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Postglacial vegetation history of Mitkof Island, Alexander Archipelago, southeastern Alaska

Quaternary Research

By:
, , , ,
DOI: 10.1016/j.yqres.2009.12.005

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Abstract

An AMS radiocarbon-dated pollen record from a peat deposit on Mitkof Island, southeastern Alaska provides a vegetation history spanning ???12,900??cal yr BP to the present. Late Wisconsin glaciers covered the entire island; deglaciation occurred > 15,400??cal yr BP. The earliest known vegetation to develop on the island (???12,900??cal yr BP) was pine woodland (Pinus contorta) with alder (Alnus), sedges (Cyperaceae) and ferns (Polypodiaceae type). By ???12,240??cal yr BP, Sitka spruce (Picea sitchensis) began to colonize the island while pine woodland declined. By ???11,200??cal yr BP, mountain hemlock (Tsuga mertensiana) began to spread across the island. Sitka spruce-mountain hemlock forests dominated the lowland landscapes of the island until ???10,180??cal yr BP, when western hemlock (Tsuga heterophylla) began to colonize, and soon became the dominant tree species. Rising percentages of pine, sedge, and sphagnum after ???7100??cal yr BP may reflect an expansion of peat bog habitats as regional climate began to shift to cooler, wetter conditions. A decline in alders at that time suggests that coastal forests had spread into the island's uplands, replacing large areas of alder thickets. Cedars (Chamaecyparis nootkatensis, Thuja plicata) appeared on Mitkof Island during the late Holocene.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Postglacial vegetation history of Mitkof Island, Alexander Archipelago, southeastern Alaska
Series title:
Quaternary Research
DOI:
10.1016/j.yqres.2009.12.005
Volume
73
Issue:
2
Year Published:
2010
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Quaternary Research
First page:
259
Last page:
268
Number of Pages:
10