水库消落带碳氮输移转化研究进展

水库消落带处于水域生态系统与陆地生态系统的交错区域。受水库水位周期性涨落影响，消落带土壤、植物与水库水体间频繁发生碳氮物质交换转化。河流-水库碳埋藏及其温室气体排放是当前全球碳循环研究的热点问题，而当前消落区相关研究仅对植物、土壤或水体等单个对象开展碳氮输移循环研究，而并未将水库消落带作为整体考虑其对河流-水库碳氮输移转化的贡献。本文综合消落带土壤淹水后碳氮含量变化、植被碳氮输入、土壤侵蚀研究，阐明消落带营养物质向筑坝河流的输入作用；并进一步分析与此相关的消落带碳氮循环及温室气体排放研究，明确消落带对筑坝河流碳氮元素转化的作用。提出当前亟待开展消落带碳氮输入源追溯、土壤侵蚀和温室气体通量长期监测，并基于同位素等技术手段明确消落带在水库碳氮输移转化中的贡献等若干问题，旨在系统明确碳氮元素在消落带和水体间的输移、水土界面的多途径生物地球化学循环转化过程，评估水库消落带在河流上、下游及河口碳氮输送转化中的作用。

Research Advances in Transport and Transformation of Carbon and Nitrogen in Water-level Fluctuating Zone (WLFZ) of Reservoir

Water-level fluctuation zone (WLFZ) of reservoir is located in the interlaced area between aquatic and terrestrial ecosystem. Under the influence of periodic fluctuation of reservoir water level, carbon (C) and nitrogen (N) exchanges and transformation frequently occur between soil and plant of WLFZ and water body of reservoir. C burial and greenhouse gas emission of river-reservoir are hot issues in the global C cycle, however, current studies on WLFZ C and N cycles were only focused on single object such as plant, soil or water body, and did not take WLFZ as a whole in considering its contribution to river-reservoir C and N transport and transformation. This paper reviewed study progresses in the changes of soil C and N contents, C and N inputs by vegetation, soil erosion, C and N cycles and greenhouse gas emission from two aspects of transport and transformation of nutrients in the WLFZ. In order to further systematically clarify the multi-pathway biogeochemical cycling and transformation processes of C and N between WLFZ and water bodies and in soil and water interfaces and evaluate the role of WLFZ in C and N transport and transformation in upstream, downstream and estuary of river, it is suggested that to urgently carry out researches on tracing C and N input sources in WLFZ, long-term monitoring of soil erosion and greenhouse gas flux in WLFZ, and WLFZ contribution to C and N transport and transformation of reservoir based on isotopes, etc.