海涂区不同植被类型下土壤盐渍剖面及其电磁感应响应特征

针对滨海滩涂区植被类型与土壤盐渍化间的内在联系，以黄河三角洲典型海涂区为研究对象，结合电磁感应仪EM38与田间采样，分析了不同植被类型下土壤盐渍剖面分布特征，并对各植被类型下土壤盐渍剖面的电磁感应响应特征进行了比较.结果表明：研究区土壤盐分具有较强的表聚性与变异强度，水平磁感式表观电导率(EM_h)对浅层土壤盐分响应较好，而垂直磁感式表观电导率(EM_v)对深层土壤盐分的响应优于EM_h；土壤盐渍剖面分为表聚型、底聚型和平均型3类，表聚型盐渍剖面主要为光板地和盐蒿地，底聚型的地表植被以棉花为主，平均型主要为杂草，且土壤盐分表聚强度为光板地>盐蒿地>杂草地>棉花地；随着植被类型由棉花—杂草—盐蒿—光板地变化，各剖面的EM_v/EM_h值逐渐降低.经非参数检验，植被类型与电磁感应响应特征具有显著相关性，且不同植被类型的EM_v/EM_h分布特征差异明显.

Characteristics of soil salinity profiles and their electromagnetic response under various vegetation types in coastal saline area

Aiming at the intrinsic relationships between vegetation type and soil salinity in coastal saline area, and by using electromagnetic induction EM38 and field sampling method, the characteristics of soil salinity profiles under various vegetation types in typical coastal saline region of the Yellow River Delta were analyzed, and the electromagnetic response characters of the salinity profiles were compared. The results showed that across the study area, soil salinity exhibited the characteristics of top enrichment and strong spatial variation. The horizontal electromagnetic conductivity EM_h responded well to soil salinity at upper layers, and the response of vertical electromagnetic conductivity EM_v to soil salinity at deeper layers was superior to that of EM_h. Soil salinity profiles were classified into inverted, normal, and uniform types. The vegetation types of inverted salinity profiles were mainly bare land and Suaeda salsa, while those of normal and uniform salinity profiles were cotton and weed, respectively. The sequence of top enrichment intensity was bare land >S. salsa land>weed land>cotton land. With the change of vegetation type of cotton-weed-S. salsa-bare land, the EM_v/EM_h value of salinity profiles decreased gradually. Nonparametric test results showed that there was a significant correlation between vegetation type and electromagnetic response characters, and the distribution characters of EM_v/EM_h under various vegetation types varied significantly.