杉木人工林土壤氮矿化对长期氮添加和季节的响应  

Response of soil N mineralization to long-term N addition and season in Cunninghamia lanceolata plantation

作　　者：杨仕明 蔡乾坤 刘文飞[3] 吴建平[1,2] YANG Shiming;CAI Qiankun;LIU Wenfei;WU Jianping(Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology,Yunnan University,Kunming 650500,Yunnan,China;Key Laboratory of Soil Ecology and Health in Universities of Yunnan Province,School of Ecology and Environmental Science,Yunnan University,Kunming 650500,Yunnan,China;Jiangxi Key Laboratory for Restoration of Degraded Ecosystems&Watershed Ecohydrology,Nanchang Institute of Technology,Nanchang 330099,Jiangxi,China)

机构地区：[1]云南大学云南省植物繁殖适应与进化生态学重点实验室,云南昆明650500 [2]云南大学生态与环境学院云南省高校土壤生态与健康重点实验室,云南昆明650500 [3]南昌工程学院江西省退化生态系统修复与流域生态水文重点实验室,江西南昌330099

出　　处：《浙江农林大学学报》2021年第5期945-952,共8页Journal of Zhejiang A&F University

基　　金：国家自然科学基金资助项目(31570444,31360175);江西省教育厅科技项目(KJLD12097,GJJ14744)。

摘　　要：【目的】探讨长期氮沉降和季节变化对杉木Cunninghamia lanceolata人工林无机氮及氮素转化速率的影响。【方法】以福建省三明市沙县官庄国有林场亚热带人工杉木林为研究对象,开展长期(10 a)氮添加梯度(对照:N_(0);低氮:N_(1);中氮:N_(2);高氮:N_(3))野外控制试验,通过野外原位培养方法测定氮添加对净氮矿化、硝化和淋溶的影响。【结果】①氮添加显著提高了铵态氮(NH_(4)^(+)-N)、硝态氮(NO_(3)^(−)-N)和总无机氮质量分数,从大到小均依次为N_(3)、N_(2)、N_(1)、N_(0),且铵态氮质量分数均高于硝态氮。②氮素转化速率随氮添加梯度而增大,高氮显著促进了氮素转化(P<0.05)。③季节显著影响氮素转化(P<0.05),净氮矿化速率、硝化速率与淋溶速率均表现为夏季高、冬季低的季节动态。【结论】氮添加显著增加了土壤无机氮与氮素转化速率,土壤pH、碳氮比(C/N)和土壤温度可能是研究区氮添加驱动氮素转化的主要因子。在杉木人工林的经营与管理中需要更多关注土壤养分和氮素转化速率对外源氮输入的响应。[Objective]With an experiment conducted Guanzhuang National Forestry Farm,Sha County,Sanming City of Fujian Province,this study is aimed to investigate the effects of long-term nitrogen(N)deposition and seasonal change on inorganic N and N transformation rates in the Cunninghamia lanceolata plantation.[Method]Besides a long-term(10-year-long)N addition experiment with four gradients(control:N_(0),low:N_(1),medium:N_(2),high:N_(3)),the cultivation experiment in situ was conducted to determinate the N mineralization,nitrification and leaching rates in response to N addition.[Result](1)N addition significantly increased the mass fractions of ammonium N(NH_(4)^(+)-N),nitrate N(NO_(3)^(−)-N)and total inorganic N,showing the trend of N_(3),N_(2),N_(1)and N_(0),and the ammonium N was higher than nitrate N.(2)N transformation rates increased with the N addition gradients,while high N addition significantly promoted the N transformation rates.(3)Seasonal changes significantly affected N transformation rates,and the N mineralization,nitrification and leaching rates were higher in summer and lower in winter.[Conclusion]N addition significantly increased soil inorganic N and N transformation rates whereas soil pH,C/N ratio and temperature may be the factors of N addition driving soil inorganic N and N transformation rates in the C.lanceolata plantation.Therefore,closer attention should be paid to the response of soil nutrients and N transformation rates to exogenous N input in the management of C.lanceolata plantation.

关 键 词：氮矿化 硝化作用 氮素淋溶 全球变化 土壤养分 

分 类 号：S718.5[农业科学—林学]