Aims Larix forest is important in northern China. Our objective was to understand its biomass carbon accounting factors: biomass conversion and expansion factor (BCEF), biomass expansion factor (BEF), root-shoot ratio (R) and community biomass expansion factor (CBEF).
Methods We collected data on biomass and related parameters for natural forests and plantations from published literature, calculated carbon accounting factors, and analyzed their relationships to stand age (A), diameter at breast height (DBH) and stand density (D). Natural forests and plantations were analyzed separately.
Important findings Mean BCEF for Larix forests was 0.683 4 t·m-3 (n=113, SD=0.355 1), and BCEF for natural stands (0.555 1 t·m-3 (n=56, SD=0.058 2)) was significantly smaller than for plantations (0.809 5 t·m-3 (n=57, SD=0.465 0)) (p<0.05). MeanBEF was 1.349 3 (n=134, SD=0.384 4), and plantations had larger mean BEF value (1.176 3 (n=63, SD=0.039 9)) than natural stands (1.502 9 (n=71, SD=0.478 0)) (p<0.05). Values ofBCEF and BEF for natural forests increased exponentially with increasing A and DBH and decreased exponentially with increasing D. Mean R was 0.245 6 (n=156, SD=0.092 6), and there was no significant difference between natural forests (0.237 6 (n=64, SD=0.061 8)) and plantations (0.251 1 (n=92, SD=0.109 0)) (p<0.05).R value of natural stands increased exponentially with increasing A and DBH, but decreased with increasing D. Moreover, R values of plantations had no significant correlations to A, DBH and D. Mean CBEF was 1.102 0 (n=51, SD=0.150 5), and the CBEF value of natural forests (1.139 8 (n=31, SD=0.177 8)) was larger than plantations (1.043 4 (n=20, SD=0.061 4)) (p<0.05). Due to significant differences between natural forests and plantations, it is better to account biomass carbon stock for natural forests and plantations separately. The relationships of these biomass factors (i.e.BCEF vs. D and BEF vs. D of plantations and CBEF of natural forests and plantations) deserve further study.