福建漳江口3种红树植物光合作用日变化特性研究

A Study on the Diurnal Change of Photosynthesis of Kandelia candel,Avicennia marina,and Aegiceras corniculatum at Zhangjiang Estuary

应用Li-6400XT便携式光合作用测定系统,首次对漳江口红树林天然群落中秋茄、白骨壤、桐花树在自然生境中夏季晴天的叶片净光合速率(Pn)、气孔导度(Cond)、蒸腾速率(Tr)、胞间CO2浓度(Ci)生理因子的日变化进程及其相互关系,以及环境因子对净光合速率的影响等进行研究。结果表明:秋茄、桐花树叶片净光合速率(Pn)的日变化趋势相似,两者Pn的峰值出现在8∶00和14∶00,而白骨壤Pn的峰值出现在8∶00和16∶00,日均Pn大小为白骨壤>秋茄>桐花树;3种红树的蒸腾速率(Tr)日变化规律各不相同,秋茄和桐花树Tr值最高均出现在8∶00,白骨壤Tr值最高出现在10∶00,日均Tr大小为白骨壤>桐花树>秋茄;水分利用效率(WUE):秋茄和白骨壤16∶00时最高,而桐花树12∶00时最高,日均WUE大小为秋茄>白骨壤>桐花树;植物的Pn和Tr不仅受到环境因子的影响,同时还受到内在生理因子的调节。相关分析结果表明,对Pn和Tr影响最高的环境因子是光合有效辐射(PAR),生理因子则为气孔导度(Cond)。

Measured with Licor-6400XT pothosynthesis system,the study focus on the diurnal change of some physiology factors in summer sunny days.Factors include net photosynthetic rate（Pn）,stomatal conductance（Cond）,intercellular CO2 concentration（Ci） and transpiration rate（Tr） etc.,of mangrove species Kandelia candel（Kc）,Avicennia marina（Am）,and Aegiceras corniculatum（Ac） in their natural habitat The research were yat Zhangjiang Estuary.Meanwhile,the correlation between Pn,Tr and the other physiology factors of the tree finds of mangrove and the influence of the ecological factors,such as photosynthetic available radiation（PAR）,temperature of leaf（Tl）,and air CO2 concentration etc.,to their photosynthesis were carried out too.The main results were as follows：The Pn diurnal change of Kc and Ac was similar,the double-peak value of Pn of Kc and Ac was 8 o’clock and 14 o’clock,and of Am was 8 o’clock and 16 o’clock.The average Pn of three mangrove species demonstrated the pattern of Am〉Kc〉Ac.The curves of daily course of Tr were different among the three mangrove species,the highest value of Tr of Kc and Ac was 8 o’clock and of Am was 10 o’clock.The average Tr of three mangrove species demonstrated the pattern of Am〉Ac〉Kc.The WUE diurnal variation of the three mangrove species were different,the highest value of WUE of Kc and Am was 16 o’clock and of Ac was 12 o’clock.The average WUE of three mangrove species demonstrated the pattern of Kc〉Am〉 Ac.The result of correlate analysis was that the correlation co-efficient between Pn,Tr and eco-physiological factors to the three mangrove species was that PAR and Cond were the most important influencing factors.