Effects of water stress on Haloxylon ammodendron seedlings in the desert region of Heihe inland river watershed, Gansu Province, China

编号 zgly0000302947

文献类型 期刊论文

文献题名 Effects of water stress on Haloxylon ammodendron seedlings in the desert region of Heihe inland river watershed, Gansu Province, China

学科分类 220.99;林学其他学科

作者 LIUFa-min  WUYan-qing  SUJian-ping  DUMing-wu 

作者单位 ColdandAddenvironmentalandEngineenngResearchInstitute 

母体文献 Journal of Forestry Research;林业研究: 英文版 

年卷期 2003,14(3)

页码 197-201

年份 2003 

分类号 S793.9 

关键词 梭梭  水分胁迫  黑河流域  荒漠地区  水分关系  叶气体交换  气孔导度  光合作用  蒸腾作用 

文摘内容 The water relation and leaf gas exchange of saxoul (Haloxylon Ammodendron Bge, a C4 shrub) seedlings were studied under water stress in 2001. Saxoul seedlings maintained high transpiration when the soil moisture was above 11%. The seedlings were able to take up water from soil with above 6 % soil water content, which was the threshold level of soil moisture for seedlings. The relationship between transpiration and potential evaporation was linear for well-watered seedlings. The decrease of soil water availability led to different degrees of down-regulation of stomatal conductance, leaf transpiration and net CO2 assimilation rate. The stomata played a relatively small part in determining the net CO2 assimilation rate for the same seedling. The relationship between net CO2 assimilation rate and transpiration was linear diurnally, and reduction scale of leaf transpiration was much bigger than that of net CO2 assimilation rate by waters tress treatments, therefore intrinsic water-use-efficiency increased. High evaporative demand increased the leaf transpiration but inhibited net CO2 assimilation rate.Because of the effect of VPD on transpiration in this region, the transpiration of well-watered and mild water stress seedlings becomes responsive to change in stomatal conductance over a wider range。