2020 年 36 巻 1 号 p. 53-64
The urban public forest management needs much energy input from field management to the disposition or recycling of waste. For desirable urban forest management, considering the efficiency that CO2 emissions caused by using the machine or transportation, the mineral resources of the machine, labor input for forest maintenance and occupied land use for resources are needed. This study focus on the assessment of the urban public forest management using the Resources Time Footprint (RTF). RTF is defined as the resource occupancy to capacity ratio, that uses the multidimensional aspects related to sustainability. In this study, RTF was estimated for the urban forest management wastes like the pruned branches as following indicators; 1) iron resources of the material of machine for maintenance of urban forest, 2) environmental capacity of CO2 emissions derived by energy consumption, 3) work times for labor input as human resources and 4) occupied land use for resources. The several scenarios set based on the recycling way and intensity of management were assessed in 100 years. The result provides that the amount of RTF value of the current recycling system for paper manufacture plants is higher than the case of a recycling system for power plants. This result indicates that an increase of RTF when to continue the present recycle method and intensify the volume of forest maintenance. These results indicate that to recycle the Urban forest management wastes, the recycling system of the pruned branches for paper manufacture plants is desirable that the way of a recycling system for power plants.