森林溶解性有机碳淋溶驱动机制及模拟研究进展

Research advances in underlying mechanism and modeling of dissolved organic carbon leaching in forests

溶解性有机碳(DOC)淋溶是陆地生态系统碳循环中一个关键环节。森林生态系统是陆地生态系统DOC的主要来源之一。DOC通过淋溶作用进入底层土壤,引起底层土壤有机碳变化。森林生态系统DOC通过地表径流汇集和地下水渗漏进入水体,最终参与海洋碳循环。因此,探索森林生态系统DOC淋溶驱动机制对理解全球碳循环关键过程具有重要意义。本文阐述了森林生态系统DOC来源和去向,总结了DOC淋溶的几种重要驱动机制,包括土地利用、气候变化、酸沉降、大气CO2增加和土壤铁铝氧化物等影响因素,并归纳了模拟DOC淋溶及输出通量的经验统计模型和过程机理模型的优缺点。结合目前中国森林生态系统DOC研究现状和不足,我们建议建立中国森林生态系统DOC淋溶观测网络,为模型预测DOC变化提供准确和可靠的观测数据。此外,在未来研究中,需要将野外观测-室内实验-模型模拟相结合,深入研究森林生态系统DOC淋溶驱动机制,尤其要加强环境变化情境下典型区域或国家尺度DOC淋溶的模拟研究。

Leaching of dissolved organic carbon(DOC)is a key process in carbon cycling of terrestrial ecosystems.Forests are one of the main sources of DOC in terrestrial ecosystems.DOC can reach the bottom layer of soil through leaching,resulting in changes of organic carbon in the bottom layer of soil.The DOC in forest ecosystems enters water systems through surface runoff and groundwater seepage,and finally participates in marine carbon cycle.Therefore,exploring the underlying mechanisms of DOC leaching in forest ecosystems is of great significance for understanding key processes of global carbon cycle.Here,we reviewed the sources and sinks of DOC in forest ecosystems,and summarized several important underlying mechanisms of DOC leaching,including land use changes,climate change,acid deposition,atmospheric CO2 increase,soil FeAl oxides.The advantages and disadvantages of empirical statistical models and process-based models for simulating DOC leaching and output fluxes were summarized.Considering the current status and shortcomings of DOC-related researches in forest ecosystems of China,we propose to establish a DOC leaching observation network across forest ecosystems in China to provide accurate and solid data for predicting DOC changes.Moreover,field observations,laboratory experiments,and model simulations should be combined to explore the underlying mechanisms of DOC leaching in forest ecosystems.It is necessary to strengthen the modeling of DOC leaching at typical regional and national scales in the context of environmental change.