Soil quality and plant diversity in managed forests in the hilly purple soil, southwestern China

The purple soils in the hilly areas of Southwestern China are experiencing severe erosion. Understanding the effects of forest management practices on soil quality and the vegetation variety is very important during vegetation restoration. Three replicated plots of four forest stands subjected to different forest restoration practices, namely, natural secondary forests (NSF), robur tree (Lithocarpus glabra) plantations, sweetgum (Liquidambar formosana) and camphor tree (Cinnamomum camphora) plantations, Chinese fir (Cunninghamia lanceolata) plantations (CFP), and control areas were established to estimate the effect of management practices on soil properties and plant diversity in this hilly purple soil region. The results show that all reforestation patterns were effective in improving soil quality and plant diversity compared with the control. Moreover, the NSF had better soil properties than the other three differently treated plantations because of the low-disturbance management. Fewer disturbances also produced richer plant species mixtures and more diverse forests. Soil quality is a good indicator for the effect of management practices. Management practices should attempt to minimize disturbance to soil properties to prevent soil degradation. Therefore, management approaches that result in lower disturbance and less land shaping that leaves the understory unchanged, should be applied during restoration processes. Mimicking natural disturbances may be better in improving the ecological functions of plantations than mechanical cultivation.