Advances of study on atmospheric methane oxidation (consumption) in forest soil

森林土壤氧化(消耗)大气甲烷研究进展(英文)

Next to CO2, methane (CH4) is the second important contributor to global warming in the atmosphere and global atmospheric CH4 budget depends on both CH4 sources and sinks. Unsaturated soil is known as a unique sink for atmospheric CH4 in terrestrial ecosystem. Many comparison studies proved that forest soil had the biggest capacity of oxidizing atmospheric CH4 in various unsaturated soils. However, up to now, there is not an overall review in the aspect of atmospheric CH4 oxidation (consumption) in forest soil. This paper analyzed advances of studies on the mechanism of atmospheric CH4 oxidation, and re-lated natural factors (Soil physical and chemical characters, temperature and moisture, ambient main greenhouse gases con-centrations, tree species, and forest fire) and anthropogenic factors (forest clear-cutting and thinning, fertilization, exogenous aluminum salts and atmospheric deposition, adding biocides, and switch of forest land use) in forest soils. It was believed that CH4 consumption rate by forest soil was limited by diffusion and sensitive to changes in water status and temperature of soil. CH4 oxidation was also particularly sensitive to soil C/N, Ambient CO2, CH4 and N2O concentrations, tree species and forest fire. In most cases, anthropogenic disturbances will decrease atmospheric CH4 oxidation, thus resulting in the elevating of atmos-pheric CH4. Finally, the author pointed out that our knowledge of atmospheric CH4 oxidation (consumption) in forest soil was insufficient. In order to evaluate the contribution of forest soils to atmospheric CH4 oxidation and the role of forest played in the process of global environmental change, and to forecast the trends of global warming exactly, more researchers need to studies further on CH4 oxidation in various forest soils of different areas.

甲烷(CH4)是大气中仅次于CO2对全球变暖贡献第二大的温室气体,全球大气CH4的收支取决于CH4的源与汇。水分未饱和土壤是陆地生态系统唯一已知的CH4汇。对比研究发现,在各种土壤类型中了森林土壤具有最大的消耗CH4的能力。到目前为止,还没有文献对森林土壤氧化(消耗)甲烷进行过全面的综述。本文概述分析了大气CH4在森林土壤中氧化的机制与影响这一生物学过程的自然因素(土壤理化性质、土壤温湿度、环境主要温室气体浓度、树种和林火)和人为因素(森林皆伐与择伐、施肥、外源铝盐与大气酸沉降、杀生剂的使用和森林土地利用改变)。结果表明:森林土壤消耗CH4的速率受气体扩散的限制,对土壤水分状况和温度变化敏感。土壤C/N、环境主要温室气体(CO2,CH4与N2O)浓度、树种和火状况对CH4氧化有显著影响。在大多数情况下,人类活动的干扰使CH4氧化速率下降,促进大气CH4浓度升高。作者最后指出,准确估算森林土壤氧化(消耗)大气CH4的能力对全面认识森林在全球环境变化过程中所起的作用与预测全球变化的趋势具有重要意义,但现有的知识还远远不够,需要在不同地区的各种不同类型的森林中开展进一步的研究。图1参90。