【摘要】 将新疆天山云杉林分布区划分为1 800～2 000、2 000～2 200、2 200～2 400、2 400～2 600m和2 600～2 800m5个海拔梯度,利用S型采样法分别采集不同海拔梯度0～20、20～40、40～60cm的土壤混合样品。在28℃的室内条件下分别培养1、4、6、8、12、14、24、34、44、54、65、75、86d和96d,测定不同培养时间土壤有机碳的累积矿化量,并进一步利用双指数模型拟合土壤有机碳的矿化过程,探讨不同海拔梯度下土壤有机碳矿化异同以及土壤活性碳、微生物碳含量、降雨量和温度对土壤有机碳矿化的影响。结果表明,双指数模型可以很好地拟合出不同海拔各层土壤有机碳矿化过程,R²达到0.97～1.00;云杉林土壤有机碳96d的累积矿化量和矿化速率随土层加深而降低,随海拔的升高表现出先降低、再升高,此后逐渐降低的变化趋势,两者最大值位于海拔2 200～2 400m,0～20cm土壤分别为4.10g·kg^-1和42.71mg·kg^-1·d^-1;0～20cm土壤活性碳含量为1.98～13.68g·kg^-1,表聚现象明显,具有与土壤有机碳累积矿化量和矿化速率相同的海拔变化特征;土壤微生物量和土壤有机碳矿化特征呈显著正相关,土壤微生物是影响土壤有机碳矿化的主要因素。更多还原

【Abstract】 The distribution area of Picea schrenkiana occurring in Xinjiang was divided into five elevation gradients:1 800-2 000,2 000-2 200,2 200-2 400,2 400-2 600 and 2 600-2 800 m.Stype sampling method was adopted to collect the soils with the depths of 0-20,20-40,and 40-60 cm in different elevations.Soil samples were cultured in door at 28℃for 1,4,6,8,12,14,24,34,44,54,65,75,86 and 96 days,respectively.The cumulative amounts of soil organic carbon mineralization（SOCM）in different culture time were determined.The mineralization process was simulated by the double exponential model.Effects of soil active carbon,microbial carbon content,rainfall and temperature on SOCM in different elevations were studied.The results showed that the double exponential model could well fit the process of SOCN at different elevations.The values of R² reached 0.97-1.00.The cumulative amount and rate of SOCM in 96 days decreased with the soil depth.With the increase of the elevation,the cumulative amount and rate of SOCM presented a trend of decrease-increase-decrease.The maximum values of cumulative amount and rate of SOCM were 4.10 g·kg^-1 and 42.71 mg·kg^-1·d^-1,respectively in 0-20 cm soil layer with the elevation of 2 200-2 400 m.The content of soil active carbon in 0-20 cm soil layer ranged from 1.98-13.68 g·kg^-1.The apparent aggregation phenomenon was significant.The variation pattern of soil active carbon with the change of elevation was the same as cumulative amount and rate of SOCN.The soil microorganism quantity was significantly correlated with SOCM characteristics,which was the main factor affecting the soil organic carbon mineralization.更多还原