典型毛乌素沙漠-黄土高原过渡带土壤盐渍化空间异质性及其影响因素  

Spatial heterogeneity of soil salinization and its influencing factors in the typical region of the Mu Us Desert-Loess Plateau transitional zone,Northwest China

作　　者：赵宣[1,2,3] 郝起礼 孙婴婴 

机构地区：[1]陕西省土地工程建设集团有限责任公司,西安710075 [2]陕西地建土地工程技术研究院有限责任公司,西安710075 [3]国土资源部退化及未利用土地整治工程重点实验室,西安710075

出　　处：《应用生态学报》2017年第6期1761-1768,共8页Chinese Journal of Applied Ecology

基　　金：陕西省重点科技创新团队计划项目(2016KCT-23)资助~~

摘　　要：毛乌素沙漠-黄土高原过渡带土壤盐渍化的空间异质性和生态学过程,对沙荒地整治的机理研究具有重要的意义.以毛乌素沙漠-黄土过渡带为研究区,结合布点取样和室内分析,运用经典统计学和地统计学方法对其pH、电导率、全盐含量的空间异质性进行分析.结果表明:1)土壤pH、电导率、全盐含量的平均含量分别为8.44、5.13 mS·cm^(-1)和21.66 g·kg^(-1),变异系数范围为6.9%~73.3%,pH属于弱变异,电导率和全盐含量属于中等程度变异.2)半方差分析结果显示,3个指标的空间变异性的最佳拟合模型均为球形模型,块金值/基台值比值范围为8.6%~14.3%,均具有强烈的空间自相关性,结构性因素对变异起主导作用;变程由小到大表现为pH<全盐<电导率.克里金插值图显示,pH、电导率、全盐含量整体呈条带状分布,连续性较好.pH值表现出随着地势的升高而升高的特点,而电导率和全盐含量则表现出随着地势的升高而降低的特点.3)在垂直分布上,重度盐渍化区域的盐分有表聚现象,轻度盐渍化区域盐分垂直分布为先减少后增大.毛乌素沙漠-黄土过渡带土壤盐渍化的空间变异性与气候、地质条件、地形地貌、水文地质条件、植被分布等有关,以地形因素和水文地质条件的影响为主.Studies on the spatial heterogeneity of saline soil in the Mu Us Desert-Loess Plateau transition zone are meaningful for understanding the mechanisms of land desertification. Taking the Mu Us Desert-Loess Plateau transition zone as the study subject, its spatial heterogeneity of pH, electrical conductivity （EC） and total salt content were analyzed by using on-site sampling followed with indoor analysis, classical statistical and geostatistical analysis. The results indicated that： 1 ） The average values of pH, EC and total salt content were 8.44, 5.13 mS · cm-1 and 21.66 g · kg-1 , respectively, and the coefficient of variation ranged from 6.9% to 73.3%. The pH was weakly varia- ble, while EC and total salt content were moderately variable. 2） Results of semivariogram analysis showed that the most fitting model for spatial variability of all three indexes was spherical model. The Co/（Co＋C） ratios of three indexes ranged from 8.6% to 14.3%, which suggested the spatial variability of all indexes had a strong spatial autocorrelation, and the structural factors played a more important role. The variation range decreased in order of pH 〈total salt 〈 EC. The terpolation showed that pH, EC tinuity. The pH value increased Kriging in- and total salt content distributed in a striped pattern with good con- with increasin terrain slope, while EC and total salt contont rio-creased. 3） In terms of vertical distribution, the salt aggregated on surface in the area with severe salinization. In the area with light salinization, the vertical distribution of salinity was firstly de- creased and then increased. In general, the heterogeneity of soil salinization in the Mu Us Desert- Loess Plateau transition zone was influenced by climate, landscape, plant distribution, especially affected by geological conditions, topography and hydrogeological conditions. This study provided a theoretical basis for future land engineering and ecosystem restoration programs.

关 键 词：毛乌素沙漠-黄土高原过渡带 土壤盐渍化 空间异质性 影响因素 

分 类 号：S156.41[农业科学—土壤学]