桂西北喀斯特典型土壤有机碳矿化过程中微生物活性的变化  

Changes of soil microbial activity during the mineralization of organic carbon in typical soils in Karst region of Northwest Guangxi, South China

作　　者：胡乐宁[1,2,3] 苏以荣[1,2] 何寻阳[1,2] 李杨[1,2] 黎蕾[1,2] 

机构地区：[1]中国科学院亚热带农业生态研究所亚热带农业生态重点实验室,长沙410125 [2]中国科学院环江喀斯特农业生态试验站,广西环江547100 [3]广西师范大学环境与资源学院,广西桂林541004

出　　处：《生态学杂志》2012年第8期2023-2028,共6页Chinese Journal of Ecology

基　　金：中国科学院知识创新重要方向项目(KSCX2-YW-436);中国科学院战略性先导科技专项(XDA05070403);国家科技支撑计划项目(2012BAD05B03);亚热带农业生态研究所青年人才领域前沿项目(ISACX-LYQY-QN-1101)资助

摘　　要：为了研究喀斯特地区典型土壤有机碳积累与转化过程,采取野外取样分析与室内培养相结合的方法,以红壤为对照,采集2种喀斯特典型土壤(即棕色石灰土和黑色石灰土),设置不添加外源物质(CK)、添加14C标记的稻草(T1)、添加碳酸钙粉末(T2)和同时添加14C标记的稻草与碳酸钙粉末(T3)4个处理,进行室内培养试验,以土壤微生物指标(微生物生物量碳、基础呼吸、微生物碳熵和代谢熵)指示土壤有机碳积累与转化过程。结果表明,土壤有机碳矿化过程中,土壤呼吸的累积量依次为黑色石灰土>棕色石灰土>红壤(P<0.05)。微生物碳熵随土壤有机碳矿化变化依次为黑色石灰土>棕色石灰土>红壤(P<0.05)。同时添加外源稻草和钙对提高土壤微生物碳稳定性的效果最强。桂西北喀斯特地区土壤微生物指标的变化因土壤类型不同而存在差异。利用微生物指标来衡量土壤有机碳稳定性较为可靠。In order to understand the accumulation and transformation of organic carbon in typical Karst soils, soil samples were collected from terra fusca and rendzina, and a 100-day incubation experiment was conducted to study the accumulation and transformation of soil organic carbon under no exogenous substance addition （CK）, 14C-labeled rice straw addition （T1）, calcium carbonate addition （T2）, and 14C-labeled rice straw ＋ calcium carbonate addition （T3）, taking soil microbial biomass carbon （MBC）, basic respiration （BR）, BR/MBC ratio （qCO2）, and MBC/SOC ratio as the indicators and with red soil as the contrast soil. During the mineralization of the organic carbon in test soils, both the BR and the qCO2 followed the order of rendzina 〉 terra fusca 〉 red soil （P〈0.05）. Treatment T3 had the greatest effect in enhancing the stability of soil MBC. The changes of the soil microbial indicators differed significantly with test soils, and thus, using these indicators to measure the stability of soil organic carbon would be more credible.

关 键 词：喀斯特 土壤微生物 有机碳 矿化 

分 类 号：S153.6[农业科学—土壤学]