摘要
养殖塘作为重要的温室气体排放源,水体中温室气体浓度的变化不仅是准确量化温室气体排放量的基础,还是明确其影响因素的重要依据.基于顶空平衡-气相色谱仪法对长三角一处典型的小型养殖塘水体中CH_④、CO_②和N_②O浓度的时空变化特征以及影响因素进行了分析.结果表明,除春季外,在水温影响下,CH_④和N_②O浓度在午间或午后出现高值;受水温和水生植物光合作用影响,CO_②浓度的高值出现在晨间光合作用较弱的时候.养殖塘水体中CH_④和CO_②浓度呈现秋季最高、冬季最低的季节变化特征,c(CH_④)在秋季和冬季的均值分别为176.34 nmol·L_(-1)和32.75 nmol·L_(-1),主要受气温、水温和溶解氧(DO)影响;c(CO_②)秋季和冬季的均值分别为134.37μmol·L_(-1)和23.10μmol·L_(-1),主要受水生植物光合作用和pH影响;c(N_②O)在夏季最高,冬季最低,均值分别为97.05 nmol·L_(-1)和19.41 nmol·L_(-1),主要受气温和水温影响.在空间上,垂直方向上,夏季养殖塘c(CH_④)随水深的加深而降低,表层与底层、中间层的浓度差值为71.28 nmol·L_(-1)和42.80 nmol·L_(-1),秋季随水深的加深而升高,底层与表层的浓度差值为163.94 nmol·L_(-1).c(CO_②)在夏季和秋季都表现为随着水深的加深而升高,其底层与表层的浓度差值分别为18.69μmol·L_(-1)和29.90μmol·L_(-1).N_②O浓度在垂直方向上无明显变化规律.水平方向上,夏季饲料及春季鸡粪投放的区域会出现CH_④、CO_②和N_②O浓度的高值,春季和夏季CH_④浓度约为其他区域的1.34~1.98倍和1.95~2.42倍,春季N_②O浓度和夏季CO_②浓度约为其他区域的1.13~1.26倍和1.39~1.74倍.
As an important source of greenhouse gases,the changes in greenhouse gas concentrations of aquaculture ponds are not only the basis for accurate quantification of greenhouse gases emissions but are also important for identifying their influencing factors.The spatial and temporal variation characteristics of CH_④,CO_②,and N_②O concentrations and the influencing factors in a typical small aquaculture pond in the Yangtze River Delta were analyzed based on the headspace equilibrium-gas chromatograph method.Except in spring,the concentrations of CH_④,and N_②O appeared high at noon or afternoon and were influenced by water temperature.Impacted by water temperature and aquatic plant photosynthesis,the concentrations of CO_②were high in the morning when photosynthesis was weak.The concentrations of CH_④and CO_②were the highest in autumn and the lowest in winter.The mean concentrations of CH_④in autumn and winter were 176.34 nmol·L_(-1)and 32.75 nmol·L_(-1),respectively,which were mainly affected by air temperature,water temperature,and dissolved oxygen.The average CO_②concentrations in autumn and winter were 134.37μmol·L_(-1)and 23.10μmol·L_(-1),respectively,and were mainly affected by aquatic vegetation photosynthesis and pH.N_②O concentration was the highest in summer and the lowest in winter,with mean values of 97.05 nmol·L_(-1)and 19.41 nmol·L_(-1),respectively,which were mainly affected by air temperature and water temperature.In terms of the vertical spatial variations of the three greenhouse gases,the concentration of CH_④decreased with water depth in summer,and the concentration differences between the surface layer and the bottom and middle layers were 71.28 nmol·L_(-1)and 42.80 nmol·L_(-1),respectively.The concentration of CH_④increased with water depth in autumn,and the concentration difference between the bottom layer and surface layer was 163.94 nmol·L_(-1).The CO_②concentration increased with water depth in summer and autumn.The concentration differences between the bottom and surface concentrations were 18.69μmol·L_(-1)and 29.90μmol·L_(-1),respectively.N_②O concentration showed no obvious change in the vertical direction.For the horizontal variations,the concentrations of CH_④,CO_②,and N_②O in the feeding area in summer and in chicken manure in spring were approximately 1.34-1.98 times and 1.95-2.42 times those in other areas,respectively,and the concentrations of N_②O and CO_②in spring and summer were approximately 1.13-1.26 times and 1.39-1.74 times those in other areas.
作者
石婕
张弥
邱吉丽
万梓文
赵若男
谢燕红
陈明健
赵佳玉
肖薇
刘寿东
SHI Jie;ZHANG Mi;QIU Ji-li;WAN Zi-wen;ZHAO Ruo-nan;XIE Yan-hong;CHEN Ming-jian;ZHAO Jia-yu;XIAO Wei;LIU Shou-dong(Yale-NUIST Center on Atmospheric Environment,Intemational Joint Laboratory on Climate and Enviroment Change(ILCEC),Nanjing University of Information Science&Techology,Nanjing 210044,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2022年第9期4867-4877,共11页
Environmental Science
基金
国家重点研发计划项目(2020YFA0607500)
国家自然科学基金项目(41575147,41975143)。
