exception of white birch, where we observed some individuals
with exceptionally high C values. These high C values in white
birch are likely related its high concentration of C-rich betulinic
acid (O’Connell et al., 1988). The observed difference in trends
between shade-tolerant and intolerant species supports our
hypothesis that size-associated changes in total C concentration
depend on shade tolerance. The potential reason for this sizeassociated
interaction with contrasting shade tolerance may be