抄録
Forest lands are utilized and managed for a multiplicity of purposes, with usually one use, frequently timber production, dominant on a particular area. Forest lands can often be utilized and managed for several uses, sometimes on the same area and sometimes with different dominant uses assigned to separate areas. Utilization and management of the whole are directed to obtain the total net benefit of forest lands. Forest lands managed primarily for timber production can be frequently, and with comparatively small adjustment, served watershed, wildlife, or recreational purposes. A major use, well managed, often ensures others. In some conditions, the usage of forest lands are incompatible, one with another, and priority decision must be made.
Japan, compared with western countries, even with asiatic countries having relatively high percentage of forest land, is one of the most forested countries in the world. However, there was no precise knowledge of the effect of forest cover upon environmental supplies. Much has been explained about sustained yield as a major objective of timber management, and it has been regarded as something of a general cureall.
Environmental stress of forest lands refers to a discordance between man's economic activities and his natural surroundings. The result of the discordance is a deterioration in the quality of the natural surroundings that leads to a reduction in social welfare. The phyical environment and its characteristics have an important influence on the economic and ecological structure of a region. I took a statistical approach, (principal component analysis) to the collection and presentation of envionmental data of forest lands, and indicated the results of valuation and classification of forest lands in Yamagata Prefecture on the use of a map and graphs, to summarize information visually, for easy comparisons among forest lands.
If the above-mentioned standards of classification of forest lands are supplied by public organizations, they may be possible to indicate the appropriate environmental measures such as the choice species and regeneration procedures.
