北亚热带山地不同海拔土壤有机碳分布特征——以鄂东龟峰山为例

Soil Organic Carbon Distribution Characteristics along an Altitudinal Gradient in the Northern Subtropical Region:A Case Study in Guifeng Mountains of Eastern Hubei,China

气候变暖背景下研究气候过渡区森林土壤有机碳沿海拔梯度的分布格局,是土壤碳库时空动态变化研究的重要内容。为研究北亚热带—暖温带气候过渡区典型森林土壤有机碳分布特征,以100 m为高差在鄂东龟峰山南、北坡5个不同海拔高度设置10个采样点,以[0,20)、[20,30)、[30,40)和[40,50)(单位cm)深度分层采集土样,测定土壤有机碳含量和土壤理化性质,研究有机碳分布特征及其影响因素。结果表明:1)龟峰山南、北坡表层土壤有机碳含量和有机碳密度均随海拔升高而显著增加(P<0.01);2)土壤有机碳沿土层深度的增加而下降,但不同海拔土壤有机碳随土层深度下降的幅度不同;3)相关分析表明土壤有机碳含量与土壤容重、石砾含量存在极显著相关关系。本研究对评估北亚热带山地土壤有机碳储量及变化特征具有重要的参考价值。

To study the spatial and temporal dynamics of soil carbon pool is one of the important parts of the research on the distribution pattern of forest soil organic carbon along the altitude gradient in the climate transition zone.In order to study the distribution characteristics of typical forest soil organic carbon in the northern subtropical and warm-temperate climate transition zone,10 sampling points were set up at five different altitudes on the south and north slopes of Guifeng Mountain in eastern Hubei province with a height difference of 100 meters.Soil samples were collected stratified[0,20)、[20,30)、[30,40)and[40,50)(cm)to measure SOC content and soil physical and chemical properties,and to study the distribution characteristics and influencing factors of SOC.The results indicated that:(1)the surface soil organic carbon content and organic carbon density showed a strong regularity along the altitude gradient,that is,the soil organic carbon content and organic carbon density increased significantly with the elevation(P<0.01).(2)SOC decreased with the increase of soil depth,but the decreasing amplitude of SOC was different at different soil depth at different altitudes.(3)Correlation analysis showed that there was a significant correlation between soil organic carbon content and soil bulk density and gravel content.The study has an important reference value for the evaluation of soil organic carbon storage and its change characteristics in the northern subtropical mountainous region.