The spatial distribution of cities, landscape change and traditional agriculture in the Tokushima region

Abstract

Tokushima Prefecture is located on the eastern side of Shikoku Island, and 80% of its area is mountainous with 75% of the soil surface covered with trees. In the 1950's period, the local population in such rural mountainous areas reached its peak. In Tokushima and across Japan, people needed to develop agricultural fields even on the steep slopes, and tried to grow rice by making terraced paddy fields, by piling stones vertically. Since the Rapid Economic Growth period, which began in the middle of 1950's, people started to leave their home villages and move to urban areas for work. When they left their agricultural fields, they planted cedar trees, because cedar wood was sold at a high price at that time. Decades later, however, the cedar lumber price dropped due to the increase in the importation of cheaper woods. Abandoned cedar trees continued to grow covering the former agricultural fields. Today, many villages in mountainous areas of Tokushima are at risk of extinction due to the falling population and aging (genkai shūraku). Many agricultural fields are left abandoned. In the context of re-vitalization of the diminishing rural communities, traditional landscape is being reappraised as a local treasure. Consequently, the UN Food and Agriculture Organization (FAO) founded the World Agricultural Heritage Systems in 2002, and 45 regions in 19 countries were registered by the end of 2017, of which 9 regions are located in Japan. The traditional farming systems on the steep slopes in mountainous areas of Tokushima are among the candidates for registration. The top 100 Terraced Paddy Fields in Japan were selected by the Ministry of Agriculture, Forestry and Fisheries in 1999, and two of them are located in Tokushima Prefecture. Stone walls (ishigaki), built to make flat land on a steep slope, are constructions that use a traditional type of architectural technique, and recently it has been reappraised from an ecological viewpoint in comparison with contemporary concrete constructions. Generally, the earths and soil slide down the steep slopes due to gravity, so it is necessary to bring these back upward from time to time. On the steep slopes people try to keep earth and soil in its present position by mixing thatch with earth and soil. If local people abandon their agricultural activities and discontinue the maintenance works, this kind of traditional landscape on the steep slopes will deteriorate soon. The speaker will discuss about steep slope agricultural systems, terraced paddy fields (tanada), and a village rich in stone walls in Tokushima.