本文以三库一级动力学为理论基础,通过土壤样品的实验室培养,运用SAS9.0的非线性过程进行数据分析研究土壤有机碳分解动态和其碳库大小及分配,并结合土壤基本理化性质探索土壤有机碳分解动态通用模式：kc=a*{1+[b*(t/c)d-1]/et/c}，其中a、b、c、d为待定参数。研究区域主要以气候带和生态系统划分，包括：湿润亚热带草地生态系统、湿润温带草地生态系统、湿润温带森林生态系统、湿润亚热带森林生态系统、干旱温带森林生态系统和湿润亚热带农田生态系统。 结果表明：土壤有机碳分解均呈现出前期快速分解（0-30天）和后期稳定分解两个阶段。快速分解期土壤有机碳分解量占整个培养时间分解量的30 % ~ 50 %。土壤类型对表层土壤有机碳分解动态影响为：湿润亚热带草地生态系统黄壤〉红壤；湿润温带地区草地生态系统亚高山灌丛草原土〉高山草甸土〉山地栗钙土〉山地粗骨栗钙土〉灰钙土；湿润亚热带灌木林生态系统石灰岩土〉黄壤〉红壤〉黄棕壤；湿润温带桦树林生态系统沼泽土〉白浆土〉腐殖质火山灰土；湿润温带常绿针叶林森林灰褐土〉暗棕壤〉亚高山草原土；温带干旱地区红柳林生态系统砂壤土〉砂土；湿润亚热带地区花生地生态系统红粘土红壤〉红砂岩类红壤；湿润亚热带地区水稻田生态系统潜育黄泥田≈潴育黄泥田〉淹育黄泥田〉漂洗黄泥田。湿润亚热带森林生态系统中植被类型对表层土壤有机碳分解动态影响为：红壤针阔混交林〉针叶林〉灌木林〉常绿阔叶林；黄壤灌木林〉常绿阔叶林〉针叶林；黄棕壤表层针阔混交林〉灌木林。在森林生态系统林龄对表层土壤有机碳分解的影响需要上百年时间才能表现出差异：湿润温带成年云杉林〉原始云杉林；农田生态系统几十年耕作时间就能对表层土壤有机碳分解产生明显差异：耕作0年和耕作5年的玉米地无明显差异，均显著大于耕作30年玉米地。从垂直尺度看绝大多数研究样点是表层土壤有机碳分解速率大于心土层和底层。 土壤活性有机碳含量为0.033 g/kg - 1.731 g/kg，比例为0.45 % -42.12 %，其周转时间为4天到161天；缓效性有机碳含量取值较宽,为0.083 g/kg - 64.082 g/kg，占总有机碳的比例为5.38 % -81.68 %，其周转时间为1年到161年；惰效性碳含量为0.407 g/kg – 70.910 g/kg，占总有机碳的比例为17.100 % - 77.320 %。由于土壤类型、生态环境、土地利用方式、气候条件和垂直分布等因素的影响，但不同生态系统之间各分库所占比例及周转时间有所不同。从不同生态系统碳库比例差异可知：频繁耕作降低土壤固碳能力；缺水状态不利于土壤有机碳固定；温带气候更有利于有机碳固定；湿润温带草地生态系统是很好的固碳系统。 运用SAS9.0的非线性过程拟和研究区土壤有机碳分解动态通用模型各参数。拟和分解曲线与实测曲线具有很好的一致性。将参数a、b、c、d与土壤理化参数（包括土壤总有机碳含量、惰性碳含量、非惰性碳含量、PH、土壤粘粒含量、土壤水分含量和土壤容重）进行相关性分析发现：参数a与土壤总有机碳含量显著正相关（R2=0.706），与土壤水分含量中度正相关（R2=0.413）；参数b与土壤粘粒中度正相关（R2=0.476），与PH中度负相关（R2=-0.415）；参数c与土壤容重中度正相关（R2=0.428），与土壤粘粒轻度负相关（R2=-0.269）；参数d与土壤总有机碳（R2=-0.363）和非惰性碳均轻度负相关（R2=-0.371），同时参数c的取值在一定程度上影响d的取值（R2=-0.37453）。用各参数的相关因子表达参数拟和曲线，得到关于ａ、ｂ、ｃ、ｄ的曲线相关性分别为：0.781、0.789、0.473、0.485。

This paper studied the size and the dynamics of soil organic carbon in main temperate zones of different ecosystems basing on the three pool theory and simulated the general model for the dynamics (kc=a*{1+[b*(t/c)d-1]/et/c}, a, b, c, d are parameters to be determined ) combining with soil physical and chemical properties. Soil samples are obtained from humid subtropical grassland ecosystem, humid temperate grassland ecosystem, humid subtropical forest ecosystem, humid temperate forest ecosystem, arid temperate forest ecosystem and humid subtropical maize farmland ecosystem. The results show: there is a fast decomposition rate in the early incubation stage ( about 0 - 30 days ) and a slower in the late. Decomposition quantity in the fast stage amounts to 30 % - 50 % of the whole decomposition quantity. The decomposition rate of topsoil organic carbon in different soil types is yellow soil > red soil in humid subtropical grassland ecosystem; Subalpine shrub meadow soil > alpine meadow soil > alpine chestnut soil > alpine coarse chestnut soil > sierozem in humid temperate grassland ecosystem; limestone soil > yellow soil > red soil > yellow brown soil in humid subtropical shrub forest ecosystem; bog soil > albic planosol > humus volcanic ash soil in humid temperate birch forest ecosystem; graycinnamon soil > dark brown soil > subalpine meadow soil in humid temperate evergreen conifer forest ecosystem; sandy loam > sandy soil in arid temperate red willow forest ecosystem; red clay of red soil > red sandstone ofred soil in humid subtropical peanut farmland ecosystem; gley yellow clayey soil ≈ water-logging yellow clayey soil > submerging yellow clayey soil > bleached yellow clayey soil in humid subtropical rice farmland ecosystem; The decomposition rate of topsoil organic carbon with different vegetations in humid subtropical forest ecosystem is mixed wood > conifer forest > shrub forest > evergreen broadleaf forest of red soil; shrub forest > evergreen broadleaf forest > conifer forest of yellow soil；mixed wood > shrub forest of yellow brown soil. The soil organic carbon dynamics of forest ecosystem would change with hundreds of years, which shows that mature spruce forest’s decomposition rate is faster than original spruce forest’s in humid temperate climate. The soil organic carbon dynamics of farmland ecosystem would change with several decades, which shows that there was no significant difference between 0 year cultivation and 5 years cultivation, while 30 years cultivation’s decomposition rate was significantly slower than theirs. In the vertical scale the decomposition quantity in topsoil is faster than that in second layer and the bottom layer. The pool size of active soil organic carbon is from 0.033 g/kg to 1.731 g/kg, and the proportion is from 0.45 % to 42.12 %. The pool size of slow soil organic carbon is from 0.083 g/kg to 64.082 g/kg, and the proportion is from 5.38 % to 81.68 %. The pool size of passive soil organic carbon is from 0.407 g/kg to 70.910 g/kg, and the proportion is from 17.100 % to 77.320 %. The mean residue time for active and slow pool are 4~ 161 days and 1 ~ 161 years. Because of the influence with soil types, entiroment, landuse, climate and soil layers, the proportion and mean residue time of each soil organic carbon pool in different ecosystem are discrepant. Those difference shows: frequent cultivation reduced soil carbon sequestration capacity; a lack of water is not propitious to organic carbon fixation; temperate climate is propitious to organic carbon fixation; humid temperate grassland ecosystem is the best for carbon sequestration. Simulating parameters for the general model of soil organic carbon dynamics with SAS9.0 non-linear process, the simulated curve and the mensurated curve have a good consistency. Combine parameter a, b, c, d with soil physical and chemical parameters (including total soil organic carbon, passive carbon, unpassive carbon, PH, soil clay, soil water and bulk density) to find the relativities of them: a has a significant positive correlation (R2 = 0.706) with total soil organic carbon, and a moderate positive correlation (R2 = 0.413) with soil water; b has a moderate positive correlation (R2 = 0.476) with soil clay, and a moderate negative correlation (R2 =- 0.415) with PH; c has a moderate positive correlation (R2 = 0.428) with bulk density, and a mildly negative correlation (R2 =- 0.269) with soil clay; d has a mildly negative correlation with total organic soil Carbon (R2 =- 0.363), unpassive carbon (R2 =- 0.371) and parameters c (R2 =- 0.37453). set up equations to express a, b, c and d with soil physical and chemical parameters which are correlative to them, and the precisions of each equation are 0.7806, 0.7894, 0.4725, 0.4854.