Soil organic carbon reserve of different forests in Taiyue mountain

Four different forest types were selected to make soil research.They are Pinus tabulaeformis forest,Platycladus orientails forest,Quercus liaotungensis forest and the mingled forest and Quercus liaotungensis.Soil organic carbon content and distribution were researched on different soil levels(0-10cm,10-20cm,20-30cm,30-50cm,50-100cm).Three points were concluded.Firstly,the soil organic carbon concentration in Taiyue Mountains forest is not beyon 30g·kg-1,mostly is among 16.2g·kg-1 to 29.6g·kg-1.Secondly,soil organic carbon concentration generally decreases with the soil depth in all forest type.In Pinus tabulaeformis forest,Platycladus orientails forest and Quercus liaotungensis forest the soil organic carbon concentrations exceed 85% in 30cn depth.Thirdly,soil organic carbon concentrations of broad-leaved forest is more than that of coniferous forest,mingled forest is more than that of pure forest.