文献类型：期刊文献

英文题名：Macrophytes and crabs affect nitrogen transformations in salt marshes of the Yangtze River Estuary

作者：Zhang, Xiaodong[1] Cui, Lijuan[1] Nie, Ming[2] Shao, Junjiong[2] Wei, Shujuan[2] Kang, Xiaoming[1] Li, Bo[2]

第一作者：张骁栋

通信作者：Li, B[1]

机构：[1]Chinese Acad Forestry, Beijing Key Lab Wetland Serv & Restorat, Inst Wetland Res, Beijing 100091, Peoples R China;[2]Fudan Univ, Coastal Ecosyst Res Stn Yangtze River Estuary, Key Lab Biodivers Sci & Ecol Engn, Minist Educ,Shanghai Inst Ecochongming, Shanghai 200438, Peoples R China

年份：2019

卷号：225

外文期刊名：ESTUARINE COASTAL AND SHELF SCIENCE

收录：;Scopus(收录号：2-s2.0-85066760420);WOS:【SCI-EXPANDED(收录号:WOS:000478712800014)】；

基金：This study was supported by the National Key R&D Program of China [2017YFC0506200]; and the National Natural Science Foundation of China [41630528, 31670491]. We are grateful to Dr. Xin Jia who provided insightful comments on the manuscript and helped with linguistic edits.

语种：英文

外文关键词：Salt marsh; Nitrogen cycle; Dissolved organic carbon; Mineralization; Nitrification; China; Shanghai; Yangtze river estuary; Chongming Dongtan

摘要：Nitrogen (N) cycling is important in determining ecosystem primary productivity and the succession of plant communities in coastal marshes. In order to examine the effects of biotic disturbances (i.e. vegetation change and crab burrowing) on N transformations, we conducted a field experiment in which crabs were either removed or left intact in three marsh types (bare flat, Phragmites australis marsh and Spartina alterniflora marsh) at Chongming Dongtan in the Yangtze River Estuary. The potential rates of soil gross nitrogen mineralization (GNM), gross ammonium immobilization (GAI), gross nitrification and gross nitrate consumption were determined using an ex situ incubation approach. Gross N mineralization was significantly lower in vegetated marshes than in the bare flat, probably because dissolved organic carbon (the main energy source for microbes) was lower in vegetated marshes. Less dissolved organic carbon in vegetated marshes may be attributable to high microbial demand for labile carbon relative to the supply of labile carbon in the rhizosphere. The presence of crabs increased the GAI:GNM ratio, indicating that crabs may increase the soil microbial demand for ammonium. Ammonium immobilization competed with nitrification for ammonium, and limited nitrification in crab-present plots. Furthermore, the lower nitrate production by nitrifies in crab-present plots resulted in lower rates of nitrate consumption. These results highlight the role of labile carbon and N in mediating the effects of macrophyte and soil fauna on N transformations.