摘要
缓解碳汇饱和的碳固定及其机制是寻找陆地生态系统碳管理可持续战略的主要科学问题。土壤有机碳是地球表层系统中最大且最具有活动性的生态系统碳库之一。近年来 ,国际学术界在探讨温带森林、湿地和极地生态系统与土壤碳汇效应的同时 ,越来越重视农业土壤有机碳库的变化及其对陆地生态系统和大气CO2 的源汇效应 ,以及其在人类利用和管理与生态环境演变中的动态变化。西方国家已将固碳农业作为环境管理的导向。对土壤中有机碳固定作用的研究已应用颗粒分组13 CNMR或CPMAS NMR技术 ,揭示土壤有机碳的微团聚体分布、腐殖质的转化和分子结构变化及其与土壤矿物质结合机制的微观水平。土壤有机碳在生态环境变化和全球变化下的稳定性是认识土壤碳库对于全球变化的长期效应的基本问题 ,成为土壤碳研究的热点。目前主要从土壤升温和空气CO2 加倍两方面进行研究 ,但短期的实验结果用于讨论长期效应时仍存在不定性。中国大面积的水稻土自 1980年以来显示出的有机碳库增加现象说明农业生产对大气CO2 可能产生汇效应。但对于水稻土中有机碳的分布和结合状态与农业管理措施、水稻土质量变化、农业生态环境变化的关系仍不清楚。因而建议就这一问题从土壤物理学、化学和生物学的相互作用与土壤微团聚体中矿物质。
Carbon sequestration is one of the research targets for mitigating the carbon sink saturation trend and seeking feasible carbon management strategies of terrestrial ecosystem.Soil organic carbon(SOC)has been shown as one of the largest and most mobile carbon pools of the earth surface ecosystem.For the last decade,increasing attention has been given to the SOC pool change in relation to the sink or source effect of air CO 2 and to the dynamics under global change scenarios.Carbon sequestration agriculture has been recognized as the key approaches to sustainable agriculture in western countries.The research of SOC sequestration has been increasingly directed to SOC partitioning and binding behavior in soil aggregates(soil particle fractions)by constitutional characterization with modern SOC structure analysis technologies such as 13 C NMR.The lability of SOC has become one of the research foci in understanding the long term effects of SOC pool under climatic change and environmental stresses.However,uncertainty of SOC turnover is still in debt when interpreting the results from short term laboratory incubation by using both soil warming and air CO 2 doubling treatments.Despite of arguments on the general SOC loss,an increasing trend of SOC in paddy soils has been evidenced by many pilot experiments and statewide soil survey data since 1980s in China.Nevertheless,less is understood on SOC distribution,binding mechanisms in paddy soils of China and their changes in response to agricultural practices,soil fertility evolution and environmental stresses.Interaction of physical,chemical and biological features in paddy soils,association of SOC with mineral and bioorganic materials in aggregates deserves urgent research needs.
出处
《南京农业大学学报》
CAS
CSCD
北大核心
2002年第3期100-109,共10页
Journal of Nanjing Agricultural University
基金
国家自然科学基金资助项目 (4 0 1710 5 2 )
国家自然科学基金重点项目资助
