浑善达克沙地植物蒸腾特征的研究

采用 L i-1 60 0型气孔仪测定了浑善达克沙地主要建群乡土植物种不同季节的蒸腾速率及其环境因子的日进程 ,结果表明 :浑善达克沙地中榆树、黄柳、圆叶桦、砂杞柳、羊草蒸腾速率的日变化均呈单峰曲线 ,而叉分蓼和楔叶茶子呈双峰曲线。同一种植物在不同样地土壤水分条件下 ,蒸腾速率不同。各植物种蒸腾速率的季节变化明显 ,7、8月份蒸腾速率高 ,6月份最低。各植物种中 ,黄柳为低蒸腾植物。回归分析表明 ,影响蒸腾速率最主要的因子为光照强度 ,其次为气温和空气相对湿度 ;蒸腾速率与各因子呈线性相关 ,其关系可用方程 Tr=a+b RH+c T+d Q表示。通过蒸腾速率的比较 ,提出了浑善达克沙地植被恢复应以建立“人工疏林草原”为主。

Research on Plant Transpiration Characteristics of Hunshandake Sand

This paper measured the transpiration rate (Tr) of main natural species and environmental factors by Li-1600 steady porometer at the different seasons on the Hunshandake sand. The result indicated the diurnal change trends of transpiration rate of the five plants (Ulmus pumila , Salix gordeievii,Salix kochiana?Betula gmelinii,Aneurolepidium chinense ) is single-range curve, whereas the other species (Polygonum divaricatum,Ries diacantha) transpiration rate diurnal course are bi-range curve. The transpiration rate of same plant is different in different soil water content of different plot. The changes of mean transpiration rate of these species are distinct in different seasons. The transpiration rate is highest in July, and lowest in June. The average transpiration rate of S. gordeievii is lowest in all species. The regression analysis suggests that the most dominant factor is photic intensity; the other factors are air relative humid and air temperature for every plant. The relationship between transpiration rate and environment factors are liner, the transpiration rate model can be expressed by the equation Tr=a+bRH+cT+dQ.