夏季黄土丘陵区不同土地利用方式土壤CO_2分布特征及影响因素  

Distribution characteristics and influencing factors of soil CO_2 in different land use patterns in loess hilly region in summer

作　　者：邵明玉 张连凯[1,2] 刘朋雨 覃小群[1,2] 邵天杰 曹建华[2] 张春来 SHAO Mingyu;ZHANG Liankai;LIU Pengyu;QIN Xiaoqun;SHAO Tianjie;CAO Jianhua;ZHANG Chunlai(Institute of Karst Geology,CAGS /Key Laboratory of Karst Ecosystem and Treatment ofRocky Desertification,MNR,Guilin,Guangxi 541004,China;Key Laboratory of Karst Dynamics,MNR&GZAR,Guilin,Guangxi 541004,China;School of Tourism and Environment,Shaanxi Normal University,Xi’an,Shaanxi 710062,China)

机构地区：[1]中国地质科学院岩溶地质研究所/自然资源部岩溶生态系统与石漠化治理重点实验室,广西桂林541004 [2]自然资源部广西岩溶动力学重点实验室,广西桂林541004 [3]陕西师范大学旅游与环境学院,西安710062

出　　处：《中国岩溶》2019年第1期70-79,共10页Carsologica Sinica

基　　金：国家自然科学基金项目(41671213);中国地质调查局地质调查项目(DD20160305);国家重点研发计划项目(2017YFC0406104);山东省地质勘查项目(科研类;鲁勘字[2016]79号)

摘　　要：为了解不同土地利用方式对土壤剖面CO_2含量的影响,分析了吕梁山西侧黄土丘陵区不同土地利用类型(果树林地、大田作物地、荒地)土壤理化性质和不同深度的CO_2分布特征及其影响因素。其结果表明:果树林地、大田作物地和荒地三种不同土地利用方式全磷、全钾含量差别不大,大田作物地土壤有机碳含量(2.95±1.19 g·kg^(-1))>荒地(2.63±1.36 g·kg^(-1))>果树林地(2.38±0.78 g·kg^(-1)),而大田作物地土壤无机碳含量(14.36±5.17 g·kg^(-1))>果树林地(14.16±1.32 g·kg^(-1))>荒地(12.40±4.04 g·kg^(-1));同样,土壤全氮含量在大田作物地中含量最高,在其他两种土地利用方式中全氮含量大致相同。不同土地利用方式对土壤剖面CO_2体积分数的影响较大,果树林地0～20 cm深度土壤CO_2含量高于大田作物地和荒地,其原因:一方面为果树林地地表调落物较多,表层有机碳积累较多,在微生物分解作用下,形成了大量的CO_2,另一方面,果树林地人为扰动小,而大田作物地人为扰动较大,土壤CO_2浓度更大程度上取决于农田的耕作管理措施和种植作物的品种。三种土地利用方式在土壤80 cm处土壤CO_2含量均突然下降,其原因可能为雨水下渗吸收了土壤CO_2后与下部碳酸盐矿物发生作用,即碳酸盐矿物的溶蚀过程消耗吸收土壤CO_2。土壤温、湿度也影响了土壤CO_2的产生,但相关性均不显著,其原因为研究区土壤呼吸对温度响应高度依赖于土壤含水量,土壤CO_2的产生速率更多受水热因子耦合作用的影响。The Loess Plateau has a deep soil layer and contains a huge inorganic carbon pool.In order to understand the effects of different land use patterns on soil CO 2 content,the physical and chemical properties of soil from different land use types(fruit trees,field crops,wasteland)and the CO 2 distribution characteristics and their influencing factors at different depths of soil in the loess hilly region were analyzed.The results showed that there were no significant differences in total phosphorus and total potassium content in three different land use types of fruit trees land,field crops land and wasteland.The contents of soil organic carbon has the order of field crops land(2.95±1.19 g·kg^-1)>wasteland(2.63±1.36 g·kg^-1)>fruit woodland(2.38±0.78 g·kg^-1),while the content of soil inorganic carbon has the order of field crop land(14.36±5.17 g·kg^-1)>fruit woodland(14.16±1.32 g·kg^-1)>wasteland(12.40±4.04 g·kg^-1).Similarly,soil total nitrogen content is highest in field crops land,and the other two land use patterns have roughly the same total nitrogen content.Different land use types have a great impact on the CO 2 volume fraction of the soil profile.The soil CO2 content in the depth of 0-20 cm in the fruit trees land is higher than that in the field crops land and wasteland.The reason for this is that on the one hand,the surface of the fruit trees land has more litter,and the surface organic carbon results in a large amount of CO2 under the action of microbial decomposition;On the other hand,the artificial disturbance of fruit trees land is small,while the field crops land are highly disturbed.The concentration of CO2 in soil depends to a greater extent on the management practices of cropland and the varieties of crops.The soil CO2 content in the soil at 80 cm in the three land use patterns suddenly decreased,which may be caused by the absorption of soil CO2 by rainwater infiltration and the action of lower carbonate minerals.That is,the dissolution process of carbonate minerals consumes soil CO2.Soi

关 键 词：黄土理化性质 CO2浓度 土壤无机碳 土壤有机碳 土地利用类型 

分 类 号：S154.1[农业科学—土壤学]