树木年轮与其根部土壤化学元素含量的相关性

Correlation between chemical element contents in tree rings and those in soils near tree roots in the southern suburbs of Beijing,China.

运用树木年轮学方法研究了北京南郊土壤环境中元素含量随时间序列演变的规律。依据吸收系数研究了相同土壤类型上生长的不同树种对12种化学元素的吸收状况,结果表明不同树种对元素的吸收情况不同。Zn、Cd和P3个元素吸收系数较高。对杨树年轮及其根部土壤中9种化学元素(Na、K、Cu、Zn、As、Sr、Cd、Ba、Pb)的相关性研究结果表明,年轮中元素的含量与其根土中对应元素的含量呈正相关。采用对数线性相关模式(lgC'=algC+b),根据逐年年轮中Cu、Zn、As、Cd、Ba、Pb6种化学元素的含量,反演6种元素在土壤中的逐年(1982—2004年)演变状况。本技术方法能为追溯近代城市化几十年以来的环境污染变迁历史、预测未来污染演变趋势提供更为丰富和科学的信息。

The evolution of heavy metal concentrations with time in the soft environment in the southern suburbs of Beijing was studied by using annual growth rings of trees, The absorption of 12 elements by different tree species in the same soft types was studied according to their absorption coefficients. The study indicates the difference in adsorption of elements by different species of trees. The adsorption coefficients of the elements Zn, Cd and P are higher. The correlation of nine elements （Na, K, Cu, Zn, As, Sr, Cd, Ba and Pb） in growth rings of poplar trees and those in soils near their roots shows that the element contents in growth rings have a positive correlation with the contents in soils near the roots. Based on the logarithrnic linear correlation model （1gC＇=a 1gC＋b）, the evolution of the contents of the elements Cu, Zn, As, Cd, Ba and Pb in soils from 1982 to 2004 were deduced. This method can be used to provide richer and more scientific information for tracing the history of environmental pollution and changes during modem urbanization in the past few decades and predicting the evolutionary trend of pollution change.