Changes in leaf nutrient traits and photosynthesis of four tree species: effects of elevated [CO_(2)], N fertilization and canopy positions  

作　　者：Juxiu Liu Deqiang Zhang Guoyi Zhou Honglang Duan 

机构地区：[1]Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems,South China Botanical Garden,Chinese Academy of Sciences,Guangzhou 510650,China

出　　处：《Journal of Plant Ecology》2012年第4期376-390,共15页植物生态学报（英文版）

基　　金：National Natural Science Foundation of China(31070439);the Knowledge Innovation Program of the Chinese Academy of Sciences(KSCX2-EW-Q-8);the National Key Technology R&D Program(2009BADC6B02);the Natural Science Foundation of Guangdong Province,China(8351065005000001).

摘　　要：Aims Leaf traits of trees exposed to elevated[CO_(2)]in association with other environmental factors are poorly understood in tropical and subtropical regions.Our goal was to investigate the impacts of elevated[CO_(2)]and N fertilization on leaf traits in southern China.Methods Four tree species,Schima superba Gardn.et Champ.(S.superba),Ormosia pinnata(Lour.)Merr(O.pinnata),Castanopsis hystrix AC.DC.(C.hystrix)and Acmena acuminatissima(Blume)Merr.et Perry(A.acuminatissima)were studied in a factorial combination of atmospheric[CO_(2)](ambient at~390μmol mol^(-1)and elevated[CO_(2)]at~700μmol mol^(-1))and N fertilization(ambient and ambient+100 kg N ha^(-1)year^(-1))in open-top chambers in southern China for 5 years.Leaf mass per unit leaf area(LMA),leaf nutrient concentration and photosynthesis(A_(sat))were measured.Important Findings Results indicated that leaf traits and photosynthesis were affected differently by elevated[CO_(2)]and N fertilization among species.Elevated[CO_(2)]decreased LMA in all species,while N fertilization did not affect LMA.Leaf mass-based N concentration(N_(M))was significantly greater in O.pinnata and C.hystrix grown in elevated[CO_(2)]but was lower in S.superba.Leaf mass-based P concentration(P_(M))was significantly greater in C.hystrix and A.acuminatissima exposed to elevated[CO_(2)]but was lower in S.superba.N fertilization significantly increased P_(M) in O.pinnata but decreased P_(M) in S.superba.Photosynthetic stimulation in O.pinnata,C.hystrix and A.acuminatissima was sustained after 5 years of CO_(2)fumigation.N fertilization did not modify the effects of elevated[CO_(2)]on photosynthesis.Leaf traits(N_(M),N_(A),P_(M),P_(A))and light-saturated photosynthesis were decreased from the upper to lower canopy.Canopy position did not alter the responses of leaf traits and photosynthesis to elevated[CO_(2)].Results suggest that photosynthetic stimulation by elevated[CO_(2)]in native species in subtropical regions may be sustained in the long term.

关 键 词：PHOTOSYNTHESIS elevated CO_(2) nitrogen phosphorus subtropical China 

分 类 号：G63[文化科学—教育学]