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研究凋落物等外源有机碳输入和温度变化对土壤有机碳分解的影响对我们深入理解森林土壤碳动态具有非常重要的意义。以亚热带天然次生林和杉木人工林土壤为研究对象,向土壤中添加13C标记的杉木凋落物和葡萄糖,研究不同温度下外源有机碳添加对原有土壤有机碳(SOC)分解的影响。结果显示:外源有机碳添加使原有SOC分解速率显著提高,表现出显著的正激发效应。葡萄糖引发的激发效应强度显著高于杉木凋落物,并且杉木人工林土壤的激发效应强度显著高于天然次生林。激发效应强度随着培养温度升高呈下降趋势。此外,由于外源有机碳的加入,SOC分解的温度敏感性显著降低。研究表明:凋落物输入及温度在亚热带森林SOC周转过程中发挥重要作用。
Studying the effects of litter and other exogenous organic carbon inputs and temperature changes on soil organic carbon decomposition is of great significance for us to understand the carbon dynamics of forest soils. The subtropical natural secondary forest and Cunninghamia lanceolata plantation soil were used to study the effects of exogenous organic carbon at different temperatures on the decomposition of organic carbon (SOC) in soils with 13C-labeled Chinese fir litter and dextrose. The results showed that the exogenous organic carbon addition significantly increased the decomposition rate of original SOC and showed significant positive excitation effect. The excitation intensity induced by glucose was significantly higher than that of Chinese fir litter, and the excitation intensity of soil in Chinese fir plantation was significantly higher than that of natural secondary forest. The intensity of excitation effect decreased with the increase of culture temperature. In addition, due to the addition of exogenous organic carbon, the temperature sensitivity of SOC decomposition is significantly reduced. Studies have shown that litter input and temperature play an important role in the SOC turnover of subtropical forests.