Abstract: It is investigated and simulated for the response of chlorphyll fluorescence of Artemisia ordosica, Salix psammophila,Hedysarum mongolicum and Caragana intermedia four dominant plants in Maowusu sandland,to global precipitation change by artificially controlling four water supply levels.The results show that different water supply significantly affected the initial fluorescence,maximal fluorescence,variable fluorescence and PSII photochemical efficiency of the dominant plants,and there were obviously differences in the effects of different water supply on those variables among the four plants.There were obvious water stress on S.psammophila,H.mongolicum,A.ordosica and C.intermedia treated by 157.5 mm water supply and C.intermedia treated by 630.0 mm water supply,and they showed clearly photoinhibition.

Key words: Simulated precipitation, Maowusu sandland, Dominant plant, Chlorophyll fluorescence, Water stress, Photoinhibition

摘要： 以毛乌素沙地4种优势植物沙柳、杨柴、油蒿和柠条为对象,研究人工控制4种施水量模拟叶绿素荧光的对全球降水量变化的响应。结果表明,不同施水量对供试植物的初始荧光、最大荧光、可变荧光和PSII光化学效率均具有显著影响。4种植物的以上参数对不同施水量的响应差异明显。施水量157.5mm,沙柳、杨柴、油蒿和柠条以及施水量630.0mm的柠条受到明显的水分胁迫,表现出明显的光抑制现象。

关键词: 模拟降水量, 毛乌素沙地, 优势植物, 叶绿素荧光, 水分胁迫, 光抑制