We analysed the pattern of a forest road network, with the assumption that the road network may be transformed to a fundamental circuit with the addition of connecting routes from nodes and links of primary dendritic pattern roads. In this paper, an α-index is applied as a parameter to express the formation of a road network, and it is clear that the grade of development of a road network is indicated by this α-index to some extent. Furthermore, the adaptability of utilizing HORTON'S law is studied in the case of a constructed road network which was classified with α-index. As a result, it is cleared that the bifurcation ratio is almost equal in all processes of the development of a road network, and the ratio of road length takes a different value in each area in the primary stage of development, but it is almost made even according to the development.

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From the standpoint of the statistical decision theory the author studied about which combinations of standard annual cuts under uncertain lumber prices minimized the loss of profits during the period of the management plan. For this study of forest management, the Amagi District was selected, and a stand of sugi (Cryptomeria japonica D. DON) was selected for cutting. Three yield regulation methods were selected: namely, the area-allotment method, WADA'S method, and the Kameraltaxe method, as indices of the action in the statistical decision theory. The fluctuating rates of lumber prices, as indices of the states were divided into three parts. Furthermore, a loss table that corresponded to the combinations of the states and the actions was made on the basis of these indices. The prediction of states estimated from the trend cycle for the past five years, and their predicted values were divided into three parts. Finally, the decision procedure having the minimum risk was selected by adopting the BAYESIAN decision theory for all possible decision procedures. As a result, it was decided that decision procedures d₁₉ and d₂₅ minimize the risks in such cases because they established a prior probability with an empirical probability and a prior probability with an even probability, respectively. Next, the cycle of the time series data of the fluctuating rates of lumber prices was noticed. It confirmed that decision procedure d₂₇ minimized the risk in such cases because this pattern regarded as appearing in the period of the management plan, established the prior probability as its pattern.

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First, this paper reports the investigation of the characteristics of the “present value of future profits” (PVFP) and discusses the following points of issue; the defectiveness of the “internal rate of return” (IRR) in evaluation, the problem of discount rates, the need to distinguish between owned capital and borrowed capital, and the relationship with “net present value” (NPV). Next, the optimal rotation is considered by the possessional forms of capital from the viewpoint that the rotation for the maximum PVFP per unit area is rational in forest management. This way of thinking systematically explains the main kinds of optimal rotations, including the soil-rent theory and the forest-rent theory. Finally, this paper proposes a formula for plantations established on owned bare-land with owned capital.

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Cation amounts in throughfall, stemflow, litterfall, and undergrowth were measured for the three years after 40 and 50% removals of branches of crown lengths in a 10-year-old stand of sugi (Cryptomeria japonica D. DON). Effects of the removal of the different amounts of crown biomass on cation circulation are discussed. The 40 and 50% removals of branches of crown length caused the leaf biomass to decrease to 40 and 20% respectively of the amounts present before cutting. K, Ca, and Mg were decreased to 40_??_48% of the original contents for the 40% removal and to 20_??_23% for the 50% removal. The amount of throughfall plus stemflow relative to total precipitation was 70% for the control, but it increased to average 75 and 90% in the 40 and 50% removals, respectively. These increases depended on the increasing throughfall. The relationship between the leaf biomass and the enrichment cations (throughfall+stemflow-total precipitation) from crowns was shown approximately by a linear equation, and it was the largest for K with Ca and Mg following in order. Total Ca and Mg (throughfall+stemflow+litterfall+undergrowth) applied to the forest floor decreased with decreasing amounts of removal, but total K did not a definite tendency.

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One-year-old sugi (Cryptomeria japonica D. DON) seedlings were potted in April, ammonium (NH₄ series) and nitrate nitrogen (NO₃ series) were applied separately in July. Soil moisture was controlled under dry or wet conditions. Contents of inorganic nitrogen and free amino-acids were determined for three weeks after the application of nitrogen. Ammonium was not found in the roots with neither series. Ammonium might be assimilated immediately to amino-acids in roots. Nitrate was found in roots with the NO₃ series. A little nitrate nitrogen might be translocated from roots to shoots when nitrate was accumulated in the roots, but most of nitrate was reduced in roots. Large amounts of free amino-acids were found in the roots with the NH₄ series rather than in those with the NO₃ series. In shoots, free amino-acids increased soon after the nitrogen applications in the wet conditions of both series. The increments of amino-acids in shoots continued until the end of the experiment with the NH₄-wet series. Nitrate accumulation in roots with the NO₃ series might show that nitrate reduction is the rate-limiting factor in the process of nitrate utilization. The influences of soil moisture on nitrate reduction rarely were observed under the condition of -0.035 MPa. However, this soil moisture deficit was considered as influencing nitrate absorption, and ammonium absorption or amino-acids translocations from roots to shoots also might be influenced.

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On a small forested watershed of sugi (Cryptomeria japonica D. DON), the qualitative and quantitative vertical changes in water-chemicals were investigated in regard to precipitation, throughfall, soil water in seven layers, spring water, and stream run-off water, over a period of three years. Soil water was sampled using column lysimeters containing undisturbed soil. The precipitation, caused by the northwestern winter winds, contained much Cl^-, reaching a yearly peak concentration in precipitation and throughfall. By means of spectrum analyses, it was confirmed that the seasonal Cl^- concentration peaks in the soil water were caused by the downward movement of the peak in each upper layer with water infiltration. The height of the peak concentration became lower, and the range at the base of the peak became wider as the infiltration moved downward. The downward velocity of Cl^- was calculated to be 0.15_??_0.39cm/day through the time lag of the Cl^- peak appearance in each layer. The real downward water velocity, which was calculated based on the Cl^- peak velocity and the amount of run-off water through the lysimeters, was 0.28_??_1.06 cm/day more than that of Cl^-. The same seasonal trend for Na⁺ as that for Cl^- was observed only on the surface and in the soil water in the shallow layers. The seasonal trend disappeared in the deeper layers because of the effect of Na⁺ adsorption into the soil and its leaching from the soil. In run-off stream water, such seasonal trend did not appear because of the mixing of the water components, which passed along different run-off pathways.

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