【作者】 李侃；

【导师】 李登煜； 朱波； 陈强； 张小平；

【作者基本信息】 四川农业大学 ， 微生物学， 2006， 硕士

【摘要】 自工业革命以来，由于人类活动和化石燃料使大气中CO₂、CH₄和N₂O等温室气体的浓度不断上升。由此导致的全球气候变暖会引起海平面上升、降水分布变异、植被分布和生产力的改变等一系列严重的全球环境问题，对人类自身的生存和社会经济的持续发展带来巨大的威胁。 生态系统碳循环是全球气候变化研究的一个核心，陆地生态系统碳循环研究是预测未来大气CO₂和其它温室气体含量、认识大气圈与生物圈的相互作用等科学问题的关键，也是认识地球生态系统的水循环、养分循环和生物多样性变化的基础。 利用静态箱／气相色谱法对川中丘陵区不同轮作水稻土壤系统进行全生长季CO₂、CH₄和N₂O排放观测，探讨土壤微生物量与CO₂、CH₄和N₂O排放通量以及植株生长的关系：讨论CO₂、CH₄和N₂O排放通量的季节变化特征及其环境因子和植物生长对其的影响。结果表明： （1） 稻田土壤微生物碳量与水稻成熟期CH₄和CO₂排放通量高度相关，与水稻植株箱外平均生物量和不同处理的氮肥施用量分别达到0.05和0.01的显著和极显著相关水平。 （2） 稻—油轮作、稻—麦轮作和冬水田水稻系统CH₄和CO₂排放均呈现明显的季节变化规律。稻—油轮作和冬水田水稻系统CH₄排放呈现“两边低，中间高”的特点；不同轮作水稻系统的CO₂排放通量均呈现“前低后高”的季节变化规律。 （3） 在水稻的整个生育期中，稻-麦轮作、稻-油菜轮作、冬水田常规栽培稻田CH₄平均排放通量分别为11.52、6.88和25.41mg·m^-2·h^-1，冬水田的CH₄排放通量远大于水旱轮作稻田的CH₄平均排放通量。 （4） 不同轮作系统水稻生长期CO₂总的排放通量为冬水田水稻系统＞稻—麦轮作系统＞稻—油轮作系统，其中冬水田水稻系统的CO₂排放通量分别比稻—油轮作系统和稻—麦轮作系统高出22.83％和17.65％。 （5） 不同轮作水稻系统的N₂O排放在整个水稻生长期的平均排放通量均很小。稻—油轮作和稻—麦轮作的常规和高氮处理在水稻返青期有一个N₂O排放的高峰期；水稻收割前的晒田期间稻田N₂O的排放通量也有不同程度的上下波动。更多还原

【Abstract】 Since industrial revolution, greenhouse gases such as CO₂, CH4 and N₂O have rised constantly because of human activity and fossil fuel combustion. A series of serious global environmental problems, such as sea level rising, a variation of precipitation distribution, vegetation and production change, made great challenge on living of human beings and the sustainable development of social economy.Carbon circle in ecosystem is a core topic in the global change study. Carbon circulation in land ecosystem is crucial to predict the content of CO2 and other greenhouse gases in atmosphere in the future, so as to know the interaction between the atmosphere and the biosphere, and it is foundation to know water circulation, nutrient circulation and bio-diversity change in the earth ecosystem.Based on the observation of CO₂, CH₄ and N₂O emission,measured by static chamber-gas chromatographic techniques from different paddy rotation ecosystems, daily and seasonal variation characteristics.Using the static chamber-gas chromatographic techniques,the quatity of CO₂, CH₄ and N₂O from different paddy field rotation ecosystem,daily and seasonal variation aspects in the hilly area of the central Sichuan Basin was determined ,the results were as the following:（1） There was highly significant relation between paddy soil microbial biomass and CO₂, CH₄ and N₂O emission flux from paddy field in autumn, while the correlation between the microbial biomass and the mean plant biomass out-chamber, and fertilizer used parting reached 0.05 and 0.01 level,respectively.（2） Both methanic gas and carbon dioxide emission from rice-rape system , rice-wheat system and winter paddy field varified remarkably seasonally. Methane emission from rice-rape system and winter paddy field was low in the earlier and latter growth stage; while the CO2 emission fluxes from different rotation paddy system rised gradually during the whole growth period.（3） During the rice growth season , methane emission flux from rice-rape system , rice-wheat system and winter paddy field was 11.52, 6.88 and 25.41mg · m^-2 · h^-1 respectively .The mean methane emission flux from winter paddy field was higher than that更多还原