SOIL CARBON POOL CHARACTERISTICS AND DRIVING FACTORS IN MOUNTAINOUS AREAS - A CASE STUDY OF FUPING COUNTY, CHINA

This study examined the changes in soil organic carbon (SOC) component contents and the carbon pool management index across different altitudes and land use patterns.Fuping County, China, was selected as the study area.Soil samples were collected from five altitude gradients under four land use patterns.The variations in SOC, easily oxidizable organic carbon (EOC), dissolved organic carbon (DOC) and inert organic carbon (ROC) were analyzed.The main driving factors that caused the variations in these organic carbon components were analyzed via redundancy analysis.At the same altitude, the overall trends in soil SOC, EOC, DOC and ROC were forestland>orchards>cultivated land>grassland.Under the same land use pattern, soil SOC, EOC, DOC and ROC increased with increasing altitude.At the same altitude, soil carbon pool activity ranked as follows: orchards>cultivated land>grassland>forestland.Under the same land use pattern, carbon pool activity decreased with increasing altitude.Total nitrogen, C/N ratio, and amylase activity were the main driving factors influencing variations in the SOC pool across different land use patterns.At different altitudes, land use type and available nitrogen were the main driving factors.