Carbon Sink and Storage Capacity of Forest Ecosystems in Oze, Central Japan

Publisher Summary Forests are considered to play an important role in suppressing global warming by acting as a sink of carbon. COP3, which was held in 1997 in Kyoto, recognized that carbon sinks of forests provide a means of absorbing carbon emissions. Methods for transparent and verifiable evaluation of the carbon sink effect of forests need to be developed, but such evaluation is difficult, especially for a whole ecosystem including vegetation and soil. Various studies have been carried out for this purpose; such as CO 2 flux measurement, measurement of standing biomass increment, and model simulations. Measurements of carbon storage in forest ecosystems are also important to clarify the significance of reservations or rehabilitation of forests, because forest ecosystems are estimated to contain several hundred tons of carbon per hectare. Tokyo Electric Power Company (TEPCO) owns some 180 km 2 of land in Oze, Gunma Prefecture, almost all of which is covered with forests. The carbon sink and carbon storage of forest ecosystems including vegetation and soil were evaluated using two methods. The results showed that the ecosystems stored about 300 tC/ha and the vegetation functioned as a carbon sink of 2 to 4 tC/ha/year. The amount of carbon sink varied according to the type of forest. The sink effect of vegetation of a planted larch forest was twice that of a natural beech forest and a natural fir forest.