007. Phytophthora ramorum Colonizes Tanoak Xylem and is Associated with Reduced Stem water Transport. Phytopathology 97 (In Press)
Paul W. Reeser, Everett M. Hansen, and Wendy L. Sutton. 2007. Phytophthora siskiyouensis, a new species from soil, water, myrtlewood ( Umbellularia californica ) and tanoak ( Lithocarpus densiflorus ) in southwestern Oregon. Mycologia (submitted).
S. Prospero, J.A. Black, and L.M. Winton. 2007. Isolation and characterization of microsatellite markers in Phytophthora ramorum , the causal agent of sudden oak death. Molecular Ecology Notes 4: 672-674. doi: 10.1111/j.1471-8286.2004.00778.x
Winton, L.M., J.K. Stone, and E.M. Hansen. 2006. The systematic position of Phaeocryptopus gaeumannii. Mycologia 98 (In Press).
Oh, E, E.M. Hansen, and R.A. Sniezko. 2006. Port-Orford-cedar resistant to Phytophthora lateralis . For. Path. 36:385-394.
Winton, L.M., E.M. Hansen, J.K. Stone. 2006. Population structure suggests reproductively isolated lineages of Phaeocryptopus gaeumannii . Mycologia 98:781-791.
Goheen, E.M., E. Hansen, A. Kanaskie, N. Osterbauer, J. Parke, J. Pscheidt, and G. Chastagner. 2006. Sudden Oak Death and Phytophthora ramorum . A Guide for Forest Managers, Christmas Tree Growers, and Forest-Tree Nursery Operators in Oregon and Washington . Oregon State University Extension Service. EM 8877, April 2006. 16p.
Greslebin, Alina y E. Hansen. 2006. Novedades con relación al Mal del Ciprés. Patagonia Forestal Año XII Nº 1 (Marzo 2006). CIEFAP, Esquel , Argentina . 19p.
Hansen, E.M., Parke, J.L., and Sutton, W. 2005. Susceptibility of Oregon forest trees and shrubs to Phytophthora ramorum : A comparison of artificial inoculation and natural infection. Plant Disease 89:63-70.
Greslebin, A., E.M. Hansen, L.M. Winton, and M. Rachenberg. 2005. Phytophthora species from soil and streams of declining Austrocedrus chilensis forests in Patagonia , Argentina. Mycologia 97:218-228.
Rizzo, D. M., Garbelotto, M. and E.M. Hansen. 2005. Integrative Research and Management of an Emerging Pathogen in California and Oregon Forests . Ann. Rev. Phytopath. 43:309-336.
Hansen, E.M. and J. Stone. 2005. Impacts of plant pathogens on plant communities. Pp. 461-474, IN: THE FUNGAL COMMUNITY: ITS ORGANIZATION AND ROLE IN THE ECOSYSTEM. Ed. J. Dighton, P Oudemans & J. White eds. Taylor and Francis. London . 936 p.
