不同地下水位条件下骆驼刺水分和光合生理特性

2006年8-10月对塔克拉玛干沙漠南缘策勒绿洲——荒漠过渡带不同地下水位（15m、11m和6m）条件下骆驼刺（Alhagi sparsifoliaShap.）的水势（ψ）、光合速率（An）、蒸腾速率（E）进行了测定,分析了骆驼刺生理指标的变化特点。结果表明,不同地下水位条件下：（1）骆驼刺在研究期间均未出现明显的水分亏缺。清晨水势（ψp）的季节变化幅度不大,正午水势（ψm）随着生长期末的到来缓慢增加,水势的日变化幅度较大;（2）光合速率（An）日变化的形态不同,且达到峰值的时间不尽一致;（3）骆驼刺均有较高的蒸腾速率（E）,同光合速率有相似的变化趋势。因此,塔克拉玛干沙漠南缘策勒绿洲-荒漠过渡带不同地下水位下骆驼刺水分和光合生理特性并没有表现出明显差异,表明骆驼刺可以在过渡带不同地下水位处生长。研究为策勒绿洲-荒漠过渡带骆驼刺植被自然或半自然恢复提供一定的理论依据。

The Water and Photosynthetic Physiological Characteristics of Alhagi sparsifolia Shap. In Different Groundwater Level Conditions

The Southern margin of the Taklimakan Desert is one of the most severe desertification areas in China. The major reason is that the natural vegetation there has been seriously destroyed by human activity. In order to give some advice for restoring the natural vegetation especially of Alhagi sparsifolia Shap, the water potential （ψ）, photosynthetic rate （An）, transpiration rate （E） of A. sparsifolia were observed from August to October in 2006, and the discussion was thus made on the variation of A. sparsifoliars physiologic index in different groundwater lever conditions. The results show that. （1） A. spasifolia. in transition strip is able to balance the deficits that develop during a day until the next morning,and maintains nearly constant and rather high predawn water potentials. The afternoon water potentials increase slowly with the end of the growing season of A. sparsifolia, the extent of the diurnal variation of water potential is larger. （2）In different groundwater tables, the type of photosynthetic rate and the time of photosynthetic rate which achieves peak aredifferent. （3）The transpiration rate of A. sparsifolia, is higher and has the similar variation trend with photosynthetic rate. （4） The groundwater is the most important water source of A. sparsifolia. In order to adapt to the particular environment, the desert plants should depend the deep root system to draw the groundwater. So it is necessary to maintain the relative stability of the groundwater level for protection the growing of A. sparsifolia. This research can provide some theoretic advice for the natural restoration of vegetation in Oasis--Desert transition strip of Cele, Xinjiang.