Sociological studies of the forests in the Tohoku district.

Abstract

(3)Forest communities and forest zones in the northern range of Abies fuma. The plant sociological studies of the stable forest communities in the vicinity of Ichinoseki, Iwate Prefecture, show that in the plains the climax forest is the Abies firma-Fagus japonica-Pleioblastus chino community, whlie in the hills higher than 100 m. above the sea level it is the Fagus crenata-Abies firma-Rhododendron japonica community. The northern limits of the former climax community, whose typical structure was shown in the previous paper, fall approximately on the prefectural border between Miyagi prefecture and Iwate prefecture(about39°N.). This community stretches southward to the northern limits of the evergreen forest occupying the areas between the deciuous, and the evergreen, forest zone chiefly in the Pacific side. In the warmer districts the coniferous forests, chiefly composed of Abies firma and Tsuga Sieboldii and similar in structure and physiognomy to the Abies firma-Fagus japonica-Pleioblastus chino community of the present work, occupy the areas on the sides of the mountains, and between the evergreen forest zone and the decidous one. A zone which includes these coniferous forests, be it horizontal or vertical, may be said to be the Abies firma forest zone. It is not so characteristic as evergreen, and deciduous, forest zone, so much so that it may be regarded as a transition zone between them.