河口区淡水与微咸水潮汐湿地CH_4和CO_2的产生速率

通过室内培养试验研究盐度差异对闽江河口短叶茳芏潮汐湿地CH_4和CO_2的产生速率以及土壤理化性质的影响.结果显示,淡水湿地和微咸水湿地土壤CH_4的产生速率分别为0.03~0.76μg·g~(-1)·d~(-1)和0.01~0.22μg·g~(-1)·d~(-1),平均值分别为(0.27±0.06)μg·g~(-1)·d~(-1)和(0.10±0.03)μg·g~(-1)·d~(-1).土壤CO_2产生速率分别为0.44~6.68μg·g~(-1)·d~(-1)和0.64~6.77μg·g~(-1)·d~(-1),平均值分别为(3.03±0.42)μg·g~(-1)·d~(-1)和(3.47±0.41)μg·g~(-1)·d~(-1).淡水湿地土壤CH_4的产生速率显著高于微咸水湿地(P<0.05),而2个潮汐湿地土壤CO_2的产生速率并无显著差异.微咸水湿地的电导率、pH、总碳(TC)、总磷(TP)均极显著高于淡水湿地(P<0.01),总氮(TN)含量显著高于淡水湿地(P<0.05).相关分析显示,土壤CH_4和CO_2产生速率主要受温度、电导率、pH、TC、TN、TP的影响.

CH4 and CO2 production rates from freshwater and brackish marshes in the Min River estuary

Using laboratory incubation experiment, the effects of salinity on CH4 and CO2 production rates from Cyperus malaccensis tidal wetlands in Min River estuary were measured. Then soil physical-chemical properties were examined to elucidate the dynamic characteristics. The results showed that under anaerobic conditions, CH4 production rates from the freshwater and brackish marsh amountedto 0.03-0.76μgg-1d-1 and 0.01- 0.22μgg-1d-1, with (0.27±0.06) μgg-1d-1 and (0.10±0.03) μgg-1d-1 being the averages, respectively. CO2 production rates from the freshwater and brackish marsh amounted to 0. 44-6. 68μgg-1d-1and 0.64-6.77μgg-1d-1, with (3.03±0.42) μgg-1d-1 and (3.47±0.41) μgg-1d-1 being the averages, respectively. CH4 production rate was significantly higher from freshwater marsh than brackish marsh ( P<0.05) , while no statistical differences between CO2 production rates from both marshes. Physical-chemical property analysis showed that EC, pH, total carbon (TC), total nitrogen (TN), total phosphorus (TP) were significantly higher at the freshwater marsh than brackish marsh (P<0.05 or P<0.01) . Moreover, correlation analysis revealed that CH4 and CO2 production rates were mainly controlled by temperature, EC, pH, TC, TN and TP.