Effects of Vegetation Succession on Soil Quality in Karst Region of Guangxi,China

The space list method was used to replace the time list in selecting four plots in their different stages of vegetation succession as grass stage,grass-shrub stage,shrub stage and forest stage in the open karst region of Guangxi,reports were based on the responses of the soils physical,chemical and biological properties to the four vegetation succession.This study indicate that the different vegetation succession led to significant differences in the soils physico-chemical and biological properties.The soil quality increased with progressive succession,the indices of soil quality for grass stage,grass-shrub stage,shrub stage and forest stage were 0.09,0.16,0.61 and 0.89,respectively,vegetation succession was an effective approach to improving soil quality.The factors that led to the poor soil quality of the grass and grass-shrub plantations were lower plant productivity,lower accumulation soil nutrients,lower soil nutrient especially organic matter,lower soil microbes and lower soil enzyme.Soil microbial amount combined with enzyme was the better indicator for reflecting soil biological activity and soil quality.