Nutrient contents of vegetation and their allocation characteristics in main forests of Guizhou Province

Based on the survey on the nutrient contents (N, P, and K) of vegetation in nine major forests of Guizhou, the allocation characteristics of the nutrients in the arbors, shrubs and herbs were analyzed. The results revealed that the nutrient contents in undergrowth vegetations were higher than those in the tree layer, and overall the highest in herb layer. The nutrient contents in shrub layer and tree layer varied among communities. The nutrient contents in mixed forests were higher than those in pure forests, higher in natural forests than in artificial forests, and higher in fast-growing tree species than in slow-growing tree species. In all these forest vegetations, the contents of N and K were more than those of the P with N 3.0--24.1 times and K 3.6--16.8 times as high as P. The allocation of nutrient contents in the tree layers was shown as leaf bark branch root timber, in the shrub layers as leaf root stem, and in the herb layers as aboveground underground.