控水处理对胡杨、灰胡杨生长特性及水分利用效率的影响

为提高塔里木盆地农田防护林灌溉水的利用效率，选择适宜的防护林树种，以塔里木荒漠优势树种胡杨和灰胡杨为试验材料,利用盆栽方法研究不同控水处理对2树种的生长特性、光合参数、叶绿素荧光动力学参数、蒸腾耗水特性和水分利用效率的影响。结果表明，2树种光合参数、叶绿素荧光动力学参数（除非光化学猝灭系数qN）、耗水量、耗水强度、生物量和水分利用效率均随供水量的减少而下降，重度胁迫下明显降低。与适宜水分相比，不同水分胁迫处理下胡杨的光合参数、叶绿素荧光参数、耗水量与生物量下降幅度均小于灰胡杨，重度胁迫下明显高于灰胡杨。胡

Effects of water stress on growth characteristics and water use efficiency of Populus euphratica and Populus pruinosa

In order to improve the irrigation water utilization efficiency of farmland shelterbelt and select the appropriate tree species in the Tarim basin, the growth characteristics, the photosynthetic and chlorophyll fluorescence kinetics parameters, transpiration and water use efficiency (WUE) of Populus euphratica and Populus pruinosa were investigated with pot-culture experiment.The results showed that the photosynthetic and fluorescence kinetics parameters (except non-photochemical quenching coefficient, qN), water consumption and intensity, biomass and WUE declined with water stress, with the least values of these parameters occurring at the severe water stress. Compared with parameters under normal water irrigation, the reductions of photosynthetic and fluorescence parameters, water consumption and biomass of Populus euphratica were all lower than those of Populus pruinosa under different water stress, however, the reductions of Populus euphratica were higher than those of Populus pruinosa under severe water stress. The whole water use efficiency (WUEM), intrinsic water use efficiency (WUEP), instantaneous water use efficiency (WUEL) of Populus euphratica and Populus pruinosa were the highest under moderate stress and light stress respectively. For both poplar species, the water-consumption intensity and periodic consumption ratio reached maximum in July. Based on these findings, Populus euphratica was the preferred tree species than Populus pruinosa in establishing shelter forest on farmlands in Tarim basin. The soil water contents of forestland of Populus euphratica and Populus pruinosa should be about 45%~50% and 60%~65% of the field capacity, respectively, key time of irrigation is July.