Overlap relationship between the priority of land consolidation and the floodplain wetland potential in paddy field

Abstract

Ecosystems that offer several ecosystem services can be used as green infrastructure for human well-being. In recent years, human activities have substantially engineered ecosystems to produce the desired ecosystem services. However, such efforts could lead to losses of other ecosystem services. Paddy fields are a seminatural ecosystem that can provide several ecosystem services other than rice production. Land consolidation in paddy fields aim to increase the efficiency of food production as a provisioning service, but it could depress the quality of wetland habitat as a supporting service. Recently, the Japanese government aimed to agricultural production with biodiversity conservation. Therefore, prioritizing a control strategy for future land consolidation is needed. Land consolidation work is effective for large areas and may incorporate the paddy field, previously a floodplain wetland that played a crucial role in regional biodiversity. However, land consolidation could result in the loss of this function. In this study, I investigated the spatial overlapping between land consolidation and paddy fields, which were previously natural floodplain wetlands in Kanagawa Prefecture, Japan. Here, terrain parameters and flow accumulation value (FAV), that can reflect wetland potential, along with the latest land use map, were used. The consolidation records in 1-km cell for the whole of Kanagawa prefecture were used to test the hypothesis. Results showed that high FAV area with high wetland potential has large paddy fields and was heavily consolidated. Thus, there is need for drastic policy changes to align both food production and biodiversity in paddy fields in Japan.