毛乌素沙地SPAC系统中各部分水分状况及其关系的研究

Water conditions and relationship among the components of the SPAC system of Mu Us sandy land, China

以SPAC理论为指导,用压力室法及烘干法测定了宁夏盐池沙地表征沙生植物油蒿(Artemisia ordosica Krasch.)和中间锦鸡儿(Caragana intermedia Kuang et H.C. Fu)水分生理特征的系列指标____植物水势、组织含水量等,比较了两种植物的水分生理特征;同时用TDR水分速测仪结合烘干法测定了土壤水分参数;通风干湿表和气压计测定大气水分状况。分析了两种植物的水分生理特征与环境的相互关系。结果表明油蒿和中间锦鸡儿有着适应干旱生境的水分生理特征,但避旱的具体方式不同。雨季时期土壤含水量较大,除了10 cm左右土层处于难效状态外,其它各土层都处于易效状态。表层干土层的形成利于下层土壤水分的保持。水势梯度明显,时空变异规律明显,不论是油蒿还是中间锦鸡儿的叶水势值和大气水势相关性显著。

Water physiological characteristics of two desert plants as Artemisia ordosica Krasch and Caragana intermedia Kuang et H. C. Fu were studied through using pressure chamber and drying method. The study makes a comparison of water physiological characteristics between two species and analyzes the relationship among the components of the SPAC system. The study shows that the two plants both have physiological characteristics adapt to the arid climate, but the ways to resist the aridity are different. Water content of the soil is comparatively higher in the rainy season. A dry layer formed under the surface benefits water conservation of the lower layers. The water potential gradient and space-time variation are evident. The relationship between water potential of the plants and water potential of the air is notable.