The Diameter Distribution of the Cut Tree Rootlets under Forest Road Construction

Abstract

In this paper we assume that the physical process of cutting of the tree rootlets by the large-sized construction machine under forest road construction is as same as the mechanism of the mountain slope slide and the diameter of the cut rootlets of 8 spicies was measured. As the result of measurement, it become clear as following.
1) The distribution of cut diameter of the tree rootlets was statiscally significant among the same species.
2) The distribution of cut diameter of the tree rootlets was statiscally significant among the different species.
3) The 95% of cut rootlets were included to the extent of 6 mm of the diameter class except Carpinus Japonica.
The mechanism of the tree rootlets cutting process was modelled and the decomposition process after felling of the tree was investigated. As the result of investigation, it was suggested that if the decomposition process reach to the 6 mm diameter class, it will be disapear the protection effect against land slide.