海螺沟冰川退缩区原生演替中土壤重金属的积累

Accumulation of Heavy Metals in Soil during Primary Succession in Hailuogou Glacier Retreat Area

以海螺沟冰川退缩区形成的原生演替序列为载体,研究近127年土壤形成过程中重金属贮量的积累过程并反演其污染历史。研究表明:(1)Cr、Mn、Ni、Cu、Zn、As、Cd、Pb这8种常见重金属元素在原生演替不同阶段的含量特征不尽相同,但Pb、Zn、Cd在土壤表层存在明显富集,在半分解层中富集系数分别达4.23、5.04、37.18,在全分解层中略有下降;(2)随演替的发展,表层土壤中Pb、Zn、Cd的贮量均随演替不断增加,到演替末期分别达13.01、32.19和0.68 kg/hm^2,但积累速率均于1965年左右达到峰值,这可能与该时期大气污染特征有关;(3)除大气沉降外,凋落物的归还也是影响表层土壤Pb、Zn、Cd变化的重要因素。

This paper studied the accumulation of heavy metal storage during the soil formation process in the last 127 years and tacked the pollution history by using the primary succession sequence formed in the Hailuogou Glacier Retreat Area.Our results showed that:(1)The content characteristics of Cr,Mn,Ni,Cu,Zn,As,Cd and Pb in different stages of the primary succession were different,while Pb,Zn and Cd were significantly enriched in surface soil,their enrichment coefficients in the semi-decomposed layer were 4.23,5.04 and 37.18,respectively,and decreased slightly and correspondingly in the fully decomposed layer.(2)With the development of the succession,storages of Pb,Zn and Cd in surface soil increased and reached 13.01 kg/hm^2,32.19 kg/hm^2 and 0.68 kg/hm^2,respectively,at the end of the succession,but their accumulation rates peaked around 1965,which may be related to the heavy atmospheric pollution in this period.(3)In addition to atmospheric deposition,the return of litter is also an important factor in affecting of Pb,Zn and Cd in surface soil.