野外条件下土壤砷浓度对蜈蚣草砷富集特征的影响  

As-Hyperaccumulation of Pteris vittata L. as Influenced by As Concentrations in Soils of Contaminated Fields

作　　者：刘颖茹[1] 陈同斌[1] 黄泽春[1] 廖晓勇[1] 

机构地区：[1]中国科学院地理科学与资源研究所环境修复中心,北京100101

出　　处：《环境科学》2005年第5期181-186,共6页Environmental Science

基　　金：国家杰出青年科学基金项目(40325003);国家自然科学基金重点项目(40232022);国家重大基础研究前期研究专项资助项目(2002CCA03800)

摘　　要：以As超富集植物蜈蚣草广泛分布的湖南省郴州市为例,调查了不同As污染程度下植物对As的富集和转运特点.结果表明,在野外条件下根际土壤中As浓度相对较低时(64～1000mg/kg),蜈蚣草地上部As浓度随根际土壤中As浓度的增加而逐渐增加,而在根际土壤中As浓度相对较高(1000～2 712mg/kg)时,蜈蚣草地上部As浓度表现为逐渐下降的趋势.在调查的所有样点中,蜈蚣草对As的转运系数介于1.08到6.03之间,显示出超富集植物的典型特征.结果还表明,在污染区土壤As浓度存在很大的空间变异性,根际土壤与非根际土壤之间的As浓度也存在很大差异.因此,在野外调查时最好是直接采取距离植物根部最近的根际土壤.As soil arsenic concentration might have great effect on arsenic accumulation of hyperaccumulator Pteris vittata L. , three sample areas with different As pollution level in the soils are investigated in Chenzhou, Hunan Province, where Pteris vittata L. grows broadly. Great variation of As concentrations is found to be not only among different samples in the same sampling areas but also between rhizosphere and bulk soil of P. vittata L. So it is suggested that rhizosphere soil should be sampled to study the effect of soil contamination on plant accumulation. The As concentration in frond of P. vittata L. increased dramatically at lower As level but decreased slowly when As concentration higher than 1 000mg/kg. Arsenic translocation factors of P. vittata L. were greater than 1 in all samples in this study, whereas As concentration in shoots in lower As contaminated soil and bioaccumulation factors in higher As contaminated soil are fail to meet the definition of As hyperaccumulator.

关 键 词：植物修复 空间变异 蜈蚣草 根际 A5 富集系数 转运系数 

分 类 号：X53[环境科学与工程—环境工程]