Late-glacial vegetation and environment on the eastern slope foothills of the Rocky Mountains, Alberta, Canada

Abstract

Stratigraphic pollen analysis done on sediment cores from two sites in the upper North Saskatchewan drainage basin of the eastern slopes foothills of the Rocky Mountains in west central Alberta, Canada combined with sedimentological data provide a local vegetational and environmental history. Radiocarbon AMS dates provide a chronology back to 17 960 BP. Reconstruction and interpretation of the local pollen zones includes reevaluation of steppe and grassland as analogs for full-and late-glacial vegetation. Regional vegetation from c. 17 960 to 16 100 BP is interpreted as an extremely cold semi-arid Artemisia steppe, the vegetation c. 16 100 to 11 900 BP as an Artemisia-Betula shrubland, and the vegetation c. 11900-10200 BP as a Picea woodland, in an environment characterized by consistently arid and windy conditions. This reconstruction emphasizes the significance of aridity, as opposed to simply low temperatures, as the critical factor in determining the late Quaternary vegetation of Alberta.

Reframing the mammoth steppe: Insights from analysis of isotopic niches

“…Alberta is not traditionally considered part of the ecosystem but has been reconstructed to have been cold and arid, with herb-steppe-tundra flora during the periods where it was not glaciated. Alberta also contained similar fauna, including the woolly mammoth, as traditionally defined mammoth steppe regions (Burns, 1991(Burns, , 2010Burns and Young, 1994;Heintzman et al, 2016;Jass et al, 2011;Kahlke, 2015;Mandryk, 1996). Further, the southernmost woolly mammoth remains in Europe occurred on the Iberian peninsula where mammoths lived during periods of dry, steppe conditions and in association with other mammoth steppe herbivores (Álvarez-Lao and García, 2011;García-Alix et al, 2012;Kahlke, 2015).…”

“…Pollen, plant macrofossil and ancient DNA studies suggest that the mammoth steppe was a highly productive herb-steppe-tundra environment, dominated by grasses, sedges, forbs and herbaceous species, with some shrubs such as willow also present. There is little evidence for trees during stadials; however the region contained forests during interstadial and interglacial times (Binney et al, 2017;Burns, 1991;; Guthrie, 1990Castaños et al, 2014;Huntley et al, 2013;Mandryk, 1996;Muhs et al, 6 2001; Schweger et al, 2011;Willerslev et al, 2014;Zimov et al, 2012). Plant species were unevenly distributed across the mammoth steppe due to local effects such as topography, drainage and latitude, and thus formed a "vegetational mosaic" .…”

Glacial kettles as archives of early human settlement along the Northern Rocky Mountain Front

“…As attractive as they may be, these models remain for the most part contested, as archaeological and paleoenvironmental evidence that may either support or falsify them is limited (but see Mandryk [1996], Beaudoin and Oetelaar [2003], Dyke [2005], and Heintzman et al [2016] for the latter). The general dearth of early archaeological sites in stratigraphic context in the Northern Front hinders discussions of local or regional material culture variability and ecological or social mechanisms of population movement.…”

Late Quaternary Vegetation History of Northern North America Based on Pollen, Macrofossil, and Faunal Remains*

“…Extinct or extirpated taxa are marked with an asterisk northern part (Szeicz et al, 1995), birch shrub tundra in its southern part (White et al, 1985;Mandryk, 1996), and grassland still farther south (Klassen, 1994). Meanwhile, shrub tundra had extended into newly deglaciated parts of New England and Atlantic Canada.…”

“…As before, the few sites representing herb tundra from Minnesota eastward were dominated by sedge. Sage dominated the newly formed herb tundra in Alberta, thus indicating drier conditions there (Mott and Jackson, 1982 [chronology adjusted]; Schweger, 1991, 1993;Beaudoin et al, 1996;Mandryk, 1996). The sage could have spread from either the grassland or the alpine tundra to the south, and indeed a distinction of herb tundra from periglacial FIGURE 3.…”