On the relation between the contemporary pollen spectra and vegetation of the forest-grassland transition in Manitoba
To provide a basis for the interpretation of late-Pleistocene fossil data, pollen spectra were tabulated from 72 sites in the forest-grassland transition of Manitoba. The area under study was divided into 8 landform-vegetation zones: I. Main Boreal Forest (with upland and lowland subgroups); II. Southern Boreal Forest, primarily on uplands; III. Deciduous Forest on uplands; IV. Deciduous Forest on lowlands and alluvium; V. Aspen Parkland on till plains and lacustrine deposits; VI. Grasslands on till plains; VII. Pine Forest on upland sand plains; VIII. Spruce Parkland on a sandy glacial delta. Distinct differences in the preponderance of main pollen types were recorded across the forest-grassland transition, and between the main regions I-VIII. The 52 atmospheric spectra demonstrated that Populus is represented proportionally, while it is absent or rare in the 19 sediment samples. The results were applied to a specific problem of interpretation of Holocene pollen spectra from Manitoba, confirming the tentative reconstructions suggested earlier.