林分类型对亚热带森林土壤团聚体中真菌反硝化微生物丰度的影响  

Effects of Forest Types on the Abundance of Fungal Denitrifiers in Soil Aggregates from a Subtropical Forest

作　　者：邓米林 林永新 叶桂萍 胥超[2,4] 宛颂 贺纪正 DENG Milin;LIN Yongxin;YE Guiping;XU Chao;WAN Song;HE Jizheng(State Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province,Fujian Normal University,Fuzhou 350117,China;School of Geographical Sciences,Fujian Normal University,Fuzhou 350117,China;College of Geography and Oceanography,Minjiang University,Fuzhou 350108,China;Fujian Sanming Forest Ecosystem and Global Change National Observation and Research Station,Sanming 365000,China)

机构地区：[1]福建师范大学湿润亚热带山地生态国家重点实验室培育基地,福建福州350117 [2]福建师范大学地理科学学院,福建福州350117 [3]闽江学院地理与海洋学院,福建福州350108 [4]福建三明森林生态系统与全球变化国家野外科学观测研究站,福建三明365000

出　　处：《福建师范大学学报（自然科学版）》2024年第1期45-51,68,共8页Journal of Fujian Normal University：Natural Science Edition

基　　金：国家自然科学基金资助项目(42077041);福建省自然科学基金资助项目(2020J01187)。

摘　　要：选取位于福建省三明市的米槠次生林、杉木人工林和马尾松人工林土壤为研究对象,利用荧光定量PCR分析了FnirK基因丰度,同时测定反硝化潜势。结果表明:FnirK基因丰度受林分类型显著影响,但受团聚体影响较小。马尾松人工林土壤FnirK基因拷贝数最高,为5.30×10^(8)copies·g^(-1),显著高于杉木人工林土壤的2.49×10^(8)copies·g^(-1)和次生林土壤的1.21×10^(8)copies·g^(-1)。各粒级团聚体的FnirK基因拷贝数也呈现出相同趋势。杉木和马尾松人工林土壤两种粒径较大团聚体的FnirK基因拷贝数较高,粒径较小团聚体中FnirK基因拷贝数较低,而次生林中4种粒级团聚体FnirK基因拷贝数无显著差异。马尾松和杉木人工林土壤的反硝化潜势分别为10.23和6.41μg·kg^(-1)·h^(-1),显著高于次生林土壤的2.76μg·kg^(-1)·h^(-1)。相关性分析表明,FnirK基因丰度与土壤含水率和有效磷含量呈显著正相关;反硝化潜势与土壤pH值、含水率、有效磷含量和FnirK基因丰度均呈显著正相关,表明真菌可能在酸性森林土壤反硝化过程中发挥重要作用。综上,不同林分类型主要通过影响土壤含水率和有效磷含量影响FnirK基因丰度和反硝化潜势,而团聚体粒径对土壤FnirK基因丰度影响相对较小。因此,在未来的森林管理过程中,人工林土壤真菌反硝化过程对N_(2)O产生的贡献不容忽视。Soil samples were collected from Castanopsis carlesii secondary forest,Cunninghamia lanceolata plantation and Pinus massoniana plantation in Sanming City,Fujian Province to determine the abundance of FnirK gene using real-time quantitative PCR and denitrification potential measurements.Results showed that forest types significantly affected the abundance of the FnirK gene,but less by aggregate sizes.The highest gene copy number of FnirK was 5.30×10^(8)copies·g^(-1)in the P.massoniana plantation,which was significantly higher than 2.49×10^(8)copies·g^(-1)in the C.lanceolata plantation and 1.21×10^(8)copies·g^(-1)in the secondary forest.The same trend was observed in different aggregate sizes.Larger aggregates in C.lanceolata and P.massoniana plantations exhibited higher FnirK gene copy numbers and lower in smaller aggregates,while no significant difference was found in the four aggregate sizes in secondary forests.The denitrification potential in soils from P.massoniana plantation and C.lanceolata plantations was 10.23 and 6.41μg·kg^(-1)·h^(-1),respectively,which was significantly higher than the 2.76μg·kg^(-1)·h^(-1)in soils from the secondary forest.Correlation analysis showed that FnirK gene abundance was positively correlated with soil moisture and available phosphorus content,and denitrification potential was positively correlated with soil pH,moisture content,available phosphorus content and FnirK gene abundance.These findings indicate an important role of fungi in denitrification in acidic forest soils.Overall,different forest types influenced the abundance of FnirK gene and denitrification potential mainly through regulating soil moisture and available phosphorus content,while the aggregate size had a relatively minor impact on FnirK gene abundance.Consequently,the contribution of soil fungal denitrification to N_(2)O production in plantations should not be overlooked in forest management.

关 键 词：次生林 人工林 森林土壤 Fungal nirK 团聚体 

分 类 号：S154.36[农业科学—土壤学]