中文摘要：

农田生态系统是陆地生态系统的重要组成部分,占全球陆地面积的10.5%,其CO2排放量占人为温室气体排放量的21%-25%;由于农田生态系统受到强烈的人为干扰,因此农田生态系统土壤呼吸作用及其影响因素对准确评估陆地生态系统碳收支具有重要的意义。中国是个有悠久历史的农业大国,不仅为农田土壤作用的研究提供了天然的实验室,而且中国农田土壤呼吸作用的研究对全球的碳循环研究及碳收支准确评估具有非常重要的示范与指导意义。该文综述了近10年来中国农田生态系统土壤呼吸作用研究进展,指出水热因子、作物生物学特性和农业管理活动是造成中国农田生态系统土壤呼吸作用时空变异的主要因素;作物根系呼吸作用占土壤作用的比例在13%-77.2%之间,存在极大的不确定性;合理施肥、秸秆还田和免耕有助于农田生态系统土壤呼吸作用减排和固碳。指出了中国农田生态系统土壤呼吸作用拟重点加强不同区域典型农田生态系统土壤呼吸作用的比较、空间异质性、影响因素模拟及减排对策等方面的研究。

英文摘要：

Farmland ecosystems are important terrestrial ecosystems, representing about 10.5 % of the earth＇s surface, and their CO2 emission amounts about 21% - 25% of anthropogenic greenhouse gases emission. Farmland ecosystems are affected intensively by human activities; therefore, soil respiration of farmland ecosystems and their impacts are very important in the carbon budget of terrestrial ecosystems, as well as the global carbon cycle and carbon budget. With a long history of extensive agriculture, China provides a laboratory for soil respiration research. We review the previous decade of research advances in soil respiration of farmland ecosystems in China. Heat-water factors, crop biological characteristics and agricultural management activities played key roles in regulating the spatial and temporal variations of soil respiration. Root respiration accounts for 13% - 77% of soil respiration, but the amounts are uncertain. Rational fertilization, straw return to soil and no-tillage are useful to soil C02 emission reduction and soil carbon sequestration. We discuss key issues and further tasks, including comparison of soil respiration among typical farmland ecosystems in different areas, spatial variations of soil respiration, simulation of factors controlling soil respiration, and mitigation options of soil CO2 emission.