Ice Age steppe vegetation

Bakc in 2003 Nature journal published a short piece in volume 423 (5th June) 'Ice Age steppe vegetation in Alaska and Yukon' … . The authors say the region must have been covered with vegetation as it supported huge populations of mammoth, horse, bison etc, during the Late Glacial Maximum. Why was it colder in Europe and NE N America where an ice sheet existed but Siberia and Beringia, were unglaciated. The plot thickens. Researchers have now found macro fossils of praire sage, bush grasses, and fobs – quite unlike the modern Arctic tundra flora. The researchers also looked at the contents of a permafrost frozen horse carcase (embedded in alluvial peat) and woolly mammoth remains in a creek in central Yukon. In addition, they recovered macro fossils from a rodent nest in northern Yukon. Abundant sage leaves and flowers and seeds of bluegrass and wild rye grasses, sedges, and rushes, support the idea of a steppe vegetation rather than that of a tundra. Also, potentilla, goosefoot, mustard, poppies,  buttercups, chickweed and campion were found, indicating a diverse number of herbs and wild flowers. Such an ecology has no modern example in the Arctic. Indeed, in central Beringia the vegetation was even more diverse. See www.nature.com/articles/423603a