黄河三角洲不同类型湿地稀土元素配分模式
REE distribution characteristics of different kinds of wetlands in Yellow River delta
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摘要: 本文利用ICP-MS对2006—2008 年采自黄河三角洲湿地系统的208 个表层土壤(沉积物)样品进行了14 项稀土元素(REE)分析,研究了黄河三角洲不同植被覆盖下REE的配分模式特征?结果表明:上三角洲平原湿地表层土壤稀土元素总量(ΣREE)分布范围为137.29×10-6~267.82×10-6,平均值为166.73×10-6?碱蓬湿地和光滩湿地的配分曲线比较接近;芦苇湿地和柽柳湿地的配分曲线也比较接近,具有配分曲线整体低于碱蓬湿地和光滩湿地的趋势?研究区浅海湿地表层沉积物ΣREE为143.11×10-6~222.48×10-6,平均值为180.80×10-6?黄河上三角洲平原各类湿地稀土元素配分曲线高于黄河浅海湿地的稀土元素配分曲线,黄河浅海湿地的稀土元素配分曲线高于黄河沉积物的稀土元素配分曲线,且其配分曲线LREE较分散,而HREE较集中甚至重合?由此证明,稀土元素与植物分带具有成因关系,即黄河三角洲湿地系统LREE较多的参与到了植被的生物地球化学循环,而HREE在湿地生态系统呈生物化学惰性?Abstract: Utilizing 208 surface soil samples collected from the coastal wetlands of Yellow River delta in 2006—2008, the authors studied REE distribution characteristics in wetlands covered by different kinds of vegetation and measured 14 kinds of elements in each sample by ICP-MS method. Some conclusions have been reached: ΣREE content in surface soil of wetlands in upper delta plain is 137.29×10? 6-267.82×10? 6, with an average of 166.73×10? 6; the REE distribution characteristics in sea-blite wetlands are similar to those in bare wetlands; the REE distribution characteristics in reed wetlands are similar to those of China's Tamarisk wetlands, but both of them are lower than the REE distribution characteristics in sea-blite and bare wetlands; the ΣREE content of the surface sediments of wetlands in shallow sea is 143.11×10?6-222.48×10?6, with an average of 180.80×10?6; the distribution curve of REE of wetlands in upper delta plain of the Yellow River is higher than that in shallow sea of the Yellow River; the distribution curve of REE of wetlands in shallow sea of the Yellow River is higher than that in sediments of the Yellow River. LREE has more possibility to participate in the circulation of biogeochemistry than HREE.