SOIL QUALITY EVALUATION DURING VEGETATION RECOVERY AT HILL SLOPES WITII PURPLE SOIL IN HENGYANG, CHINA

To investigate the effect of vegetation recovery on soil quality at hill slopes with purple soil in Hengyang, China, 4 typical sample plots with vegetation recovery chronosequencc, i.e. grassplot (GT) (2 a). frutex and grassplot (FG) (5-8 a), frutex (FX) (20-25 a). arbor and frutex (AF) (approximately equal to 50 a). with basically similar site conditions, were selected as test objects. The comprehensive index of soil quality was applied to investigate the changes of soil quality in the process of vegetation recovery. As vegetation recovery proceeded from GT to FG, FX and AF, soil quality improved significantly (p < 0.05). As soil depth increased, the degree of soil quality improvement decreased significantly (p < 0.05). The comprehensive indexes of soil quality in various stages of vegetation recovery showed a decreasing pattern: AF (0.527), FX (0.519), FG (0.483), GT (0.481). All the results indicated vegetation recovery significantly improved the soil quality of hillslopes with purple soil in Hengyang of Hunan province, China.