Fagus-Walderdes Berglandes von Chichibu

Phytosociological studies were conducted on Fagus（F. crenata and F. japonica） forests in the Chichibu mountains, middle Honshu. Two associations were determined : a Carici Tsugetum sieboldii and a Corno-Fagetum crenatae The Carici-Tsugeturn Sieboldii occurs in lower altitudes of the Fagetea crenatae region, while the Corno-Fagetum crenatae grows at higher altitudes. These 2 associations of Fagus forest were divided into 4 subassociations, 2 variants and 4 subvariants, with different altitudinal habitats and topography. The Carici-Tsugetum sieboldii in this area is composed of about 40 species and has four characteristic and differential species with high constancy. The Corno-Fagetum crenatae, however, consists of fewer than 30 species and has only two characteristic and differential species with low constancy. The Corno-Fagetum crenatae has many elements of the Carici-Tsugetum sieboldii in its units at lower elevation. This appeared to be because about these mountains are located far from the sea, with annual precipitation less than about 1500 mm