Temporal and spatial distribution characteristics for the availability of soil nitrogen,phosphorus,and potassium among four successional communities of forest ecosystem on Mt.Jinyun are studied in this paper.The results showed that,(1)Except for available potassium of shrub\|grassland,the content of nitrogen,phosphorus and potassium of soil profiles in different communities has evident gradients,i.e.,humus horizon(A)>illuvial horizon(B)>parent material horizon(C);(2)The content of available nitrogen and p...