Soil Water Balance of Runoff Plot Forestlands in Nanxiaohegou Basin of the Loess Plateau, China

摘要

The black locust (Robinia pseudoscacia), Chinese pine (Pinus tabulaeformis) and oriental arborvitae (Platy-cladus orientalis) are used as the main arbor species for ecological construction of soil and water conservation in the loess area of Nanxiaohegou basin, Gansu Province. Based on the on-site observation, water consumption regularity of evapotranspiration was analyzed. By means of water balance methods, the relationship between water supply and water consumption of black locust, Chinese pine forests and oriental arborvitae was determined. The inter-seasonal and interannual changes are significantly different. The result shows that water consumption by evapotranspiration is relatively higher in July than other growing months. The result of water balance of different forestlands in their growing season showed that soil moisture in black locust (Robinia pseudoscacia), Chinese pine (Pinus tabulaeformis) and oriental arborvitae (Platycladus orientalis) were in a dynamic cycle imbalance, because the inputs were greater than the outputs of soil moisture, which is in a positive balance and conducive to forest growth.