Effects of fast growing exotic eucalyptus plantations(EPs)on soil attributes have been widely studied in the world; however,findings have been inconsistent.Such eucalyptus plantations comprise one of the most commercially important forest types in China.Due to fast growth rates,short rotations,and a continuously expanding area being brought under plantation management,EPs receive much more attention from the public and researchers than other plantations in the region with respect to the effects on soil quality and the environment.Eucalyptus plantation establishment is often not socially acceptable and is consequently forbidden by forestry authorities in some cities and counties of South China due to its reported adverse impacts on environment.To better understand the influences of EPs on soil quality and the differences among forest types,we compared soil physicochemical properties,soil organic matter(SOM),and nutrient contents under EPs with those under Masson pine(Pinus massoniana Lamb.)plantations(MPPs)and natural broadleaved forest(NBF)in over 3 0 sites in South China.Results revealed that EPs had significantly lower porosity,water holding capacity,and available Zn in the A horizon,significantly lower SOM,total N,available N,and available K contents in both the A and B horizons,and significantly lower available Cu in the B horizon than NBF.Eucalyptus plantations had significantly higher SOM in the A horizon and total N in the B horizon compared to those in MPPs,and EPs had significantly lower available K in the A and B horizons,and available Zn in the B horizon relative to those in MPPs.No significant differences were observed in pH,cation exchange capacity,or base saturation among EPs,MPPs,and NBF,or in soil physical properties between EPs and MPPs.We conclude that EPs showed soil degradation in terms of physical properties,SOM,and nutrient contents in comparison to NBF,but did not exhibit any apparent soil deterioration compared to MPPs.