树木年轮分析在环境监测中的应用进展

Progress on the Applications of Dendroanalysis in Environmental Monitoring

关键词:  树木年轮  年轮化学  污染物  环境监测

Key words:  tree ring  dendrochemistry  pollutants  environmental monitoring

摘要:

阐述树木年轮在环境中应用的基本原理,综合分析树木年轮分析在环境监测中应用的发展历程和最新进展,通过研究实例扼要综述树木年轮在大气痕量金属沉降的监测、水体和土壤重金属沉降的监测、有机污染物的推断和人工合成放射性元素的调查研究中的重要领域,探讨树木年轮研究存在的不足、难以解决的问题及可能改进的途径。认为今后利用树木年轮研究环境变化的重要领域是树木逆境条件下生理特性的基础理论研究、污染元素时空分异规律的研究、污染元素进入树木体内动力学过程及其与环境相关性的研究,以及多学科交叉、与其他环境信息源记录的比较研究

Abstract:

Environmental pollution is a major problem in many parts around the world,especially in the developed and fast developing countries or areas. In order to provide scientific bases for natural resource management and environmental protection,it is necessary to evaluate the impacts of the progressive anthropogenic activities on natural environment by using correct and effective means and tools.Trees are well recognized as one of most reliable chronological information sources in reconstructing the environmental change,e.g. the past pollution episodes, due to their geographical distribution in both heavily human-influenced industry area and remote countryside and mountains In this paper,we reviewed the latest progresses in dendrochemistry of trees over the past three decades,clarified the major fields of its application through several case studies These fields included:(1) Monitoring the deposition of atmospheric trace metals and heavy metals,(2) Deducing changes of these metals in soils and waters,(3) Detecting organic pollutants,(4) radioactive pollution. Based on the data and results available,the drawback of dendrochemical analysis and its application,as well as the possible approaches to improve the accuracy were briefly discussed. Consequently,we proposed several priority research areas.They are:(1) Mechanism oriented research including crucial physical,chemical and biological processes and their interactions;(2) Hetergeneity in temporal and spatial distribution of toxic metals in tree rings;(3) Kinetics for elements entering plants and interactions with other abiotic factors;(4) Comparison of the results obtained from tree ring analyses with those from other environmental sources.