摘要
Denitrification is the primary contributor to soil N_(2)O emissions.Although bacterial denitrification has been extensively studied in diverse ecosystems,the contribution of fungal denitrification to soil N_(2)O emissions in karst areas remains unexplored,especially after vegetation restoration.In this study,we compared cropland(control)with a naturally restored forest(60 years old)by collecting 24 soil samples from both land use types.We analyzed the abundance,community structure,and contribution to soil N_(2)O emissions of denitrifying fungi under different land use types using inhibitor methods,quantitative PCR(qPCR),and Illumina MiSeq sequencing.We found that after vegetation restoration,the abundance of nirK-containing denitrifying fungi(7.72×10^(9)±1.82×10^(9)copies g^(-1))was nearly threefold higher than in cropland(2.61×10^(9)±0.29×10^(9)copies g^(-1)).Moreover,vegetation restoration markedly altered the community composition of nirK-containing denitrifying fungi,leading to an enrichment of Fusarium,Trichoderma,Chloridium and Aspergillus.Additionally,the contribution of fungal denitrification to N_(2)O emissions was greater after vegetation restoration(35.40%)than in cropland(28.70%).Furthermore,the increase in fungal nirK-derived N_(2)O after vegetation restoration was closely related with high soil nitrate nitrogen(NO_(3)^(-)-N)and sand.Our research underscores the significance of fungal denitrification in driving soil N_(2)O emissions after vegetation restoration in karst areas.
基金
supported by the China Postdoctoral Science Foundation(Grant No.2022M713351)
the Natural Science Foundation Youth Program of Guangxi(Grant No.2023GXNSFBA026192).
