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为探讨未来降水减少对内蒙古皇甫川流域沙棘幼苗生理生态特征的影响, 特设计平均降雨水平、偏旱、干旱和极端干旱4种不同的水分梯度处理, 开展人工水分梯度实验。方差分析表明, 不同的水分梯度显著影响土壤的含水量、土壤温度等微生境因子, 并显著影响净光合速率、气孔导度、蒸腾速率等气体交换特征、资源利用效率和叶片水势特征。适度的水分胁迫(干旱环境)能够提高沙棘的水分利用效率, 同时却降低净光合速率和蒸腾速率。各种生理生态指标表明,4种水分处理的沙棘幼苗都受到不同程度的水分胁迫的影响, 极端干旱环境中沙棘幼苗的内在生理调节机制出现紊乱, 皇甫川流域沙棘不适宜在极端干旱环境中生长。
In order to investigate the impact of future precipitation reduction on the ecophysiological characteristics of seabuckthorn seedlings in Huangfuchuan watershed in Inner Mongolia, four different water gradients, average rainfall, drought, drought and extreme drought, were designed to carry out artificial water gradient experiments. Analysis of variance showed that different water gradients significantly affected soil microbial biomass factors such as water content and soil temperature, and significantly affected gas exchange characteristics such as net photosynthesis rate, stomatal conductance and transpiration rate, resource utilization efficiency and leaf water potential. Moderate water stress (arid environment) can increase the water use efficiency of seabuckthorn, while reducing the net photosynthetic rate and transpiration rate. Various physiological and ecological indexes showed that the four kinds of sea buckthorn seedlings treated with water were affected by different degrees of water stress. The physiological regulation mechanism of seabuckthorn seedlings in extreme drought environment was disordered. The seabuckthorn in Huangfuchuan watershed was not suitable for growing in extreme drought environment .