摘要
采用室内培养法测定了不同温度下（8、18、28℃）小兴安岭原始阔叶红松林和阔叶次生林土壤有机碳的矿化速率和矿化量,并用三库一级动力学模型对有机碳各库进行拟合。结果表明：基于单位干土质量的阔叶次生林土壤有机碳矿化速率和累计矿化量均大于原始红松林,但有机碳累计矿化量占总有机碳的比率小于原始红松林。2种森林类型土壤活性碳库和缓效碳库随土层加深而减小,其占总有机碳的比例增加。尽管阔叶次生林土壤活性和缓效碳库均大于原始红松林,但其占总有机碳的比例却小于原始红松林,而土壤惰性碳库及其比例均大于原始红松林,表明阔叶次生林土壤有机碳整体上更稳定。土壤活性碳库平均驻留时间（MRT）为9~24d,且随土层加深而缩短,而缓效碳库MRT为7~42a,且随土层加深而延长。土壤活性碳库及其占总有机碳的比例随温度升高而线性增加,缓效碳库则降低;原始红松林土壤活性碳随温度的增速大于阔叶次生林,表明原始红松林土壤有机碳库对温度变化反应更敏感。
Soil samples collected from virgin Korean pine forest and broad-leaved secondary forest in Xiaoxing＇an Mountains, Northeast China were incubated in laboratory at different temperatures （ 8, 18 and 28 ℃ ） for 160 days, and the data from the incubation experiment were fitted to a three- compartment, first-order kinetic model which separated soil organic carbon （SOC） into active, slow, and resistant carbon pools. Results showed that the soil organic carbon mineralization rates and the cumulative amount of C mineralized （ all based on per unit of dry soil mass） of the broad- leaved secondary forest were both higher than that of the virgin Korean pine forest, whereas the mineralized C accounted for a relatively smaller part of SOC in the broad-leaved secondary forest soil. Soil active and slow carbon pools decreased with soil depth, while their proportions in SOC in- creased. Soil resistant carbon pool and its contribution to SOC were both greater in the broad-leaved secondary forest soil than in the virgin Korean pine forest soil, suggesting that the broad-leaved secondary forest soil organic carbon was relatively more stable. The mean retention time （MRT） of soil active carbon pool ranged from 9 to 24 d, decreasing with soil depth; while the MRT of slow carbon pool varied between 7 and 24 a, increasing with soil depth. Soil active carbon pool and its proportion in SOC increased linearly with incubation temperature, and consequently, decreased the slow carbon pool. Virgin Korean pine forest soils exhibited a higher increasing rate of active carbon pool along temperature gradient than the broad-leaved secondary forest soils, indicating that the or- ganic carbon pool of virgin Korean pine forest soil was relatively more sensitive to temperature change.
出处
《应用生态学报》
CAS
CSCD
北大核心
2015年第7期1913-1920,共8页
Chinese Journal of Applied Ecology
基金
国家"十二五"科技支撑计划项目(2011BAD37B01)
国家重点基础研究发展计划项目(2011CB403202)资助
关键词
森林土壤
有机碳
矿化
周转
稳定性
forest soil
organic carbon
mineralization
turnover
stability.
