Study on Water Budget of the Typical Shrub and Arbor Woods in Sandy Land of Northwest Liaoning Province

Based on the position-monitoring data,in this paper the water balance in typical shrub and arbor woods in sandy land of northwest Liaoning Province is studied.The results show that there is a significant linear correlation between soil moisture content in 7 typical vegetation communities and annual precipitation,especially in pure Populus sp.forest,Ulmus pumila forest and Prunus sibirica L.shrub woods.On which the error of estimated total soil water storage in pure Populus sp.forest and U.pumila forest does not surpass 20%.There is a significant difference of soil water storage between grassland community and the communities of Pinus sylvestris var.mongolica forest,P.tabulaeformis forest,Populus sp.forest and U.pumila forest.There is also a significant difference of soil water storage between P.sylvestris var.mongolica forest and P.tabulaeformis forest.Soil moisture content in grassland community is higher than that in other cultivated vegetation communities.The total evapotranspiration was the highest in P.sibirica woods (516.09 mm),followed by 495.79 mm in Pinus-Populus mixed forest community,and it was higher in these two vegetation communities than the precipitation of 461.00 mm during the same period.In order to maintain the soil moisture balance,both communities of P.sibirica woods and Pinus-Populus mixed forest must be managed.The total evapotranspiration was lower in the communities of grassland,P.sylvestris var.mongolica forest,P.tabulaeformis forest and Populus sp.forest than the precipitation during the same period.The total evapotranspiration of 381.34 mm in U.pumila forest community was the lowest.