Evolution of the Beringian Landscape Flora

The Succession of Flora in Beringia

Holocene Pine-Larch forests Shrub-tundra
Late Wisconsin Herb-dominated tundra followed by shrub tundra Herb-dominated tundra followed by the Birch Interval followed by a Popular maximum
Middle Wisconsin Shrub tundra followed by modern forests Popular maximum ends and is followed by a Spruce invasion

(Table is based on Thomas D. Hamilton's compilation of data: Selected Radiocarbon-dated Glacial and Climatic Records. See West, 1998.)

Evolution of Flora on the Bering Land Bridge

Both fossil pollen and insect assemblages from peat layers of cores taken from the central and northern parts of the submerged land bridge show a widespread mesic shrub tundra environment throughout time (Elias, 1998; Elias, 1997; Elias et al, 1996). The land bridge was continental and covered with grasses, and diverse aquatic species adapted to pond and coastal marsh environments.

The dominant species of plants are Betula (birch), Sphagnum (a type of moss), Poaceae (a type of grass), and Cyperaceae (sedge). Salix, and Ericaceae (heath) were a minority. All of these species were present for at least the past 40,000 years in varying amounts.

(Heath covering the ground. Photos by James Manhart)

Plant succession on the Bering Land Bridge is based on fossil pollen and beetles found in the peat layers of the Chukchi and Bering sea cores.
Time (kya)
14-9 Alaskan Birch Interval, heath and shrub willows are locally important
14-11 birch-heath-graminoid tundra and ponds chocked by aquatic plants, insects indicate a mesic tundra dominated by open ground habitats
20-14 birch-graminoid tundra covered with ponds chocked by aquatic plants dominated the landscape
40 birch-heath-graminoid tundra with a few shrubs but no steppe plants