三瓶演習林内の落葉広葉樹林における物質循環に関する研究(IV) : 樹体の養分含有率について

The seasonal variation in nutrient concentration of leaves and the difference in nutrient concentration among the layers of trees were studied at Sanbe Forest of Shimane University.
1. The seasonal variation in nutrient concentration of leaves showed a clear trend. The concentrations of nitrogen, phosphorus, and potassium in leaves decreased with the growth of leaves. On the contrary, those of calcium, magnesium, and sodium increased. These concentrations were relatively stable in August and September.
2. The differences in nutrient concentration among the layers of trees were varied with the parts of trees. In leaves and branches, the concentrations of nutrient elements had two tendencies, i. e., that to become higher toward the top of tree and that to become lower toward the top of tree. The concentrations of nutrient elements in stems became higher at the upper layer of tree.
3. The relation between the amount of dry matter and nutrient elements was approximated by a linear regression. The mean concentration of nutrient elements did not differ among the tree species except Nemunoki(Albizzia Julibrissin).