Recovery of wetland vegetation in the Maizuru flood-retarding basin in the Chitose River Watershed

Abstract

We examined whether a flood control basin can mitigate the decreasing habitat for wetland vegetation. In the Maizuru basin constructed in Chitose-river watershed, the plant species, years from excavation, and environment factors were investigated. We found that 1) wetland vegetation was composed by native plant species, 2) years from excavation, water level, pH, and electrical conductivity of surface water were the factors differentiate the habitat of each plant community. 3) Bog's rare plant species formed wetlands until 1920's, but rich fen's common plant species mainly formed wetlands in 1990's, and the vegetation in Maizuru basin resembled to the one in 1990's.