2014 Volume 70 Issue 1 Pages 41-54
A quantitative assessment of carbon circulation was carried out between forest ecosystems and human society on a city scale from multiple aspects. A biogeochemical forest model that had been developed for the evaluation of ecosystem services (carbon sequestration, nitrogen leaching, water runoff, and wood biomass provisioning) was used for simulation under several forest management scenarios. From the perspective of trade-offs between the practice and cost of management, the management and production costs of each scenario were calculated using a forestry cost model. Management scenarios were prepared with a business-as-usual (BAU) approach, management plans proposed by local forest administrators, and the authors that promote management and forest conversion into natural (secondary) forest. From the results, carbon sequestration under active forest management was two or four times larger than that under the BAU scenario in 2100. Volumetric cost of the wood biomass production depended on the schedule of forest management (thinning and rotation length).
For an understanding of these results about carbon circulation from the models, we also investigated carbon demands from human society, such as wood consumption for construction and paper products. The production of wood was somewhat lower than the demand from the wood industry. However, promoting production according to the scenarios applied in the study was effective for meeting supply and demand. The carbon sequestration by the forest in Toyota City was one twenty-fifth of the carbon emissions from energy consumption in the city.
Finally, increased production of wood biomass that considers ecological and economic effects can be sufficient to satisfy the demand for wood biomass for the activities of human society.
