Paleoenvironmental Change on the Olympic Peninsula, Washington: Forests and Climate from the Last Glaciation to the Present
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Paleoenvironmental Change on the Olympic Peninsula, Washington: Forests and Climate from the Last Glaciation to the Present Daniel G. Gavin1, David M. Fisher1, Erin M. Herring1, Ariana White1, and Linda B. Brubaker2 1. Department of Geography, University of Oregon, Eugene, Oregon. 2. School of Environment and Forest Sciences, University of Washington, Seattle, Washington. FINAL REPORT TO OLYMPIC NATIONAL PARK Contract J8W07100028 March 13, 2013 Table of Contents Acknowledgements ......................................................................................................... vii 1. Introduction ....................................................................................................................1 1.1 Aims of this report ............................................................................................................... 2 2. The modern landscape of the Olympic Peninsula .......................................................5 2.1 Geography of the Olympic Peninsula and Olympic National Park ................................ 5 2.2 Regional climate on the Olympic Peninsula ...................................................................... 5 2.3 Indicators of recent climate change on the Olympic Peninsula ....................................... 7 2.4 Vegetation zones of the Olympic Peninsula and climate controls on forest vegetation . 9 2.4.1 Sitka Spruce Zone ......................................................................................................... 10 2.4.2 Western Hemlock Zone ................................................................................................ 12 2.4.3 Pacific Silver Fir Zone .................................................................................................. 14 2.4.4 Mountain Hemlock Zone .............................................................................................. 15 2.4.5 Subalpine Fir Zone ........................................................................................................ 16 2.4.6 Douglas-fir Zone ........................................................................................................... 16 2.4.7 Subalpine Parkland Zone .............................................................................................. 17 2.5 Natural disturbance regimes of the Olympic Peninsula ................................................. 17 2.5.1 Fire ................................................................................................................................ 17 2.5.2 Wind ............................................................................................................................. 21 2.5.3 Other disturbance agents ............................................................................................... 22 3. Geology and historical biogeography of the Olympic Peninsula .............................26 3.1 Late Cenozoic geologic and climatic history .................................................................... 26 3.2 Endemism, disjunction, and the insular nature of the Olympic biota .......................... 27 4. Postglacial climate on the Olympic Peninsula ...........................................................32 4.1 Forcing factors in the climate system ............................................................................... 32 4.2 The Late Pleistocene and the Last Glacial Maximum: >60–19 ka ............................... 33 4.3 The Late Glacial: 19 to 11.6 ka ......................................................................................... 35 4.4 The Early Holocene: 11.6 to 6 ka ...................................................................................... 36 4.5 The Middle-to-Late Holocene: 6 ka to present ................................................................ 38 5. Late Quaternary vegetation and fire history of the Olympic Peninsula .................39 5.1 Pioneering studies .............................................................................................................. 39 5.2 The Late Pleistocene .......................................................................................................... 40 5.3 The Late Glacial and Holocene ......................................................................................... 43 5.4 Postglacial vegetation and fire at five sites on the Olympic Peninsula. ........................ 44 5.4.1 Study sites ..................................................................................................................... 45 5.4.2 Field and laboratory methods ........................................................................................ 46 5.4.3 Sediment stratigraphy and chronology ......................................................................... 48 5.4.4 Late Glacial: 14–11.6 ka ............................................................................................... 50 5.4.5 Early Holocene: 11.6 – 6 ka .......................................................................................... 52 5.4.6 Middle and Late Holocene: 6–0 ka ............................................................................... 54 5.5 Regional synthesis of vegetation changes in the Pacific Northwest ............................... 65 5.5.1 Species dominant during the Late-Glacial: pine, spruce, mountain hemlock, and poplar ..................................................................................................................................... 66 5.5.2 Species dominant during the Early Holocene: Douglas-fir, oak, alder, and maple ...... 67 5.5.3 Species dominant during the Late Holocene: true firs, western hemlock, and western redcedar .................................................................................................................... 68 6. Brief review of the archeological record in a context of environmental change ....81 6.1 The Manis Mastodon Site .................................................................................................. 81 ii 6.2 Late Holocene cultural phases .......................................................................................... 82 7. Needed studies and actions ..........................................................................................85 Literature Cited ...............................................................................................................88 Appendix A: Treatment of pollen data for production of regional maps .................107 iii List of Figures Figure 1. Typical forests on a south-facing aspect in the western portion of Olympic National Park. ..................................................................................................................... 2 Figure 2. Elevation, vegetation and climate on the Olympic Peninsula ............................. 4 Figure 3. Wind rose diagrams for 850 mb winds at Quillayute State Airport .................... 6 Figure 4. Climate diagrams from five locations straddling the climatic gradient on the Olympic Peninsula. ............................................................................................................. 7 Figure 5. January and July precipitation and minimum and maximum temperatures at Forks and Port Townsend WA ............................................................................................ 8 Figure 6. Snow-water equivalent on April 1 at Hurricane Ridge snow course from 1949 to 2011, the length of Blue Glacier from 1815 to 2003, and monthly discharge from the Quinault River at Lake Quinault. ........................................................................................ 9 Figure 7. An elevation profile across the Olympic Peninsula showing the pattern of potential natural vegetation zones, percent cover of tree species in 639 ecological plots 11 Figure 8. Distribution of three bioclimatic variables within eight potential natural vegetation zones on the Olympic Peninsula ..................................................................... 13 Figure 9. Relative rankings of shade tolerance and drought tolerance of trees and selected shrubs on the Olympic Peninsula. ....................................................................... 14 Figure 10. Mapped fire events on the Olympic Peninsula compiled from historical records and Douglas-fir stand ages ................................................................................... 18 Figure 11. Left: Area burned in decadal time steps from 1850 to present ....................... 19 Figure 12. Aerial photograph of the 1961 Queets Fire scar photographed three years after the fire. .............................................................................................................................. 20 Figure 13. Number of fires and area burned by fire in the Olympic National Park from 1916 to 1975 ..................................................................................................................... 20 Figure 14. Peak gusts at Hoquiam WA of 24 storms between 1945 and 2010 ................ 22 Figure 15. Mapped landslides over the upper Quinault River and the Grouse Creek Landslide of 1997 ............................................................................................................. 24 Figure 16. Late successional old growth forest and non-forested areas ........................... 25 Figure 17. Global climate trajectory during the Cenozoic, and paleogeography of western North America. ................................................................................................................