Effects of different forest restorations on soil quality in purple soil area,Chongqing

To analyze the effects of different forest restorations on soil quality,the soil physical and chemical properties under four main forest restoration types and the control areas were compared.The results showed the soil quality of four forest restoration types was higher than that of control areas,and the soil quality of natural secondary forest was higher than that of plantations.The comprehensive indices for soil quality of five restorations were: natural secondary forest(0.97),Lithocarpus glaber×Schima superba×Cinnamomum camphora×Liquidambar formsan(0.67),Lithocarpus glaber×Schima superba(0.77),Cunninghamia lanceolat(0.41),control areas(0.04).The reason that plantations and control areas have worse soil quality than natural secondary forest is that periodic management had broken soil structure,less leaf litter fall,and severe nutrients loss.This research shows that in the beginning stage of forest restoration,natural restoration is an effective way to improve soil quality.