The Succession of Flora in Beringia
|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|
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.
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.
|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|