桂林岩溶石山光蜡树群落常见植物夏季光合特性研究  

Study on the photosynthetic characteristics of several common plants of Fraxinus griffithii community in summer on Guilin's karst hills

作　　者：杨红兰[1] 刘绍俊[1] 李军伟[1] 廖盛夏[1] 甘肖梅[1] 梁士楚[1,2] 

机构地区：[1]广西师范大学生命科学学院,广西桂林541004 [2]广西环境工程与保护评价重点实验室,广西桂林541004

出　　处：《中南林业科技大学学报》2010年第12期28-33,共6页Journal of Central South University of Forestry & Technology

基　　金：国家重点基础研究发展计划项目(2006CB403207);广西环境工程与保护评价重点实验室研究基金资助项目(桂科能0702Z014);广西研究生教育创新计划项目(2009106020710M56)

摘　　要：采用LI-6400型便携式光合仪,对光蜡树群落中的光蜡树Fraxinus griffithii、一叶萩Securinegasuf-fruticosa和粗糠柴Mallotus philippensis在夏季中的光合生理指标进行了测定。结果表明,在夏季,林冠层光蜡树的光饱和点和光补偿点分别为1 064μmol/(m2.s)和20μmol/(m2.s);净光合速率Pn日变化呈双峰型,最大净光合速率出现在12:00时,其值为4.45μmol/(m2.s),16:00时出现第二个峰值2.74μmol/(m2.s),与最大峰值相比降幅达38.43%。光合有效辐射VPAR、气孔导度Gs、蒸腾速率Tr、水分利用效率EWUE的日变化均呈双峰型曲线,胞间二氧化碳浓度Ci日变化呈"W"型曲线。光蜡树光合速率主要受气孔因素影响。林下植物一叶萩和粗糠柴的光饱和点和光补偿点分别为396,562μmol/(m2.s)和7,5μmol/(m2.s)。The characteristics of diurnal photosynthesis of several common plants,Fraxinus griffithii,Securinega suffruticosa and Mallotus philippensis,in Fraxinus griffithii Community in 2009 summer on Guilin＇s Karst Hills was measured using the LI-6400 photosynthesis system（LI-COR.USA）.The results show that the 1ight saturation point（VLSP） and 1ight compensation point（VLCP） of Fraxinus griffithii were respectively 1 064 μmol/（m2·s） and 20 μmol/（m2·s） in summer.The diurnal change of net photosynthetic rate（Pn） of Fraxinus griffithii leaves was a typical double peak curve with the first peak value（4.45 μmol/（m2·s）1） appearing at 12：00 pm and the second peak value（2.74 μmol/（m2·s）） at 16：00 p.m.Compared to the first peak value,the second peak value reduced by 38.43%.Diurnal course curves of photosynthetically active radiation（VPAR）,transpiration rate（Gs）,stomatal conductance（Tr） and water utilization efficiency（EWUE） were all a double-peak type,while those of intercellular CO2 concentration were a W-type.For Fraxinus griffithii,net photosynthetic rate was caused by stomatal.The 1ight saturation point（VLSP） and 1ight compensation point（VLCP） in Securinega suffruticosa and Mallotus philippensi,which grows under the forest,were 396,562 μmol/（m2·s） and 7,5 μmol/（m2·s）.

关 键 词：光蜡树 夏季 净光合速率 光曲线 日变化 

分 类 号：Q945.1[生物学—植物学]