胶州湾盐沼CH3I通量的季节特征及其影响因素

Seasonal characteristics and influencing factor s of CH3I flux in salt marsh of Jiaozhou Bay

为了探究胶州湾盐沼碘甲烷(CH3I)的排放通量、排放规律及其影响因素,在2016年7月-2017年5月期间,采用静态箱法-气相色谱法对CH3I进行了观测.结果表明,胶州湾盐沼显示为CH3I的排放源.互花米草湿地(S区)CH3I通量均值为9.61 nmol·m^-2·d^-1,光滩(M区)CH3I通量均值为6.63 nmol·m^-2·d^-1.CH3I的排放通量在S区与M区之间存在明显区别,S区CH3I通量在夏、秋季较高,最高值出现在夏季;而M区CH3I通量在冬、春季较高,最高值出现在冬季.S区与M区各月CH3I通量总体呈相反的变化趋势,且S区与M区CH3I通量的最大值和最小值都出现在7月.胶州湾盐沼环境因素较为复杂,因此,CH3I排放通量的影响因素并不单一.土壤TN、pH、温度及互花米草对CH3I通量的影响较为显著,而含水量、盐度及其他养分状况等对CH3I通量也有一定的作用.此外,冻融过程及潮汐作用的影响也不容忽视.

In order to explore the flux, characteristics, and impact factors of CH3 I emissions in Jiaozhou Bay salt marsh, CH3 I was observed by using static chamber-gas chromatography from July 2016 to May 2017. The results show that the salt marsh of Jiaozhou Bay is the source of CH3I emission. The CH3I flux of Spartina alterniflora wetland (S area) and mudflat (M area) are 9.61 nmol·m^-2·d^-1 and 6.63 nmol·m^-2·d^-1, respectively. The emission flux of CH3I has obvious differences between S and M area. In summer and autumn, CH3 I flux is higher in S area, and the highest value appears in summer. In winter and spring, CH3I flux is higher in M area, and the highest value appears in winter. The monthly CH3I fluxes in S and M regions show the opposite trend, and the maximum and minimum CH3I fluxes in S and M areas appear in July. The environmental factors of salt marsh in Jiaozhou Bay are complex, so there are multiple factors affecting CH3 I emission flux. Soil total nitrogen, pH and temperature have significant effects on CH3 I flux. Water content, salinity and other nutrient conditions are also important. In addition, the impact of freezing and thawing process and tidal action can′t be ignored.