增温对亚热带杉木枝和叶凋落物理化性质的影响  

Effects of warming on physicochemical property of Cunninghamia lanceolata branch and leaf litter in sub-tropical plantation.

作　　者：李澳归 林成芳[1,2] 胡明艳 刘小飞 宋豪威[1,2] 张磊 杨玉盛 LI Ao-gui;LIN Cheng-fang;HU Ming-yan;LIU Xiao-fei;SONG Hao-wei;ZHANG Lei;YANG Yu-sheng(School of Geographical Sciences,Fujian Normal University/Cultivation Base of State Key Laboratory of Humid Subtraphical Mountain Ecology,Fuzhou 350007,China;Sanming Forest Ecosys-tem and Global Change National Observation and Research Station of Fujian Province,Sanming 365000,Fujian,China)

机构地区：[1]福建师范大学地理科学学院/湿润亚热带山地生态国家重点实验室培育基地,福州350007 [2]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：《应用生态学报》2022年第10期2711-2717,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(31770663);福建师范大学本科教改项目(I202002102)资助。

摘　　要：在区域尺度上,凋落物的底物性质是决定其分解速率的关键因素。本研究以亚热带杉木人工林为对象,通过埋设电缆进行土壤增温,分析气候变暖对杉木枝、叶凋落物理化性质的影响。结果表明:经过5年的土壤增温试验(4℃),杉木枝凋落物的氮(N)、磷(P)含量和可萃取物含量分别增加35.2%、40.8%、7.6%,叶凋落物分别增加41.2%、45.9%、5.9%;枝凋落物的碳(C)含量、纤维素含量和C/N分别降低5.1%、11.6%、28.8%,叶凋落物分别降低5.3%、11.3%、33.3%。土壤增温导致杉木叶凋落物的比叶面积提高29.8%,抗拉强度减小40.7%,但增温对杉木枝和叶凋落物木质素含量和pH值无显著影响。^(13)C NMR和红外光谱分析显示,增温后杉木凋落物中氨基酸、多糖、多酚和脂肪族化合物含量变化显著,而且在不同器官凋落物之间有所差别,表现为多糖类物质只在叶凋落物中显著增加,枝凋落物中氨基酸的增加量大于叶凋落物。土壤增温显著改变了杉木枝、叶凋落物的理化性质,N、P养分含量的提高以及抗拉强度减小等特征可能加速初期凋落物的分解速率,而由于复杂大分子化合物的增多,后期凋落物的分解速率可能较慢。At the regional scale,substrate properties are the key factors driving litter decomposition rate.In this study,soil temperature was increased by buried heating cables to explore the impacts of climate warming on the physical and chemical properties in branch and leaf of Cunninghamia lanceolata litter.The results showed that after 5 years of soil warming(4℃),the contents of nitrogen(N),phosphorus(P)and water-soluble substance in branch litter increased by 35.2%,40.8%and 7.6%,while that in leaf litter increased by 41.2%,45.9%and 5.9%,respectively.The contents of carbon(C),cellulose and C/N in branch litter decreased by 5.1%,11.6%and 28.8%,and in leaf litter decreased by 5.3%,11.3%and 33.3%,respectively.Soil warming led to 29.8%increase in specific leaf area(SLA)and 40.7%decrease in tensile strength(LTS)of leaf litter.However,warming did not affect lignin content and pH value in both branch and leaf litter.^(13)C NMR and infrared spectrum analysis showed that the contents of amino acids,polysaccharides,polyphenols and aliphatic compounds in litter changed significantly after warming.Warming effect differed between litter organs,in that polysaccharides increased signifi-cantly only in leaf litter and the increase of amino acids in branch litter was greater than that in leaf litter.Overall,soil warming significantly changed the physical and chemical properties in C.lanceolata branch and leaf litter,which might accelerate the decomposition rate at the initial stage due to the increase of N,P contents and the decrease of LTS,but might decelerate the decomposition rate at the later stage due to an increase of complex poly-mers content in the litter.

关 键 词：土壤增温 凋落物 理化性质 亚热带杉木人工林 

分 类 号：S714[农业科学—林学]