向家坝工程扰动区3种先锋灌木的光合生理特性

The Photosynthetic Physiological Characteristics of Three Pioneer Shrub Species in the Disturbed Area of Xiangjiaba Project

通过对向家坝工程扰动区内的木蓝(Indigofera tinctoria)、盐肤木(Rhus chinensis)、海桐(Pittosporum tobira)等3种生态恢复先锋灌木的光合与水分生理特性的分析测定,结果表明:海桐、盐肤木及木蓝的光饱和点在1 000～1 200μmol.m-2.s-1,光补偿点均低于30μmol.m-2.s-1,各物种的表观量子效率均在0.05～0.06间,表明3种灌木均为喜阳植物,对弱光利用能力均比较强。在光强为1 000μmol.m-2.s-1的光照条件下,3种灌木净光合速率差异不显著,均表现出较强的净光合能力;海桐和木蓝的蒸腾速率显著低于盐肤木,但水分利用率显著高于盐肤木。

Through the analysis and test of photosynthesis and water physiology of three kinds of pioneer shrubs, including Indigofera tinctoria, Rhus chinensis and Pittosporum tobira in the disturbed Area of Xiangjiaba Project. Results showed that the light saturation points of three kinds of pioneer shrubs ranged between 1 000 -1 200 μmol· m^-2 ·s^-1 respectively, and their light com- pensation points were all below 30μmol· m^-2 ·s^-1. The apparent quantum efficiency of them were 0.05 - 0.06. It indicated that all of them were heliophilous plants which had a good ability to take use of low light. The net photosynthetic rate did not differ significantly among the three species, they had shown strong net photosynthetic capacity. The transpiration rates of Pittosporum tobira and Indigo fera tinctoria were significantly lower than that of Rhus chinensis, however, the water used efficiency of them significandy higher than that of Rhus chineusis.