西北干旱区森林和草原SOC向SIC转移的研究进展

Research Progress of Soil Organic Carbon Transfer to Soil Inorganic Carbonates in Forest and Grassland Soil in Northwest Arid Areas

干旱区的土壤碳是全球碳库的重要组成部分。西北干旱区土壤无机碳比重较大,且通过"SOC-CO2-SIC"的微碳循环系统存在着土壤有机碳(SOC)向土壤无机碳(SIC)的转移,研究该迁移转化过程、估算其转移量,可揭露"遗漏"的一部分碳汇。表述了该地区SOC向SIC转移的机理,介绍了几种常用计算碳转移量的方法,并对其进行对比分析;重点阐述了应用碳稳定同位素技术的生物地球化学方法在碳转移量计算中的应用。但目前国内外对该方面的研究仍较少见,且计算碳转移量的过程以及对土壤CO2区分等还存在着许多不确定性,测定结果只为估算值。在以后的研究中,应加强SOC向SIC转移的影响因子研究,降低试验误差。

The soil carbon in arid regions is an important component of the global carbon pool. Northwest arid area includes larger proportion soil inorganic carbon. Through the ＂SOC-CO2-SIC＂ micro-carbon cycle, the soil organic carbon can transfer to the soil inorganic carbon. To study the migration and transfor- mation process and estimate the transfer amount can expose part of the ＂missing＂ carbon sink. This paper described the mechanism of the transfer and introduced several methods to calculate the amount of carbon transfer. We contrasted to these methods, and expounded the biogeochemical ways of stable isotope tech- niques, Problems existed in the research were discussed. It was found the few research was carried out in the area. Many uncertainties existed in the process of calculating the amount of carbon transfer and the distinction from COz of soil. Most results were only from estimation. It was suggested that the study of impact factor of the SOC transfer to the SIC should be strengthened to reduce the test errors.