闽江口湿地主要土壤-植物系统硒的分配特征

研究闽江河口湿地的5种典型土壤-植物系统中硒的分配特征.结果表明,不同类型的土壤-植物系统中,土壤硒的质量比为0.137~0.437 mg.kg-1.各湿地植物土壤的不同层次,其硒的质量比的垂直分布无明显的规律性;各湿地植物土壤的硒的质量比与土壤全磷的相关性较强,而受土壤有机质的影响较弱.不同的湿地植物及同一植物不同部位的硒的质量比存在较大差异,在同一植物中,根、枝或茎的硒质量比大于叶.植物各部位对土壤中硒的富集能力,表现根大于枝或茎大于叶,但富集系数均小于0.5.

Study on Content and Distribution of Selenium in the Soil-Plant Systems of Minjiang Estuary Wetland

Distribution characteristics of selenium in five typical soil-plant systems of Minjiang estuary wetland was studied.The results indicated that mass ratios of selenium in the soils of different types of soil-plant systems were 0.137～0.437 mg· kg~(-1).Vertical distribution of selenium in the soil layers under the wetland plants had no significant regulation.The correlations were strong between the selenium content and the total phosphorus.However,the soil organic matter had weak impacts on the wetland selenium.Large differences of mass ratios of the selenium were found in the different wetland plants and the different organs of the same plant Roots and shoots/stalks had higher selenium contents than leaves for the same plants.The selenium accumulation abilities of all the surveyed wetland plants showed roots> shoots/ stalks>leaves.However,all of the accumulation coefficients were less than 0.5.