Understanding variation in carbon (C) concentration of live trees is essential for quantifying forest C stocks and validating forest C accounting models. Previous studies in boreal forests have assumed 50% C concentration or focused on species-specific C concentration estimation based on samples mostly taken from stem wood tissue of large trees. Yet, little is known about differences in C concentration between woody tissues, as well as the effects of tree size and life-history traits, such as shade tolerance, and the role of volatile C on total C concentration in live trees. In this study we examined variation in total and volatile C concentration in bark and stem wood tissues for trees of different size for six major North American boreal tree species
Results/Conclusions
We found that bark had significantly higher total C and volatile C concentrations than stem wood, and that both total C and volatile C concentration significantly varied among tree species. Further, total C and volatile C concentration in stem wood and bark of almost all shade-intolerant species increased with tree size, while those of shade-tolerant species showed negative or neutral size-associated change. Our results show that volatile C concentration is a key driver of variation in total C concentration and highlight the importance of considering variation in C concentration when quantifying forest C stocks, which has important consequences for predicting future global C emissions scenarios.