摘要
芦苇（Phragnutes australls）是河口、河岸和湖泊等湿地广泛分布的大型水生植物（aquatic macrophyte），是影响以上湿地类型甲烷排放的重要生物因子。芦苇湿地甲烷排放是甲烷产生、氧化和传输过程的最终结果，通过综述国内外研究结果表明：①芦苇湿地中，芦苇是甲烷产生的底物的重要提供者；②芦苇为氧气的传输提供了内部通道，加速了甲烷的氧化；③植物体传输在芦苇湿地甲烷传输中占有重要地位，芦苇对甲烷的传输有对流传输和分子扩散传输2种传输方式。2种传输机制的选择与光强有关，光照充足时，以对流传输为主；低光照和夜间以分子扩散传输为主。比较而言，对流传输更为重要，其对甲烷排放量的贡献率占54％～87％；分子扩散传输仅占13％～46％；④芦苇湿地甲烷排放日动态与对流传输和分子扩散传输2种传输机制密切相关；甲烷排放的年季变化也较为显著，温暖、湿润的生长季甲烷排放较多，而低温的非生长季甲烷排放减少；⑤水位、温度和光照等是影响芦苇湿地甲烷排放量与变化规律的主要环境因子。表1，参40。
Reed （Phragmites australis） is a common aquatic macrophyte widely distributing in the estuaries, fiver and lake marsh, and is an important biological factor controlling methane emission of above wetland types. The methane emission is the final result of methane production, oxidation and transport process in marsh. For reed marsh, reed is the main provider of substrate for methane production, and the exudation of reed root is the key source of methane production. Reed offers the internal pass way for the transport process of oxygen, therefore, accelerates the oxidation of methane. Methane transport through plant is dominant in the methane transport of reed marsh. Methane transport through reed consists of diffusive transport and convective transport, depending on the light level. For sufficient illumination, methane transport relies mainly on convective transport;for low illumination and night, diffusive transport is main approach. Convective transport contributes 54% - 87% of the methane emission, and diffusive transport only contributes 13% - 46%.Reed exhibits a two peaks pattern of diel methane emission, and may be correlated with convective and diffusive transports. Annual variation of reed methane emission is also significant, more methane emits in warm and moist summer season, and the opposite is in winter. Water table, temperature and light intensity are the most important factors controlling methane emission.
出处
《农业系统科学与综合研究》
CSCD
2008年第1期20-25,共6页
System Sciemces and Comprehensive Studies In Agriculture
基金
国家自然科学基金资助项目(40671174)
关键词
芦苇
沼泽湿地
对流传输
甲烷排放
Phragmites australis
marsh
convective transport
methane emission
