Abstract: Quality characteristics of soils in rocky-desertified areas with ecosystem under restoration succession in Karst regions of Guangxi were studied using spatial sequence instead of temporal one.The Chengjiang Subwatershed in Du′an County,Guangxi was selected as a subject of the study. Sampling sites typical of the eight phases of the restoration succession,i.e.rocky-desertified land,cultivated slopeland,shortgrass land,tall-grass land,shrub-grass land,shrubbery land,artificial arbor forestland,and natural arbor forestland,were picked out in the subwatershed for comparative study of chemical and biological properties of the soils with a view to exploring how soil quality was remedied in the process.Results show soils differed sharply in chemical and biological properties between the phases.With vegetation developing into a higher phase,soil quality on the whole displayed a trend of improvement and so did its various quality indexes.When the vegetation restoration succession went on,soil quality index presented a rising trend,i.e.rocky-desertified land(134.78),cultivated slopeland(192.24),shortgrass land(235.18),tall-grass land(260.67),shrub-grass land(317.89),shrubbery land(359.80),artificial arbor forestland(363.39),and natural arbor forestland(460.77).Positive evolution of natural vegetation is an effective path towards better soil quality and an outright reverse process of rocky desertification.

Key words: Karst rocky desertification, restoration succession, soil quality index