Three experimental plots were chosen for study on genesis

symptoms and spatial and temporal change of land degradation in subtropical hill and mountain regions of South China. Land degradation

caused by water erosion

closely related to the inherent vulnerabilities of its ecological environment.Spatial variation of land degradation from top to foot along the slope was mainly induced by differentiation of surface material and their properties of erodibility

nutrient and moisture due to downslope variation of soil erosion. Land degradation manifests itself not only soil degradation but also vegetation degradation and deterioration of land surface. Comparison between land degradation maps of 1950's and 1980's showed that temporal changes of land degradation were different from one area to another because of differences of human activities. Changes of land degradation were mainly attributed to reclamation of land and depletion of vegetation led by adverse human activities. Most severe land degradation took place neither in the less populated and less developed mountain area nor in the densely populated and more developed undulating hill area

but in the low mountain and hill area

where increase of population is more quick but economy less developed.