闽江河口感潮段淡水湿地CO_2排放通量对SO_4^(2-)沉降的响应

Effects of Simulated Sulfate Deposition on Carbon Dioxide Emissions from a Freshwater Tidal Wetland in the Min River Estuary

以闽江河口感潮段塔礁洲野慈姑(Sagittaria trifolia L.)淡水湿地为研究对象,2015年12月—2016年10月每月小潮日定期向试验样地施加0、60和120 kg S·hm-2·a-1的K2SO4溶液,探讨闽江河口感潮段淡水湿地CO_2排放通量特征对SO_4^(2-)沉降的响应,并同步观测主要环境因子。结果表明,1)对照(CK)和2个SO_4^(2-)沉降处理CO_2排放通量具有相似的月变化动态,夏秋季节排放通量较高,冬春较低。2)除夏季60 kg S·hm-2·a-1的SO_4^(2-)输入显著降低CO_2排放通量外(P<0.05),2种SO_4^(2-)处理均未显著影响河口感潮段淡水湿地CO_2排放通量(P>0.05)。3)相关分析显示,不同处理下的CO_2排放通量与土壤温度显著正相关(P<0.01)。

Effects of simulated sulfate deposition on carbon dioxide emissions from a freshwater tidal wetland with vegetation of Sagittaria trifolia L in the Min River Estuary were studied. During the neap tide days,potassium sulphate was applied at concentrations of 0,60 and 120 kg S·hm-2·a-1 over a period of 11 months,between December 2015 and October 2016. Measurements of carbon dioxide fluxs and related environmental data were carried out at one month intervals. The results showed that,1） the monthly dynamics of carbon dioxide fluxs were similar among two sulfate deposition treatments and control. Carbon dioxide fluxs from all treatments were higher in summer and autumn,lower in winter and spring. 2） Sulfate deposition did not affect the carbon dioxide fluxs from freshwater tidal wetland in the min river estuary（P 0. 05） except the treatment of 60 kg S·hm-2·a-1 in summer（P 0. 05）. 3） There was a positive correlation between carbon dioxide fluxs and soil temperature in all treatments（P 0. 01）.