One major exception is the research group at the University of Western Ontario which has established long tree-ring chronologies for the Canadian Rockies, to reconstruct climatic and glacial history of the last millennium and evaluate tree growth - climate relationships at altitudinal treeline (e.g. The general absence of trees has obviously discouraged the pursuit of dendrochronology in the southern Interior Plains.
Although a belt of aspen parkland extends across the prairie provinces, much of the original aspen polar was removed for crop production and this tree species is much inferior to coniferous trees for tree ring research (Fritts, 1976).
In seasonal climates, trees preserve a continuous record of annual events, in particular, climate.
Dendrochronology, the study of the annual growth in trees, is the only method of paleoenvironmental research that produces proxy data of consistently annual resolution. Initially the cells are thin walled to conduct the abundant spring soil moisture.
Cores are glued to a grooved pieces of wood such that the tracheids were approximately 30 from their original vertical orientation, ensuring maximum visibility of the latewood to earlywood transition between successive years.
Shortly afterwards, Powell (1932) compared variation in wheat yields in Saskatchewan to ring-width variation in white spruce and some hardwood species.
Much of the tree ring research in western Canada has at the Laboratory of Tree Ring research in Tucson, Arizona, including the first studies of Douglas Fir in Alberta (Schulman, 1947), the first regional dendrochronological network for western North America (Drew, 1975), regional climatic reconstructions (Fritts, 1971; Fritts, et al., 1979; Fritts and Lough, 1985), and a dendrohydrological study of the Peace-Athabasca delta (Stockton and Fritts, 1973).