不同火烈度对四川泸山林场云南松林土壤有机碳组分的影响  

Effects of different fire severities on soil organic carbon components of Pinus yunnanensis forest in Lushan Forest Farm,Sichuan Province

作　　者：高钰 索奥丽 高敏 王忆文 陈锋 刘晓东[1,2] GAO Yu;SUO Aoli;GAO Min;WANG Yiwen;CHEN Feng;LIU Xiaodong(Key Laboratory of Forest and Grassland Fire Risk Prevention Ministry of Emergency Management,Beijing 100083,China;Beijing Key Laboratory for Forest Resources and Ecosystem Processes,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]森林草原火灾风险防控应急管理部重点实验室,北京100083 [2]北京林业大学森林资源生态系统过程北京市重点实验室,北京100083

出　　处：《生态学报》2023年第22期9281-9293,共13页Acta Ecologica Sinica

基　　金：国家重点研发计划项目(2020YFC1511601)。

摘　　要：林火通过改变土壤理化性质显著影响土壤固碳能力及土壤有机碳各组分含量。阐明不同火烈度对云南松林土壤有机碳的影响,对于云南松林火后生态系统恢复及土壤碳库管理具有重要意义。以火烧2年后四川泸山林场云南松林0—5、5—10、10—15、15—20cm层土壤为研究对象,根据不同火烈度(未过火、低烈度、中烈度、高烈度)设置3块20m×30m样地,共12块样地,野外采集土壤样品,室内测定土壤全氮、容重等理化性质和土壤有机碳(Soil organic carbon,SOC)、土壤活性有机碳(易氧化有机碳,Readily oxidizable carbon,ROC;颗粒有机碳,Particulate organic carbon,POC;微生物生物量碳,Microbial biomass carbon,MBC;水溶性有机碳,Water-soluble organic carbon,WSOC),采用方差分析研究不同火烈度下土壤有机碳各组分含量的差异性和变化趋势,并采用相关性分析和冗余分析从土壤理化性质角度探究林火对土壤有机碳的影响机制。研究结果表明:(1)不同火烈度显著影响土壤理化性质,其中土壤全氮、有效磷、阳离子交换量、毛管孔隙度、总孔隙度随火烈度增大而增加,而土壤pH、速效钾、碱解氮、容重随火烈度增大而减少。(2)SOC随火烈度增大而减少,其中5—10cm土层降幅最大为44.79%;4种土壤活性有机碳随火烈度增大而减小,其中0—5cm土层下降幅度最明显,各组分降幅大小依次为ROC(36.31%—61.31%)>POC(30.05%—53.61%)>MBC(20.60%—48.19%)>WSOC(13.47%—29.29%),不同组分对林火的不同响应显著影响了土壤ROC、POC、WSOC的占比。(3)土壤有机碳及其活性组分与阳离子交换量、毛管孔隙度、总孔隙度、有效磷、碱解氮呈显著正相关(P<0.05),与容重呈极显著负相关(P<0.01)。火烧后土壤有机碳的变化主要与阳离子交换量、容重、全氮、含水率有关,且阳离子交换量影响最大(解释率为61.7%)。Forest fire significantly affects soil carbon sequestration capacity and components of soil organic carbon content by changing soil physicochemical properties.Explaining the effects of different fire severities on soil organic carbon of Pinus yunnanensis forest is of great significance for ecosystem restoration and soil carbon pool management of Pinus yunnanensis forest after fire.In this study,the soils of Pinus yunnanensis after 2 years fire in different soil layers(0—5,5—10,10—15,and 15—20 cm)in Lushan Forest Farm,Sichuan Province were taken as the research object.According to different fire severities(unburned,low severity,moderate severity,height severity),three 20m×30m sample plots were set,and a total of 12 plots were set.Collecting soil samples from the field,soil total nitrogen,soil bulk density and other physicochemical properties as well as soil organic carbon(SOC),soil labile organic carbon(readily oxidizable carbon(ROC),particulate organic carbon(POC),microbial biomass carbon(MBC),and water-soluble organic carbon(WSOC))were measured.Variance analysis was used to analyze the differences and trends in change of soil organic carbon components under different fire severities.Correlation analysis and redundancy analysis was used to explore the effect mechanism of forest fire on soil organic carbon from the point of view of soil physicochemical properties.The results showed that:(1)different fire severities significantly affected soil physicochemical properties,in which soil total nitrogen,available phosphorus,cation exchange capacity,capillary porosity,and total porosity increased with the increase of fire severity,while soil pH,available potassium,available nitrogen,and bulk density decreased with the increase of fire severity.(2)The SOC decreased with the increasing of fire severity,and the maximum decrease of 5—10 cm soil layer was 44.79%.With the increase of fire severity,the labile organic carbon of four kinds of soil decreased,which the decrease in 0—5 cm soil layer was the most obvious

关 键 词：火烈度 云南松 土壤有机碳 活性有机碳 土壤理化性质 

分 类 号：S714[农业科学—林学]