摘要
为探明浑善达克沙地土壤湿度的时空变化规律 ,于 1 998一 1 999年在浑善达克沙地中部取样分析了地形和植被与土壤含水量的相关性及生长季内土壤含水量的动态。发现在坡度 <1 5°时 ,随坡度的增大 ,土壤含水量降低 ,在坡度 >1 5°时 ,沙丘阴坡上土壤的含水量随坡度的增大而增加。高沙丘阳坡的土壤含水量 ,受坡度的影响很小 ,略有降低。由于沙地土壤类型复杂 ,土壤剖面变异也比较大 ,所以随深度的增加土壤含水量的变化规律也不同。土壤含水量的动态特征在不同土层也有差异 ,表土层 ,春末夏初之前土壤比较干 ,以后在波动中上升 ,8月份土壤含水量比较大 ,8月底以后又迅速下降到春末夏初的水平。心土层则在前期土壤比较湿润 ,而后逐渐下降 ,在 6月中旬至 7月中旬出现土壤含水量的低谷 ,7月中以后又逐渐升高 ,并在 8月底达最大含水量 ,9月中旬后又降到年初的水平。6、7月间含水量的低谷可能是由于植物大量耗水造成的。表土层和心土层 (70 cm以上土层 )在 9月上旬基本降到了5月初的水平。但底土层土壤含水量在波动中升高 ,9月上旬虽有所下降 ,但仍高于 5月初的土壤湿度。在某些地形部位 ,随植被盖度的增加 ,土壤含水量有增大的趋势。
In order to understand the varying rule of soil moisture in Hunshandske sandy land,a study had been carried out from 1998 to 1999.The results suggest: The soil water content decreases with the slope degree increase On a slope which is smaller than 15°,especially on the lowland around by sandy dune.But the soil moisture increase with the slope degree increase on the north slope which is bigger than 15°.The moisture of soil on south slope of high dune varies little with the slope degree change. Soil water regime of a profile varies greatly with the depth increase . The soil moisture dynamie of surface Aeolian sandy soil can be divided into three stages: dry and stable stage (May); moist and varying stage (June to middle of August) and dry stage. The soil moisture decreases slowly to a lowest point at the middle of July, then increase to moist until the end of August. After the end of August,the soil moisture decrease to level of May. The low soil moisture during July and June may be caused by the plant taking in soil water greatly.But Soil moisture increases with the plant coverage increase.
出处
《干旱区资源与环境》
CSSCI
CSCD
2000年第1期80-85,共6页
Journal of Arid Land Resources and Environment
基金
国家自然基金重大项目!( No.49790 0 2 0 )
国家基金项目!( No.3 9660 0 19)
关键词
浑善达克沙地
土壤水分
植被
Hunshandake sandy land, soil water regime, vegetations,
