大都市圏の耕作放棄水田における水田雑草群落復元に向けた継続的な耕起と代かきの効果

Abstract

Since paddy weed communities are declining with the intensification and abandonment of agricultural activities, restoring these species become important. To confirm the occurrence of species assemblages represented in rice paddy fields, we carried out two extensive managements; tillage and puddling for four years in an abandoned paddy field in a metropolitan area. We defined specialist species in paddy fields that were represented in cultivated paddy fields and not represented in abandoned paddy fields as well as other terrestrial habitats in the study area. We also investigated restored paddy fields where rice culture was restarted, and cultivated paddy fields where local farmers practice low-intensity farming as a reference. By comparing ecological properties between experimental fields and referred fields, we sought to clarify the effect of such management regimes. As a result, although ecological properties were more or less different between experimental fields and cultivated paddy fields, the number of specialist species in paddy fields remained high throughout the experiment period in puddled plots, while in tilled plots, these species declined significantly. This indicates that annual puddling is effective enough to restore specialist species at least for four years.