Holocene pollen assemblages from the Tiger Hills, Manitoba
Coring of three kettle lakes in the moraine area known as the Tiger Hills, Manitoba, yielded sections of sediment which span the Holocene for this region. Detailed pollen analysis of two of the sections suggests five main pollen assemblage zones for the Holocene, numbered I to V from above. Zone V is interpreted as a spruce-dominated vegetation associated with such pioneering species as Shepherdia canadensis and Artemisia, a type found at present as local fragments and having no regional equivalent. Zone IV also has no analogue among recent pollen spectra, and is interpreted as a mosaic of mixed coniferous–broadleaved deciduous forest stands, and extensive scrub with Juniperus and grassland. Zone III is dominated by non-arboreal pollen types and suggests grassland, while Zone II has an oak component, which indicates a savanna type. Zone I is the modern assemblage, with prominent representation by weedy species. Radiocarbon age determinations suggest that the area was occupied by the Zone V assemblage from...