Soil Water Dynamics And Precipitation Redistribution In Mu Us Sandland

Through the study of Artemisia ordosica community in the area to reveal the dynamics of soil moisture and precipitation redistribution. Artemisia ordosica is the study area in the most important building flora of, community area accounts for 31.2% of the total area of the Maowusu sandy land, area of the area’s largest community types. In the study is the most representative. Mu Us Sandland of Artemisia ordosica community experiencing from flowing Sandlot pioneer species stage, semi fixed sandy land, sparse stage-Fixed Sand built stage-old fixed sandy land degradation stage-the flow of sand, so that a cyclic succession process. The existing research argues that soil moisture is an important factor driving the Artemisia ordosica community succession. However, the research of Artemisia ordosica community soil moisture is timing, spot sampling, data quantity is less and lack of continuity, cannot reflect the dynamic of soil moisture. On the fixed and semi fixed and mobile dune are built in stages, the rarefaction phase and pioneer species of Artemisia ordosica community of soil moisture long-term continuous monitoring of this research through analysis different degree of fixation of Artemisia ordosica community characteristics of soil water and precipitation on soil moisture recharge condition, in order to provide the scientific basis for the reasonable protection of vegetation in Maowusu sandy land. The main conclusions are as follows:three kinds of soil moisture are temporal and spatial differences, the flow of sand each layer soil water content was significantly higher than that in the fixed and semi fixed sandy land; soil moisture affected by precipitation is large, rainfall is an important factor influencing soil water depth is less than 10mm, the precipitation is mainly surface soil absorption,10～recharge depth on soil moisture of 20mm precipitation is more than 30cm, less than 60cm, the precipitation recharge depth greater than 30mm and less than 40mm is greater than 60cm, but less than 100cm; the 30cm and the upper soil moisture fluctuation,60cm soil moisture is mainly affected by the influence of more than 20mm, the precipitation events of small fluctuations,100cm soil water only affected by the large precipitation events, the soil moisture content was relatively stable; different levels of infiltration depth and vegetation water demand is the root of precipitation resulted in 3 soil samples The important factors of water time and spatial heterogeneity. The soil infiltration rate control, rainfall intensity, infiltration is also large, the linear relationship between the permeability and the depth of rainfall and rainfall intensity. The wetting front migration rate is smaller in the beginning of rainfall, and then increased gradually, reached the peak, and decreased with time, and finally tends to be stable.13.4mm rainfall is invalid the demarcation point of precipitation and groundwater recharge; more than 20mm rainfall the evaporation layer of soil at the end of the redistribution to minimum water holding capacity; greater than 50 mm of rainfall through the redistribution of soil moisture can make 120cm depth soil moisture saturated water holding capacity, and lower level of saturated water infiltration.