水稻植株对稻田甲烷排放的影响  

Effects of rice plants on methane emission from paddy fields

作　　者：贾仲君[1] 蔡祖聪[1] 

机构地区：[1]中国科学院南京土壤研究所,南京210008

出　　处：《应用生态学报》2003年第11期2049-2053,共5页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金(4 0 0 710 79);国家重点基础研究发展规划项目(G19990 1180 5);中国科学院知识创新工程重要方向资助项目(KZCX2 3 0 2 )

摘　　要：稻田CH4排放是稻田土壤中CH4产生、氧化和传输不同过程的净效应 .水稻植株强烈影响稻田CH4的产生、氧化和传输过程 ,是导致稻田CH4排放季节性变化规律的一个重要因素 .本文综述了水稻植株对稻田CH4排放过程的不同影响 .水稻植株根系分泌物和脱落物作为产甲烷前体促进稻田土壤中CH4的产生 ,在水稻生长后期 ,植株根系分泌物和脱落物被认为是稻田土壤甲烷产生的主要基质 ,是导致这一时期稻田CH4高排放通量的主要原因 ;水稻植株根系泌氧在根际环境形成一个微氧区域氧化稻田甲烷 ,整个水稻生长季稻田土壤中产生的CH4大约 36 %～ 90 %在植株根际环境中被氧化 ;约 80 %甚至更多的稻田CH4通过水稻植株的通气组织进入大气圈 。Methane emission from rice paddy fields is the net result of the combination of many processes, i.e., CH 4 production, CH 4 oxidation and CH 4 transportation in paddy soil. Rice plants play a key role in the CH 4 emission from paddy fields, particularly in all the processes involved. The positive and negative effects of rice plants on CH 4 emission from paddy fields are well recognized as the main factors influencing the temporal variation of CH 4 emission flux in paddy field. Process-based studies about the effects of rice plants on methane emission from paddy fields were summarized, and different roles of rice plants on this emission were discussed. Root exudates and litters of rice plants could serve as the substrate for methanogenesis and enhance the CH 4 production of paddy soils, resulting in a high CH 4 emission peak, particularly in rice late growing season. Rhizospheric CH 4 oxidation induced by rice root-excreted oxygen constitutes a main biogenic sink of CH 4, which could account for 36～90% of CH 4 produced in paddy soil over the entire growing season of rice. Up to 80% and more of CH 4 released from rice field during a growing season could be emitted by rice plant-mediated transport. The fully developed aerenchyma of rice plants could be of importance in CH 4 emission during rice growing seasons, and responsible for the CH 4 emission peak observed at rice early growing season.

关 键 词：水稻植株 水稻田 甲烷排放 

分 类 号：X51[环境科学与工程—环境工程]