Response of Salix psammophila seedlings to simulated precipitation change in Ordas plateau
鄂尔多斯高原沙柳幼苗对模拟降水量变化的响应

Ordas plateau is a typical dry and semi dry sandland in China.The distribution pattern and productivity of terrestrial ecosystem are greatly affected by the global change,especially the global precipitation change.Response is investigated for seedlings of Salix psammophila ,a dominant shrub in Ordas plateau,to the global precipitation change by artificially controlling water supply at four levels.The results show that photosynthetic rate,transpiration rate,stomatal conductance and fluorescence efficiency increased as water supply increased,and water use efficiency was not affected by water supply.The growth changes of tree height,branch number,leaf number and leaf area had obviously difference among the four water supply treatments.The growth characters,such as tree height,stem diameter,leaf number,leaf area,dry biomass and value of shoot/root dry biomass,and bifurcation characters,such as bifurcatin ratio,branch number,length,leaf number,leaf area of each order,increased when water supply increased.