Late Quaternary biomes of Canada and the eastern United States

• Main Authors: John W. Williams, Thompson Webb Iii, Pierre H Richard, Paige Newby
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2000
• Subjects: Canada; Tundra; Siberia
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.557.7089; http://www.bridge.bris.ac.uk/projects/BIOME_6000/SpecialIssue2/BIOME2_downloads/williams.pdf

Biome reconstructions for Canada and eastern US 2 1 Pollen data have been used to construct biome maps for today, 6000 14C yr B.P., and 18,000 14C yr B.P. for Canada and the eastern United States 2 The inferred modern biome distributions agree well with independent reconstructions of North American vegetation prior to European settlement. Some discrepancies between the pollen data and the modern potential vegetation are caused by post-settlement clearing of the landscape and the consequent increase of herbaceous types in the recent pollen record. 3 Biome distributions at 6000 14C yr B.P. reflected the warmer and drier conditions then prevalent in the continental interior, but the overall position of biomes was similar to that today. Boreal treeline in North America was not significantly north of its present position, in contrast to the 100-300 km shift reported for Siberia. At the last glacial maximum (18,000 14C yr B.P.), steppe and tundra were prevalent in the Midwest and northwestern Canada, and coniferous forests and woodlands grew in eastern North America. The open vegetation at 18,000 14C yr B.P. was likely due to drier conditions and/or lower concentrations of atmospheric CO2.