1999年与2014年贡嘎山峨眉冷杉枝和叶中常见重金属的生物富集特征对比

经济的快速发展使得生态环境的承载力日益接近上限，而关于偏远地区森林系统的重金属污染的时间变化趋势却鲜有报道.本文测定了贡嘎山1999年与2014年采集的峨嵋冷杉枝、叶中的Pb、Hg、Cr、As、Cd、Mn、Cu、Zn与Ba.结果表明：11999年枝、叶样品中Pb、Hg、As、Cd、Mn与Cu显著高于2014年的量，而2014年枝、叶样品中Cr、Zn和Ba高于1999年的量；2枝中Pb、Hg、Cr、As、Cd、Mn、Cu、Zn和Ba与生长龄无统一的变化趋势，而在叶中的含量随着生长龄的增加有增加的趋势；3Hg易在叶中富集，而其它元素更易在枝中富集；通过在主成分分析的基础上进行多元线性回归判断常见重金属元素的来源，枝、叶中的Pb、Cr、As、Cd、Cu、Zn和Ba有42.3%~92.2%的含量来自于土壤，而枝、叶中的Hg有70.6%的含量来自于大气.这说明Hg存在与其他重金属在森林系统不同的累积机制.

Bioaccumulation of Heavy Metals in Twigs and Leaves of Abies fabri at Mount Gongga in China: A Comparison Study Between 1999 and 2014

The rapid economy growth led to the environmental carrying capacity reaching the maximum level.Given that the time changing trend of heavy metal pollution in the remote forest ecosystems has rarely been reported, we reported the differences of Pb, Hg, Cd, As, Cr, Mn, Cu, Zn and bioaccumulation in twigs and leaves of fir(Abies fabri) between samples collected in 1999 and 2014 at the Mt. Gongga, which was located at eastern Tibet Plateau. Our results suggested that the concentrations of Pb, Hg, As, Cd, Mn and Cu in the samples collected in 1999 were significantly higher than those collected in 2014, while the concentrations of Cr, Zn and Ba in samples collected in 2014 were higher than those collected in 1999. The correlation analysis indicated that concentrations of Pb, Hg, Cr, As, Cd, Mn, Cu, Zn and Ba in leaves were positive correlated to the age of the leaves. In addition, Hg was apt to enrich in leaves while the other metals were prone to enrich in twigs. According to the multiple linear regression result, about 70.6% of Hg in leaves and twigs was from air, while the other heavy metals, including Pb, Cr, As, Cd, Cu, Zn, and Ba, were mainly from soil(42.3%-92.2%). These results suggest that there may be different accumulation mechanisms in forest ecosystems between Hg and the other heavy metals.