不同浸提剂处理森林土壤溶解性有机碳含量比较  

Comparison of Dissolved Organic Carbon Contents in Forest Soils Extracted by Different Agents

作　　者：丁咸庆 柏菁 项文化[1] 侯红波 彭佩钦 DING Xianqing;BAI Jing;XIANG Wenhua;HOU Hongbo;PENG Peiqin(Faculty of Life Science and Technology,Central South University of Forestry and Technology,Changsha 410004,China;Faculty of Environmental Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,China)

机构地区：[1]中南林业科技大学生命科学与技术学院,长沙410004 [2]中南林业科技大学环境科学与工程学院,长沙410004

出　　处：《土壤》2020年第3期518-524,共7页Soils

基　　金：国家自然科学基金项目(31470629)资助。

摘　　要：为了解亚热带森林土壤溶解性有机碳(DOC)的特征规律,采用培养离心的方法获取土壤溶液测得DOC含量,对比传统水溶性有机碳(WSOC)提取法间的差异。选取湖南大山冲森林公园保存完好的3种亚热带典型次生林地,按10cm一层采集剖面土壤,采用不同方法提取测定土壤DOC和WSOC含量,分析与土壤理化指标的相关性及方法间的显著性关系。结果表明:①典型森林土壤DOC或WSOC含量随土壤剖面深度的增加,呈显著下降趋势。培养离心提取测得的土壤DOC含量明显较低,仅0.82~9.52 mg/kg,超纯水浸提的风干土WSOC含量达10.56~249.19 mg/kg,而0.5 mol/L K_2SO_4提取的鲜土WSOC含量达155.70~576.94 mg/kg,0.5mol/L K_2SO_4浸提的干土WSOC含量最高,达158.94~797.56 mg/kg,含量表现为:DOC<干土超纯水浸提WSOC<鲜土K_2SO_4浸提WSOC<干土K_2SO_4浸提WSOC;②3种次生林土壤DOC或WSOC含量存在显著差异,不同方法测定的含量均表现为针叶林<常绿阔叶林<落叶林;③培养离心法测得土壤DOC含量与其他测定方法间存在极显著正相关(P<0.01),并且土壤DOC和WSOC均与土壤pH、总有机碳、胡敏酸、富啡酸、全氮、全磷、速效态氮以及微生物生物量碳氮达到极显著相关(P<0.01),与土壤含水率和容重显著相关(P<0.05)。培养离心法测得土壤DOC含量远低于水溶液提取WSOC含量,该方法下的测得值更接近于原位土壤溶解性有机碳实际值。0-10 cm soil samples were collected under three secondary forests in Dashanchong Forest Park in Hunan,the contents of dissolved organic carbon(DOC)and water-soluble organic carbon(WSOC)were measured with different extraction agents.The results showed that:(1)DOC and WSOC contents were decreased significantly with the increase of soil depth.DOC content measured by cultivation-centrifugation method was the lowest(only 0.82-9.52 mg/kg),followed by WSOC content extracted by ultra-pure water in air-dried soils(10.56-249.19 mg/kg),WSOC contents extracted by K2SO4 in fresh and air-dried soils were the highest(155.70-576.94 mg/kg and 158.94-797.56 mg/kg,respectively).The average content was in the order of DOC<WSOC extracted by ultra-pure water in air-dried soils<WSOC extracted by K2SO4 in fresh soils<WSOC extracted by K2SO4 in air-dried soils.(2)Significant differences were found in soil DOC or WSOC contents under three forests,and both DOC and WSOC contents determined by different methods were in the order of coniferous forests<evergreen broad-leaved forests<deciduous forest.(3)Extremely significant positive correlation was found between DOC contents measured by the cultivation-centrifugation method and other methods(P<0.01).DOC or WSOC contents were extremely significantly correlated with soil organic carbon,humic acid,fulvic acid,total nitrogen,total phosphorus,available N,microbial biomass carbon,microbial biomass nitrogen and pH(P<0.01),and significantly correlated with soil bulk density and soil water content(P<0.05).DOC content measured by the cultivation-centrifugation method was far lower than WSOC content extracted by salt solution,however,it was closer to the actual value of in-situ measured soil dissolved organic carbon.

关 键 词：溶解性有机碳 水溶性有机碳 森林类型 培养离心 测定方法 

分 类 号：S714[农业科学—林学] S153.6