论文部分内容阅读
沙冬青 (Ammopiptanthusmongolicus (Maxim) )是沙漠地区及干早荒漠区唯一的天然常绿灌木 ,其独特的生物学特性与适应性对于研究干旱环境条件下植物的适应机制与植物生态系统多样性具有重要意义 .研究结果表明 ,沙冬青在严重干旱环境条件下 ,其光合速率的日变化在上午10 :0 0时左右即达到最大值 ,日平均值仅为 2 .14umol.m- 2 .s- 1,表现出典型的旱生植物光合作用特性 ;其蒸腾速率在一天中也表现为较低水平 ,日平均值为 7.0 3mmol.m- 2 .s- 1.此外 ,沙冬青叶片气孔的调节作用与叶片的光合作用和蒸腾作用都没有表现出密切关系 ,这与植物自身的生理特性有关 ,也受环境条件尤其是干旱条件的影响
Ammopiptanthus mongolicus (Maxim) is the only natural evergreen shrub in desert and dry desert areas. Its unique biological characteristics and adaptability are very important to study plant adaptation mechanisms and plant ecosystem diversity in arid environments Significance.Results showed that under the severe drought conditions, the annual change of photosynthetic rate of A. astigmatum reached its maximum at about 10: 00 in the morning with the daily average of only 2.14umol.m-2 .s-1 , Showing photosynthetic characteristics of typical xerophytes; its transpiration rate also showed a low level in one day with a daily average value of 7.0 3 mmol.m -2 .s -1. In addition, the regulation of leaf stomatal conductance Neither the photosynthesis nor the transpiration of the leaves showed any close relationship, which was related to the physiological characteristics of the plants themselves and also influenced by the environmental conditions, especially the drought conditions