不同时期毛乌素沙区主要植物种光合作用和蒸腾作用的变化

CHANGES IN PHOTOSYNTHESIS AND TRANSPIRATION OF MAIN CONSTRUCTIVE PLANTS IN WU US DESERT

采用ＬＩ－６０００便携式光合分析系统对毛乌素沙区主要植物种油蒿、中间锦鸡儿、旱柳进行了不同时期光合作用，蒸腾作用日进程的测定，并同步测定有效光辐射、空气相对湿度、叶温、气温、胞间ＣＯ２浓度、气孔阻力、叶片水势及土壤水势等因子；结果表明：不同时期、不同植物种其光合、蒸腾特征各异；植物的光合、蒸腾与环境因子和植物内部因子之间有密切关系，其中有效光辐射是影响光合作用、蒸腾作用诸因子中的主导因子，而气孔阻力变化则在调节光合和蒸腾中起着重要作用；不同植物种间气孔对环境条件变化的响应程度不同，以中间锦鸡儿最为灵敏；３种植物的水分利用效率表明，中间锦鸡儿的水分利用效率较油蒿、旱柳为高．

Photosynthesis and transpiration of main constructive plants (Artemisia ordosica, Caragana intermedia and Salix matsudana) in Mu US Desert were measured with model LI 6000 photosynthesis system in different periods. In addition, the photosynthesis active radiation, relative humidity, leaf temperature, air tempeatue, intercellular CO2 concentration, stomatal resistance, leaf water potential, soil moisture and so on were also measured. The results showed that photosynthesis and transpiration for different species at different periods were different and closely related to environmental conditions and plant internal factors. Photosynthesis active radiation was the dominant factor,and leaf stomatal resistance also played an important role in plant photosynthesis and transpiration. Different plant species had different responses to natural conditions, among them, Caragana intermedia was more sensitive than the other two species. The effect of soil moisture condition on leaf water potential of Artemisia ordosica was most noticeable. Water use efficiency of Caragana intermedia was also higher as compared with the other two species.