寒温带林区不同林型下冻融土壤活性有机碳的变化  

Changes of active organic carbon in frozen thawed soil under different forest types in cold temperate forest region

作　　者：王世佳 郭亚芬[1] 崔晓阳[1] Wang Shijia;Guo Yafen;Cui Xiaoyang(School of Forestry,Northeast Forestry University,Harbin 150040,Heilongjiang,China)

机构地区：[1]东北林业大学林学院,黑龙江哈尔滨150040

出　　处：《北京林业大学学报》2021年第12期65-72,共8页Journal of Beijing Forestry University

基　　金：国家自然科学基金项目(31370617);国家重点研发计划(2017YFD0600601);大学生创新训练项目(201910225542)。

摘　　要：【目的】研究不同冻融频次的寒温带林区4种典型林型下土壤溶解性有机碳(DOC)、微生物量碳(MBC)含量变化规律,整合所测定的理化因子,为揭示冻融交替作用与土壤中主要活性有机碳及其他潜在驱动因素的相关性规律,以及寒温带林区区域性碳库平衡提供理论依据。【方法】以寒温带林区大兴安岭地区的4种林型(偃松林、杜鹃白桦林、杜鹃落叶松林以及杜香落叶松林)下的土壤凋落物层(O层)与表层矿质土壤(A层)为研究对象,利用室内模拟冻融交替方法对土壤样品进行不同冻融频率累积的循环处理,测定土壤中的DOC、MBC、团聚体含量,pH和含水量;最后,利用主成分分析法对上述多元变量之间的相关性进行探究。【结果】整体而言,杜香落叶松林和杜鹃白桦林的DOC、MBC含量均较高,杜鹃落叶松林以及偃松林的碳含量较低,且后者显著低于前者。同一土层不同林型土壤中,DOC和MBC含量均随着冻融频率的累积呈现先增加后减小的趋势,且冻融作用显著地增加了土壤的DOC含量,同时降低了MBC含量。而在土壤层次方面,O层DOC、MBC含量显著高于A层。此外,温度、冻融频次对土壤中的活性有机碳、团聚体,pH和含水量等潜在驱动因子亦有影响。【结论】寒温带地区不同林型因冻融频次的改变,导致土壤中DOC、MBC含量发生动态变化。与未经冻融处理相比,冻融循环后的DOC含量增加、MBC含量下降,且中海拔地区的阔叶林(杜鹃白桦林)以及低海拔地区的杜香落叶松林更有利于碳含量的累积。[Objective]This paper studies the changes of soil dissolved organic carbon(DOC),microbial biomass carbon(MBC)under four typical forest types in cold temperate forest region with different freezing and thawing frequencies,integrates the measured physical and chemical factors,and reveals the correlation between freezing and thawing alternation and main active organic carbon and other potential driving factors in soil to provide a theoretical basis for regional carbon pool balance in cold temperate forest region.[Method]The soil litter layer(O layer)and surface mineral soil layer(A layer)under four forest types(Pinus pumila forest,Rhododendron simsii-Betula platyphylla forest,Rhododendron simsii-Larix gmelinii forest and Ledum palustre-Larix gmelinii forest)in the Great Hinggan Mountains,northeastern China of cold temperate zone were studied.Soil samples were cyclically treated with different freezing-thawing frequency accumulation by indoor simulated freezing-thawing alternating method,and the content levels of DOC,MBC,aggregates,pH and water content in the soil were determined.Finally,principal component analysis method was used to explore the correlation between the above multivariate variables.[Result]On the whole,the contents of DOC and MBC in Ledum palustre-Larix gmelinii forest and Rhododendron simsii-Betula platyphylla forest were higher,while the carbon contents in Rhododendron simsii-Larix gmelinii forest and Pinus pumila forest were lower,and the latter was significantly lower than the former.In the same soil layer and different forest types,the contents of DOC and MBC increased first and then decreased with the accumulation of freezing and thawing frequency,and freezing and thawing significantly increased the content of DOC and decreased the content of MBC.In the soil layer,the contents of DOC and MBC in O layer were significantly higher than those in A layer.In addition,temperature and freeze-thaw frequency also affected the potential driving factors such as active organic carbon,aggregate,pH and water

关 键 词：冻融交替 林型 溶解性有机碳 微生物生物量碳 潜在驱动因子 

分 类 号：S714[农业科学—林学] TU111.25[建筑科学—建筑理论]