Seasonal response of nitrogen exchange fluxes to crab disturbance at sediment-water interface in coastal tidal wetlands  

作　　者：Guo-fen Hua Shang-qing Liu Xiang-dong Liu Jin-li Li Yue Fang Wen-ting Xie Xiang Xu 

机构地区：[1]College of Water Conservancy and Hydroelectric Power,Hohai University,Nanjing 210098,China [2]College of Renewable Energy,Hohai University,Nanjing 210098,China

出　　处：《Water Science and Engineering》2024年第2期129-138,共10页水科学与水工程（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.52271273);the Open Foundation of the Key Laboratory of Ministry of Education for Coastal Disaster and Protection(Grant No.Z202201)。

摘　　要：Coastal wetlands are hotspots for nitrogen(N)cycling,and crab burrowing is known to transform N in intertidal marsh soils.However,the underlying mechanisms remain unclear.This study conducted field experiments and used indoor control test devices to investigate the seasonal response of nitrogen to crab disturbance at the sediment-water interface in coastal tidal flat wetlands.The results showed that crab disturbance exhibited significant seasonality with large seasonal differences in cave density and depth.Due to crab disturbance,nitrogen fuxes at the sediment-water interface were much greater in the box with crabs than in the box without crabs.In summer,NH-N showed a positive flux from the sediment to the overlying water,but NO2-N and NOg-N showed positive fluxes from the sediment to the overlying water only in early stages.In winter,NH-N showed a positive flux from the sediment to the overlying water,but NO-N and NO,-N both exhibited positive and negative fluxes.These results indicated that the presence of crab burrows can cause the aerobic layer to move downward by approximately 8-15 cm in summer and directly promote nitrification at the sediment surface.

关 键 词：Coastal tidal flat wetland Crab disturbance Nitrogen flux NITRIFICATION DENITRIFICATION Sediment-water interface 

分 类 号：TV148[水利工程—水力学及河流动力学] TV143