适度高温下高氮和低光对演替树种光合和能量转换的复合影响  

Combined effects of high-N and low-light on photosynthesis and energy transduction of successional tree species under moderate high-temperature.

作　　者：孙谷畴[1] 赵平[1] 曾小平[1] 蔡锡安[1] 

机构地区：[1]中国科学院华南植物研究所

出　　处：《北京林业大学学报》2009年第2期58-68,共11页Journal of Beijing Forestry University

基　　金：中国科学院知识创新工程重要方向项目(KSCX2-SW-133);国家自然科学基金项目(30428022;30770328);广东省自然科学基金项目(07006917)

摘　　要：利用CO2交换系统和叶绿素荧光法,研究适度高温(38℃)、高氮(HN)和低光(LL)对早、中和后期演替树种木荷、红椎和黄果厚壳桂幼树光合过程影响的初始靶的,及其对群落演替的潜在影响。结果表明:适度高温提升木荷和红椎高氮高光(HNHL)植株的光合速率(Pn),但高光强(>500μmol/(m2.s))限制木荷、红椎及黄果厚壳桂低氮高光(LNHL)和高氮低光(HNLL)植株Pn对适度高温的响应。当光强<500μmol/(m2.s),适度高温提高木荷LNHL植株的光下PSⅡ最大量子效率(Fv′/Fm′)、开启PSⅡ中心(Fq′/Fm′)和开启PSⅡ反应中心的比例(qL),以及非循环光启电子传递效率(ETR)和吸收光能利用于PSⅡ光反应(ΦPSII),但黄果厚壳桂不呈现类似响应。黄果厚壳桂HNLL植株多以非光辐射耗散吸收能和表现低的光化反应效率。气候变暖,华南珠江三角洲过量氮沉降和频繁的灰霾天气可能延缓当地森林植物群落的正向演替。CO_2 gas exchange and chlorophyll fluorescence measurement systems were used to investigate the potential effects of high nitrogen（HN） and low light（LL） on photosynthetic processes and forest succession of the saplings of early-successional species Schima superba,intermediate-sucessional species Castanopsis hytrix,and late-successional species Cryptocarya concinna under moderate high-temperature（38℃）.The results showed that moderate high-temperature increased net photosynthetic rates（P_n） of high nitrogen and high light（HNHL） plants of S.superb and C.hytrix.High light（〉500 μmol/（m^2·s）） restricted P_n-responses of low nitrogen and high light（LNHL） and high nitrogen and low light（HNLL） plants of all examined species to moderate high-temperature.Increases of the maximum quantum yield of PSII（F_v′/F_m′）,quantum efficiency（F_q′/F_m′）,fraction of opened PSII centers（q_L）,non-cycle photosynthetic electron transfer rate（ETR） and absorbed light energy used in photochemical reaction of PSII（Φ_（PSII）） in LNHL plants of S.superb and C.hystrix under moderate high-temperature were observed at the light level 〈500 μmol/（m^2·s）,but similar response was not found in HNLL plants of C.concinna.C.concinna plants dissipated more absorbed energy in thermal form and showed low photochemical efficiency.The results imply that increasing N deposition and frequent haze in Pearl River Delta area in southern China would defer the succession of forest community.

关 键 词：光合能量转换 适度高温 过量氮输入 演替树种 

分 类 号：S718.5[农业科学—林学]