色季拉山不同海拔土壤可溶性有机碳与养分分布特征及影响因素研究

Study on Distribution Characteristics and Influencing Factors of Soil Dissolved Organic Carbon and Nutrients at Different Altitudes in Sygera Mountain

研究色季拉山土壤可溶性有机碳在不同海拔带的分布特征和影响因素,为后期相关研究提供基本资料。在色季拉山东坡3600~4300 m区域,海拔每升高100 m设置一个样地,在每块样地分别挖取3个土壤剖面,同时采集0~20 cm、20~40 cm、40~60 cm层的土壤样品进行土壤可溶性有机碳的测定并进行统计和模型回归分析。不同海拔土壤可溶性有机碳含量随海拔升高而增加,且其表层(0~20 cm)土壤中含量较高。表层可溶性有机碳占总有机碳的比例随海拔逐渐上升,但在20~40 cm和40~60 cm层无明显变化规律。土壤可溶性有机碳与总有机碳、易氧化有机碳、颗粒有机碳以及全氮、全钾的含量随土层和海拔变化趋势基本一致。可溶性有机碳与上述因子之间的关系均可用二阶函数模型进行准确(0.82<R2<0.94)的表达。相关性分析显示,土壤可溶性有机碳与颗粒有机碳、总有机碳、有机质、易氧化有机碳、全氮、pH均呈极显著的相关性,且相关系数依次为0.94>0.85>0.84>0.83>0.79>0.722。回归分析表明,土壤可溶性有机碳与土壤有机碳主要组分和主要养分元素间存在密切的联系,其含量与分布特征能够很好的反映土壤质量和肥力状况。色季拉山土壤可溶性有机碳具有表聚性,其含量随海拔变化均存在明显差异。土壤总有机碳、颗粒有机碳、有机质、易氧化有机碳、全氮含量和pH值是影响不同海拔可溶性有机碳分布差异性的主要因素。

The paper studied the distribution characteristics and influencing factors of soil dissolved organic carbon in different altitude zones of Sygera Mountain,which provided basic data for the later research.on the east slope of Sygera Mountain,a sample plot was set for every 100 m elevation rising from the area of 3600 m to 4300 m,the soil samples in layers of 0~20 cm,20~40 cm and 40~60 cm were collected for the determination of soil dissolved organic carbon,and statistical and model regression analysis were perfromed.The results showed that the dissolved organic carbon content of soils increased with altitude,and the dissolved organic carbon of different soil layers mainly accumulated in the surface layer(0~20 cm).The proportion of surface dissolved organic carbon in total organic carbon increased gradually with altitude,but there was no obvious regularity in the layers of 20~40 cm and 40~60 cm.The contents of soil dissolved organic carbon,total organic carbon,easily oxidized organic carbon,particulate organic carbon and total nitrogen and total potassium were basically consistent with soil layer and altitude.The relationship between the dissolved organic carbon and the above factors can be accurately expressed by a second-order function model(0.82<R2<0.94).Correlation analysis showed that dissolved organic carbon was significantly correlated with particulate organic carbon.Total organic carbon,organic matter,easily oxidized organic carbon,total nitrogen,pH and the correlation coefficients were 0.94>0.85>0.84>0.83>0.79>0.722.Regression analysis showed that soil dissolved organic carbon was closely related to main components and main nutrient elements of soil organic carbon,and its content and the distribution characteristics can reflect soil quality and fertility.It was indicated that the soil of Sygera Mountain had higher DOC content and obvious surface aggregation,and the content of dissolved organic carbon in different soil layers varies significantly with altitude.Soil total organic carbon,particle organic carbon,organic matter,easily oxidized organic carbon,total nitrogen content and pH value were the main factors affecting the different dissolved organic carbon distributions at different altitudes.