Denitrification Rates and Their Controlling Factors in Streams of the Han River Basin with Different Land-Use Patterns

作     者：S.P.JUNG Y.J.KIM H.KANG 

作者机构：School of Civil and Environmental EngineeringYonsei UniversitySeoul 120-749(Korea) River and Coastal Research DivisionKorea Institute of Construction TechnologyGoyang 211-712(Korea) 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：2014年第24卷第4期

页      面：516-528页

核心收录：

学科分类：12[管理学] 1204[管理学-公共管理] 0818[工学-地质资源与地质工程] 0903[农学-农业资源与环境] 0901[农学-作物学] 120405[管理学-土地资源管理] 

基　　金：Supported by the National Research Foundation of Korea(No.2013056833) 

主　　题：denitrifier communities denitrifying genes nutrient cycle stream ecosystem 

摘      要：Land-use patterns can affect various nutrient cycles in stream ecosystems, but little information is available about the effects of urban development on denitrification processes at the watershed scale. In the presented study, we investigated the controlling factors of denitrification rates within the streams of the Han River Basin, Korea, with different land-use patterns, in order to enhance the effectiveness of water resource management strategies. Ten watersheds were classified into three land-use patterns （forest, agriculture and urban） using satellite images and geographic information system techniques, and in-situ denitrification rates were determined using an acetylene blocking method. Additionally, sediment samples were collected from each stream to analyze denitrifier communities and abundance using molecular approaches. In-situ denitrification rates were found to be in the order of agricultural streams （289.6 mg N20-N m-2 d-1） 〉 urban streams （157.0 mg N20-N m-2 d-1） 〉 forested streams （41.9 mg N20-N m-2 d-l）. In contrast, the average quantity of denitrifying genes was the lowest in the urban streams. Genetic diversity of denitrifying genes was not affected by watershed land-use pattern, but exhibited stream-dependent pattern. More significance factors were involved in denitrification in the sites with higher denitrification rates. Multiple linear regression analysis revealed that clay, dissolved organic carbon and water contents were the main factors controlling denitrification rate in the agricultural streams, while dissolved organic carbon was the main controlling factor in the urban streams. In contrast, temperature appeared to be the main controlling factor in the forested streams.