真红树植物的净光合速率与其相关生理生态因子的关系

Analysis of Net Photosynthetic Rate and Related Physio-ecological Factors of Mangrove Trees in Zhanjiang

为探讨真红树植物光合生理生态特性,以常见真红树林树种为研究对象,用Li-6400便携式光合仪测定了净光合速率(Pn)日变化、光合有效辐射(PAR)、气孔导度(Gs)、叶片细胞间CO2浓度(Ci)、叶面温度(Tl)、叶面水气压亏缺(Vpdl)、蒸腾速率(Tr)等指标。结果表明:1)白骨壤、木榄、桐花树、无瓣海桑的Pn日变化呈"双峰"趋势,秋茄的接近"双峰",红海榄为"单峰";2)以Gs(X1)、Ci(X2)、Tr(X3)、Vpdl(X4)、PAR(X5)、Tl(X6)与Pn(Y)进行多元逐步分析得最优回归方程,白骨壤:Y=4.419+0.07 X5-6.429 X4+0.813 X6-0.064 X2+0.668 X3(R=0.969**),红海榄:Y=-8.035+32.787 X1-0.053 X2-3.503 X4+0.945 X6(R=0.963**),木榄:Y=13.528+40.28 X1-0.045 X2(R=0.938**),秋茄:Y=21.211-0.055 X2+18.951 X1+0.001 X5(R=0.975**),桐花树:Y=63.637-0.448 X1-0.053 X2+1.995 X3+1.770 X4+0.001 X5-1.461 X6(R=0.990**),无瓣海桑:Y=27.368-0.067 X2+20.081 X1(R=0.985**);3)白骨壤的Pn与Ci和PAR相关关系最强,其中与Ci是负相关关系,与PAR是正相关关系。红海榄、木榄和无瓣海桑的Gs和Ci对Pn的影响最大,分别是正相关和负相关。秋茄Ci与Pn的相关关系最强,为负相关。桐花树Ci、Tr及Tl与其Pn的偏相关显著性水平高。

A portable photosynthetic system （Li-6400） was used to measure the diurnal changes of net photosynthetic rate （Pn）, photosynthetic active radiation （PAR）, stomata conductance （Gs）, intercellular carbon dioxide concentration （Ci）, leaf temperature （Tl）, vapor pressure deficit at the leaf surface （Vpdl）, transpiration rate （Tr） of mangrove plant in sunny day. The results showed as follow： 1） the diurnal variation Pn of Avicennia marina, Bruguiera gymnorhiza, Aegiceras corniculatum and Sonneratia apetala appeared a trend of ＂double peaks＂, the diurnal change of Kandelia candel closed to ＂double peaks＂, Rhizophora stylosa was ＂single peak＂. 2） The optimal regression equations of each species were obtained by multiple stepwise analysis： A. marina, Y=4. 419 4-0.07X5-6. 429X4 ＋0. 813X6-0. 064X2 ＋0. 668Xa （R=0. 969 ^＊＊ ） ; R. stylosa, Y= -8. 035＋32. 787X1 -0. 053X2 -3. 503X4 ＋0. 945X6 （R=0. 963^＊＊ ） ; B. gymnorhiza, Y 13. 528 ＋ 40. 28X1- 0. 045X2 （R = 0. 938^＊＊ ）; K. candel： Y= 21. 211- 0. 055X2 ＋ 18. 951X1 -0. 001X5 （R=0. 975^＊＊ ）, Aegiceras corniculatum, Y=63. 637-0. 448X1 -0. 053X2 ＋1. 995X3 ＋1. 770X4 ＋ 0. 001X5 - 1. 461X6 （R = 0. 990 ^＊＊ ） ; S. apetala. Y= 27. 368 - 0. 067X2 ＋ 20. 081X1 （R = 0. 985^＊＊ ）. 3） Pn of Avicennia marina had the strongest correlation with Ci and PAR, which was negatively correlated with Ci, and positively with PAR. Gs and Ci of R. stylosa, B. gymnorhiza and S. apetala exhibited maximum impacts to Pn, and positively and negatively correlated, respectively. Correlation between Ci and Pn of K. candel had the strongest negative correlation. Ci, Tr and TI of Aegiceras corniculatum had high level of partial correlation significance with Pn.