哈尼梯田湿地核心区水稻土重金属分布与潜在的生态风险  

Distribution of heavy metal in paddy soil of Hani Terrace core zone and assessment on its potential ecological risk

作　　者：任华丽[1] 崔保山[1] 白军红[1] 董世魁[1] 胡波[1] 赵慧[1] 

机构地区：[1]北京师范大学环境学院,环境模拟与污染控制国家重点联合实验室,北京100875

出　　处：《生态学报》2008年第4期1625-1634,共10页Acta Ecologica Sinica

基　　金：国家重点基础研究发展计划资助项目(2003CB415104)~~

摘　　要：选取了牛角寨河片区、麻栗寨河片区、阿勐控河片区和大瓦遮河片区4个核心区为样区,分析了样区水稻土表层的重金属As、Cd、Cr、Cu、Pb、Zn的分布特征,与云南土壤背景值进行了比较,结果显示4个样区Cd的含量都略高于背景值,Cr是背景值的两倍;牛角寨河片区的Cu含量由于铜矿的存在而远远高出背景值和其他3个样区的Cu含量,4个样区的As、Pb和Zn的平均含量低于背景值,样区之间差异性也不是很大。由相关性分析可知,湿地土壤偏酸性对Cd的活性有很大影响,高含量的有机质和全氮对Pb和Zn的土壤吸附和积累起到了一定的作用,Pb和Zn在各样区内相似的分布趋势可能与相似的成土母质、耕作模式和人类干扰强度等有关。采用Hakanson潜在生态危害指数法对样区的重金属潜在生态风险进行评价,结果显示(1)从潜在生态危害指数来看,4个片区Cd的危害系数均达到或接近中度危害程度,牛角寨河片区受到Cu的中度危害,其他样区均是轻微的生态危害,甚至Zn还处于缺乏状态;(2)从潜在生态危害指数看,牛角寨河片区的潜在生态危害指数表现为中等生态危害,高于其他3个样区,贡献因子是Cd和Cu,C、rAs、Pb次之,Zn最小;其他样区危害程度顺序为阿勐控河片区>大瓦遮河片区>麻栗寨河片区,都处在轻微的生态危害状态,产生生态危害的主要重金属是Cd,Cu、Cr、As、Pb次之,Zn影响最小。This paper studied the distribution of the heavy metals including As, Cd, Cr, Cu, Pb, and Zn in the paddy soils of Hani Terrace core zone, which is comprised of four sections, Niujiaozhai River patch, Malizhai River patch, Amengkong River patch, Dawazhe River patch. Means of heavy metals in the soils collected from four zones were compared with the background values （BV） of soil heavy metals in Yunnan Province. The results show that the average content of Cd in sampled soils was a little higher than the BV, the average content of Cr was more than 2 times of BV, and the average contents of As, Pb and Zn were lower than BV. The difference of heavy metal was not obvious between different sample sites （patch）. Due to Cu mine in Niujiaozhai zone, the content of Cu there was much higher than and those in other zones and the BV. Correlation analyses indicate that acid soil of wetland affected the activity of Cd greatly. High organic matter and total nitrogen play an important role in improving accumulation of Pb and Zn in soil. There was a similar distribution of Pb and Zn in four zones. This may be attributed to similar parent materials of soil, pattern of cultivation and human disturbance. By using the Hakanson＇ method of potential ecological risk assessment, the potential ecological risk of heavy metals were estimated. The result show that the potential ecological risk of Cd in four zones was up to moderate, which of Cu was moderate in Niujiaozhai River patch and light in other patches. Moderate potential ecological risk region may occur in Niujiaozhai River patch, stressed by Cu and Cd heavily and As, Cr and Pb, Zn slightly. The potential ecological risk in other three patch was light with the order of risk as follows Amengkong River patch 〉 Dawazhe River patch 〉 Malizhai River patch. In these patches, Cd was the major ecological stressor, followed by As, Cr and Pb, Zn.

关 键 词：哈尼梯田湿地 重金属 相关分析 潜在生态危害评价 

分 类 号：X53[环境科学与工程—环境工程]