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Everett M. HansenProfessor, Emeritus
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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
Ebba Peterson (PhD expected 2011)
Laura Sims (MS)
Sarah Navarro (MS)
Eun Sung Oh, PhD, 2005, Resistance Mechanisms of Port-Orford-cedar to Phytophthora lateralis
Angel Saavedra, MS, 2006, Phytophthora cambivora on golden chinquapin
Aaron Smith , MS , 2007, Biology of Chlamydospores of Phytophthora ramorum
Ebba Peterson , MS , 2009, Preliminary investigations into the spatial epidemiology of Phytophthora ramorum in Oregon forests
Molly Botts, MS, 2009, Histological examination of Phytophthora ramorum in Notholithocarpus densiflorus bark tissues
Robin Mulvey, MS, 2010, Castilleja and Pedicularis are confirmed as telial hosts for white pine blister rust in whitebark pine ecosystems of Oregon and Washington
BOT 415/515 Forest Insect and Disease Management
BOT 616 Forest Pathology
Winton, L.M., J.K. Stone, and E.M. Hansen. 2007. The systematic position of Phaeocryptopus gaeumannii. Mycologia 99 :240-252.
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 causing lethal crown rot of golden chinquapin. Forest Pathology 37:409-419.
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: 16:2958-2973.
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 97:1558-1567.
Reeser, Paul W., 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 99:639-643.
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
Hansen, E. 2007. Alien forest pathogens: Phytophthora species are changing world forests. Boreal Environment Research 13:33-41.
Hansen, E.M., A. Kanaskie, S. Prosper, M. McWilliams, E.M. Goheen, N. Osterbauer, P. Reeser, and W. Sutton. 2008. Epidemiology of Phytophthora ramorum in Oregon tanoak forests. Can. J. For. Res. 38:1133-1143.
Reeser, Paul W., Wendy L. Sutton, and Everett M. Hansen. 2008. Phytophthora species causing tanoak stem cankers in southwestern Oregon . Plant Disease 92:1252.
Adams , G.C., M. Catal, L. Trummer, E. M. Hansen, P. Reeser, J. J. Worrall. 2008. Phytophthora alni subsp. uniformis found in Alaska beneath thinleaf Alders. Online. Plant Health Progress doi:10.1094/PHP-2008-1212-02-BR
Hansen, E. M., Wayne F. Wilcox, Paul W. Reeser, and Wendy Sutton. 2009. Phytophthora rosacearum and P. sansomeana , new species segregated from the Phytophthora megasperma "complex." Mycologia 101: 129-135.
Prospero , S., N. J. Grünwald , L. M. Winton , and E. M. Hansen . 2009. Migration patterns of the emerging plant pathogen Phytophthora ramorum on the west coast of the United States of America . Phytopathology 99: 739-749.
Grünwald NJ, Goss EM, Ivors K, Garbelotto M, Martin F, Prospero S, Hansen E, Bonants P, Hamelin R, Chastagner G, Werres S, Rizzo R, Brasier C, Blomquist C, Brière SC, Denman S, Frankel S, Goheen EM, Hunter S, Inman A, Jones J, Kanaskie A, Lane CR, McWilliams M, Moralejo E, Osterbauer N, Palm M, Parke J, Shamoun S, Shishkoff N, Tjosvold S, Tooley P, and Vettraino A. 2009. Standardizing the nomenclature for clonal lineages of the sudden oak death pathogen, Phytophthora ramorum . Phytopathology: 99: 792-795.
Collins, B., Parke, J.L., Lachenbruch, B. and E. M. Hansen.2009. The effects of Phytophthora ramorum infection on hydraulic conductivity and tylosis formation in tanoak sapwood. Can. J. For. Res. 39: 1766-1776 .
Sutton, W., E. M. Hansen, P. Reeser, and A. Kanaskie. 2009. Stream Monitoring for Detection of Phytophthora ramorum in Oregon Tanoak Forests. Plant Disease 93:1182-1186.
Greslebin, A. and E. M. Hansen. 2010. Pathogenicity of Phytophthora austrocedrae on Austrocedrus chilensis and its relation with mal del ciprés in Patagonia . Plant Pathology (In Press).
Vaclavik, T., A. Kanaskie, E. Hansen, J. Ohmann, and R. Meentemeyer. 2010. Modeling potential vs. actual distribution of sudden oak death in Oregon : Prioritizing landscape contexts for early detection and eradication of disease outbreaks. For. Ecol. Man. 260 (2010) pp. 1023-1032.
Manter, DK, EH Kolodny, EM Hansen, and JL Parke. 2010, Virulence, sporulation, and elicitin production in three clonal lineages of Phytophthora ramorum . Physiol. Molec. Plant Path. 74: 317-322.
Reeser, PW, W. Sutton, EM Hansen, P. Remigi, and GC Adams. 2010. Phytophthora species in forest streams in Oregon and Alaska . Mycologia (In Press). Doi 10.3852/10-013.
Mulvey, Robin; Hansen, Everett . 2010 Castilleja and Pedicularis Confirmed as Telial Hosts for Cronartium ribicola in Whitebark Pine Ecosystems of Oregon and Washington" submitted to Forest Pathology.
Niklaus J. Grünwald, Frank N. Martin, Meg Larsen, Chris Sullivan, Caroline M. Press, Michael D. Coffey, Everett M. Hansen, and Jennifer L. Parke 2010. Phytophthora-ID.org: A sequence based Phytophthora identification tool. Plant Disease. In Press.
C. Robin 1,6 , D. Piou 1, 2 , N. Feau 1 , G. Douzon 3 , N. Schenck 4 , E.M. Hansen 5 . 2010. Root and aerial infections of Chamaecyparis lawsoniana by Phytophthora lateralis : a new threat for European countries. In Press. Forest Pathology
