三代木麻黄林中稀土元素的含量与分布

Content and Distribution of Rare Earth Elements in Three Generations of Casuarina Equisetifolia Plantation

研究了海南岛滨海砂土上3代木麻黄林生态系统中稀土元素含量和分布。土壤稀土元素分布模式基本上与世界土壤和我国土壤相同,呈负斜率分布,轻稀土相对富集,土壤和植物都存在不同程度的Eu负异常。木麻黄林下砂土的稀土元素总含量很低,从第1代林到第3代林分别为:42.716、45.416、14.457μg/g。植物体中的稀土元素的总含量也很低。从第1代林到第3代林,木麻黄根ΣREE分别为0.722、1.444、1.887μg/g,枝分别为0.354、0.318、0.267μg/g,叶分别为0.492、1.312、0.715μg/g。第3代木麻黄林土壤中ΣREE最低,但根中的ΣREE最高,叶中的ΣREE高于第1代林。表明幼林对稀土元素摄取强烈。在土壤植物—系统中稀土元素分布为土壤>根>叶>粗枝。

The content and distribution of rare earth elements in the ecosystem of 3 generations of Casuarina equisetifolia plantation in the coast in Hainan Island are studied in this paper,The distribution pattern of soil REE in the study area is similar to that in soils of China and the world,which are in negative slope patterns.Light REE is relatively enriched and Eu is to certain extent negatively anomaly.The total content of REE in the soils is in very low levels with the value of 42.716μ,45.416,14.457μ g/g from first to third generation of C.equsetifolia is in the plantations respectively.ΣREE in the plants are also very low.From the first to the third generation ΣREE are 0.722,1.444,1.887μ g/g in the root,0.354,0.318,0.267μ g/g in the branch and 0.492,1.312,0.715μ g/g in the needle respectively.It reflects strong uptake of REE in the young trees.The distribution of REE in the soil-plant system is that soil>root>needle>branch.