Full-glacial vegetation in Beringia left a relatively uniform pollen signal across the whole region, with nearly all sites being dominated by pollen of grass, sedge, and Artemisia. This pollen signature has proved hard to interpret. For example, few close modern analogues exist (Anderson et al., 1989). The vegetation was too productive to have been polar desert, and suites of indicator taxa imply that is was tundra, rather than steppe, even though the three dominant taxa are all characteristic of steppe, as well as tundra, vegetation (Cwynar, 1982; Wolfe and Birks, in press).
      About 12,000 14C years ago, birch-shrub (Betula) tundra replaced herb-dominated tundra across the region. In western Beringia, alder (Alnus) expanded along with birch (Lozhkin et al., 1983). By ca 10,000 14C years ago larch (Larix) was established in western Beringia and Poplar (Populus) formed a (probably discontinuous) woodland across eastern Beringia. At about 8500 14C yr B.P. stone-pine (Pinus pumila) became established in western Beringia, forming a pine-shrub tundra in Chukotka as well as expanding in the larch zone. At about the same time in Alaska, spruce (Picea) began to expand in an east-west direction across the interior and south of the state, with white spruce (Picea glauca) predominating at most sites between ca 9000 and 5000-6000 years ago. Black spruce (Picea mariana) was also present, and a major shift to black spruce dominance occurred between 6000 and 4000 years ago at many sites (e.g., Hu et al. 1993). Alder expanded eastwards across northern and interior Alaska between ca 9500 and 6500 years ago (Anderson and Brubaker 1994). Hemlock (Tsuga mertensiana) expanded during the late Holocene along the coast of southern and southeastern Alaska (Ager 1983).

Biomized Vegetation:

Modern

6000 yr. B.P.

18,000 yr. B.P.

Rules-Based Vegetation:

Modern

6000 yr. B.P.

18,000 yr. B.P.

Palynological Data:

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