Variations of soil organic carbon content along an altitudinal gradient in Wuyi Mountain
In order to explore the relationship between soil organic carbon(SOC) content and the four variables(including altitude, slope, bulk density and pH value), the distribution characteristics of SOC content along the altitudinal gradient ranging from 295 to 2 130 m in Wuyi Mountain Nature Reserve were analyzed and the regression model of SOC based on the main control factors was constructed. The results showed that, in the same altitude, the SOC content generally decreased with the increase of soil depth and its decreasing amplitude was also decreased. The SOC content ranging from 6.12 to 120.41 g?kg-1showed obvious surface assembly in the soil profile. The SOC content at the same soil depth generally increased with the increasing altitude, but its growth rate decreased accordingly. The SOC content was highly significantly positively correlated with altitude (P<0.01) and was negatively correlated with bulk density (P<0.01). There was significantly negative correlation (P<0.05) between SOC content and pH value only in the layer at the depth of 30-40 cm. The multiple linear regression model had higher goodness of fit than simple linear regression model for predicting SOC content. The combination of different factors can explain most of the variation of SOC in different soil layers with the explanation between 74.1% and 89.1%.
Wuyi Mountainnational parksoil organic carbonaltitudinal gradientmultivariable linear regression model