黄土高原西部人工灌木林土壤水分分布规律

利用便携式中子水分测定仪，对黄土高原西部丘陵区不同立地条件、不同灌木类型覆盖下土壤水分含量进行观测研究，同时对人工灌木林土壤水分分布规律进行了初步的探讨。结果表明：阴坡土壤水分储量最高，其次为半阴坡和半阳坡，阳坡最低，坡向因子与土壤水分储量呈显著正相关，坡位因子与土壤水分储量相关性不显著。柠条(Caragana korshinskii)、半日花(Helianthemum songaricum)耗水量较大，沙木蓼(Atraphaxis bracteata）、梭梭(Haloxylon ammodendron)等耗水量居中，荒漠锦鸡儿(Caragana roborovskyi)、甘蒙锦鸡儿(Caragana opulens)、枸杞(Lycium chinense)耗水量较低，在植被恢复过程中，应根据物种抗旱性的不同在不同坡向进行合理的配置。从单株植物对土壤水分水平分布的影响看，随着离树干距离的加大，土壤水分含量越高，但在不同的土层深度土壤水分水平分布特征有差异。

Distribution of Soil Moisture under Different Planted Shrubs on the West Loess Plateau

The distribution of soil moisture on slope in the western loess hilly areas was studied based on the observed data of soil moisture content under different shrubs in different habitats with neutron moisture meter. The results showed that soil moisture content was the highest on shady slope, then on semi shady and semi sunny slopes, and it was the lowest on sunny slope. There was a significant positive correlation between slope aspect and soil moisture storage, and the correlation between slope position and soil moisture storage was not significant. For the same slope aspect, Caragana korshinskii and Helianthemum soongoricum consumed more soil moisture than other shrubs, and the soil moisture consumption of Caragana opulens,C.roborovskyi and Lycium chinense was low. Therefore, the choice of shrubs for regenerating vegetation on different slope aspects should depend on the drought resistance of plant species. Horizontally, soil moisture content increased generally along with the increase of distance away from rhizosphere, but there was a difference of soil moisture content among different soil depth.