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【目的】研究长白山原始红松林土壤可溶性有机碳(dissolved organic carbon, DOC)、微生物生物量碳(microbial biomass carbon, MBC)、易氧化碳(easily oxidized organic carbon, EOC) 的含量随海拔变化的垂直地带性规律、生长季动态及差异机制。【方法】以长白山海拔699~1 177 m的原始红松阔叶林为对象，以100 m为间隔选择原始红松林，同一海拔设置3块重复样地，在每个样地内选取10个随机观察样方(15 cm×15 cm)。分析0~20 cm表层土中土壤3种活性有机碳的含量随海拔及生长季的动态变化。【结果】DOC随海拔升高而增大，EOC除在1 177 m处较低外，在海拔699~1 044 m间整体上呈现出高海拔处大于低海拔的趋势；MBC仅在5、6月表现为低海拔处大于高海拔，其他月份也呈现出与EOC相同的规律。3种活性有机碳占土壤总有机碳(total organic carbon, TOC)比例分别在0.10%～1.45%、0.08%～2.18%和5.20%～69.18%之间，随海拔变化规律与其含量变化规律相似。在5—10月的生长季内，3种土壤活性有机碳含量及占TOC比例在月份间差异显著(P＜0.05)。土壤DOC含量最高值出现在9月，MBC在6月和9月较高，EOC的最高值则出现在5月和6月。土壤活性有机碳各组分含量与土壤有效氮、有效磷、有效钾、pH、含水率、容重的相关性均达到显著水平(P＜0.05)，且与土壤含水率的相关性最强（r = 0.835）。【结论】处于海拔699~818 m间原始红松林的土壤有机碳库稳定性更高，土壤碳汇功能更强。土壤碳素的积累主要发生在5、7、8、10月，此期TOC分解速度较慢，土壤碳汇功能更强。森林土壤活性有机碳含量可作为衡量土壤中N、P、K动态变化的敏感性指标。
【Objective】 The objective of this study was to investigate the effects of dissolved organic carbon (DOC), microbial biomass carbon (MBC) and easily oxidizable organic carbon (EOC) Zonal law, growth season dynamics and differences in mechanism. 【Method】 The original Korean pine broad-leaved forest at an altitude of 699 ~ 1 177 m in Changbai Mountain was taken as the object. The original Korean pine forest was selected at an interval of 100 m. Three replicate plots were set at the same altitude. Ten random observations Square (15 cm × 15 cm). The dynamic changes of soil active organic carbon (COC) content in 0 ~ 20 cm soil topsoil along with the altitude and growing season were analyzed. 【Result】 The results showed that the DOC increased with the altitude increasing. The EOC showed a trend that the altitude above sea level was greater than the low altitude at the altitude of 699 ~ 1044 m except at 1 177 m. The monthly performance is greater than the high altitude at low altitude, and other months also show the same rules as EOC. The percentages of total organic carbon (TOC) and total organic carbon (TOC) in the three soils varied from 0.10% to 1.45%, 0.08% to 2.18% and 5.20% to 69.18%, respectively. Within the growing season from May to October, the contents of three kinds of soil active organic carbon and the proportion of TOC in the soil were significantly different in the month (P <0.05). The highest soil DOC content appeared in September, the MBC was higher in June and September, and the highest EOC appeared in May and June. The correlations of soil active organic carbon components with soil available nitrogen, available phosphorus, available potassium, pH, water content and bulk density all reached significant levels (P <0.05), and their correlation with soil water content was the strongest = 0.835). 【Conclusion】 The soil organic carbon pool at the altitude of 699 ~ 818 m in the original Korean pine forest had higher stability and stronger carbon sink. The accumulation of soil carbon mainly occurred in May, July, August and October, and the TOC decomposition rate was slower during this period, and the soil carbon sink function was stronger. Soil active organic carbon content can be used as a sensitive index to measure the dynamic changes of N, P and K in soil.