巢湖水-气界面N_(2)O通量排放特征及影响因素  

Characterization of N_(2)O emission at the water-gas interface and influences of Lake Chaohu

作　　者：杨帆 苗雨青 叶爱中 崔乾 孙奕琳 罗浩 洪炜林 孙方虎 Yang Fan;Miao Yuqing;Ye Aizhong;Cui Qian;Sun Yilin;Luo Hao;Hong Weilin;Sun Fanghu(School of Geography and Tourism,Anhui Normal University,Wuhu 241002,P.R.China;State Key Laboratory of Earth Surface Processes and Resource Ecology,Institute of Land Surface System Science and Sustainable Development,Fculty of Geographical Science,Beijing Normal University,Beijing 100875,P.R.China;Key Laboratory of Land Surface Processes and Regional Response in Jianghuai Basin,Anhui Province,Wuhu 241002,P.R.China)

机构地区：[1]安徽师范大学地理与旅游学院,芜湖241002 [2]北京师范大学地理科学学部,地表过程与资源生态国家重点实验室,陆地表层系统科学与可持续发展研究院,北京100875 [3]江淮流域地表过程与区域响应安徽省重点实验室,芜湖241002

出　　处：《湖泊科学》2023年第6期2000-2009,共10页Journal of Lake Sciences

基　　金：安徽省自然科学基金项目(2108085MD126);国家自然科学基金项目(41601083,41601103)联合资助。

摘　　要：湖泊是温室气体氧化亚氮(N_(2)O)的潜在排放源,但由于自然环境以及人类活动的差异,其N_(2)O排放规律也存在特殊性和地域性。为探究巢湖N_(2)O排放通量的时空特征,利用静态暗箱-气相色谱法于2018年3月至2019年12月对巢湖不同区域(东、中、西)N_(2)O的排放进行观测。结果表明,巢湖水体N_(2)O年均排放通量为(25.14±55.01)μg/(m^(2)·h),表现为N_(2)O的“源”,且具有较为明显的时空分布规律。在时间分布上,季节变化趋势呈现“M”形模式,7月出现最小值且表现为N_(2)O的“汇”((-12.97±16.32)μg/(m^(2)·h)),在6月和8月为峰值,全年最大值出现在8月((68.25±78.05)μg/(m^(2)·h)),极值均出现在夏季。在空间分布上,东、中、西3个湖区N_(2)O排放通量差异显著(P=0.03),N_(2)O排放通量最大值((43.32±79.96)μg/(m^(2)·h))出现在西巢湖,最小值(10.37±19.31)μg/(m^(2)·h)出现在东巢湖,整体上呈现从湖岸向湖中心逐渐降低的趋势,但从不同湖区来看仅西巢湖呈现出相似的规律,中巢湖和东巢湖在距湖岸4 km时分别出现最大值和最小值,主要受外源输入影响。巢湖N_(2)O排放通量总体上与pH呈显著负相关,但在不同季节及不同湖区,环境因子与N_(2)O排放通量的相关性不同,营养盐输入及温度变化对N_(2)O的产排都会产生不同程度影响。湖泊N_(2)O排放并不只受单一或固定环境因子控制,而是多种环境因素综合作用的结果。Lakes are potential sources of nitrous oxide(N_(2)O).The N_(2)O emission pattern of lakes also has special and regional characteristics due to the differences in natural environment as well as human activities.In order to explore the spatial and temporal characteristics of N_(2)O flux from Lake Chaohu,this study observed N_(2)O emissions from different regions(east,middle,and west)of the lake from March 2018 to December 2019 using a dark floating chamber.The results showed that the annual average N_(2)O flux from Lake Chaohu was(25.14±55.01)μg/(m^(2)·h),which behaved as a“net source”of N_(2)O and had a obvious spatial and temporal distribution pattern.In terms of temporal variation,the seasonal trend showed an“M”pattern,with a minimum value in July((-12.97±16.32)μg/(m^(2)·h)),a peak in June and August,and a maximum value in August((68.25±78.05)μg/(m^(2)·h)).The extreme values all happened over the summer.Maximum N_(2)O emission flux((43.32±79.96)μg/(m^(2)·h))occurred in the west sub-lake zone and the minimum((10.37±19.31)μg/(m^(2)·h))occurred in the east sub-lake zone,showing an overall trend of gradually decreasing from the shore to the center of the lake.However,only the west sub-lake zone showed a similar pattern from different lake areas,the central sub-lake zone had a maximum value of 4 km from the lake shore and the east sub-lake zone had a minimum value of 4 km from the lake shore,which were mainly influenced by exogenous input.The N_(2)O emission from Lake Chaohu was significantly negatively correlated with pH,but the relationships between environmental factors and N_(2)O emission varied depending on the season and region of the lake.The flux of N_(2)O from lakes is not controlled by a single or fixed environmental factor,but is a combination of multiple environmental factors.

关 键 词：巢湖 氧化亚氮 时空特征 影响因素 

分 类 号：X143[环境科学与工程—环境科学] X16