Tomakomai Research Site is located in a national forest in the city of Tomakomai, Hokkaido. It is part of the national forest compartment 1205, forest group, which is managed by the Eastern Iburi District Forest Office of the Hokkaido Forest Office. The Tomakomai Research Site is a mixed broad-leaved and conifer-leaved forest that consists of Picea jezoensis (Sieb. et Zucc.) Carr. mixed in with cool temperate broad-leaved trees such as Acer mono, Prunus ssiori Fr. Schm., and Cercidiphyllum japonicum Sieb. et Zucc. The volcanic plain outside the City of Tomakomai contains soils that have been disturbed primarily by the eruption of Mt. Tarumae. Around that are expansive man-made forests of Larix kaempferi (Lamb.) Carr., Abies sachalinensis, etc., but there is no record that the 43 ha forest group which contains the research site has been cut. From summer to autumn, the forest floor is covered with Dryopteris crassirhizoma Nakai, with scattered patches of Sasa senanensis (Franch. et Savat.) Rehd. This research is maintained jointly by the Hokkaido Research Center of the FFPRI and the Graduate School of Environmental Earth Science of Hokkaido University.