Carbon and nitrogen accumulation during secondary succession

Background/Question/Methods Stand-replacing disturbances play a key role in regulating carbon (C) and nitrogen (N) cycling in global forest ecosystems. Succession-driven changes in C pools have received considerable interests, but little is known about N dynamics and C-N coupling during forest development after stand-replacing disturbances. In this synthesis, we compiled data from 110 published papers that determine changes in C and N pools along forest age sequence. The compiled database contains C contents, N contents, and C: N ratio in various plant and soil pools. Results/Conclusions Our results indicated that C and N pool sizes in plant increased with forest age. Similarly, the C and N contents in forest floor showed increasing trend along age sequence. However, C and N contents in soil exhibited diverse trends with forest age (increase, decrease, no trend, and Covington curve). The rate of C and N accumulation was positively correlated with mean annual temperature, with greater C and N accumulation rate occurring in plantation than in natural forests. C: N ratio in both plant and soil increased with forest age, suggesting that N will progressively limit long-term C sequestration in secondary forests.