The relationship between cell length and ring width and circumferential growth rate in five Canadian species

Variation in cell length and the relationship between cell length and ring width and circumferential growth rate were studied in jack pine (Pinus bank siana Lamb.), balsam fir (Abies balsamea Mill.), white spruce (Picea glauca Voss), black spruce (Picea mariana Britton, Stems & Pogg.) and trembling a spen (Populus tremuloides Michx.) collected in the natural forest in Ontari o, Canada. There was a negative relationship between cell length and ring w idth in jack pine, balsam fir and black spruce, and a positive relationship in trembling aspen. No relationship was found in white spruce. There was a negative relationship between tracheid length and circumferential growth r ate in all conifers. In trembling aspen fibre length decreased in both high er and lower circumferential growth rate. Circumferential growth rate is a good index of the effect of tree growth on cell length.