Citizen Participation in Conservation Activities Enhances Plant Biodiversity in Rice Terraces in Sengamachi-no-Tanada, Kikugawa, Japan

The ridges of traditional paddy rice terraces are important for the conservation of plant species diversity. In order to propose an appropriate conservation management method, in the present study, the author compared the flora of terraced rice ridges managed by farmers and the flora of ridges managed by citizens, including rice terrace owners (membership area) and volunteers (participant area). There was no difference in the number of plant species per ridge, but the number of plant species and diversity index per area were higher in the membership and participant areas than in the farmers’ areas. It is considered this factor is that various mowing by citizens with both machines and traditional sickles produces the same mowing pressure as like the old way before mechanization and contributes to the maintenance of traditional ridge vegetation. In addition, the number of naturalized plants in the membership and participant areas was lower than that in farmers’ areas. These results suggested that the participation of people other than farmers in paddy rice terrace ridge management contributes to the maintenance of plant diversity in traditional paddy rice terraces.