藏东南典型山地森林生态系统POPs环境行为研究

The mountain forest ecosystem in the southeast Tibetan Plateau (TP) simultaneously has the characteristics of low temperature and high organic carbon content, which is regard as an ideal natural laboratory to study the fate of mountain-cold trapping and forest-filtering effect (FFE) of persistent organic pollutants (POPs). The following research will be carried out in the proposed project: 1) to comparatively study the FFE in different forest types and different growth cycle of forest; 2) to study the partition and sorption behavior of POPs between air-vegetation matrices; 3) to study the deposition fluxes of POPs in different forest types; 4) to study geochemical cycles of POPs in soils and to establish the model of its environmental fate in typical forest ecosystems in the southeast TP. This innovative project will play important roles for the elucidation of key processes of POPs in mountain forest ecosystems in the southeast TP. The research results can provide scientific basis for the evaluation of the ecotoxicological risk and environmental protection of the TP.

藏东南山地森林系统同时具有低温和高有机碳含量的特点，是研究持久性有机污染物（POPs）高山冷凝效应与森林过滤效应的天然实验室。本项目针对POPs森林过滤效应差异性机制和森林系统POPs循环过程的科学问题，以“大气-植被-土壤”为体系拟开展以下研究：1）藏东南不同森林系统POPs过滤效应的差异性和季节性特征；2）不同森林植被POPs大气/植被环境界面过程研究；3）不同森林类型POPs沉降通量研究；4）森林土壤中POPs的循环过程及其环境归趋模型建立。本项目的实施将对揭示藏东南典型森林生态系统POPs的环境过程具有重要意义，为青藏高原生态系统科学评估和环境保护提供参考依据。

藏东南山地森林系统是研究持久性有机污染物（POPs）长距离传输行为和沉降机理的典型区域。本项目以有机氯农药（OCPs）和多环芳烃(PAHs)为目标污染物，对藏东南森林生态系统POPs关键环境过程进行系统研究，并取得以下研究成果：1）证实了森林过滤效应能够显著加剧藏东南POPs的沉降，藏东南森林土壤成为较强疏水性POPs的汇区；2）揭示了藏东南不同森林类型POPs过滤效应差异性机制；3）评估了藏东南典型森林系统POPs的沉降通量；4）阐明了藏东南山地森林土壤POPs汇效应机理。该成果为揭示森林过滤效应的微观机理和提高模型预测的准确性提供理论依据和场地实验验证，对科学评估外源污染物对青藏高原的生态环境风险具有重要意义。