Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; Beijing Key Laboratory of Environmental Damage Assessment and Remediation, Beijing, China.
Sci Total Environ. 2018 Aug 15;633:240-248. doi: 10.1016/j.scitotenv.2018.03.190. Epub 2018 Mar 22.
Selenium (Se) is an essential trace element for humans. In order to investigate how soil Se is influenced by topography and soil properties, we selected Yongjia County, an area with mountainous topography, as a study area. This study used cultivated soil data to comprehensively analyze the effects of topography and soil properties on Se mobility and bioavailability and to identify the key factors influencing Se distribution in the environment. Factors considered in this study were elevation, slope, topographic wetness index, the coefficient of weathering and eluviation, pH, organic matter, and FeO. The concentration of total soil Se (0.382±0.123mgkg) was far higher than the background value of soil in China, and 98% of the soil samples were classified as having moderate Se levels (>0.175mgkg), indicating Yongjia County is a Se-rich region in China. Phosphate extracted Se accounted for an average of 9% of the total Se and was significantly associated with soil total Se, FeO, pH, and the coefficient of weathering and eluviation. FeO primarily controlled Se adsorption, fixation, and availability in soil. Under the geo-environmental conditions in the study area, the total Se in the soil increased first and then decreased with increases in elevation, slope, and the topographic wetness index, and the phosphate extracted Se showed similar patterns except for the elevation. The findings showed that topographical attributes and soil physicochemical properties synthetically influenced the distribution and bioavailability of Se in soil.
硒（Se）是人体必需的微量元素。为了研究土壤硒受地形和土壤性质的影响，我们选择了地形多山的永嘉县作为研究区域。本研究利用耕地土壤数据，综合分析了地形和土壤性质对硒迁移性和生物有效性的影响，确定了影响环境中硒分布的关键因素。本研究考虑的因素有海拔、坡度、地形湿度指数、风化淋溶系数、pH 值、有机质和 FeO。土壤全硒（0.382±0.123mgkg）的浓度远高于中国土壤的背景值，98%的土壤样品被归类为具有中等硒水平（>0.175mgkg），表明永嘉县是中国富硒地区。磷酸盐提取硒占总硒的平均 9%，与土壤总硒、FeO、pH 值和风化淋溶系数显著相关。FeO 主要控制土壤中硒的吸附、固定和有效性。在研究区域的地球环境条件下，土壤中的总硒随海拔、坡度和地形湿度指数的增加而先增加后减少，磷酸盐提取硒则呈现出相似的模式，但不包括海拔。研究结果表明，地形特征和土壤理化性质综合影响了土壤中硒的分布和生物有效性。
