乌梁素海野生芦苇光合和蒸腾特性研究

Study on the Photosynthetic and Transpiration Properties of Wild Phragmites australis in the Wuliangsuhai Lake, Inner Mongolia

芦苇(Phragmitesaustralis)是草型浅水湖泊最常见的湿地植物。本文选取生物量不同的两块样地对成熟期乌梁素海野生芦苇叶片光合和蒸腾速率进行测定。研究表明,(1)生物量较高样地的饱和净光合速率和光量子利用效率分别为27.46μmol·s-1·m-2和0.052,高于生物量较低样地的23.94μmol·s-1·m-2和0.041;(2)光合有效辐射是决定芦苇叶片瞬时光合速率的首要因素,而叶片的蒸腾速率主要取决于大气温度和光合有效辐射;(3)叶片的光合速率和蒸腾速率与气孔导度呈显著正相关关系。并且蒸腾速率和气孔导度的相关性更强;(4)芦苇的光合速率和蒸腾速率都高于附近的草原植物。

Wild Phragmites australis is one of the common species of cosmopolitan perennial plants and of the species of wetland plants growing in shallow water lakes in arid regions, offering many ecosystem services to local environment. In September 2002, the photosynthetic and transpiration properties of wild Phragmites australis growing in the Wuliangsuhai Lake, a eutrophicated wetland in Inner Mongolia, were studied, and the environmental factors were surveyed by using the portable photosynthesis system (type CIRAS-1). The results are as follows: (1) The net photosynthetic rate and the photons use efficiency in the leaves of Phragmites australis were 27.46 μmol CO 2·s -1 ·m -2 and 0.052 respectively at the sampling site with high biomass, which were higher than 23.94 μmol CO 2 ·s -1 ·m -2 and 0.041 at the sampling site with low biomass; (2) The photosynthetic effective radiation was the dominant factor affecting the instantaneous photosynthetic rate of the leaves of Phragmites australis, and the transpiration rate of the leaves of Phragmites australis was mainly affected by air temperature and the photosynthetic effective radiation; (3) There was a significant positive correlation between the photosynthetic rate and transpiration rate and the stomatal conductance of the leaves of Phragmites australis, and there was also a significant correlation between the transpiration rate and the stomatal conductance of the leaves of Phragmites australis; (4) The photosynthetic rate and transpiration rate of the leaves of Phragmites australis were higher than that of other plants nearby.