Pre-Glacial Vegetation | Boreal At Memorial

Pre-Glacial Vegetation (18,000-15,000 ybp)

Biological evidence has suggested that South of the Wisconsin ice sheet, cold tundra like conditions existed. Pollen and fossil records of tundra plants revealed dryad, moss champion and crowberry species, to name a few. Observations of woolly mammoth tusks have also given insight into environmental conditions that these organisms endured to obtain food. The wear and tear patterns of the tusks suggest snow covered strips of low vegetation immediately South of the maximum Wisconsin glaciation. It is believed that this tundra vegetation may have resembled modern arctic tundra environments. Other theories suggest these strips may have consisted of grassy steppe like conditions

Additionally, Temperate and Boreal forests were mainly confined to the Southeastern United States. A large portion of these plants species were cold tolerant evergreens. In the Northwestern United States, scattered cold-tolerant woodlands were believed to be present in the central Rockies.

Crowberry.

Taken from Scandinavian Mountains ©

Laurentide Ice Sheet

White Dyras, an arctic-alpine flowering plant.

Taken from 123RF Limited.

Lake level records from the Western interior of North America during last maximum glaciation (21,000-18,000 ybp) indicate climates were wetter than present. It is believed conifer woodlands grew in wide expansion where presently, desert environments exist.

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