Fig. 1. Total and volatile C concentrations in relation to wood tissue type and DBH for jack pine, trembling aspen, white birch. Closed and open circles represent C
concentrations of bark and stemwood, respectively. Solid lines represent the significant relationship between DBH and total or volatile C concentration of bark (P < 0.05),
whereas short dashed lines represent the significant relationship between DBH and total or volatile C concentration of stemwood (P < 0.05). Dotted lines represent a marginal
relationship between DBH and total or volatile C concentration of bark (0.05 < P < 0.3), whereas dash-dot lines represent a marginal relationship between DBH and total or
volatile C concentration of stemwood (0.05 < P < 0.3).