天目山自然保护区典型阔叶林的光合生理特性

Photosynthetic Physiological Characteristics of the Broad-Leaved Forests in the Tianmu Mountain Nature Reserve

对天目山自然保护区内典型阔叶林树种交让木(Daphniphyllum macropodum),小叶青冈(Cyclobalanopsis myrsinaefolia),中国绣球(Hydrangea chinensis Maxim)不同月份和冻雨胁迫下的光合作用光响应、叶绿素荧光以及相对叶绿素含量进行了测定分析,以期了解其光合固碳能力、适应性以及抵御胁迫的内在机制.结果表明:(1)随季节变化3者Pn(净光合速率)、LSP(光饱和点)、Amax(最大净光合速率)、Rd(暗呼吸速率)、Fv/Fm(最大光化学效率)、Fv'/Fm'(实际光化学效率)、Fv/F0(潜在活性)、q P(光化学猝灭系数)、Yield(实际量子产量)、ETR(表观电子传递速率)、SPAD(相对叶绿素含量)均有不同程度下降,与此同时,LCP(光补偿点)、NPQ(非光化学猝灭系数)则是上升趋势;(2)交让木和小叶青冈净光合速率下降主要是由气孔因素引起,中国绣球主要是非气孔限制因素;(3)Pn亦有不同程度下降,但始终大于零.即他们抗耐性较强,光合效率较高,可为通量观测系统分析该生态系统碳汇角色提供依据.

In order to understand photosynthetic Carbon sequestration ability, adaptability and the internal mechanism of different months and the seasonal variation of the typical broad-leaved species in Tianmushan National Nature Reserve, we measured their photosynthesis light response, chlorophyll fluorescence and chlorophyll relative content in autumn and winter. The species included Daphniphyllum macropodum, Cyclobalanopsis myrsinaefolia and Hydrangea chinensis Maxim. The results showed as the followings. （1）along with the seasonal variation, Pn （net photosynthetic rate）, LSP （light saturation point）, Amax （maximum net photosynthetic rate）, AQY （ apparent quantum efficiency）, Fv＇/Fm＇ （ the actual photochemical efficiency）, Yield （the actual quantum yield）, ETR （the apparent electron transport rate）, as well as SPAD （the chlorophyll relative content） were all decreased firstly and then increased in different degree, and LCP （light compensation point） and NPQ （Non photochemical quenching coefficient） were increased; （2） the decrease of Daphniphyllum macropodum, Cyclobalanopsis myrsinaefolia Pn were mainly controlled by stomatal factor, and Hydrangea chinensis Maxim were non-stomatal factor （3） The means of Pn decreased to varying degrees, but always greater than zero. Overall, they had strong resistance and higher photosynthetic efficiency, could provide the basis to the flux observation system analysis of this ecosystem as carbon sequestration.