Soil quality assessment under different forest types in the Mount Tai, central Eastern China

Forest soils, are important components of forest ecosystems and can be influenced by forest vegetation. Evaluating soil quality of forests is essential for sustainable forest management and forest ecosystem functions. We evaluated soil quality of seven forest stands (I: Pinus tabulaeformis × Alnus sibirica, II: Pinus tabulaeformis, III: Robinia pseudoacacia, IV: Pinus tabulaeformis × Platycladus orientalis,V: Pinus densiflora × Platycladus orientalis, VI: Platycladus orientalis × Sophora japonica,VII: Platycladus orientalis) in Mount Tai, Central Eastern China. Seventeen soil physical, chemical and biological properties were analyzed at 0–20 and 20–40 cm, respectively. Soil quality index (SQI) was determined using the established minimum data set (MDS) based on the selection results of principal component analysis (PCA). Non-capillary porosity, water holding capacity (WHC), total nitrogen (TN), total phosphorus (TP), available potassium (AK), and catalase were finally selected into the MDS. The mean SQI values of seven forest stands were calculated ranging from 0.253 (V) to 0.630 (I). Forest types of deciduous broad-leaved forest and needle-broadleaf mixed forest had higher soil quality in the study area. WHC, soil organic matter, TN and AK, altitude appeared to be the main limiting factors of soil quality. Our results demonstrate that the SQI based on the MDS method could be a useful tool to indicate the soil quality of forest systems, SQI can be viewed as a primary indicator of sustainable forestry management.