A Proposal of Method to Reforestate the Face of Excavation Slope Based on Vegetation on Dry Site

Abstract

Face of excavation slope is difficult to reforestation introducing various treespecies, since it is rock-exposed and steep site. The authors propose a method for reforestation under the strict environment of face of excavation slope.This method was tested at face of slope of dam site in Surikamigawa-river dam, Fukushima (under construction) and summarized as (1)-(4).(1) The most important properties of face of excavation slope are thin top soil and dry condition. Expected vegetation (vegetation that finaly expected to stabilize on the site) was selected from forest vegetation based on the properties of the face of slope.(2) More resistive species against dry condition were picked up as species for introduction among the whole species of selected forest vegetation. A vegetation table was constructed from phytosociological vegetation reserch at 45 points around there, and the table produced the species.(3) Seedlings of the selected species were introduced on the face of slope by spraying basement (alternative top soil) after put of the seedlings, and covering the root of them.(4) The basement was mainly composed of sandy soil to make poor nutrient condition.