Abstract: Experiments were conducted by taking sandy soil at different stages of vegetation succession（primary stage, middle stage, later stage, and maturation stage of succession）in the eastern Hobq Desert, China, as a sand-binding area. Soil volumetric moisture content from 0 to 180 cm of the top, middle, and bottom of the windward slope of sandy land was measured from during the growing season between 2017 and 2018. This study aimed to investigate the spatiotemporal dynamic characteristics of soil moisture content and reveal the response of desert soil moisture content to environmental factors. The results showed that precipitation differences caused annual fluctuation of average soil moisture content in the study area; 2018（8.8%）> 2017（4.8%）. Affected by precipitation and plant growth, the soil moisture content in the four sample plots showed obvious seasonal variations. Moisture content decreased slowly in the early growing season, increased rapidly after replenishment with precipitation during the intense growing season, and remained constant at the end of the growing season. Soil moisture content at different vegetation succession stages is generally shown as primary stage（7.3%）>maturation stage（7.2%）>later stage（6.7%）>middle stage（5.9%）. Soil moisture content in the middle of the windward slope was the lowest in all four sample plots. Soil moisture content in the top and bottom layers varied in different succession stages. The soil moisture content of four sample plots showed clear vertical changes, decreasing first and then increasing with soil depth. The moisture content of the surface layer（0-20 cm）was significantly higher than that of the other layers. There was an inflection point in the moisture content of the deep soil in each sample plot, which was the dry sand layer with the lowest moisture content. The depth of the dry sand layer changed at different succession stages or precipitation conditions. At the end of the growing season, the precipitation supply and vegetation consumption of soil moisture in the study area reached a positive balance. Besides, the soil moisture storage was able to sustain the normal growth of artificial vegetation in the sand-binding area.

Key words: sand-binding area, soil moisture content, vegetation succession, spatiotemporal variations, Hobq deser