氮添加对杉木凋落物分解过程中酶活性的影响  

Effects of Exogenous Nitrogen Input on Enzyme Activity during Litters Decomposition of Cunninghamia lanceolata

作　　者：费裕翀 伍丽华 陈义堂 叶义全[1] 曹世江 郑宏 林开敏[1] 曹光球[1] Fei Yuchong;Wu Lihua;Chen Yitang;Ye Yiquan;Cao Shijiang;Zhen Hong;Lin Kaimin;Cao Guangqiu(Fujian Agriculture and Forestry University,Fuzhou 350002,P.R.China;Fujian Yangkou State-owned Forest Farm)

机构地区：[1]福建农林大学,福州350002 [2]福建省洋口国有林场

出　　处：《东北林业大学学报》2023年第5期66-73,共8页Journal of Northeast Forestry University

基　　金：福建省引导性项目(2018N0001),国家重点研发计划项目(2016YFD0600301)。

摘　　要：为了探究氮添加下,凋落物分解微环境碳氮比凋落物碳质量分数(w(C))与凋落物氮质量分数(w(N))的比(w(C)∶w(N))在杉木凋落物分解过程中的作用机制。以福建省洋口国有林场南元管护站的杉木人工林为研究对象,在林下植被保留和林下植被去除林分内,各设置3块样地,经外源氮素喷施处理后,将具有不同w(C)∶w(N)比(40.6、30.5、20.3)处理和未处理(w(C)∶w(N)为60.9)的杉木凋落叶分别布置于杉木人工林样地内,每个样地放置35袋,每袋10 g,间隔60 d,每个样地取出6袋,测定杉木凋落叶在300 d内的分解速率和酶活性的动态变化。结果表明:当w(C)∶w(N)为40.6和30.5对杉木凋落叶的分解具有促进作用;氮添加对杉木凋落叶分解过程中纤维素酶、脲酶活性具有促进作用,对酸性磷酸酶、过氧化物酶和多酚氧化酶活性具有抑制作用;与林下植被去除林分相比,林下植被保留林分更有利于杉木凋落叶的分解和酶活性的提升,但氮添加输入量过高对于凋落叶分解和酶活性产生抑制作用;杉木凋落叶质量损失率与各类酶活性呈显著正相关和线性关系,其中拟合效果以纤维素酶活性最佳。因此,w(C)∶w(N)为40.6和30.5时,有利于杉木凋落叶分解酶活性的提升,但杉木凋落叶分解速率受林分环境的影响。In order to explore the internal mechanism of C/N ratio regulating the decomposition of Cunninghamia lanceolata litters,C.lanceolata litters with different C/N ratios(40.6,30.5,20.3)and untreated(60.9,C/N ratio)regulated by nitrogen addition was placed in the C.lanceolata plantations managed by understory vegetation preservation and undergrowth vegetation removal,and the dynamic changes of decomposition rate and enzyme activity of C.lanceolata litters were studied within 300-d decomposition.C/N ratios of approximately 40.6 and 30.5 could promote the decomposition of C.lanceolata litters;In general,reduction of the initial C/N ratio can promote the activities of cellulase and urease in the decomposition process of C.lanceolata litters,and had an inhibitory effect on the activities of acid phosphatase,peroxidase and polyphenol oxidase.Compared with undergrowth vegetation removal,undergrowth vegetation preservation was more conducive to the decomposition of litters and the increase of enzyme activity of C.lanceolata litters,however,high nitrogen input is more likely to inhibit the decomposition and enzyme activities of leaf litter of C.lanceolata litters.The weight loss rate of C.lanceolata litters was significantly positively and linearly correlated with the activities of various enzymes,and the equation of cellulase activity and weight loss rate has the best fitting effect.Studies have shown that that C/N ratios of approximately 40.6 and 30.5 is conducive to the improvement of enzyme activity of C.lanceolata litters,butits decomposition speed is affected by the stand environment.

关 键 词：杉木凋落叶 林下植被管理 碳氮比 酶活性 

分 类 号：S571.1[农业科学—茶叶生产加工]