萌芽2次林のリターフォール量および養分還元量の変化

The amounts of nutrient elements returned by litter fall were measured for seven years in the clear cutting area of Shimane University Forest at Sanbe. The nutrient return which was broken by clear cutting recovered gradually by the vegetation regenerating, sprouting, and the sorrounding forest. In seven years after cutting，the amount of nitrogen returned by litter fall became largest on the middle part of solpe. The amounts of phosphorus and other elements also became largest on the middle part. The amounts of nutrient elements returned except those by the surrounding forest were accounted to 21-60% for nitrogen, 21-51% for phosphorus, 15-34% for potassium, 21-69% for magnesium, and 55-139% for calcium, respectively. These amounts werelarger on the middle part(P2) or upper part(P3) than on thelower part(P1) and ridge top(P4).