高塔涡度相关观测长三角农业区CO_(2)通量变化特征及影响因素  

Dynamics and environmental controls of CO_(2)flux with tall-tower eddy covariance in heterogeneous agricultural landscape of Yangtze River Delta

作　　者：包恒鑫 张弥[1] 谢燕红 贾磊 葛培 邱吉丽 何洋 张圳 肖薇[1] 刘寿东[1] BAO Hengxin;ZHANG Mi;XIE Yanhong;JIA Lei;GE Pei;QIU Jili;HE Yang;ZHANG Zhen;XIAO Wei;LIU Shoudong(Key Laboratory of Ecosystem Carbon Source and Sink,China Meteorological Administration,Nanjing University of Information Science and Technology,Nanjing 210044,China;Guangxi Zhuang Autonomous Region Ecological and Environmental Monitoring Centre,Nanning 530028,China;Meteorological Bureau of Nanjing Jiangning District,Nanjing 211100,China)

机构地区：[1]南京信息工程大学,中国气象局生态系统碳源汇开放重点实验室,南京210044 [2]广西壮族自治区生态环境监测中心,南宁530028 [3]南京市江宁区气象局,南京211100

出　　处：《生态学报》2024年第17期7552-7568,共17页Acta Ecologica Sinica

基　　金：国家重点研发计划项目(2019YFA0607202);江苏省自然科学基金杰出青年基金(BK20220055)。

摘　　要：人类活动对景观尺度农业下垫面的CO_(2)收支有着不可忽视的影响,明确在人类活动影响下景观尺度农业区CO_(2)通量的变化特征及影响因素对增汇减排策略的制定具有重要的意义。使用高塔涡度相关法对长三角地区一处农业区CO_(2)通量开展连续观测以明确其源汇特征及影响因子。结果表明:该农业区CO_(2)通量在春夏秋季表现为白天吸收CO_(2),夜间排放CO_(2)的日变化动态,三个季节CO_(2)通量的变化范围分别为-0.15—0.14、-0.60—0.28、-0.21—0.19 mg m^(-2)s^(-1),冬季则表现为全天排放CO_(2),日变化范围为0—0.14 mg m^(-2)s^(-1)。每年的6—11月CO_(2)吸收明显,其余时间段以排放为主,吸收峰值和排放峰值分别出现在每年的8月和11月,多年均值分别为-0.14、0.08 mg m^(-2)s^(-1)。研究区2019—2021年表现为一个逐年上升的大气碳源,CO_(2)通量年总量均值为(142.73±99.01)gC m^(-2)a^(-1)。在半小时尺度上光量子通量密度(PPFD)、10 cm处土壤温度(Ts)以及饱和水汽压差是影响CO_(2)收支的关键环境要素,日尺度上PPFD、Ts是主要控制因子,月尺度上,Ts是最为重要的影响因素,同时降雨量以及归一化植被指数也影响着CO_(2)通量。经人为CO_(2)开源数据清单得到的通量塔15 km范围内人为CO_(2)排放量为(429.7±30.01)gC m^(-2)a^(-1),抵消了该农业区稻田、森林等自然生态系统的碳汇作用。Human activities affect CO_(2)budget strongly in heterogeneous agricultural landscape.Clarifying the dynamics of CO_(2)flux and its environmental control is important for making carbon sequestration increase and emission reduction strategies in heterogeneous agricultural landscape.In this study,CO_(2)flux was observed with tall-tower eddy covariance continuously in a typical heterogeneous agricultural landscape of Yangtze River Delta in order to investigate CO_(2)source and sink characteristics and its environmental controls.The results showed that the diurnal variation of CO_(2)flux presented that CO_(2)was absorbed in the daytime and was emitted at night in spring,summer and autumn.The diurnal variation range of CO_(2)flux was-0.15-0.14,-0.60-0.28,-0.21-0.19 mg m^(-2)s^(-1)in the three seasons,respectively.In winter,CO_(2)was released throughout the day,and the diurnal variation range was 0-0.14 mg m^(-2)s^(-1).The agricultural landscape absorbed CO_(2)from June to November,and released CO_(2)in the rest months of each year.The CO_(2)absorption and emission peaks appeared in August and November of each year,with the multi-year mean values of-0.14 and 0.08 mg m^(-2)s^(-1),respectively.The agricultural landscape was carbon source for the atmosphere.The CO_(2)emission increased from 2019 to 2021.The multiyear averaged annual total CO_(2)flux was(142.73±99.01)gC m^(-2)a^(-1).The photosynthetic photon flux density(PPFD),soil temperature at 10 cm depth(Ts),and saturated vapor pressure deficit(VPD)were the key environmental factors affecting the CO_(2)flux on half-hour scale.On the daily scale,PPFD and Ts were the main control factors.On the monthly scale,Ts was the most important influencing factor,while precipitation(Pre)and normalized difference vegetation index(NDVI)also affected the CO_(2)flux.The anthropogenic CO_(2)emission within 15 km of the flux tower obtained by the Open-source Data Inventory for Anthropogenic CO_(2)was(429.7±30.01)gC m^(-2)a^(-1),which offset the carbon sink effect of natural ecosystems

关 键 词：农业区 CO_(2)通量 高塔涡度相关法 人类活动 

分 类 号：X71[环境科学与工程—环境工程]