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(Article of periodic en Anglais - 1981)

Document title

A record of late Quaternary vegetation from Davis Lake, southern Puget Lowland, Washington

Authors(s) and Affiliation(s)

BARNOSKY C. W. ;

Abstract

The late Pleistocene pollen sequence records two intervals of tundra parkland vegetation. The earlier of these has high percentages of Picea, Gramineae, and Artemisia pollen and represents the vegetation during the Evans Creek Stade (Fraser Glaciation) (ca.25,000 17,000yr B.P.). The later parkland interval is dominated by Picea, Tsuga mertensiana, and Gramineae. It corresponds to the maximum ice advance in the Puget Lowland during the Vashon Stade (Fraser Glaciation) (ca.14,000yr B.P.). An increase in Pinus contorta pollen between the two tundra parkland intervals suggests a temporary rise in treeline during an unnamed interstade. After 13,500yr B.P., a mixed woodland of subalpine and lowland conifers grew at Davis Lake during a period of rapid climatic amelioration. In the early Holocene, the prolonged expansion of Pseudotsuga and Alnus woodland suggests dry, temperate conditions similar to those of present rainshadow sites in the Puget Lowland. More-mesic forests of Tsuga heterophylla, Thuja plicata, and Pseudotsuga, similar to present lowland vegetation, appeared in the late Holocene (ca.5500yr B.P.).

Source

Article of periodic

published at : Quaternary research New York

Editor :

Millesime : 1981, vol. 16, no2 [pp. 221-239]

Bibliographic references : 44 réf.

Language

Anglais

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