Abstract: The variations of soil nutrients under four vegetation types (grassland, shrubs, secondary forest and natural forest) in karst mountainous area of central Guizhou Province, Southwest China were investigated. Soil samples (0-15 and 15-30 cm layers) were collected from the four vegetation types in different seasons (January, April, July and October). The results showed that the SOC and TN concentrations changed obviously under different vegetation types. The seasonal average concentrations of SOC and TN were 72.61 and 7.39 g·kg^-1 in the natural forest, respectively, being significantly higher than those in the secondary forest (30.33 and 2.90 g·kg^-1), shrubs (19.32 and 2.04 g·kg^-1) and grassland (17.75 and 1.83 g·kg^-1). Moreover, SOC and TN stocks were significantly correlated with SOC and TN concentrations, C/N, and bulk density. Soil nutrient indexes were dominantly affected by vegetation type (74.31%), followed by season (14.85%). Changes of SOC and TN concentrations and stocks had the same trend in each season under different vegetations, being higher in spring and autumn, and lower in summer and winter.

Key words: driving force., urbanization, ethnic township, landscape pattern, Aerla Town