氮添加对亚热带毛竹林土壤硝化潜势和氨氧化微生物的影响季节差异  

Differential seasonal effects of nitrogen addition on nitrification potential and ammonia-oxidizing microorganisms in soil of subtropical moso bamboo forest

作　　者：元晓春 曾泉鑫 周茜 任梦潇 李文周 陈亚婷 林开淼 陈岳民 YUAN Xiaochun;ZENG Quanxin;ZHOU Qian;REN Mengxiao;LI Wenzhou;CHEN Yating;LIN Kaimiao;CHEN Yuehmin(College of Tourism,Wuyi University,Wuyishan 354300,China;School of Geographical Science,Fujian Normal University,Fuzhou 350007,China;Daiyun Mountain National Nature Reserve Administration Bureau,Dehua 362500,China)

机构地区：[1]武夷学院旅游学院,武夷山354300 [2]福建师范大学地理科学学院,福州350007 [3]福建戴云山国家级自然保护区管理局,德化362500

出　　处：《生态学报》2024年第23期10734-10744,共11页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(32201532,32371846);福建省自然科学基金项目(2020J01397,2020J01142)。

摘　　要：氨氧化是硝化作用的限速步骤,也是评估氮沉降如何影响土壤氮循环过程的重要指标。氮添加5年后,在湿季(6月)和干季(12月)采集亚热带毛竹林土壤样本,结合室内磷添加实验,探究了不同季节氮添加对土壤硝化潜势和氨氧化微生物的影响及其机理。研究结果表明,在两个季节中,氮添加显著提高土壤铵态氮含量,降低土壤磷有效性;氮添加仅显著降低干季土壤pH。相比于湿季,氮添加对干季土壤硝化作用和氨氧化微生物的影响更大。高氮添加显著增加干季土壤硝化潜势、氨氧化古菌(AOA)基因丰度和多样性,改变AOA的群落结构;而氮添加仅显著改变湿季土壤氨氧化细菌(AOB)的群落结构。在两个季节中,与仅添加磷的土壤相比,氮和磷共同添加下土壤的AOA、AOB基因丰度和硝化潜势显著更高。上述结果表明,磷添加改变了氮添加对氨氧化微生物活性和硝化潜势的影响。此外,回归分析显示,在没有添加磷时,土壤硝化潜势与AOA基因丰度呈显著正相关关系;在添加磷后,土壤AOA和AOB基因丰度均与土壤硝化潜势存在显著的正相关关系。这说明氮添加下土壤磷有效性的降低在一定程度上抑制了AOB活性及其对硝化潜势的贡献。总之,该研究结果为更好理解气候变化下亚热带贫磷土壤硝化作用和氮循环过程提供了理论基础。Ammonia oxidation is the rate-limiting step of nitrification and an important indicator for assessing how nitrogen(N)deposition affects soil N cycling processes.After a five-year N addition experiment,we collected soil samples from a subtropical Moso bamboo forest during the wet season(June)and dry season(December).In conjunction with a phosphorus(P)addition experiment in vitro,we investigated the effects of N addition on soil nitrification potential and ammonia-oxidizing microorganisms in different seasons,along with their underlying mechanisms.The results showed that N addition significantly increased soil ammonium N content and decreased soil P availability in both seasons.Additionally,N addition significantly reduced soil pH only in the dry season.N addition had more pronounced effects on nitrification and ammonia-oxidizing microorganisms in the dry season compared to the wet season.High N addition significantly increased soil nitrification potential,abundance,and diversity of ammonia-oxidizing archaea(AOA),and altered the community structure of AOA in the dry season.In contrast,N addition only significantly altered the community structure of ammonia-oxidizing bacteria(AOB)in the wet season.In both seasons,the gene abundance of AOA and AOB,as well as nitrification potential,were significantly higher in soil with combined N and P additions compared to soil with P additions alone.The above results indicated that P addition altered the effects of N addition on ammonia-oxidizing microbial activity and nitrification potential.Moreover,the regression analyses revealed that the nitrification potential was significantly positively correlated with the abundance of AOA gene in the absence of P addition.However,the nitrification potential was significantly positively associated with the gene abundance of both AOA and AOB when P was added.It suggests that the decrease in soil P availability caused by N addition suppressed AOB activity and its role in nitrification potential to some extent.The study collectively provides

关 键 词：毛竹 氨氧化微生物 硝化作用 氮添加 季节 磷有效性 

分 类 号：S714[农业科学—林学]