This paper deals with the concentration of nutrient elements of trees and the amount of nutrients in a deciduous broad-leaved forest. The sampling of trees were carried out in three plots which located on the upper, middle and lower part of slope in Sanbe Forest of Shimane University.
1. The concentration of nutrient elements of trees were the following order; leaves> twigs>branches>stems.
2. The frequency distribution of the nutrient concentrations showed the normal distrilbu tion which the mode corresponded with the mean concentration.
3. The concentration of nutrient elements of leaves became higher as the diameter or height of trees became larger.
4. The concentration of nutrients of leaves showed a clear difference among the tree species. Carpinus laxiflora, Carpinus Tschonoskii and Quercus acutissima had a high concentration of nitrogen and phosphorus ofleaves. Styrasx Obassia and Styrax japonica showed a high oontent of potassium and Cornus controversa and Cornus Kousa had a high ooncentration of maagnesium and calcium.
5. The amount of nutnents in tree biomass were 235.0-368.2 for nitrogen, 13.0-22.3 for phosphorus, 137.0-194.4 for potassium, 31.4-52.3 for magnesium and 583.3-6l0.7kg/ha for calcium. These amount were larger at the lower part than at the upper part of slope.