土壤碳循环研究进展

土壤碳是陆地碳库的主要组成部分，全球土壤有机碳总量达1270 Gt。气候变化影响植物生长、植物碎屑分解速率以及土壤—大气碳通量，这对大气CO₂含量有重要影响。土壤有机质模型是研究生态系统尺度土壤碳循环的唯一可用工具，目前已开发出多种。大量研究表明，¹⁴Ｃ测试是研究土壤有机碳组成及驻留时间的重要手段，土壤有机碳由一系列具不同更新时间的组分构成。土壤粒级组成、矿物特征及土体结构等内在因素制约土壤有机碳存量及状态，对于长时间尺度碳的更新具有重要意义。研究不同气候带土壤有机碳储量及动态变化特征，可为预测未来农、林生态系统变化提供理论依据。

PROGRESSES IN SOIL CARBON CYCLE RESEARCHES

Soil carbon is the main part of terrestrial carbon pool, and the total amount of soil organic carbon is about 1 270 Gt C globally. Climate changes influence plant production and decomposition rate of plant debris in/on soils, which contributes to the alterations of carbon fluxes between soils and the atmosphere, and can make great impacts on concentration of atmospheric CO 2. Soil organic matter model is the only practical tool for the carbon cycle researches at ecosystem level, many kinds of which have been developed up to now. A great number of studies suggest that 14 C measurement is an important method for the research on constitution of soil organic carbon and residual times of different components, soil organic carbon is composed of a series of components with different residual times. Grain size, mineral composition and soil texture are the main characteristics of soils controlling the amount and occurring states of soil organic carbon, and exert great impacts on the turnover of soil carbon with long residual times. Studies on the amount and dynamics of soil organic carbon could provide valuable theoretical bases for the predictions about alterations of agricultural and forest ecosystems under the influences of global changes.