太行山退化生境主要乔木树种光合日进程分析

研究太行山低山丘陵区退化生境上侧柏Platycladus orientalis,臭椿Ailanthus altissima,赞皇大枣Ziziphus jujuba var.inermis和刺槐Robinia pseudoacacia的光合日进程变化特征.结果表明:赞皇大枣的光合日变化类型属于左偏单峰型;其他树种光合生理代谢进程所属类型出现分异现象,表现为侧柏的光合速率属于左偏单峰型,气孔导度和蒸腾速率属于双峰型,刺槐光合速率和蒸腾速率属于单峰型,气孔导度属于左偏单峰型.侧柏、臭椿和刺槐的Fv/Fm谷值出现在13:00,赞皇大枣的Fv/Fm在10:00～13:00出现谷底;刺槐在傍晚时Fv/Fm恢复较快,而臭椿、侧柏和赞皇大枣恢复相对较慢.依据树种生理代谢过程日进程所属类型的分异现象,可为人工群落构建时的树种选择提供理论佐证.图5表4参17

Photosynthesis diurnal courses of main species in degraded habitat of Taihang Mountains

The photosynthetic diurnal courses of Ziziphus jujuba var.inermis,Robinia pseudoacacia,Platycladus orientalis and Ailanthus altissima were studied.The results showed that the diurnal changes of net photosynthesis(Pn),transpiration rate(Tr) and stomotal conductance(Cond) of Z.jujuba var.inermis were one-peaked curves,reaching a maximum at 10:00.The diurnal changes of Cond of R.pseudoacacia and Pn of P.orientalis were one-peaked curves,reaching a maximum at 9(:)00 and 10(:)00 respectively.And the diurnal changes of Pn and Tr of R.pseudoacacia were one-peaked curves,but that of Cond and Tr of P.orientalis were two-peaked curves.The F_v/F_m ratio of P.orientalis,A.altissima and R.pseudoacacia reached a minumin at 13(:)00 in a clear day of autumn,but F_v/F_m ratio of Z.jujuba var.inermis reached a minumin from 10(:)00 to 13(:)00.The F_v/F_m ratio of R.pseudoacacia came back quickly at sunset,but that of A.altissima, P.orientalis and Z.jujuba var.inermis came back slowly at sunset compared with that of R.pseudoacacia.The diunal courses of the photosynthesis of the tree species measured are different,so some suggestions about how to selecting these tree species in reconstructing artificial communities are put forward.Ch,5 fig.4 tab.17 ref.]