作为陆地和水生生态系统之间的重要过渡带，河岸带生态系统不仅是陆地生态系统中氮（N）污染物迁移至水生生态系统的天然屏障，亦是反硝化作用活跃的热点区域。然而，现有研究对河岸带不同植被类型区土壤反硝化的关键驱动因子和作用机制的认识尚不甚清楚。本项目拟以太湖流域南苕溪上游的河岸带为研究对象，调查其植被分布并据此划分不同植被类型区，查明河岸带不同植被类型区土壤和毗邻水体中可溶性碳氮的季节变化特点；运用乙炔抑制法和15N示踪法，探明河岸带不同植被类型区土壤反硝化的时空分异特征，明确河岸带不同植被类型区对农业源水体N污染物反硝化脱N效率的影响及关键驱动因素；结合分子生物学技术，揭示河岸带不同植被类型区土壤反硝化的微生物驱动机制。以期最终确定能够对研究区农业源水体N污染物进行有效反硝化脱N的河岸带植被类型，为完善河岸带生态系统N循环和维持太湖上游水生生态系统健康提供科学依据和技术支持。

The riparian zone, the transition area between terrestrial and aquatic ecosystems, is a natural barrier for migrating nitrogen (N) pollutants from terrestrial to aquatic ecosystems and a hot spot with active denitrification. However, the key controlling factors and mechanisms of soil denitrification under different vegetation types in riparian zones are poorly understood. In this proposal, the riparian zones in the upper reaches of South Tiaoxi Stream in the Taihu Lake Basin will be investigated. The riparian zones will be categorized based on the dominant vegetation types, and seasonal variations of soluble carbon and N of soils in the riparian zones and adjacent water bodies will be measured. The temporal and spatial distribution of soil denitrification in riparian zones under different vegetation types will be explored using the acetylene inhibition and 15N tracer methods to reveal the key driving factors and the impact of vegetation type on the efficiency of soil denitrification for removing N pollutants from agricultural source water, and the microbiological mechanism of vegetation type on soil denitrification will be clarified using molecular biology techniques. This research will be helpful to determine the local special vegetation types that can effectively remove N pollutants from agricultural source water through denitrification in this study area, and to provide scientific basis and technical support for understanding the N cycle in riparian ecosystems and improving the health of aquatic ecosystems in the upper reaches of the Taihu Lake Basin.