半干旱区人工固沙灌丛发育过程土壤水分及水量平衡研究

Study on Soil Moisture and Water Balance in Processes of Dune Fixation Shrubs Development at Semi-arid Region

在野外条件下测定了不同林龄小叶锦鸡儿人工固沙灌丛区生长季节土壤水分动态和蒸散量变化。结果表明:不同林龄灌丛区土壤水分状态和蒸散量存在明显差异,土壤水分含量随着植被林龄增加而降低,16年生、19年生灌丛区土壤含水量随着深度增加呈下降趋势,在70cm深度产生低含水区,土壤转变为非淋溶性土壤;生长季土壤水分受降水和植被双重影响,在6月期间含水量最低;生长季节蒸散量随着植被林龄增加而增大,以19年生灌丛区最高,所有灌丛区生长季节蒸散量均低于同期降水量,占同期降水量的95%以上。流动沙丘生长季节土壤水分含量高于灌丛区,蒸散量低于灌丛区。

Determined the soil moisture dynamic and evapotranspiriation of Caragana microphylla plantations with different ages during growth period in field condition. Result showed ： there are distinctly differences on soil moisture and evapotranspiriation between plantations with different ages. Moisture of soil under artificial plantations is continual decreasing along with the increasing of ages. The moisture contents of 16 and 19 years old shrubs decreased along with the depths of soil. There is a low moisture contents lay in 70cm depths of soil. The soil under these plantations gradually translated from leached soil to anti-leached soil. Precipitation and vegetations effected soil moisture contents during growth period, and soil moisture contents appeared lowest point in June. Evapotranspiriation is continual increasing along with the plantations ages increasing and the 19 years old shrubs had the maximal evapotranspiriation. During growth phases, quantities of evapotranspiriation of all plantations are low than rainfall and occupied above 95% of rainfall at the same time. The floating dunes are different from fixation dunes. Soil moisture under floating dunes are high and quantities of evapotranspiriation are low than shrubs area.