【摘要】 以湖北省咸宁市桂花林场管理局5种林分类型(苦槠林、枫香林、马褂木林、檫木林、楠木林)土壤为研究对象,分析其重金属(Zn、Cu、Cd、Ni、Pb、Co)含量特征,并以湖北土壤背景值和全国土壤背景值为标准值,采用Hakanson潜在生态危害指数法进行环境质量评价,结果表明:森林土壤中Zn(11.48～99.05mg·kg-1)的含量最高,Cd(0.03～0.25 mg·kg-1)的含量最低,重金属含量排序为:Zn> Ni> Pb> Cu> Co> Cd,且Zn、Cu、Cd、Ni、Pb含量变异系数较大,Co变幅相对较小,分布较均匀。楠木林和檫木林土壤重金属明显高于其它三种森林土壤,马褂木林土壤重金属含量最低。与湖北土壤背景值和全国土壤背景值相比,5种森林土壤重金属含量大部分在相应的背景值以下,少数样地重金属含量严重超过其背景值。6种重金属间,重金属与pH值、有机质(OM)间存在不同的相关性。苦槠林土壤中的Cu-Pb,枫香林土壤中的Zn-Cu、Cu-Cd、Cd-Pb,马褂木林土壤中的Pb-Zn、Pb-Cu,檫木林土壤中的Cu-Zn,楠木林土壤中的Zn-Cd、Ni-Cu均表现出显著(P <0.05)或极显著(P <0.01)相关性。重金属与有机质(OM)都表现出一定程度的正相关,pH值与重金属之间的相关性不明显。5种森林土壤的潜在生态风险指数具体排序为:楠木林>檫木林>枫香林>马褂木林>苦槠林,均在150以下,为轻微危害程度;Cd的潜在生态风险系数最大,明显高于其他5种元素,生态危害中等,Cu、Ni、Pb、Co的潜在生态风险系数差异不明显,Zn的最小,生态危害轻微。更多还原

【Abstract】 In order to analyze the forest soil heavy metals(Zn, Cu, Cd, Ni, Pb and Co) content characteristics in Southeastern Hubei, five stand types(Castanopsis sclerophylla、Liquidambar formosana、Liriodendron chinensis、Sassafras tzumu、Phoebe zhennan) were choosed as objects,and the pollution level of these heavy metals were calculated by Hakanson potential ecological risk index basing on the background values of heavy metals in surface soil form Hubei province and China.The results showed that Zn(11.48-99.05 mg·kg-1) was the highest concentration and Cd(0.03-0.25 mg·kg-1) was the lowest, the concentration of heavy metals in forest soil was in the Zn > Ni > Pb > Cu > Co > Cd, and the concentration of Zn、Cu、Cd、Ni、Pb varied greatly, while the amplitude of Cd was smaller, distributed more evenly. The concentration of heavy metals in Sassafras tzumu, Phoebe zhennan were significantly higher than the rest, Liriodendron chinensis was the lowest. Compared with background values of Hubei province and China, most of heavy metals in forest soils are lower than their background values, few plots serious exceed its background value. Correlation analysis showed that: there were different correlation between six heavy metals, heavy metals and pH、organic matter(OM). Cu-Pb in Castanopsis sclerophylla stand soil, Zn-Cu、Cu-Cd、Cd-Pb in Liquidambar formosana stand soil, Pb-Zn、Pb-Cu in Liriodendron chinensis, CuZn in Sassafras tzumu, Zn-Cd、Ni-Cu in Phoebe zhennan showed a significant(P < 0.05) or highly significant(P < 0.01) correlations. Heavy metals and organic matter(OM) showed a certain degree of positive correlation, the pH of the correlation between heavy metals and is not obvious. The potential ecological risk index of heavy metals in five stands soil was in the order: Phoebe zhennan > Sassafras tzumu > Liquidambar formosana > Liriodendron chinensis > Castanopsis sclerophylla, all the calculation results were below 150, indicated that the heavy metals pollution in five stands soil was in slight ecological risk level; Cd had the highest potential ecological risk index,which significantly higher than the other five elements and it was in medium ecological risk level,the potential ecological risk coefficient differences in Cu, Ni, Pb, Co were not obvious, and the lowest was Zn, which showed slight ecological risk level.更多还原