This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Gavin, D. G. Articles by Young, K. A. Search for Related Content Social Bookmarking                         What's this?

Postglacial history of subalpine forests, Olympic Peninsula, Washington, USA

College of Forest Resources, University of Washington, Box 352100, Seattle, WA 98195, USA

Jason S. Mclachlan

Department of Botany, Duke University, Durham, NC 27708, USA

Linda B. Brubaker

College of Forest Resources, University of Washington, Box 352100, Seattle, WA 98195, USA

Kyle A. Young

Centre for Applied Conservation Biology, Department of Forest Sciences, 3041-2424 Main Mall, University of British Columbia, Vancouver, BC V6T 1Z4, Canada

To investigate subalpine vegetation history on the Olympic Peninsula, Washington (USA), two pollen, macrofossil and charcoal records were studied in climatically distinct zones: Martins Lake (1415 m) in the moist Tsuga mertensiana zone and Moose Lake (1508 m) in the drier Abies lasiocarpa zone. The interpretation of fossil pollen assemblages was aided by comparisons with 308 modern assemblages from the Olympic Peninsula and western North America. Both pollen records show a cold/dry period following deglaciation (.10000 radiocarbon years BP) with sparse tundra and little similarity to any modern pollen assemblage. In the early Holocene, when summer temperatures are thought to have been higher than present, high percentages of Alnus sinuata-type pollen at both lakes suggest increased avalanche activity. At Martins Lake warmer summers were not accompanied by forest establishment, possibly because persistent spring snow pack, snow avalanches, and/or edaphic constraints limited tree establishment at this site. The Martins Lake record shows a steplike shift in vegetation to modern Tsuga mertensiana Abies amabilis parkland across the Mazama tephra (6730 BP). In contrast to Martins Lake, Abies lasiocarpa forest quickly established at Moose Lake in the early Holocene, though forests were probably initially open and fires may have been frequent. From 7800 to 5100 BP forests near Moose Lake shifted gradually to cooler and moister species composition, with the addition of Chamaecyparis nootkatensis, Tsuga mertensiana and Pinus, though Abies lasiocarpa remained dominant. Forest cover was probably greatest during this transition, with parklike conditions at Moose Lake beginning at c. 5100 BP. The major differences in the records between the two sites may be due to differences in the local expression of regional climatic change and/or differences in soil development and stabilization.

Key Words: Climatic change • pollen analysis • rain shadow • tree-line • tree establishment • vegetation history • subalpine forest • Holocene

The Holocene, Vol. 11, No. 2, 177-188 (2001)
DOI: 10.1191/095968301670879949


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				K.J. Brown, A.B. Nielsen, R.J. Fitton, and R.J. Hebda Postglacial evolution and spatial differentiation of seasonal temperate rainforest in western Canada The Holocene, August 1, 2008; 18(5): 715 - 727. [Abstract] [PDF]

				D. G. Gavin, L. B. Brubaker, J. S. McLachlan, and W. W. Oswald Correspondence of pollen assemblages with forest zones across steep environmental gradients, Olympic Peninsula, Washington, USA The Holocene, July 1, 2005; 15(5): 648 - 662. [Abstract] [PDF]

				K. W. Wegmann and F. J. Pazzaglia Holocene strath terraces, climate change, and active tectonics: The Clearwater River basin, Olympic Peninsula, Washington State Geological Society of America Bulletin, June 1, 2002; 114(6): 731 - 744. [Abstract] [Full Text] [PDF]