模拟酸雨对福州平原水稻田温室气体排放的影响

农田生态系统是温室气体的重要排放源,研究酸雨对水稻田温室气体排放及其综合增温潜势的影响,对我国酸雨背景下农田生态系统固碳减排具有重要的现实意义.本文以福州平原水稻田为研究区,通过模拟酸雨探讨其对水稻田CO_2、CH_4和N_2O排放通量及其综合增温潜势的影响.结果表明:模拟酸雨并未显著改变早、晚稻田CO_2、CH_4和N_2O排放的季节变化规律,但降低了其排放通量.与对照组相比,pH=4.5酸雨作用下,早稻田CO_2、CH_4和N_2O平均排放通量依次降低11.54%、133.33%和22.22%,晚稻田CO_2和N_2O平均排放通量依次降低39.53%、156.00%,而CH_4平均排放通量与对照组差异不显著;pH=3.5酸雨作用下,早稻田CO_2、CH_4和N_2O平均排放通量分别降低10.82%、75.00%、54.00%,晚稻田平均排放通量分别降低17.32%、20.00%和197.67%.综合增温潜势表明,CO_2的增温潜势显著高于CH_4和N_2O,是稻田生态系统中温室效应的主要温室气体,在pH=4.5和pH=3.5的酸雨作用下,早、晚稻田生态系统温室气体综合增温潜势均降低.

Simulation of effect of acid rain on greenhouse gases emissions in paddy field of Fuzhou plain

Agricultural ecosystem is a main emission source of greenhouse gases. It is important to study the effects of acid rain on greenhouse gases emissions and their comprehensive warming potential for understanding the carbon sequestration and reduction in agricultural ecosystem. The early and late rice paddy in Fuzhou plain were taken as the study area,and the variations of CO₂,CH₄ and N₂O emissions and their comprehensive warming potential after acid rain were discussed. The results showed that simulated acid rain did not significantly change the patterns of seasonal variation of CO₂,CH₄ and N₂O emissions in early and late rice field,but reduced their emissions. Compared with the control group,acid rain with pH=4.5 reduced CO₂,CH₄ and N₂O emissions by 11.54%,133.33% and 22.22% in the early rice paddy,while reduced CO₂ and CH₄ emissions by 39.53% and 156.00% in the late rice paddy. On the other hand,acid rain with pH=3.5 decreased CO₂,CH₄ and N₂O emissions by 10.82%,75.00% and 54.00% in early rice paddy,and by 17.32%,20.00% and 197.67% in late rice paddy. As the global warming potential of CO₂ were obviously higher than that of CH₄ and N₂O,CO₂ was the dominant gas of greenhouse effect in the paddy field,and the comprehensive global warming potentials of greenhouse gases were decreased both in early and late rice paddy after acid rain.