Geographical variation in wood properties of Larixlaricina juvenile wood in northern Ontario

Abstract

Growth rate, latewood ratio, specific gravity, and tracheid length of Larixlaricina (Du Roi) K. Koch juvenile wood were studied with two 12-mm increment cores extracted at breast height from 240 healthy trees from 12 locations at a range in latitude from 46 to 56° N in northern Ontario. Ten trees were selected from each stand and two stands were chosen from each location. Univariate analyses of variance indicated that growth rate and latewood of juvenile wood varied significantly in various locations, stands, and trees at the α = 0.01 level of significance. Growth rate of juvenile wood decreased from a lower latitude to a higher latitude, whereas latewood ratios displayed a reverse trend, i.e., a higher latewood ratio was found at a higher latitude. Specific gravity of juvenile wood varied significantly in individual trees. Tracheid length varied significantly among locations, stands, and trees. The overall average growth rate, tracheid length, and specific gravity are 1.29 mm per ring, 2.10 mm, and 0.43, respectively. An unexpected relationship was found between growth rate and tracheid length. Growth rate of juvenile wood has a positive relationship with tracheid length and an inverse relationship with specific gravity.