The invasion and growth of woody plants on slopes along the prefectural road, the Shikaoi-Nukabira line, in eastern Hokkaido

Abstract

1.This road was constructed in 1973-78, and its slopes were covered with grass. 2.Alnus hirsute and Salix spp. which were pioneers and anemochoryl species, invaded and established themselves. The oldest is 7 years of age. 3.As successors, the anemochoryl species of Fraxinus, Acer, Abies, etc., and the zoochoryl species of Quercus, Phellodendron, etc. also invaded. 4.The species number and density of woody plants that invaded were much more on the northern slopes than on the southern ones. 5.These pioneer and successional trees are very effective both for the soil conservation of the slopes along the road and for the protection of natural forests that were cut off by the road.