北京官厅水库周边农药类POPs暴露的土壤生态效应研究

Study on Ecological Effects of Soils Exposed to POPs around the Guanting Reservoir of Beijing

在前期研究的基础上,围绕北京官厅水库周边2-10km范围内按不同农药类POPs残留量划分4个区域,监测了土壤中主要农药类POPs(HCHs和DDTs)的含量,分析了土壤酶活性和土壤呼吸强度特征。结果表明,4个区域中有机氯农药残留最高为北辛堡区,其次是怀来县区和官厅镇区,最低为延庆县区,平均含量分别为27.59ng.g-1、21.17ng.g-1、9.39ng.g-1和0.86ng.g-1,相应的土壤呼吸强度分别为:0.13μmol.m-2.s-1、0.38μmol.m-2.s-1、0.30μmol.m-2.s-1和0.30μmol.m-2.s-1;土壤脱氢酶活性为56.4μg.g-1.h-1、27.5μg.g-1.h-1、29.6μg.g-1.h-1和50.8μg.g-1.h-1;过氧化氢酶活性为1.07mL.g-1、0.80mL.g-1、0.88mL.g-1和1.10mL.g-1;脲酶活性为197μg.g-1.h-1、172μg.g-1.h-1、129μg.g-1.h-1和181μg.g-1.h-1;磷酸酶活性分别为7.44μg.g-1.h-1、5.75μg.g-1.h-1、5.83μg.g-1.h-1和6.16μg.g-1.h-1。Pearson相关性分析表明在野外长期低浓度有机氯农药暴露的情况下,其含量与土壤酶活性和土壤呼吸值之间无显著相关性。有机氯农药残留不同程度的区域上酶活性和土壤呼吸强度差异不显著。

Surface soil samples around the Guanting Reservoir of Beijing ranging from 2-10 km were divided in four fields according to the types and the amount of residues of POPs.Samples collected from four locations were measured for concentrations of pesticide（HCHs and DDTs） residues,soil enzyme activities,and soil respiration.The results show that the order of pesticide residues is as follows Beixinbao,Huailai,Guanting and Yanqing,and the concentrations of organochlorine pesticides in soils are 27.59 ng·g-1,21.17 ng·g-1,9.39 ng·g-1and 0.86 ng·g-1,respectively;the activities of soil dehydrogenase are 56.4 μg·g-1·h-1,27.5 μg·g-1·h-1,29.6 μg·g-1·h-1and 50.8 μg·g-1·h-1,respectively;the activities of soil catalase are 1.07 mL·g-1,0.80 mL·g-1,0.88 mL·g-1and 1.10 mL·g-1,respectively;the activities of soil urease are 197 μg·g-1·h-1,172 μg·g-1·h-1,129 μg·g-1·h-1and 181 μg·g-1·h-1,respectively;the activities of soil phosphatase are 7.44 μg·g-1·h-1,5.75 μg·g-1·h-1,5.83 μg·g-1·h-1and 6.16 μg·g-1·h-1,respectively.Pearson correlation analysis shows that there is no significant correlation between the concentrations of organochlorine pesticides and soil enzyme activities and soil respiration when the soils are exposed to low concentrations of organochlorine pesticides in the wild in a long term.There is no significant difference between different levels of residue of organochlorine pesticides.