去除根系或枯落物对湿地松和尾巨桉人工林土壤碳氮库的影响  

Effects of root and litter removal on the soil carbon and nitrogen pools of Pinus elliottii and Eucalyptus urophylla×E.grandis plantations

作　　者：沈健 何宗明[1,2] 郜士垒 林宇 赵文东 董强[1,2] SHEN Jian;HE Zongming;GAO Shilei;LIN Yu;ZHAO Wendong;DONG Qiang(College of Forestry,Fujian Agriculture and Forestry University Fuzhou 350002,Fujian,China;Chinese Fir Engineering Technology Research Center of the State Forestry and Grassland Administration,Fujian Agriculture and Forestry University Fuzhou 350002,Fujian,China;Minhou Baisha State-Owned Forest Farm of Fujian Province,Minhou 350100,Fujian,China)

机构地区：[1]福建农林大学林学院,福建福州350002 [2]福建农林大学国家林业和草原局杉木工程技术研究中心,福建福州350002 [3]福建省闽侯白沙国有林场,福建闽侯350100

出　　处：《中南林业科技大学学报》2023年第2期114-123,共10页Journal of Central South University of Forestry & Technology

基　　金：国家重点研发计划项目(2016YFD0600300);福建省自然科学基金项目(2021J011045)。

摘　　要：【目的】研究地上枯落物和地下根系在土壤碳氮循环中的作用,为提高滨海沙地人工林土壤碳氮保留能力提供科学依据,为促进沿海地区人工林可持续经营提供启示。【方法】以福建长乐滨海沙地2种典型人工林(湿地松和尾巨桉)为研究对象,设置去除根系、去除枯落物以及对照3种处理,1 a后采集土壤样品,测定土壤碳氮及其组分。【结果】滨海沙地湿地松林和尾巨桉林碳氮储量差异不明显,去除地上枯落物使尾巨桉林土壤可溶性有机碳含量显著下降,去除地下根系使湿地松林土壤可溶性有机氮含量显著上升,去除根系或枯落物处理均降低了2种人工林土壤微生物有机碳和微生物有机氮含量,湿地松人工林去除根系或枯落物后土壤矿质氮含量均有所升高,尾巨桉人工林则与之相反。回归分析表明不同碳输入下土壤DOC与DON、MBC、MBN之间存在极显著正相关关系,与土壤NO_(3)^(-)-N之间存在显著正相关关系,土壤MBC与土壤NH_(4)^(+)-N、NO_(3)^(-)-N之间存在显著正相关关系。【结论】去除根系或枯落物处理对不同树种人工林土壤碳氮库的影响存在显著差异,调控地上、地下有机物输入会影响土壤碳氮及其组分,进而影响土壤碳氮库,表明根系和枯落物是土壤碳氮库的重要影响因素,其影响作用会因树种类型而异。【Objective】By studying the role of aboveground litter and underground roots in the soil carbon and nitrogen cycle,this work provided a scientific basis for improving the soil carbon and nitrogen retention capacity of the coastal sandy plantation,and inspired the promotion of the sustainable management of plantations in coastal areas.【Method】Taking two typical artificial plantations(Pinus elliottii and Eucalyptus urophylla×E.grandis)in the coastal sandy land of Changle,Fujian as the research objects,the study set up three treatments of root-trenching,litter removal and the control,and the soil samples were collected after one year to determine the carbon and nitrogen contents of soil and its components.【Result】The results showed that there was no significant difference in the C and N accumulation between the P.elliottii and the E.urophylla×E.grandis plantations on the coastal sandy land.The removal of aboveground litter significantly decreased the soil DOC content of the E.urophylla×E.grandis plantation,and the removal of underground roots significantly increased the soil DON content of the P.elliottii plantation.Both root and litter treatments reduced soil MBC and MBN contents in the two plantations,and the soil mineral nitrogen content increased after the root or litter was removed in the P.elliottii plantation,while it was the opposite in the E.urophylla×E.grandis plantation.Regression analysis showed that the DOC concentration was significantly positively correlated with DON,MBC and MBN,while there was a positive relationship between the soil DOC and NO_(3)^(-)-N.MBC was significantly positively correlated with soil NH_(4)^(+)-N and NO_(3)^(-)-N under different carbon inputs.【Conclusion】There were significant differences in the effects of root removal and litter removal on the soil carbon and nitrogen pools in plantations of different tree species,adjusting the input of aboveground and underground organic matters will affect soil carbon and nitrogen contents as well as the components,which

关 键 词：去除根系 去除枯落物 可溶性有机碳氮 微生物量碳氮 土壤矿质氮 滨海沙地 

分 类 号：S714.2[农业科学—林学]