Teshio Experimental Forest (TEEF) is the northernmost university experimental forest in Japan, and was established in 1912. Total area of TEEF is ca. 22,500ha and is located within the Toikanbetsu River Basin. The 45 degrees north latitudelat line goes through at the center of this Forest. Annual mean air temperature is 5.7°C , and maximum and minimum air temperatures are 30 and -30°C, respectively, and the annual range sometimes exceeds 60°C. Annual precipitation is ca. 1000 mm and snow falls from November to April. Maximum snow depth in winter is ca. 1.2 m at the experimental forest office and exceeds 2 m in the mountain range. Strong wind dominates from winter to spring caused by the dry monsoon. TEEF has been used as a study site in various field of research and education for many years.