The Vertical Distribution Characteristics of Soil Organic Carbon Stocks and Fractions in Luofu Mountain of Guangdong

Dividing 10 typical soil sampling points at different elevations in Luofu Mountain, Guangdong, and collecting soil samples of 0-20 cm, 20-40 cm, 40-60 cm, and 60-80 cm soil layers. Chemical analysis methods were used to analyze soil organic carbon (SOC) content, soil active organic carbon (POXC) content, soil organic carbon content, and basic physical and chemical indicators. The vertical distribution rules of organic carbon storage and composition in different soil profiles at different altitudes in Luofu Mountain were studied. The results indicated that SOC and POXC of Luofu Mountain mainly accumulated in 0-40 cm depth, and SOC content and stock in the soil surface horizon (0-20 cm) significantly positively correlated with altitude. With the increase of altitude, the SOC content and stock, POXC content and the content of soil organic carbon all showed an increasing trend. With the increase of soil depth, the SOC content and stock, POXC content, C_F1 and C_F2 contents showed a decreasing trend, while the contents of C_F3 and C_F4 decreased. The content of POXC, content of organic carbon in soil and SOC content were all significantly correlated. Increasing SOC accumulation was the main way to increase the content of SOC fractionss.