模拟SO_4~(2-)沉降对河口潮汐湿地甲烷排放通量的影响

2008年每月小潮日原位定期向闽江河口鳝鱼滩咸草(Cyperus malaccensis)潮汐湿地试验样地施加25,50,100kgSO42--S/(hm2·a)的硫酸钠溶液,探讨模拟SO42-酸沉降对河口潮汐湿地甲烷排放通量的影响.结果表明,SO42-酸沉降对于河口潮汐湿地甲烷排放通量基本无抑制作用.添加SO42-室内厌氧培养试验结果显示,虽然SO42-输入对湿地土壤CH4产生量具有一定的抑制作用,但相对对照组,下降幅度仅为8.5%~15.4%.室内添加甲烷产生基质的厌氧培养试验结果表明,非竞争性途径甲烷产生基质(甲醇和三甲胺)的添加可刺激并增加土壤的甲烷产生量,解释了原位施加SO42-对于河口潮汐湿地甲烷排放通量的基本无抑制作用的试验结果.

Effects of simulated sulfate deposition on CH_4 fluxes from tidal wetland in the Min River estuary

In order to examine the effects of simulated sulfate deposition on methane emissions in estuary wetlands， monthly pulses of dissolved Na_2SO_4 were applied to the Cpyerus malaccensis wetland on the neap dates in the Min River estuary over nine months in doses of 25，50，100 kg SO_4~(2-)-S/ (hm~2·a).There was no suppression in most months，only in fewer months，there was a weak suppression.A suppressive effect on methane production amount was observed in the simulated SO_4~(2-) addition in laboratory anaerobic incubation experiment，however，the suppression percentage was only between 8.5% to 15.4 % ralative to control treatment.The adding of non-competitive methane production substrates (methanol and trimethylamine) increased methane production amount in laboratory anaerobic incubation experiment，which would explain the conclusion that simulated SO_4~(2-) deposition in situ had no suppression on methane emission in estuary wetlands.