LATE QUATERNARY VEGETATION AND CLIMATE HISTORY NEAR LITTLE LAKE, CENTRAL COAST RANGE, OREGON

Citation
Ma. Worona et C. Whitlock, LATE QUATERNARY VEGETATION AND CLIMATE HISTORY NEAR LITTLE LAKE, CENTRAL COAST RANGE, OREGON, Geological Society of America bulletin, 107(7), 1995, pp. 867-876
Citations number
61
Categorie Soggetti
Geology
ISSN journal
00167606
Volume
107
Issue
7
Year of publication
1995
Pages
867 - 876
Database
ISI
SICI code
0016-7606(1995)107:7<867:LQVACH>2.0.ZU;2-X
Abstract
Pollen and plant macrofossils recovered from Little Lake, Oregon, pro; ide the first record of late Quaternary climate and vegetation changes in Oregon's central Coast Range. The pollen data suggest that the per iod from ca. 42 000 to 24 770 yr B.P. featured an open forest of weste rn white pine, western hemlock, and fir. The inferred climate was cool er and wetter than today. The full-glacial period was characterized by a parkland of spruce, lodgepole pine, and mountain hemlock, which sug gests that the climate was colder and possibly drier than today. The O regon Coast Range was not a glacial refugium for temperate conifers as has been proposed. By 16 000 yr B.P. the pollen and plant macrofossil data suggest the development of a montane forest composed of pine, fi r, western hemlock, and mountain hemlock. Temperate taxa were present in the vegetation at 13 500 yr B.P. during a period of climatic amelio ration. A reversal in this warming trend may have occurred between 11 000 and 10 500 yr B.P., when pine, western and mountain hemlock, and s pruce were slightly more abundant. Early Holocene forests featured Dou glas fir, red alder, and bracken fern, implying more severe summer dro ught and more frequent fires. After 5600 yr B.P., Douglas fir, western hemlock, and western red cedar dominated the record, marking the intr oduction of the present-day cool, moist climate; however, during the p ast 2800 yr, increased Douglas fir and decreased cedar suggest the pos sibility of reduced effective moisture at Little Lake.