Holocene Vegetation and Fire History of the Floristically
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HOLOCENE VEGETATION AND FIRE HISTORY OF THE FLORISTICALLY DIVERSE KLAMATH MOUNTAINS, NORTHERN CALIFORNIA, USA by CHRISTY BRILES A DISSERTATION Presented to the Department of Geography and the Graduate School ofthe University of Oregon in partial fulfillment of the requirements for the degree of Doctor of Philosophy March 2008 11 University of Oregon Graduate School Confirmation of Approval and Acceptance of Dissertation prepared by: Christy Briles Title: "Holocene vegetation and fire history of the floristically diverse Klamath Mountains, northern California, USA" This dissertation has been accepted and approved in partial fulfillment of the requirements for the degree in the Department of Geography by: Cathy Whitlock, Co-Chairperson, Geography Patrick Bartlein, Co-Chairperson, Geography Shaul Cohen, Member, Geography Gregory Retallack, Outside Member, Geological Sciences and Richard Linton, Vice President for Research and Graduate Studies/Dean of the Graduate School for the University of Oregon. March 22, 2008 Original approval signatures are on file with the Graduate School and the University of Oregon Libraries. 111 © 2008 Christy Briles iv An Abstract ofthe Dissertation of Christy Briles for the degree of Doctor of Philosophy in the Department of Geography to be taken March 2008 Title: HOLOCENE VEGETATION AND FIRE HISTORY OF THE FLORISTICALLY DIVERSE KLAMATH MOUNTAINS, NORTHERN" CALIFORNIA, USA Approved: _ Cathy Whitlock Approved: _ Patrick Bartlein The Holocene vegetation and fire history of the Klamath Mountains (KM), northern California, was reconstructed at three sites based on an analysis ofpollen and high resolution macroscopic charcoal in lake-sediment cores. These data were compared with five existing records to examine regional patterns. The objective was to determine the relative importance of climate history, substrate, and disturbance regime on the development ofthe Klamath vegetation. In the first study, two middle-elevation sites were compared along a moisture gradient in the northern KM. The pollen data indicated a similar vegetation history, beginning with subalpine parkland in the late-glacial period, and changing to open forest in the early Holocene and closed forest in the late Holocene. However, the timing ofthese changes differed between sites and is attributed to the relative v importance of coastal influences and topography. The second study examined the effect of substrate and nutrient limitations on the vegetation history. The pollen data suggest that ultramafic substrates (UMS), containing heavy metals and low nutrients that limit plant growth, supported xerophytic plant communities than those on non-ultramafic substrates (NUMS) for any given period. For example, between 14,000 and 11,000 cal yr BP, cooler and wetter conditions than present led to the establishment of a subalpine parkland ofPinus monticola and/or Pinus lambertina, Tsuga, Picea on non-ultramafic substrates (NUMS). On UMS, an open Pinus jeffreyi and/or Pinus contorta woodland developed. In the early Holocene, when conditions were warmer and drier than present, open forests ofPinus monticola/lambertina, Cupressaceae, Quercus and/or Amelanchier grew on NUMS, whereas open forest consisting of Pinus jeffreyilcontorta, Cupressaceae and Quercus developed on UMS. In the late Holocene, cool wet conditions favored closed forests of Abies, Pseudotsuga, and Tsuga on NUMS, whereas Pinusjeffreyilcontorta, Cupressaceae and Quercus forest persisted with little change on UMS. The charcoal data indicate that past fire activity was similar at all sites, implying a strong climatic control. The results of both studies suggest that the influence ofHolocene climate variations, disturbance regime, and substrate type have helped create the current mosaic ofvegetation in the KM. VI CURRICULUM VITAE NAME OF AUTHOR: Christy Briles PLACE OF BIRTH: Montrose, Colorado DATE OF BIRTH: 11/19/1976 GRADUATE AND UNDERGRADUATE SCHOOLS ATTENDED: University of Oregon University of Denver DEGREES AWARDED: Doctor of Philosophy in Geography, 2008, University of Oregon Master of Science in Geography, 2003, University of Oregon Bachelor of Science in Environmental Science, 1999, University of Denver AREAS OF SPECIAL INTEREST: Late-Quaternary environmental change Ecosystem response to climate change Historical controls of biodiversity Biogeography of the western US Paleoecological insights for forest policy and ecosystem management PROFESSIONAL EXPERIENCE: Research Assistant - Department of Earth Sciences, Montana State University, Bozeman, MT, 2005-2008 Lecturer - Geog 302: Biogeography, Department of Earth Science, Montana State University, Bozeman, MT, Spring 2008 Lecturer - Geog 141: Natural Environment, Department of Geography, University of Oregon, Eugene, OR, Summer 2007 Vll Teaching Assistant - Geog 416/516: Introduction to Geographic Information Science, Department of Geography, University of Oregon, Eugene, OR, Spring, 2007 Lecturer - Geog 410/510: Oregon Natural Landscapes, Department of Geography, University of Oregon, Eugene, OR, Summer 2004 Research Assistant - Department of Geography, University of Oregon, Eugene, OR, September 2001 to March 2001, September 2003 to September 2004 Lecturer - GEOG 143: Global Environmental Change, Department of Geography, University of Oregon, Eugene, OR, Summer 2002 and 2003, Spring 2003 Undergraduate Advisor - General Science Program, University of Oregon, Eugene, OR, March 2002 to June 2003 Teaching Assistant - Climatology (Fall 1999), Geography and the Environment (Winter 2000), Human Geography (Spring 2000), Natural Environment (Fall 2000), World Regional Geography (Winter 2001), Global Environmental Change (Spring 2001), Department of Geography, University of Oregon, Eugene, OR Physical Research Assistant - United States Geological Survey, Denver, CO, June 1997 to September 1999 WorkstudylResearch Assistant - University of Denver Quaternary Studies Laboratory, Denver, CO, March 1997 to June 1999 GRANTS, AWARDS AND HONORS: American Quaternary Association's Denise Gaudreau Award for Excellence in Quaternary Studies, 2006 University of Oregon Geography Department Graduate Student Research Award, 2006,2004,2003,2000 Lawrence Livermore University Collaborative Research Project Grant; Establishing a chronologyfor postglacialforest development in the biologically diverse Klamath Mountains, northern California (PI-Cathy Whitlock; Co-PI-Tom Guilderson (LLNL), 2004 to 2005 NSF-funded award to attend the biennial meeting ofthe American Quaternary Association in Lawrence, KS, 2004 Mazamas Graduate Student Research Grant, 2004 Sigma Xi Grants-in-Aid of Research Recipient, 2004 V111 Travel award to attend the biennial meeting ofthe American Quaternary Association in Fayetteville, Arkansas, 2000 University of Oregon Scholarship, 1999 United States Geological Survey Star Award, 1999 University of Denver Environmental Science Program award for Outstanding Scholarship and Research, 1999 University of Denver Partners in Scholarship, 1999 Bryce Henry Scholarship (University ofDenver), 1998 PUBLICATIONS: Briles, C.E., Whitlock, C., and Bartlein, P.J., 2005. Postglacial vegetation, fire and climate history ofthe Siskiyou Mountains, Oregon, USA. Quaternary Research 64,44-56. Briles, C.E., 2003. Postglacial vegetation and fire history near Bolan Lake in the northern Siskiyou Mountains of Oregon. M.S. thesis, Department ofGeography, University of Oregon, Eugene. Briles, C.E., 2001. A snapshot from the past - an environmental history of the Pacific Northwest forests. The Ecotone: The Journal of Environmental Studies, The University ofOregon. pp. 4-5. Power, M.J., Marlon, J., Ortiz, N., Bartlein, P.J., Harrison, S.P., Mayle, F.E., Ballouche, A., Bradshaw, R, Carcaillet, c., Cordova, C., Mooney, S., Moreno, P., Prentice, I.C., Thonicke, K., Tinner, W., Whitlock, C., Zhang, Y., Zhao, Y, Anderson, RS., Beer, R, Behling, H., Briles, C., Brown, KJ., Brunelle A, Bush, M., Camill, P, Chu, G., Clark, 1., Colombaroli, D., Connor, S., Daniels, M." Daniau, A.L., Dodson, 1., Doughty, E., Edwards, M.E., Fisinger, W., Foster, D., Frechette 1., Gaillard, MJ., Gil-Romera, G., Gavin, D.G., Gobet, E., Haberle, S., Hallett, D.1., Higuera, P., Hope, G., Hom, S., Impagliazzo, S., Inoue, J., Kaltenrieder, P., Kennedy, L., Kong, Z.C., Larsen, C., Long, C.J., Lynch, J., Lynch, B., McGlone, M., Meeks, S., Mensing, S., Meyer, G., Minckley, T., Mohr, J, Nelson, D., New, 1., Newnham, R, Noti, R, Oswald, W., Pierce, J., Richard, P.H., Rowe, c., Sanchez Gofii, M.., Shuman, B.J., Takahara, H., Toney, J., Tumey, C., Umbanhower, C., Vandergoes, M., Vanniere, B., Vescovi, E., Walsh, M., Wang, x., Williams, N., Wilmshurst, 1., Zhang, J. (in press) Changes in fire regimes since the Last Glacial Maximum: an assessment based on a global synthesis ofcharcoal data. Climate Dynamics. Whitlock, C., Marlon, J., Briles, C.E., Brunelle, A., Long, C. and Bartlein, P.J., 2008. Long-term relations between fire, fuel, and climate in the northwestern U.S. International Journal of Wildland Fire 17, 72-83. IX ACKNOWLEDGMENTS I would like to thank Cathy Whitlock for her undying support through both my masters and doctorate work. I am very grateful for all of her instruction, advice, encouragement, reviews of the dissertation, and especially, all the experiences we had coring and working in the laboratory together. She was the first to introduce me to the diversity of the Klamath Mountains; and for that I am very grateful. I need to also thank Pat Bartlein for his support throughout this process,