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Reconstruction of climate and ecology of Skagit Valley, Washington, from 27.7 to 19.8 ka based on plant and beetle macrofossils

Published online by Cambridge University Press:  27 October 2021

Jon L. Riedel Open the ORCID record for Jon L. Riedel [Opens in a new window] ,
Alice Telka ,
Andy Bunn  and
John J. Clague
Jon L. Riedel*
Affiliation:
Retired, National Park Service, 7280 Ranger Station Road, Marblemount, WA98267, USA
Alice Telka
Affiliation:
Paleotec Services, 1-574 Somerset Street, Ottawa, ON K1R 5K2, Canada
Andy Bunn
Affiliation:
Huxley College of the Environment, Western Washington University, 516 High St, Bellingham, WA 98225, USA
John J. Clague
Affiliation:
Department of Earth Sciences, Simon Fraser University, 8888 University Dr, Burnaby, BC V5A 1S6, Canada
*
*Corresponding author: 1605 24th Place, Anacortes, Washington 98221, USA. E-mail address: [email protected]
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Abstract

Glacial lake sediments exposed at two sites in Skagit Valley, Washington, encase abundant macrofossils dating from 27.7 to 19.8 cal ka BP. At the last glacial maximum (LGM) most of the valley floor was part of a regionally extensive arid boreal (subalpine) forest that periodically included montane and temperate trees and open boreal species such as dwarf birch, northern spikemoss, and heath. We used the modern distribution and climate of 14 species in 12 macrofossil assemblages and a probability density function approach to reconstruct the LGM climate. Median annual precipitation (MAP) at glacial Lake Concrete (GLC) was ~50% lower than today. In comparison, MAP at glacial Lake Skymo (GLS) was only ~10% lower, which eliminated the steep climate gradient observed today. Median January air temperature at GLC was up to 10.8°C lower than today at 23.5 cal ka BP and 8.7°C lower at GLS at 25.1 cal ka BP. Median July air temperature declines were smaller at GLC (3.4°C–5.0°C) and GLS (4.2°C–6.3°C). Warmer winters (+2°C to +4°C) and increases in MAP (+200 mm) occurred at 27.7, 25.9, 24.4, and 21.2–20.7 cal ka BP. These changes accord with other regional proxies and Dansgaard–Oeschger interstades in the North Atlantic.

Keywords

Last glaciationMacrofossilsPaleoecologyPaleoclimateSkagit ValleyWashingtonNorth Cascades
Type
Research Article
Information
Quaternary Research , Volume 106 , March 2022 , pp. 94 - 112
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Copyright © University of Washington. Published by Cambridge University Press, 2021

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Footnotes

†

Deceased.

References

REFERENCES

Aarnes, I., Kuhl, N., Birks, H., 2012. Quantitative climate reconstruction from late-glacial and early Holocene plant macrofossils in western Norway using the probability density approach. Review of Palaeobotany and Palynology 170, 27–39.CrossRefGoogle Scholar
Annan, J.D., Hargreaves, J.C., 2013. A new global reconstruction of temperature changes at the Last Glacial Maximum. Climates of the Past 9, 367–376.CrossRefGoogle Scholar
Armstrong, J.E., Crandell, D.R., Easterbrook, D.J., Noble, J.B., 1965. Late Pleistocene stratigraphy and chronology in southwestern British Columbia and northwestern Washington. Geological Society of America Bulletin 76, 321–330.CrossRefGoogle Scholar
Arno, S.F., Hammerly, R.P., 1984. Timberline: Mountain and Arctic Forest Frontiers. The Mountaineers, Seattle, WA.Google Scholar
Ashworth, A.C., Nelson, R.E., 2014. The paleoenvironment of the Olympia beds based on fossil beetles from Discovery Park, Seattle, Washington, U.S.A. Quaternary International 134(18), 243–254.CrossRefGoogle Scholar
Ashworth, A.C., Thackray, G.T., Gavin, D.G., 2021. Climate of the Last Glacial Maximum on the western Olympic Peninsula based on insect paleoecology, palynology and glacial geology. In: Waitt, R.B., Thackray, G.D., Gillespie, A.R. (Eds.), Untangling the Quaternary Period—A Legacy of Stephen C. Porter. Geological Society of America Special Paper 548. https://doi.org/10.1130/2020.2548(06).CrossRefGoogle Scholar
Barnosky, C.W., 1981. A record of Quaternary vegetation from Davis Lake, southern Puget Lowland, Washington. Quaternary Research 16, 221–239.CrossRefGoogle Scholar
Barnosky, C.W., 1984. Late Pleistocene and early Holocene environmental history of southwestern Washington state, U.S.A. Canadian Journal of Earth Sciences 31, 619–629.CrossRefGoogle Scholar
Barnosky, C.W., 1985. Late Quaternary vegetation near Battle Ground Lake, southern Puget Trough, Washington. Geological Society of America Bulletin 96, 263–271.2.0.CO;2>CrossRefGoogle Scholar
Barnosky, C.W., Anderson, P.M., Bartlein, P.J., 1987. The northwestern U.S. during deglaciation: vegetational history and paleoclimatic implications. In: Ruddiman, W.F., Wright, H.E. Jr. (Eds.), North America and Adjacent Oceans during the Last Deglaciation. Geology of North America K-3. Geological Society of America, Boulder, CO, pp. 289–321.Google Scholar
Bartlein, P.J., Anderson, K.H., Anderson, P.M., Edwards, M.E., Mock, C.J., Thompson, R.S., Webb, R.S., 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, 549–585.CrossRefGoogle Scholar
Bartlein, P.J., Harrison, S.P., Brewer, S., Connor, S., Davis, B.A.S., Gajewski, K., Guiot, J., et al. , 2011. Pollen-based continental climate reconstructions at 6 and 21 ka: a global synthesis. Climate Dynamics 37, 775–802.CrossRefGoogle Scholar
Behl, R.J., Kennet, J.P., 1996. Brief interstadial events in the Santa Barbara basin, NE Pacific, during the past 60 kyr. Nature 379, 243–245.CrossRefGoogle Scholar
Benson, L., Lund, S., Negrini, R., Linsley, B. and Zic, M., 2003. Response of North American Great Basin lakes to Dansgaard–Oeschger oscillations. Quaternary Science Reviews 22, 2239–2251.CrossRefGoogle Scholar
Berger, A.L., 1978. Long-term variations of caloric insolation resulting from the Earth's orbital elements. Quaternary Research 9, 139–167.CrossRefGoogle Scholar
Birks, H.H., Birks, H.J.B., 2014. To what extent did changes in July temperature influence Lateglacial vegetation patterns in NW Europe? Quaternary Science Reviews 106, 262–277.CrossRefGoogle Scholar
Birks, H.J.B., Birks, H.H., 1981. Quaternary Paleoecology. E. Arnold, London.Google Scholar
Bond, G., Broecker, W., Johnsen, S., McManus, J., Lagey-Rie, L., Jouzel, J., Bonani, G., 1993. Correlations between climate records from North Atlantic sediments and Greenland ice. Nature 365, 143–147.CrossRefGoogle Scholar
Braconnot, P., Harrison, S.P., Kageyama, M., Bartlein, P.J., Masson-Delmotte, V., Abe-Ouchi, A., Otto-Bliesner, B., Zhao, Y., 2012. Evaluation of climate models using palaeoclimatic data. Nature Climate Change 2, 417–424.CrossRefGoogle Scholar
Bronk Ramsay, C., 2009. Bayesian analysis of radiocarbon dates. OxCal Project version 4.3. Calibration curve “IntCal 13.” Radiocarbon 51, 337–360.Google Scholar
Campbell, J.M., 1983. A revision of the North American Omaliinae (Coleoptera: Staphylinide, the genera Olophrom Erichson). Canadian Entomologist 115, 577–622.CrossRefGoogle Scholar
Campbell, J.M., 1984. A revision of the North American Omaliinae (Coleoptera: Staphylinide, the genera Arpedium Erichson and Eunecosum Ritter). Canadian Entomologist 116, 487–515.CrossRefGoogle Scholar
Clark, P.U., Bartlein, P.J., 1995. Correlation of Late Pleistocene glaciation in the western United States with North Atlantic Heinrich events. Geology 23, 483–486.2.3.CO;2>CrossRefGoogle Scholar
Clark, P.U., Dyke, A.S., Shakun, J.D., Carlson, A.E., Clark, J., Wohlfarth, B., Mitrovica, J.X., Hostetler, S.W., McCabe, A.M., 2009. The Last Glacial Maximum. Science 235, 710–714.CrossRefGoogle Scholar
Cong, S., Ashworth, A.C., 1996. Paleoenvironmental interpretation of middle and late Wisconsinan fossil coleopteran assemblages from western Olympic Peninsula. Journal of Quaternary Science 11, 345–356.3.0.CO;2-A>CrossRefGoogle Scholar
Dansgaard, W., Jonhsen, S.J., Clauson, H.B., Dahl-Jensen, D., Gundestrup, N.S., Hammer, C.U., Hvidberg, C.S., Steffensen, J.P., Sveinbjornsdottir, A.E., Jouzel, J., 1993. Evidence for general instability of past climate from a 250-kyr ice-core record. Nature 364, 218–220.CrossRefGoogle Scholar
Deplazes, G., Lückge, A., Peterson, L.C., Timmermann, A., Hamann, Y., Hughen, K.A., Röhl, U., et al. , 2013. Links between tropical rainfall and North Atlantic climate during the last glacial period. Nature Geoscience 6, 213–217.CrossRefGoogle Scholar
Elias, A., 2002. Mutual climate range reconstruction of seasonal temperatures based on late Pleistocene fossil beetle assemblages in eastern Beringia. Quaternary Science Reviews 20, 77–91.CrossRefGoogle Scholar
Enquist, B.J, Condit, R., Peet, R.K., Schildhauer, M., Thiers, B.M., 2016. Cyberinfrastructure for an integrated botanical information network to investigate the ecological impacts of global climate change on plant biodiversity. PeerJ Preprints 4, e2615v2.Google Scholar
Farrar, J.L., 1995. Trees in Canada. Fitzhenry and Whiteside and Canadian Forest Service, Ottawa, ON.Google Scholar
Fick, S.E., Hijmans, R.J., 2017. Worldclim 2: new 1-km spatial resolution climate surfaces for global land areas. International Journal of Climatology 37, 4301–4315.CrossRefGoogle Scholar
Flint, R.F., 1971. Glacial and Quaternary Geology. Wiley, New York.Google Scholar
Franklin, J.F., Dyrness, C.T., 1988. Natural Vegetation of Oregon and Washington. Oregon State University Press, Corvallis, OR.Google Scholar
Gavin, D.G., Fitzpatrick, M.C., Gugger, P.F., Heath, K.D., Rodríguez-Sánchez, F., Dobrowski, S.Z., et al. , 2014. Climate refugia: joint inference from fossil records, species distribution models and phylogeography. New Phytologist 204, 37–54.CrossRefGoogle ScholarPubMed
Grigg, L.D., Whitlock, C., 1998. Late-glacial vegetation and climate change in western Oregon. Quaternary Research 49, 287–298.CrossRefGoogle Scholar
Grigg, L.D., Whitlock, C., 2002. Patterns and causes of millennial-scale climate change in the Pacific Northwest during Marine Isotope Stages 2 and 3. Quaternary Science Reviews 21, 2067–2083.CrossRefGoogle Scholar
Grigg, L.D., Whitlock, C., Dean, W.E., 2001. Evidence for millennial-scale climate change during marine isotope stages 2 and 3 at Little Lake, western Oregon, U.S.A. Quaternary Research 56, 10–22.CrossRefGoogle Scholar
Hansen, B.S., Easterbrook, D.J., 1974. Stratigraphy and palynology of late Quaternary sediments in the Puget Lowland, Washington. Geological Society of America Bulletin 85, 587–602.2.0.CO;2>CrossRefGoogle Scholar
Harrison, S.P., Sanchez Goni, M.F., 2010. Global patterns of vegetation response to millennial-scale variability and rapid climate change during the last glacial period. Quaternary Science Reviews 29, 2957–2980.CrossRefGoogle Scholar
Hebda, R.J., Lian, O.B., Hicock, S.R. 2016. Olympia Interstadial: vegetation, landscape history, and paleoclimatic implications of a mid-Wisconsinan (MIS-3) nonglacial sequence from southwest B.C. Canadian Journal of Earth Sciences 53, 304–320.CrossRefGoogle Scholar
Heinrich, H., 1988. Origin and consequences of cyclic ice-rafting in the northeast Atlantic Ocean during the past 130,000 years. Quaternary Research 45, 289–299.Google Scholar
Hendy, I.L., Kennet, J.P., 2000. Dansgaard-Oeschger cycles and the California current system: planktonic foraminiferal response to rapid climate change in Santa Barbara Basin, Ocean Drilling Program Hole 893A. Paleoceanography 15, 30–42.CrossRefGoogle Scholar
Herring, E.M., Gavin, D.G., Dobrowski, S.G., Fernandez, M., Hu, F.S., 2017. Ecological history of a long-lived conifer in a disjunct population. Journal of Ecology 106, 313–332.Google Scholar
Heusser, C.J., 1972. Palynology and phytogeographical significance of a late Pleistocene refugium near Kalaloch, Washington. Quaternary Research 2, 189–201.CrossRefGoogle Scholar
Heusser, C.J., 1974. Quaternary vegetation, climate, and glaciation of the Hoh River Valley, Washington. Geological Society of America Bulletin 85, 1547–1560.2.0.CO;2>CrossRefGoogle Scholar
Heusser, C.J., 1977. Quaternary palynology of the Pacific slope of Washington. Quaternary Research 8, 282–306.CrossRefGoogle Scholar
Heusser, C.J., 1978. Palynology of Quaternary deposits of the lower Bogachiel River area, Olympic Peninsula, Washington. Canadian Journal of Earth Sciences 15, 1568–1578.CrossRefGoogle Scholar
Heusser, C.J., 1983. Vegetational history of the northwestern United States including Alaska. In: Porter, S.C. (Ed.), Late-Quaternary Environments. Vol. 1, The Late Pleistocene. University of Minnesota Press, Minneapolis, MN, pp. 239–258.Google Scholar
Heusser, C.J., Heusser, L.E., 1980. Sequence of pumiceous tephra layers and the late Quaternary environmental record near Mount St. Helens. Science 210, 1007–1009.CrossRefGoogle ScholarPubMed
Heusser, C.J., Igarashi, Y., 1994. Quaternary migration pattern of Selaginella selaginoides in the North Pacific. Arctic and Alpine Research 26, 187–192.CrossRefGoogle Scholar
Heusser, C.J., Peteet, D.M., 1988. Spores of Lycopodium and Selaginella of North Pacific America. Canadian Journal of Botany 66, 508–525.CrossRefGoogle Scholar
Hicock, S.R., Armstrong, J.E., 1981. Coquitlam Drift: a pre-Vashon Fraser glacial formation in the Fraser Lowland, British Columbia. Canadian Journal of Earth Sciences 18, 1443–1451.CrossRefGoogle Scholar
Hicock, S.R., Hebda, R.J., Armstrong, J.E., 1982. Lag of the Fraser glacial maximum in the Pacific Northwest: pollen and macrofossil evidence from western Fraser Lowland, B.C. Canadian Journal of Earth Sciences 19, 2288–2296.CrossRefGoogle Scholar
Hicock, S.R., Lian, O.B., 1995. The Sisters Creek Formation: Pleistocene sediments representing a nonglacial interval in southwestern British Columbia at about 18 ka. Canadian Journal of Earth Sciences 32, 758–767.CrossRefGoogle Scholar
Hicock, S.R., Lian, O.B., Mathewes, R.W., 1999. “Bond cycles” recorded in terrestrial Pleistocene sediments of southwestern British Columbia, Canada. Journal of Quaternary Science 14, 443–449.3.0.CO;2-6>CrossRefGoogle Scholar
Hostetler, S.W., Clark, P.U., 1997. Climate controls of western U.S. glaciers at the last glacial maximum. Quaternary Science Reviews 16, 505–511.Google Scholar
INTIMATE Project Members, 2014. A stratigraphic framework for abrupt climatic changes during the Last Glacial period based on three synchronized Greenland ice-core records: refining and extending the INTIMATE event stratigraphy. Quaternary Science Reviews 106, 14–28.CrossRefGoogle Scholar
Jiménez-Moreno, G., Anderson, S.R., Desprat, S., Grigg, L., Grimm, E.C., Heusser, L., Jacobs, B.F., Lopez-Martinez, C., Whitlock, C.L., Willard, D.A., 2010. Millennial-scale variability during the last glacial in vegetation records from North America. Quaternary Science Reviews 29, 2865–2881.CrossRefGoogle Scholar
Krajina, V.J., 1970. Ecology of Forest Trees in British Columbia. Ecology of Western North America 2. University of British Columbia, Department of Botany, Vancouver, BC, Canada.Google Scholar
Krajina, V.J., Klinka, K., Worrall, J., 1982. Distribution and Ecological Characteristics of Trees and Shrubs in British Columbia. University of British Columbia, Faculty of Forestry, Vancouver, BC, Canada.Google Scholar
Kühl, N., Gebhart, C., Litt, T., Hense, A., 2002. Probability density functions as botanical-climatological transfer functions for climate reconstructions. Quaternary Research 58, 381–392.CrossRefGoogle Scholar
LaBonte, J., 1998. Terrestrial Riparian Arthropod Investigations in the Big Beaver Creek Research Natural Area, North Cascades National Park Service Complex, 1995–1996. Part 2, Coleoptera. Technical Report NPS/NRNOCA/NRTR/98-02. U.S. Department of the Interior, National Park Service, Denver, CO.Google Scholar
Leduc, G., Vidal, L., Tachikawa, K., Bard, E., 2009. ITCZ rather than ENSO signature for abrupt climate changes across the tropical Pacific? Quaternary Research 72, 123–131.CrossRefGoogle Scholar
Lian, O.B., Mathewes, R.W., Hicock, S.R., 2001. Paleo-environmental reconstruction of the Port Moody interstade, a nonglacial interval in southwestern British Columbia at about 18,000 14C yr B.P. Canadian Journal of Earth Sciences 38, 943–952.Google Scholar
MARGO Project Members, 2009. Constraints on the magnitude and patterns of ocean cooling at the last glacial maximum. Nature Geoscience 2, 127–132.CrossRefGoogle Scholar
Marshall, J.A., Roering, J.J., Gavin, D.G., Grangers, D.E. 2017. Late Quaternary climatic controls on erosion rates and geomorphic processes in western Oregon, USA. Geological Society of America Bulletin 125, 715–731.CrossRefGoogle Scholar
Marshall, S.J., Pollard, D., Hostettler, S., Clark, P.U., 2004. Coupling ice-sheet and climate models for simulation of former ice sheets. In: Gillespie, A.R., Porter, S.C., Atwater, B.F. (Eds.), The Quaternary Period in the United States. Elsevier Developments in Quaternary Science 1. Amsterdam: Elsevier, pp. 117–143.Google Scholar
Mathewes, R.W., 1991. Climatic conditions in the western and northern Cordillera during the Last Glaciation: paleoecological evidence. Géographie physique et Quaternaire 45, 333–339.CrossRefGoogle Scholar
Mathewes, R.W., 1993. Evidence for Younger Dryas-age cooling on the North Pacific coast of America. Quaternary Science Reviews 12, 321–331.CrossRefGoogle Scholar
Miller, R.F., Morgan, A.V., Hicock, S.R., 1985. Pre-Vashon fossil Coleoptera of Fraser age from the Fraser Lowland, British Columbia. Canadian Journal of Earth Sciences 22, 498–505.CrossRefGoogle Scholar
Minore, D., 1979. Comparative Autecological Characteristics of Northwestern Tree Species—A Literature Review. General Technical Report PNW-87. U.S. Forest Service, Pacific Northwest Forest and Range Experiment Station, Portland, OR.Google Scholar
National Weather Service, 2019. Co-operator Network Weather Station at Concrete Fish Station. https://www.ncdc.noaa.gov/cdo-web/datasets/GSOM/stations/GHCND:USC00451679/detail.Google Scholar
Natural Resource Conservation Service, 2019. Weather Data for Hozomeen Camp. National Water and Climate Center. https://wcc.sc.egov.usda.gov/nwcc/site?sitenum=991.Google Scholar
Okumura, Y.M., Deser, C., Hu, A., Timmermann, A., Xie, S.P., 2009. North Pacific climate response to freshwater forcing in the subarctic North Atlantic: oceanic and atmospheric pathways. Journal of Climate 22, 1424–1445.CrossRefGoogle Scholar
Oster, J.L., Ibarra, D.E., Winnick, M.J., Maher, K., 2015. Steering of westerly storms over western North America during the Last Glacial Maximum. Nature Geoscience Letters 8, 201–205.CrossRefGoogle Scholar
Peterson, E.B., Peterson, N.M., Weetman, G.F., Martin, P.J., 1997. Ecology and Management of Sitka Spruce, Emphasizing Its Natural Range in British Columbia. University of British Columbia Press, Vancouver, BC, Canada.Google Scholar
Pisias, N.G., Mix, A.C., Heusser, L., 2001. Millennial scale climate variability of the northeast Pacific Ocean and northwest North America based on radiolarian and pollen. Quaternary Science Reviews 20, 1561–1576.CrossRefGoogle Scholar
Porter, S.C., 1964, Composite Pleistocene snow line of Olympic Mountains and Cascade Range, Washington. Geological Society of America Bulletin 75, 477–482.CrossRefGoogle Scholar
Porter, S.C., Swanson, T.W., 1998. Radiocarbon age constraints on rates of advance and retreat of the Puget lobe of the Cordilleran ice sheet during the last glaciation. Quaternary Research 50, 205–213.CrossRefGoogle Scholar
Porter, S.C., Swanson, T.W., 2008. 36Cl dating of the classic Pleistocene glacial record in the northeastern Cascade Range, Washington. American Journal of Science 308, 130–166.CrossRefGoogle Scholar
R Core Team, 2019. R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org.Google Scholar
Riedel, J.L., 2007. Late Pleistocene Glacial and Environmental History of Skagit Valley, Washington and British Columbia. PhD thesis, Simon Fraser University, Burnaby, BC, Canada.CrossRefGoogle Scholar
Riedel, J.L., 2017. Deglaciation of the North Cascade Range from the Last Glacial Maximum to the Holocene. Cuadernos de Investigación Geográfica 4, 467–496.CrossRefGoogle Scholar
Riedel, J.L., Clague, J.J., Ward, B.C., 2010. Timing and extent of early marine isotope stage 2 alpine glaciation in Skagit valley, Washington. Quaternary Research 73, 313–323.CrossRefGoogle Scholar
Riedel, J.L, Haugerud, R.A., Clague, J.J., 2007. Geomorphology of a Cordilleran ice sheet drainage network through breached divides in the North Cascades Mountains of Washington and British Columbia. Geomorphology 91, 1–18.CrossRefGoogle Scholar
Riedel, J.L., Larrabee, M.A., 2016. Impact of recent glacial recession on summer streamflow in the Skagit River, Washington. Northwest Science 90, 5–22.CrossRefGoogle Scholar
Scoggan, H.J., 1978. The Flora of Canada. Part 3. Canada National Museum of Natural Sciences Publication in Botany 7. Canada National Museum of Natural Sciences, Ottawa, ON, Canada.Google Scholar
Sudworth, G.B., 1967. Forest Trees of the Pacific Slope. Dover Publications, Toronto, ON, Canada.Google Scholar
Svensson, A., Andersen, K.K., Bigler, M., Clausen, H.B., Dahl-Jensen, D., Davies, S.M., Johnsen, S.J., Muscheler, R., et al. , 2008. A 60 000 year Greenland stratigraphic ice core chronology. Climate of the Past 4, 47–57.CrossRefGoogle Scholar
Taylor, M.A., Hendy, I.L., Pak, D.K., 2015. The California Current System as a transmitter of millennial scale climate change on the northeastern Pacific margin from 10 to 50 ka. Paleoceanography 30, 1168–1182.CrossRefGoogle Scholar
Telka, A., Ward, B.C., Mathewes, R.W., 2003. Plant and insect macrofossil evidence of Port Moody interstade in eastern Fraser Lowland, Chehalis watershed, southwestern British Columbia. CANQUA-CGRG Conference Program and Abstracts, p. 139.Google Scholar
Thackray, G.D., 2001. Extensive early and middle Wisconsin glaciation on the western Olympic Peninsula, Washington, and the variability of Pacific moisture delivery to the northwestern United States. Quaternary Research 5, 257–270.CrossRefGoogle Scholar
Thackray, G.D., 2008. Varied climatic and topographic influences on Late Pleistocene mountain glaciation in the western United States. Journal of Quaternary Science 23, 671–681.CrossRefGoogle Scholar
Thompson, R.S., Anderson, K.H., Pelltier, R.T., Strickland, L.E., Shafer, S.L., Bartlein, P.J., McFadden, A.K., 2015. Atlas of Relations between Climatic Parameters and Distributions of Important Trees and Shrubs in North America Revisions for All Taxa from the United States and Canada and New Taxa from the Western United States. U.S. Geological Survey Professional Paper 1650-G. U.S. Geological Survey, Denver, CO.CrossRefGoogle Scholar
Thompson, R.S., Whitlock, C., Bartlein, P.J., Harrison, S.P., Spaulding, W.G., 1993. Climatic changes in the western United States since 18,000 yr BP. In: Wright, H.E. Jr., Kutzbach, J.E., Webb, T. III, Ruddiman, W.F., Street-Parrot, F.A., Bartlein, P.J. (Eds.), Global Climates since the Last Glacial Maximum. University of Minnesota Press, Minneapolis, MN, pp. 486–513.Google Scholar
Troost, K.G., 2016. Chronology, Lithology, and Paleo-environmental Interpretations of the Penultimate Ice-sheet Advance into Puget Lowland. PhD thesis, University of Washington, Seattle, WA.Google Scholar
Tyron, A.F., 1949. Spores of the genus Selaginella in North America north of Mexico. Annals of the Missouri Botanical Garden 36, 413–431.CrossRefGoogle Scholar
Waitt, R.B. and Thorson, R.M., 1983. The Cordilleran ice sheet in Washington, Idaho, and Montana. In: Porter, S.C. (Ed.), Late-Quaternary Environments of the United States. Vol. 1, The Late Pleistocene. University of Minnesota Press, Minneapolis, MN, pp. 54–70.Google Scholar
Wang, T., Hamann, A., Spittlehouse, D.L., Murdock, T.Q., 2012. ClimateWNA—high-resolution spatial climate data for western North America. Journal of Applied Meteorology and Climatology 51, 16–29.CrossRefGoogle Scholar
Wardle, P., 1974. Alpine treelines. In: Ives, J.D., Barry, R.G. (Eds.), Arctic and Alpine Environments. Methuen, London, pp. 371–402.Google Scholar
Whitlock, C., 1992. Vegetational climatic history of the Pacific Northwest during the last 20,000 years: implications for understanding present-day diversity. Northwest Environmental Journal 8, 5–28.Google Scholar
Williams, J.W., Grimm, E.C., Blois, J.L., Charles, D.F., Davis, E.B., Goring, S.J., Graham, R.W., et al. 2018. The Neotoma Paleoecology Database, a multiproxy, international, community-curated data resource. Quaternary Research 89, 156–177.CrossRefGoogle Scholar
Wyshnytzky, C.E., Rittenour, T.M., Thackray, G.D., Shulmeister, J., 2019. Stratigraphic and geomorphologic evidence of three MIS 2 glacial advances in the South Fork Hoh River valley, Olympic Mountains, Washington, USA. Quaternary Research 92, 708–724.CrossRefGoogle Scholar
Zhang, R., Delworth, T.L., 2005. Simulated tropical response to a substantial weakening of the Atlantic thermohaline circulation. Journal of Climate 18, 1853–1860.CrossRefGoogle Scholar
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