MODERN POLLEN SPECTRA FROM THE WESTERN INTERIOR OF CANADA AND THE INTERPRETATION OF LATE QUATERNARY VEGETATION DEVELOPMENT

Abstract

SUMMARYThe pollen spectra obtained from 127 lake sediment surface samples from the western interior of Canada are examined. Principal components biplots and discriminant analysis are used to investigate the correspondence between modern pollen rain and major vegetation zones in the study area. It is demonstrated that the major vegetation zones in the western interior of Canada can be distinguished on the basis of their modern pollen rain. Principal components biplots and discriminant analysis are also used to compare late Quaternary fossil pollen assemblages from lakes located near the southern and northern periphery of the modern boreal forest with the modern pollen spectra. The results suggest that the late Pleistocene and early Holocene pollen spectra from the southern and northern periphery of the boreal forest lack modern analogues in the western interior of Canada. The northern and southern boundaries of the boreal forest were located north of their modern positions during the mid Holocene. Vegetation developed and responded to mid Holocene climatic change at different rates at the two sites. Modern vegetation conditions were established at both sites between 5000 B.P. to 3000 B.P. Vegetation has remained relatively stable during the last three thousand years.