Speciation, Distribution, and Bioavailability of Soil Selenium in the Tibetan Plateau Kashin-Beck Disease Area-A Case Study in Songpan County, Sichuan Province, China
Speciation, Distribution, and Bioavailability of Soil Selenium in the Tibetan Plateau Kashin-Beck Disease Area-A Case Study in Songpan County, Sichuan Province, China
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青藏高原大骨节病区土壤硒形态、分布及生物有效性——以四川省松潘县为例
DOI：
10.1007/s12011-013-9822-5
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发表时间：
2013-12-01
影响因子：
3.9
通讯作者：
Chen, Zhuo
中科院分区：
文献类型：
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作者：
Wang, Jing;Li, Hairong;Chen, Zhuo
为阐明青藏高原东缘大骨节病病区土壤硒的分布及其生物有效性与病区分布的关系，采集了自然土壤（0-20 cm）、耕作表土、以及该地区的主要作物根据大骨节病区和非大骨节病区的地形地貌特征，松潘县大骨节病区。利用这些样品测定分析了土壤和青稞中的全硒含量及植物可吸收利用的有效硒。结果表明，大骨节病病区自然土壤和耕作土壤的平均全硒含量均低于非病区（自然土壤P = 0.061;耕作土壤P = 0.002），这与大骨节病病区硒的地理分布规律相一致。但土壤全硒含量具有一定的微观空间分布特征，即部分病区土壤全硒含量显著高于非病区。这一结果与大骨节病病区总硒含量低于非病区的一般分布相反。进一步研究了土壤硒在6种不同形态中的提取率和含量。结果表明，大骨节病病区土壤有效硒含量和提取率均显著低于非病区。植物有效硒与青稞硒呈明显正相关（r = 0.875，P = 0.001），与海拔高度呈明显负相关（r =-0.801，P = 0.010）。因此，在大骨节病病区，作物硒含量随土壤有效硒含量的降低而降低，并与地理环境特征（如海拔高度、降水量等）密切相关。结果表明，土壤有效硒和生态特征是制约青藏高原大骨节病病区居民膳食硒通量的重要因素，为实施农业措施调控大骨节病病区硒通量的生态循环提供了理论和实验依据。
To clarify the relationship between the soil selenium distribution and its bioavailability with the distribution of Kashin-Beck disease (KBD) endemic areas on the eastern edge of the Tibetan Plateau, samples of natural soil (0-20 cm), cultivated topsoil, and main crops of the region (highland barley) were collected at different altitudes according to topographical and geomorphological features in both KBD and non-KBD areas of Songpan County. These samples were used for determination and analysis of total selenium content in soil and highland barley and available selenium that can be absorbed and utilized by plants. The results showed that the average total selenium content of natural and cultivated topsoil in KBD areas was lower than that in non-KBD areas (natural soil, P = 0.061; cultivated soil, P = 0.002), which is in agreement with the geographical distributions of selenium in other KBD-affected areas. However, the total soil selenium content exhibits certain micro-spatial distribution features, namely, the total selenium content in some endemic areas was significantly higher than that of non-KBD areas. This result was contrary to the general distribution that total selenium content in a KBD-affected area is lower than that in a non-KBD area. We further studied the extraction rate and content of soil selenium in six different fractions. The results indicated that the content and extraction rate of available selenium in KBD-affected areas were significantly lower than those in non-KBD areas. There is a distinct positive correlation between plant-available selenium and highland barley selenium (r = 0.875, P = 0.001) and a distinct negative correlation with altitude (r = -0.801, P = 0.010). Therefore, in KBD endemic areas, the selenium content in crops decreases as the available selenium content in soil decreases and is closely related to the geographical environment features (such as altitude and precipitation). These results suggest that the soil available selenium and ecological features are important factors that restrict the dietary selenium flux for residents in KBD endemic areas of the Tibetan Plateau, providing a theoretical and experimental basis for implementing agricultural measures to regulate the ecological cycle of the selenium flux in the KBD endemic area.