The Uryu Research Forest is located in the uppermost reaches of the Uryu River in the Ishikari River system and covers an area of approximately 25,000 ha. It is one of the coldest areas in Hokkaido. The northern part of the forest, surrounding Lake Shumarinai, the largest man-made lake in Japan, is a gently sloping andesite-based mountainous area with a diverse forest cover including Quercus serrata forests, wetland red spruce forests, and riparian forests, centered on naturally occurring mixed forests. In the southern part, on the other hand, there are many mountainside slopes composed of serpentinite and metamorphic rocks, and natural forests of red spruce that depend on these geological features are distributed, while secondary forests resulting from forest fires and clear cutting cover a large area. The turbulent fluxes of sensible heat, latent heat, CO2 were measured using the eddy covariance system.
