Abstract: In order to explore the adaptability of adventitious plants of extreme arid regions and chose suit cropping patterns of Tamarix ramasissima ledeb, the paper studied the photosynthesis characteristics of Tamarix ramasissima ledeb. by Li-6400 and soil water potential under four different cropping patterns(mixed by strips, mixed by row, mixed by group, the massive interplanting)in the same environment at the desert-oasis transitional area of the Cele oasis on the southern fringe of Taklimakan Desert in October 2010. The paper analysed and compared the physiology characteristics and water physiology of Tamarix ramasissima ledeb. under the four different cropping patterns, and the results show as follows:(1)Tamarix ramasissima ledeb. has high light saturation point(679-822 umol·m^-2·s^-1)and high light compensation point(50.0-61.1 umol·m^-2·s^-1).(2)The net photosynthetic rate(Pn)was affected by cropping patterns and illumination intensity, and the difference was great significantly(P<0.01). When the photosynthetic active radiation(PAR)reached between 0 and 1500 umol·m^-2·s^-1, all photosynthesis characteristics are increasing with the enhancement of light increases except the intercellular CO₂ concentration(Ci).(3)When the photosynthetic active radiation(PAR)reached higher than 1500 umol·m^-2·s^-1, the Gs of Tamarix ramasissima ledeb. under mixed by group and the massive interplanting patterns descended with the enhancement of light increases, while the Gs of Tamarix ramasissima ledeb. under mixed by strips and mixed by row patterns are opposite; the intercellular CO₂ concentration(Ci)and transpiration rate(Tr)under mixed by row pattern are all increase with the light enhanced, but under the other three patterns the two photosynthesis characteristics are all decrease or have no change;(4)the photosynthesis characteristics and physiology characteristics reflected significantly different of four cropping patterns(P<0.05), The maximum net assimilation rate(A_max), apparent quantum requirement(AQY), light saturation point(LSP)of Tamarix ramasissima ledeb. under line-mixed cropping patterns are all highest among four different patterns, and Tamarix ramasissima ledeb. under mixed by group pattern has biggest dark respiration rate. The water use efficiency(WUE)under four cropping patterns are all increasing as the he enhancement of light increases, and the order from high to low are:linemixed cropping patterns>group mixed cropping patterns>row mixed cropping patterns>the massive interplanting cropping patterns. According to comprehensive analysis of the photosynthesis characteristics of Tamarix ramasissima ledeb. under four cropping pattern, Tamarix ramasissima ledeb. under line-mixed cropping patterns had high Pn and high WUE, it showed the best adaptation to the southern marginal zone of the Taklimakan Desert where had sufficient sun light and extreme arid climate.

Key words: Tamarix ramasissima ledeb, cropping pattern, photosynthesis characteristics, physiology characteristics, light respons