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Postglacial vegetation, fire, and climate history of the Siskiyou Mountains, Oregon, USA

  • Christy E. Briles (a1), Cathy Whitlock (a2) and Patrick J. Bartlein (a1)

The forests of the Siskiyou Mountains are among the most diverse in North America, yet the long-term relationship among climate, diversity, and natural disturbance is not well known. Pollen, plant macrofossils, and high-resolution charcoal data from Bolan Lake, Oregon, were analyzed to reconstruct a 17,000-yr-long environmental history of high-elevation forests in the region. In the late-glacial period, the presence of a subalpine parkland of Artemisia, Poaceae, Pinus, and Tsuga with infrequent fires suggests cool dry conditions. After 14,500 cal yr B.P., a closed forest of Abies, Pseudotsuga, Tsuga, and Alnus rubra with more frequent fires developed which indicates more mesic conditions than before. An open woodland of Pinus, Quercus, and Cupressaceae, with higher fire activity than before, characterized the early Holocene and implies warmer and drier conditions than at present. In the late Holocene, Abies and Picea were more prevalent in the forest, suggesting a return to cool wet conditions, although fire-episode frequency remained relatively high. The modern forest of Abies and Pseudotsuga and the present-day fire regime developed ca. 2100 cal yr B.P. and indicates that conditions had become slightly drier than before. Sub-millennial-scale fluctuations in vegetation and fire activity suggest climatic variations during the Younger Dryas interval and within the early Holocene period. The timing of vegetation changes in the Bolan Lake record is similar to that of other sites in the Pacific Northwest and Klamath region, and indicates that local vegetation communities were responding to regional-scale climate changes. The record implies that climate-driven millennial- to centennial-scale vegetation and fire change should be considered when explaining the high floristic diversity observed at present in the Siskiyou Mountains.

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* Corresponding author. Fax: +1 406 994 6923. E-mail address: (C.E. Briles).
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Agee, J.K. (1991). Fire history along an elevational gradient in the Siskiyou Mountains, Oregon. Northwest Science 65, 188199.
Agee, J.K. (1993). Fire Ecology of Pacific Northwest Forests. Island Press, Washington, DC.
Alley, R.B., Meese, D.A., Shuman, C.A., Gow, A.J., Taylor, K.C., Grootes, P.M., White, J.W.C., Ram, M., Waddington, E.D., Mayewski, P.A., and Zielinski, G.A. (1993). Abrupt increase in Greenland snow accumulation at the end of the Younger Dryas event. Nature 362, 527529.
Barron, J.A., Heusser, L., Herbert, T., and Lyle, M. (2003). High-resolution climate evolution of coastal northern California during the past 16,000 years. Paleoceanography 18, 10201029.
Bartlein, P.J., Edward, M.E., Shafer, S.L., and Baker, E.D. (1995). Calibration of radiocarbon ages and the interpretation of paleoenvironmental records. Quaternary Research 44, 417424.
Bartlein, P.J., Anderson, K.H., Anderson, P.M., Edwards, M.E., Mock, C.J., Thompson, R.S., Webb, R.S., Webb III, T., and Whitlock, C. (1998). Paleoclimate simulations for North America over the past 21,000 years: features of the simulated climate and comparisons with paleoenvironmental data. Quaternary Science Reviews 17, 549585.
Bennett, K.D. (1997). Evolution and Ecology: The Pace of Life. Cambridge Univ. Press, UK.
C.E., Briles (2003). Postglacial vegetation and fire history near Bolan Lake in the northern Siskiyou Mountains of Oregon. MS Thesis. University of Oregon, .
Burns, R.M., Honkala, B.H. Tech. Coords.(1990). Silvics of North America: 1. Conifers; 2. Hardwoods. Agriculture Handbook vol. 654, U.S. Department of Agriculture, Forest Service, Washington, DC.Vol. 2
Coleman, R.G., and Kruckeberg, A.R. (1999). Geology and plant life of the Klamath-Siskiyou Mountain region. Natural Areas Journal 19, 320341.
Davis, M.B., Brubaker, L.B., and Webb III, T. (1973). Calibration of absolute influx.Birks, H.J.B., West, R.G. Quaternary Plant Ecology John Wiley and Sons, New York.109116.
Dean, W.E. (1974). Determination of carbonate and organic matter in calcareous sediments by loss on ignition comparison to other methods. Journal of Sedimentary Petrology 44, 242248.
DellaSala, D.A., Reid, S.R., Frest, T.J., Strittholt, J.R., and Olson, D.M. (1999). A global perspective on the biodiversity of the Klamath-Siskiyou ecoregion. Natural Areas Journal 19, 300319.
Faegri, K., Kaland, P.E., and Krzywinski, K. (1989). Textbook of Pollen Analysis. John Wiley and Sons, New York.
Fall, P. (1992). Spatial patterns of atmospherical pollen dispersal in the Colorado Rocky Mountains, USA. Review of Palaeobotany and Palynology 74, 293313.
Franklin, J.F., and Dyrness, C.T. (1988). Natural Vegetation of Oregon and Washington. OSU Press, Oregon State University, Corvalis, OR.
Gedye, S.J., Jones, R.T., Tinner, W., Ammann, B., and Oldfield, F. (2000). The use of mineral magnetism in the reconstruction of fire history: a case study from Lago di Origlio, Swiss Alps. Palaeogeography, Palaeoclimatology, Palaeoecology 164, 101110.
Grigg, L.D., and Whitlock, C. (1998). Late-glacial vegetation and climate change in Western Oregon. Quaternary Research 49, 287298.
Grimm, E.C. (1988). Data analysis and display.Huntley, B., Webb III, T. Vegetation History Kluwer Academic, Dordrecht, Netherlands.4376.
Hebda, R.J., Chinnappa, C.C., and Smith, B.M. (1988a). )Pollen morphology of the Rosaceae of Western Canada: I. Agrimonia to Crataegus . Grana 27, 5113.
Hebda, R.J., Chinnappa, C.C., and Smith, B.M. (1988b). )Pollen morphology of the Rosaceae of Western Canada: II. Dryas, Fragaria, Holodiscus . Canadian Journal of Botany 66, 5113.
Hickman, J.C. (1993). The Jepson Manual: Higher Plants in California. University of California Press, Berkeley and Los Angeles, CA.
Jarvis, D.I., Leopold, E.B., and Liu, Y. (1992). Distinguishing the pollen of deciduous oaks, evergreen oaks and certain rosaceous species of southwestern Sichuan Province, China. Review of Palaeobotany and Palynology 75, 259271.
Kapp, R.O., Davis, O.K., and King, J.E. (2000). Pollen and Spores. The American Association of Stratigraphic Palynologists. Texas A&M University, College Station, TX.
Kienast, S.S., and McKay, J.L. (2001). Sea surface temperatures in the subarctic northeast Pacific reflect millennial-scale climate oscillations during the last 16 kyrs. Geophysical Research Letters 28, 15631566.
Kruckeberg, A.R. (2002). Geology and Plant Life: The Effects of Landforms and Rock Types on Plants. University of Washington Press, Seattle, WA.362
Long, C.J., Whitlock, C., Bartlein, P.J., and Millspaugh, S.H. (1998). A 9000-year fire history from the Oregon Coast Range, based on a high-resolution charcoal study. Canadian Journal of Forestry 28, 774787.
Mix, A.C., Lund, D.C., Pisias, N.G., Bodén, P., Bornmalm, L., Lyle, M., and Pike, J. (1999). Rapid climate oscillations in the Northeast Pacific during the last deglaciation reflect northern and southern hemisphere sources.Clark, P.U., Webb, R.S., Keigwin, L.D. Mechanisms of Global Climate Change Geophysical Monograph vol. 112, American Geophysical Union, Washington, DC.127146.
McGlone, M.S. (1996). When history matters: scale, time, climate and tree diversity. Global Ecology and Biogeography Letters 5, 309314.
Mock, C.J. (1996). Climatic controls and spatial variations of precipitation in the western United States. Journal of Climate 9, 11111125.
Mohr, J.A., Whitlock, C., and Skinner, C.N. (2000). Postglacial vegetation and fire history, Eastern Klamath Mountains, California. The Holocene 10, 587601.
Moore, P.O., and Webb, J.A. (1978). An Illustrated Guide to Pollen Analysis. John Wiley and Sons, New York.
Ricketts, T., Dinerstein, E., Olson, D.M., Loucks, C.J., Eichbaum, W.M., DellaSala, D.A., Kavanagh, K.C., Hedao, P., Hurley, P.T., Carney, K.M., Abell, R.A., and Walters, S. (1999). A conservation Assessment of the Terrestrial Ecoregions of North America, Volume I: The United States and Canada. Island Press, Washington, DC.
Ritchie, J.C., and Lichti-Federovich, S. (1967). Pollen dispersal phenomena in Arctic-subarctic, Canada. Review of Paleobotany and Palynology 3, 255266.
Sawyer, J.O., and Thornburgh, D.A. (1988). Montane and subalpine vegetation of the Klamath Mountains.Barbour, M.G., Major, J. Terrestrial Vegetation of California, Special Publication No. 9 California Native Plant Society, 699732.
Sea, D.S., and Whitlock, C. (1995). Postglacial vegetation history of the high Cascade Range, central Oregon. Quaternary Research 43, 370381.
Solomon, A.M., and Silkworth, A.B. (1986). Spatial patterns of atmospheric pollen transport in a montane region. Quaternary Research 25, 150162.
Stuiver, M., Reimer, P.J., Bard, E., Beck, J.W., Burr, G.S., Hughen, K.A., Kromer, B., McCormac, G., van der Plicht, J., and Spurk, M. (1998). INTCAL98 Radiocarbon age calibration 24,000-0 cal B.P.. Radiocarbon 40, 10411083.
Taylor, A.H. (1995). Forest expansion and climate change in the mountain hemlock (Tsuga mertensiana) zone, Lassen Volcanic National Park, California, USA. Arctic and Alpine Research 27, 207216.
Taylor, A., and Skinner, C.N. (1998). Fire history and landscape dynamics in a late-successional reserve, Klamath Mountains, California, USA. Forest Ecology and Management 111, 285301.
Taylor, G., and Hannan, C. (1999). The Climate of Oregon: from Rain Forest to Desert. Oregon State University Press, Corvallis, OR.
Thompson, R.S. (1988). Western North America. Vegetation dynamics in the western United States: modes of response to climatic fluctuations.Huntley, B., Webb III, T. Vegetation History Kluwer, The Hague, Netherlands.415458.
Thompson, R.S., Whitlock, C., Bartlein, P.J, Harrison, S.P., and Spaulding, W.G. (1993). Climatic changes in the Western United States since 18,000 yr B.P..Wright, H.E. Jr., Kutzbach, J.E., Webb III, T., Ruddiman, W.F., Street-Perrott, F.A., Bartlein, P.J. Global Climates since the Last Glacial Maximum University of Minnesota Press, Minneapolis.468513.
West, G.J. (1989). Late Pleistocene/Holocene vegetation and climate.Basgall, M.E., Hildebrandt, W.R. Prehistory of the Sacramento River Canyon, Shasta County, California Center for Archaeological Research, Davis, CA.3655.
Whitlock, C., and Millspaugh, S.H. (1996). Testing the assumptions of fire-history studies: an examination of modern charcoal accumulation in Yellowstone National Park, USA. The Holocene 6, 715.
Whitlock, C., and Larsen, C.P.S. (2001). Charcoal as a fire proxy.Smol, J.P., Birks, H.J.B., Last, W.M. Tracking Environmental Change Using Lake Sediments: Volume 3 Terrestrial, Algal, and Siliceous indicators Kluwer Academic Publishers, Dordrecht.7597.
Whitlock, C., Bartlein, P.J., Markgraf, V., and Ashworth, A.C. (2001). The mid-latitudes of North and South America during the Last Glacial Maximum and early Holocene: similar paleoclimatic sequences despite differing large-scale controls.Markgraf, V. Interhemispheric Climate Linkages; Present and Past Interhemispheric Climate Linkages in the Americas and their Societal Effects Academic Press, 391416.
Whittaker, R.H. (1960). Vegetation of the Siskiyou Mountains, Oregon and California. Ecological Monographs 30, 279338.
Worona, M.A., and Whitlock, C. (1995). Late-Quaternary vegetation and climate history near Little Lake, central Coast Range, Oregon. Geological Society of America Bulletin 107, 867876.
Wright, H.E. Jr., Mann, D.H., and Glaser, P.H. (1983). Piston cores for peat and lake sediments. Ecology 65, 657659.
Zdanowiez, C.M., and Zielinski, G.A. (1999). Mount Mazama eruption: calendrical age verified and atmospheric impact assessed. Geology 27, 621625.
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