Fig. 3 Variation of SIC density with stand age in different soil layers
Figure 4 reflects the linear fit trend of SIC density with increasing
stand age. Within the 0-100 cm soil layer, soil inorganic carbon density
in the top 0-40 cm layer increased significantly (P < 0.05)
with increasing stand age, and within the 100-200 cm soil layer, the
120-140 cm and 160-180 cm layers increased significantly (P <
0.05) with increasing stand age, while the rest of the soil layers did
not change significantly with stand age. As can be seen from Figure 4,
soil inorganic carbon density increased overall with increasing stand
age (not significant).