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(X) : 土壌中の養分量と乾湿度指数の関係について

This paper deals with the relation between nutrients in soil and water condition which changed along slope in deciduous broad-leaved forests on black soil type at Sanbe Forest of Shimane University.
1. The weight of dry matter in A_0 horizon increased with the increase of moisture index, but the tendency was not extremely in compared with brown forest soil type.
2. The nutrient contents of A_0 horizon became lower with the increase of moisture index. As the degree of lowerling was little, the amount of nutrient elements in A_0 horizon showed same trend as the weight of dry matter.
3. The nutrient concentrations of mineral soil also became lower with the increase of moisture index. These were related with the difference of soil type and the concentration of carbon, nitrogen and exchangeable calcium were higher in mesic soil (Bl_D) and lower on xeric soil (lBl_B ).
4. The amount of nutrient elements in mineral soil was twice or three times as much as that of brown forest soil type. The amount of carbon, nitrogen and exchangeable calcium was increased with the increase of moisture index as well as brown forest soil, but the amount of exchangeable potassium and magnesium showed opposite tendency.
5. Mean tree height of sampling plots related to the amount of carbon and nitrogen in mineral soil.