Flora and vegetation of Mt. Ashitetsu : (I) On the vertical distribution.

Abstract

1. I made this report on the vertical distribution of the plants of Mt. Ashitetsu which lies in the central part of Hokkaido. 2. The followings are assumed to be the vertical distribution regions on Mt. Ashibetst. A. Deciduous broad leaved tree region (300-500m). B. Ever-green conifer region (500-800m). C. Betula region (800-1400m). D. Higher shrub region (1400-1700m). All over the whole mountain Sasa senanensis is most dominant and is the main element in composing the third layer. Owing to the rapid invasion of S. senanensis after the opening of tree crowns, the succession of the tree is unfavorable. Though Picea jezoensis and Abies sachalinensis are the chief trees in Ever-green conifer region, deciduous broan leaved trees are so mixed that this region might be called mixed forest region. 3. Upon my investigation, it is revealed that the successive diminishing quotient of the earth temperature is 0.41℃ on Mt. Ashibetsu, e.g. in July and August on this mountain, the earth temperature is assumed to diminish 0.41℃ on average per 100m higher.