祁连山康乐自然保护区4种土壤剖面重金属含量分布特征

Distribution Characteristics of Heavy Metals of Four Types Soil Profiles in Qilian Mountain Kangle Nature Reserve

以祁连山康乐自然保护区栗钙土、山地灰褐土、亚高山灌丛草甸土和高山草甸土4种土壤为研究对象,分析了不同土层重金属Cd、Cr、Pb、Cu和Zn分布特征,结果表明:4种土壤剖面0~40 cm土层Cd、Cr、Pb、Cu和Zn均值变化顺序为山地栗钙土>山地灰褐土>亚高山灌丛草甸土>高山草甸土。4种土壤剖面0~40 cm土层Cd、Cr、Pb、Cu和Zn均值低于土壤环境质量标准。0~40 cm土层重金属均值与中国土壤相比,山地栗钙土Cd、Cr和Cu均值高于中国土壤,Pb和Zn均值低于中国土壤;山地灰褐土Cd、Cr和Cu均值高于中国土壤,Pb和Zn均值低于中国土壤;亚高山灌丛草甸土Cd和Cr均值高于中国土壤,Pb、Cu和Zn均值低于中国土壤;高山草甸土Cd均值与中国土壤相吻合,Cr均值高于中国土壤,Pb、Cu和Zn均值低于中国土壤。0~40 cm土层重金属均值与甘肃背景值相比,山地栗钙土Cd、Cr、Pb、Cu和Zn均值高于甘肃背景值;山地灰褐土Cd均值与甘肃背景值相吻合,Cr均值高于甘肃背景值,Pb、Cu和Zn均值低于甘肃背景值;亚高山灌丛草甸土和高山草甸土Cd、Cr、Pb、Cu和Zn均值低于甘肃背景值。祁连山康乐自然保护区重金属Cd、Cr、Pb、Cu和Zn主要富集在0~20 cm土层,随着土壤剖面垂直深度的增加而递减,各土层之间差异达到显著和极显著水平。

In this paper,the distribution characteristics of 5 heavy metals including Cd,Cr,Pb,Cu and Zn at different soil layers were analyzed from chestnut soil,mountain gray-cinnamon soil,subalpine shrub meadow soil and alpine meadow soil in Qilian Mountain Kangle Nature Reserve.The results showed that the mean values of 5 heavy metals at 0-40 cm soil layers of four soil profiles were mountain chestnut soil>mountain cinnamon soil>subalpine shrub meadow soil>alpine meadow soil,which were lower than those of soil environmental quality standard.The mean values of Cd,Cr and Cu in mountain chestnut soil were higher than those in Chinese soil,while the mean values of Pb and Zn were lower than those in Chinese soil.The mean values of Cd,Cr and Cu in mountain cinnamon soil were higher than those in Chinese soil,while the mean values of Pb and Zn were lower than those in Chinese soil.The mean values of Cd and Cr in subalpine shrub meadow soil were higher than those in Chinese soil,while the mean values of Pb,Cu and Zn were lower than those in Chinese soil.The mean values of 5 heavy metals in alpine meadow soil were higher than those in Chinese soil,while the mean values of Cd,Cu and Zn in alpine meadow soil were consistent with those in Chinese soil.The mean values of 5 heavy metals in 0-40 cm soil layer were higher than those in Gansu background.The mean value of Cd in mountain gray-cinnamon soil was consistent with Gansu background value,the mean value of Cr was higher than Gansu background value,and the mean value of Pb,Cu and Zn was lower than Gansu background value.The mean values of 5 heavy metals in subalpine shrub meadow soil and alpine meadow soil were lower than those in Gansu province.Five heavy metals were mainly enriched at 0-20 cm soil layer in Qilian Mountain Kangle Nature Reserve,and decreased with the increasing of vertical depth of soil profile.The differences among different soil layers were significant and extremely significant.