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(VI) : A_0層および鉱質土層の養分量

This paper deals with the amounts of nutrient elements in A_0 horizon and mineral soil in a deciduous broad-leaved forest at Sanbe Forest of Shimane UniverSity.
1. The amount of dry matter in A_0 honzon increased from the lower part to the upper part of slope. That decreased from spring to summer and increased again from summer to autumn.
2. The amounts of nutnent elements in A_0 horizon showed the same trends as that of dry matter.
3. The concentrations of nutrient elements in mineral soil became lower at under horizon. The concentrations at the upper part were about a half of those at the lower part of slope.
4. The amomts of carbon, nitrogen, available phosphorus and exchangeable magnesium accumulated in mineral soil were less at the upper part than at the lower part of slope. On the contrary, the amount of exchangeable potassium was more at the upper part.
5. The rate of A_0 horizon to total soil(A_0 horizon and mineral soil) increased from the lower part to the upper part for nitrogen, phosphorus, magnesium and sodium. This tendency was the inverse in potassium.