闽江口潮汐沼泽湿地土壤甲烷产生对温度变化的响应

Responses of methane production to temperature in tidal marshes soil of the Min River Estuary

2012年8月,采集闽江口鳝鱼滩3个典型潮汐沼泽植被带0～30 cm土壤样品进行15 d室内厌氧培养实验,通过测定不同培养温度（20、30和40℃）下土壤甲烷产生潜力,探讨了不同沼泽植被带土壤甲烷产生潜力对温度变化的响应,并探讨了温度和植被类型对土壤甲烷产生的影响.结果表明,20℃时短叶茳芏、芦苇和互花米草沼泽湿地土壤甲烷产生潜力均值分别为0.034,0.057和0.608μg·g-1·d-1,30℃时其均值分别为0.127,0.402和0.928μg·g-1·d-1;40℃时其均值分别为0.608,1.144和2.447μg·g-1·d-1.随温度升高,3个沼泽植被带土壤甲烷产生潜力均表现为显著的指数增长趋势,40℃培养条件下的土壤甲烷产生潜力的累积量显著高于20℃和30℃（p〈0.05）;温度升高对外来入侵种互花米草（Spartina alterniflora）沼泽湿地土壤甲烷产生潜力的促进作用最明显;温度和植被类型对河口区潮汐沼泽湿地土壤甲烷产生潜力均具有显著影响（p〈0.001）,且这两个因素之间存在显著的交互效应（p〈0.001）。

Soil samples（ 0 ～ 30 cm） from three typical tidal marsh ecosystems,dominated by Cyperus malaccensis,Phragmites australis and Spartina alterniflora,respectively,of the Min River estuary were collected in August 2012,and soil methane production potentials were determined using anaerobic incubation method. There was a significant exponential correlation between methane production potential and soil temperature. At 20 ℃,the averaged soil methane production potentials of three marsh vegetation zones were 0. 034,0. 057 and 0. 608 μg·g- 1·d- 1,respectively. At 30 ℃,the averaged soils methane production potential were 0. 127,0. 402 and 0. 928 μg·g- 1·d- 1,respectively. At 40 ℃,the averaged methane production potential of soils were 0. 608,1. 144 and 2. 447 μg·g- 1·d- 1,respectively. The averaged methane production potentials were significantly higher at 40 ℃ than those at 20℃ and 30 ℃（ p〈0.05）. Moreover,the accumulated soil methane production potentials were significantly higher in the S. alterniflora marsh zone than that in the C. malaccensis marsh and the P. australis marsh in every incubation temperatures. Temperature and vegetation type had significant effects on methane production potential（ p〈 0. 001）,with a significant interaction between two parameters（ p〈0.05）.