应用生态学报2017，Vol.28Issue(6)：1753-1760,8.DOI:10.13287/j.1001-9332.201706.040
川西高海拔增温和加氮对红杉凋落物有机组分释放的影响
Impacts of warming and nitrogen addition on organic fraction release in fresh litter of Larix potaninii in alpine zone of the western Sichuan Province, China
摘要
Abstract
The decomposition dynamics of organic components in fresh litter of Larix potaninii were monitored by in situ litter-bag incubation under four treatments,i.e.,field condition (CK),nitrogen addition (AN,2 g N · m-2),warming by top-open chamber (OTC),nitrogen addition with warming by top-open chamber (OTC+AN),from November to next September.Decomposition of water-soluble sugar,water-soluble phenol and total polyphenol were stimulated significantly under the treatment OTC,AN and OTC+AN during the first four months compared with the CK,but the difference of these components release narrowed with the extension of incubation time.Compared with CK,releases of dichloromethane-extractable fraction,acid soluble carbohydrates,acid soluble lignin,and acid insoluble lignin,were inhibited significantly under OTC,AN,and OTC+AN treatments,and the significance of inhibitory effect under the treatments was:OTC ＞ OTC+AN ＞ AN.Especially,in the treatment of OTC,half-life of dichloromethane-extractable fraction and acid insoluble lignin in fresh litter were doubled,and that of hot-water soluble component was prolonged by more than 50％ compared with CK.Half-life of water-soluble sugar,water-soluble phenol,total polyphenol,acid-soluble carbohydrate and acid-soluble lignin in fresh litter were respectively 182,159,127,154 and 190 d in CK,and these components seem to be easily mineralized organic fraction.Meanwhile,half-life of hot-water soluble components,dichloromethane-extractable fraction,nd acid insoluble lignin was 209,302 and 318 d,respectively,indicating these fractions recalcitrant to decomposing in the fresh litter.Decomposition of all components in L.potaninii litter occurred in cold season from November to next March,which suggested that cold season was the most important period for litter decay in the alpine conifer.Generally it was assumed that microorganisms were inactive and decomposition of organic matters was slow in alpine soil during harsh winter,while the results of fresh litter incubation in situ showed that all components decomposed very fast during the period.Therefore,in alpine treeline,nitrogen deposition and warming would inhibit rather than promote decomposition of fresh litter,which would be conducive to carbon sequestration for the alpine soil ecosystem.关键词
高山树线/红杉/凋落物分解/有机组分Key words
alpine treeline/Larix potaninii/litter decomposition/organic fraction引用本文复制引用
陈玥希,陈蓓,孙辉,马丽红,沈丹杰,刘堰杨..川西高海拔增温和加氮对红杉凋落物有机组分释放的影响[J].应用生态学报,2017,28(6):1753-1760,8.基金项目
本文由国家自然科学基金项目(41271094)资助 This work was supported by the National Natural Science Foundation of China (41271094). （41271094）
