Title: A Late-Quaternary Pollen Record from Ka‘au Crater, O‘ahu, Hawai‘i
Abstract: A pollen record from Ka‘au Crater, O‘ahu, Hawai‘i contains evidence for changes in vegetation and climate since about 28,000 14 C yr B.P. Zone 1 (ca. 28,100–ca. 22,800 14 C yr B.P.) has pollen of dry to mesic forest species, including Pipturus -type, Dodonaea viscosa, Acacia koa, Chenopodium oahuense, Claoxylon sandwicense, Myrsine, and Metrosideros -type. In zone 2 (ca. 22,800–ca. 16,200 14 C yr B.P.) Myrsine and Coprosma increase, with herbs, fern allies, and Grammitidaceae suggesting open canopies. Zone 3 (ca. 16,200–ca. 9700 14 C yr B.P.) has pollen of wet forest species, including Freycinetia arborea, abundant Pritchardia, and Metrosideros -type. Zone 4 (ca. 9700–ca. 7000 14 C yr B.P.) is similar, with less Pritchardia and more Metrosideros -type. Climate reconstruction was based on modern climatic ranges of flowering plants and an index derived from abundance of pollen in surface samples. Both methods agree on a qualitative reconstruction, although the ages are poorly constrained: 28,000–25,000 14 C yr B.P. cool and dry; 25,000–23,000 14 C yr B.P. dry and warmer; 23,000–20,000 14 C yr B.P. moderately dry with declining temperature; 20,000–16,000 14 C yr B.P. moderately dry and cool; 16,000–9000 14 C yr B.P. warm and wet; 9000–7000 14 C yr B.P. warm and possibly drier. Lower precipitation at Ka‘au Crater during the late glacial period and last glacial maximum is consistent with the interpretation that the North Pacific subtropical anticyclone was south of its present position. The pollen-derived temperature index yields an estimate of 3°–5°C temperature depression during the last glacial maximum.
Publication Year: 1999
Publication Date: 1999-07-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 60
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