摘要
在整理和统计国内对土壤有机碳及其变化的文献资料基础上,着重讨论中国土壤有机碳库及其分布、不同时期土壤有机碳的变化以及最近时期有机碳的固定趋势,分析我国不同土壤有机碳的保护机制的特点,期望对于我国当前土壤有机碳库与全球变化研究提供参考依据。我国总土壤有机碳库的估计在50～180Pg之间。估计我国表层土壤有机碳库为20Pg,它主要分配于几个与湿地和水成过程有关的土壤类型,且水稻土占有较大比例。因而我国人为土的管理在陆地生态系统碳循环与全球变化上有重要意义。
An estimation of soil organic carbon (SOC) pool and understanding of the sequestration dynamics is being one of the research foci for a country or a region to setup the total emission budget. By synthesizing and analyzing statistically the SOC data at different spatial level and temporal durations all over China, the SOC storage and distribution over geographical regions and soil types was presented, the recent C sequestration in agricultural soils was demonstrated, and uncertainty of C sequestration mechanisms was discussed in this paper. The estimates of total SOC pool of China's soil ranged from 50 Pg to 185 Pg by various estimation methodologies. Surface SOC pool was estimated being 20 Pg by the author, of which one half was found in the soils largely with hydromorphic formation or wetland origin. Paddy soil as an important anthropogenic soil played a unique role in C storage as they had a quite high C density. C sequestration trend since the 1980's could be depicted by nationwide soil monitoring data although decreasing of SOC during 19501980 was argued. Hydragric cultivation, regional soil resilience and soil conservation technologies such as straw return and crop rotation had made significant contribution to the C sequestration rate of over 50 Tg/a of China. Clay protection could not account for SOC retention in various kinds of soils from China. SOC distribution, transformation and retention by soil microaggregates of different size fractions could be a topic for urgent research for dealing with SOC storage and the effects on sink of the increasing atmospheric CO2.
出处
《地球科学进展》
CAS
CSCD
2003年第4期609-618,共10页
Advances in Earth Science
基金
国家自然科学基金重点项目"中国主要水稻土有机碳的固定机制
稳定性与碳汇效应"(编号:40231016)资助
关键词
中国土壤
土壤有机碳库
农业土壤碳固定
碳循环
China soils
C sequestration in agricultural soils
C cycling
Organic carbon pool
