荒漠绿洲过渡带土壤水分空间分布特征及对植被的影响

研究荒漠绿洲过渡带土壤水分空间特征，有利于提高干旱区水资源利用率和植被恢复。连续对黑河中游荒漠绿洲过渡带6个典型群落类型样地的地表0～120 cm深度剖面的土壤水分分布进行调查，采用烘干法分析并结合18个调查样方进行土壤含水量的空间分布特征研究，揭示荒漠植被土壤水分分布特征。结果表明，1)土壤水分的变异性随着深度的增加而减小，表层土层含水量空间变异性表现为强变异，说明土壤水分不稳定，深层土壤空间变异性变现为弱变异性，说明土壤水分较稳定。2)垂直分布上，每个样地各土层的土壤含水量均随土壤深度增加呈上升—降低—上升的总体趋势，各样地土壤含水量均是表层低，深层高。3)水平空间上，土壤含水量变化范围在0.09%～22.34%,土壤含水量的均值依次为深层(60～120 cm)>上层(0～40 cm)>中层(40～60 cm),总体来看，黑河中游荒漠绿洲过渡带各层土壤含水量均处于较低水平。4)干沙层土壤含水量最低，上覆沙土土壤含水量很少且随着深度的增加而增加，下浮沙土受地下水毛管作用和蒸腾作用影响水分含量较高且随土壤深度的增加而增加。研究结果为深入理解荒漠绿洲过渡带固沙植被的天然分布提...

Spatial Distribution Characteristics of Soil Moisture and Its Influence on Vegetation in Desert-Oasis Ecotone

Studying the spatial characteristics of soil moisture in desert oasis transitional zone is conducive to improving the utilization rate of water resources and vegetation restoration in arid areas.The soil moisture distributions in the 0-120 cm depth profile of six typical community types of sample plots in the desert oasis transitional zone in the middle reaches of the Heihe River were continuously investigated.The drying method was used to analyze the spatial distribution characteristics of soil moisture combined with 18 survey samples,and the soil moisture distribution characteristics of desert vegetation were revealed.The results were as follows1) The variability of soil moisture decreased with the increase of depth.There was considerable spatial variability of surface soil moisture,indicating that soil moisture was unstable in the surface layer.The spatial variability of deep soil was weak,indicating that soil moisture in deep layer was relatively stable.2) In the vertical distribution,the soil moisture content of each soil layer increased with soil depth,decreased and then increased.The soil moisture content of each sample plot was low in the surface layer and high in the deep layer.3) In the horizontal space,the variation range of soil water content was 0.09%-22.34%,and the mean value of soil water content was deep (60-120 cm)>upper(0-40 cm)>middle (40-60 cm).In general,the soil water content of each layer in the desert oasis transitional zone in the middle reaches of the Heihe River was at a low level.4) The soil water content of dry sand layer was the lowest,and the soil water content of upper sandy soil was very small and increased with soil depth.The soil water content of lower sandy soil was highly affected by groundwater capillary effect and transpiration,and increased with soil depth.This study provides a theoretical basis for further understanding the natural distribution of sand-fixation vegetation in the desert-oasis transitional zone.