植物残体是森林土壤碳库的重要来源，林地土壤碳通量的改变与土壤碳库及碳循环密切相关，然而目前关于土壤有机碳稳定性的研究多集中于农田土壤，为明确外源碳输入对林地土壤有机碳稳定性的影响，采用室内恒温培养试验，以凋落物种类（樱花（YH）、悬铃木（WT）、杨树（YS））、添加量（0、2%、4%、6%）、粒径大小（2 mm（D）、0.25 mm（X））为变量，设置18个不同处理和两组对照，分析不同因素及其交互作用条件下土壤CO₂释放规律、土壤有机碳质量分数以及矿化强度的变化。结果显示，不同凋落物对土壤总CO₂释放量和释放速率影响显著，樱花和杨树更易促进土壤总有机碳矿化，其中，YHX6（樱花、粒径2 mm、添加量6%）处理土壤总CO₂释放速率最高，YHD6（樱花、粒径2 mm、添加量6%）处理总CO₂累积释放量达CK1的4.37倍，6%添加量土壤潜在矿化碳矿化潜力（C _p）相较于CK1显著增加。土壤总有机碳累积矿化量随时间的动态变化可以用一级动力学方程拟合，拟合结果表明，外源碳输入加速了土壤碳周转。小粒径、6%添加量、YH类型的凋落物对土壤总有机碳周转的促进最为显著。WTX2（悬铃木、粒径0.25 mm、添加量2%）对总有机碳矿化强度的降低最为显著，仅为1.67%，小粒径处理对土壤矿化强度降低效果显著优于大粒径处理。由此，在区域土壤有机碳管理中，可以施用小粒径、低添加量的悬铃木叶以增加土壤有机碳稳定性，促进碳在土壤中的固持。

Plant residues are an important source of forest soil carbon pool， and changes in soil carbon flux in woodland are closely related to soil carbon pool and carbon cycle. However， current studies on soil organic carbon stability mainly focus on farmland soil. In order to clarify the influence of exogenous carbon input changes on the stability of soil organic carbon， an indoor constant temperature culture experiment was set to study the litter species （Cherry， YH； Sycamore， WT； Poplar， YS）， additive amount （0， 2%， 4% and 6%）， particle size （2 mm， D； 0.25mm， X） as variables， 18 different treatments and 2 controls were concluded. The changes of soil CO₂ release， soil organic carbon content and mineralization intensity under different factors and their interactions were analyzed. Results showed that different litters had significant effects on soil total CO₂ release， and cherry blossom and poplar were more likely to promote soil total organic carbon mineralization. The highest total CO₂ release rate was observed in YHX6 treatment， and the cumulative total CO₂ release of YHD6 treatment was 4.37 times that of CK1. Compared with CK1， the potential mineralizable organic carbon C _p value of 6% added dose was significantly increased. The dynamic changes of soil total organic carbon accumulation mineralization over time can be fitted by the first-order kinetic equation， and the fitting results showed that exogenous carbon input accelerated soil carbon turnover， while litters in small particle size， 6% addition amount and YH type yielded the highest total soil organic carbon turnover rate. WTX2 significantly decreased total organic carbon mineralization intensity， which was only 1.67%. Organic carbon intensity in soil with small particle size was lower than that of large particle size treatment. Therefore， sycamore leaves in small particle size and added with low addition amount can be applied to increase the stability of soil organic carbon and promote the retention of carbon in soil in regional soil organic carbon management.