J Plant Ecol ›› 2020, Vol. 13 ›› Issue (2): 233-240.DOI: 10.1093/jpe/rtaa005

• Research Articles • Previous Articles     Next Articles

Size- and age-dependent increases in tree stem carbon concentration: implications for forest carbon stock estimations

Su-Hui Ma1, *, Anwar Eziz1, Di Tian2, Zheng-Bing Yan1, Qiong Cai1, Min-Wei Jiang1, Cheng-Jun Ji1 and Jing-Yun Fang1   

  1. 1 Institute of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China, 2 College of Life Sciences, Capital Normal University, Beijing 100048, China

    *Corresponding author. E-mail: mash2015@pku.edu.cn
  • Received:2019-10-02 Revised:2020-01-05 Accepted:2020-02-02 Online:2020-02-04 Published:2020-04-01



Forest biomass carbon (C) stocks are usually estimated by multiplying biomass by a C conversion factor, i.e. C concentration. Thus, tree C concentration is crucial to the assessments of forest C cycles. As stems contribute to the large fraction of tree biomass, the canonical value of 50% or other simplified values of stem C concentration are widely used to represent the values of tree C concentration in the estimations of forest C stocks at different scales. However, C concentration variations between tree organs and within tree size and their impacts on forest C stocks are still unclear.


We conducted a global analysis of organ C concentration in age-specific trees based on 576 records of tree age, size (diameter at breast height and biomass) and C concentration data to evaluate the relationships between organ C concentrations and the changes of stem C concentration with tree age and size.

Important Findings

Tree C concentration varied significantly with organs. Stem C concentration of trees was significantly correlated with that of other tree organs, except for barks and reproductive organs. The stem C concentration increased significantly with tree size and age, which contributed to the increases in C contents of stems and trees. Using the C concentration in stems to represent the C concentrations of other organs and the whole tree could produce considerable errors in the estimations of forest C stocks (−8.6% to 25.6% and −2.5% to 5.9%, respectively). Our findings suggest that tree C accumulation in forests is related to the size- and age-dependent increases in stem C concentration and using specific C concentration values of tree organs can improve the estimations of forest C stocks.

Key words: tree organs, carbon concentration, forest carbon accounting, tree size, tree age



关键词: 乔木器官, 碳浓度, 森林碳评估, 乔木个体大小, 乔木年龄