Soil moisture characteristics of root zone on Xilamuren grassland

In order to explore the natural variation laws of soil moisture in Xilamuren grassland, north Yinshan Mountains, AZ-DT automatic soil moisture monitor was used to monitor the soil moisture of root zonewith long-term period. Soil moisture, in combination with rainfall observation and vegetation survey, was applied to analyze local soil moisture variation characteristics and its impact on vegetation. The results of this study showed rainfall was the only source of soil moisture of the slope soil and was often below 15% due to rare rainfall. However, soil moisture at slope bottom come from runoff resources and rainfall, and was higher than that of slope soil, which led the soil moisture to be saturation condition. Rainfall significantly affected the height, coverage and biomass of plant community in slope soil, however, did not affect on those of plant community in slope bottom. The plant community in slope bottom is low and thin but large number because poor ventilation and salinization of slope bottom soil was not beneficial to plants growth. The soil moisture of the slope and the bottom was higher and the fluctuation was severe in spring season every year due to freezing thawing and snow melting, which was helpful to grassland regreen with enough water supply.