Chemical Elements Content and Distributions within Different Tissue Types of White Spruce

The relative proportions of different chemical components in wood tissues is one of the underlying factors that control wood properties. These proportions vary within and between woody tissues, and an accurate description of these variations is critical for parameterizing forest biogeochemical budgets and models. White spruce (Picea glauca (Moench) Voss) spacing intensities trials in the Petawawa Research Forest, Ontario, Canada, were sampled to evaluate variations in carbon (C), nitrogen (N), and hydrogen (H) concentrations between different tissue types, i.e., bark, cambium, knots, earlywood, latewood, and wood. Samples were freeze-dried and oven-dried to test the impact of the drying methods on these chemical elements. Freeze-dried C (51.14) and H (6.18) concentrations were significantly higher than those of oven-dried C (50.55) and H (6.06). Freeze-dried N (0.18) did not differ from oven-dried N (0.17). The spacing intensities impacted C, H, and N, with C content being higher in wider square spacings (4.3 m and 6.1 m), while the reverse was true for N and H, which exhibited higher content in smaller square spacings (1.2 m and 1.8 m). The results of this study also suggested that when it comes to the content of chemical elements, bark and knots should be treated as separate fuel types, whereas other woody tissues can be aggregated.