Abstract
To propose reforestation plan by plant succession for the Second Tomei Expressway that is under construction, the changes of woody-plants on man-made slopes of three expressways being in operation now were studied. Woody plants that got into the slopes and dominated first were wind-dispersal plants. However, animal (bird)-dispersal woody plants increased after 18 to 19 years. The invasion of wind-dispersal woody plants got strong influence of surrounding land use and got highest invasion rate on the slopes adjoining natural forest. It thus appears that the existence of the forest to supply the seeds is the one of the most important factors to reforest the slopes by plant succession. There are few natural forests near the Second Tomei Expressway, so planting native trees on the slopes to supply seeds was proposed to accelerate plant succession and restore natural forest.
