中国夏尔希里土壤环境背景值特征及评价

Characteristics and Evaluation of the Environmental Background of Soil in Xarxili of China

夏尔希里自然保护区人为干扰极少,是环境背景值研究的良好区域。研究选择该保护区土壤为对象,对九个土壤重金属元素(Mn、Zn、Cr、Pb、Cu、As、Ni、Co、Hg)及有机质进行测试,结果显示:夏尔希里自然保护区各重金属元素含量依次为Mn>Zn>Cr>Pb>Cu>Ni>A s>Co>Hg;环境背景值指标的空间变异性均属于中等变异;测试结果经K-S检验,双尾渐进概率均大于0.05,符合正态分布趋势;相关性分析结果为有机质与Mn元素,Ni与Co、Cr元素,Co与Cr元素均在0.01水平上呈显著正相关;Pb与Zn元素,Co与Cr元素在0.05水平上呈显著正相关;Ni与As元素在0.01水平上呈显著负相关;As与Zn、Hg、Co、Cr在0.05水平上呈显著负相关。单因子污染指数评价结果为Ni、Cr元素属于清洁状态;As、Zn、Mn、Co元素属于清洁和轻度超标状态;其它元素均有中、重度超标现象。研究结果表明夏尔希里保护区在无人为扰动的条件下,保持了较好的生态环境,对于其它区域环境背景的研究具有很好的参照价值。

Xarxili Nature Reserve is located in the southern piedmont of the Alatao Mountain in Xinjiang. Of which,the western part is bordered on the Republic of Kazakhastan, with an area of 314 km2, and it was returned to China in 1999. Due to the nature of less artificial interference, Xarxili Nature Reserve is seen as an ideal place to study environmental background. In this study, the soil in Xarxili Nature Reserve was chosen as the object, the contents of nine heavy metal ions(Mn、Zn、Cr、Pb、Cu、As、Ni、Co、Hg) and organic matter in soils were determined. The results showed that the contents of heavy metals were in the order of Mn > Zn > Cr > Pb > Cu > Ni > As > Co > Hg; Based on the geostatistical method, the organic matter and heavy metals in Xarxili Nature Reserve showed moderate variability; The test results was accorded to the normal distribution by the PK-S was greater than 0.05; A significant positive correlation(α = 0.01) was found between organic matter and Mn, between Ni and Co, between Ni and Cr, and between Co and Cr; And, another positive correlation(α = 0.05) was between Pb and Zn, and between Co and Cr.Whereas, a significant negative correlation(α = 0.01) was found between Ni and As; And, another negative one(α =0.05) was between As and Zn, between As and Hg, between As and Co, and between As and Cr. Single factor pollution index evaluation showed that the elements of Ni, Cr were in clean state, while As, Zn, Mn and Co were in clean/slightly polluted state. Furthermore, others elements were in moderate /heavy polluted state. The study was of great significance in understanding the forming process of the soil, as well as in providing scientific reference for sustainable development and ecological protection of the arid region studied. In addition, Xarxili Nature Reserve had a good ecological environment maintained in the absence of disturbance conditions, whose environmental background had a good reference value for the related study to other regions.