FACE试验对土壤有机质库组分及其激发效应的影响  

Influence of FACE experiment on soil organic matter pools and priming effect

作　　者：尚卫辉[1] 舒薇[2] 李永涛[1] Marcel R.Hoosbeek Giuseppe E.Scarascia-Mugnozza 

机构地区：[1]华南农业大学资源环境学院 [2]华南农业大学测试中心 [3]Department of Environmental Sciences,Earth System Science Group,Wageningen University,Wageningen P.O.Box 37,6700AA,The Netherlands [4]Department of Forest Environment and Resources,University of Tuscia,Viterbo Via S. Camillo De Lellis,01100, Italy

出　　处：《生态环境》2008年第4期1518-1522,共5页Ecology and Environmnet

基　　金：国家自然科学基金项目(40771110);欧盟第五框架计划项目(EVR-CT-2002–40027)

摘　　要：以意大利的FACE(Free atmospheric CO2enrichment)长期定位试验区和大气环境控制装置为研究对象,用化学分步酸提法将土壤有机质分离为活性库、慢库和惰性库,并培养测定土壤有机氮的矿化率,研究人工模拟大气CO2富集、施氮肥及植株类型对土壤有机质库及激发效应的影响。第一茬(POP FACE)试验产生了激发效应,但第二茬(Euro FACE)试验CO2处理区的总碳增加量显著高于对照处理区,即激发效应终止。主成分分析显示,有效氮的矿化水平已成为有机质降解的制约因素。据此推断,试验区由活性碳和有效氮控制的激发效应阶段转变为氮利用受限所引起的碳积累阶段。CO2富集对N矿化率、慢库和惰性库均无显著性影响。研究结果表明,土壤的激发效应不仅受有机碳的活性库制约,氮的矿化率也是影响其发生的关键因子之一。The SOM （soil organic matter） pool, priming effect of CO2 enrichment, fertilization and plant species were investigated with FACE （free atmospheric CO2 enrichment） object. The labile, refractory and stable pool of soil C and N were partitioned by acid hydrolysis and N mineralization was simultaneously determined. A priming effect was revealed in the first rotation （POP FACE）, but total soil C content increased faster under FACE treatment than under ambient CO2 treatment in the second rotation （Euro FACE）, which indicated the termination of priming effect. The principal component analysis showed that N mineralization level was a restrictive factor of organic matter decomposition. The results suggested that labile C and sufficient N availability caused a priming effect, and extra C input was accumulating due to limited N availability. The refractory and stable fractions had not significant effects in all treatments. Both labile pool and N lnineralization are key factors affecting the priming effect.

关 键 词：有机质库 CO2富集 FACE 活性碳 酸提法 

分 类 号：X144[环境科学与工程—环境科学] S153.621[农业科学—土壤学]