Abstract
Whether wetland plants retain their seed bank in the soil even after the disappearance of the seepage marsh was examined using the seedling emergence method. Soil samples were collected from three locations where seepage marsh with wet grassland existed approximately 30 to 10 years ago and from one seepage marsh where wet grassland currently exists. The soil samples were cultured in a suitable environment, and wetland plants germinated in soils from all study sites. The seedlings of Drosera tokaiensis, Rhynchospora spp., Utricularia spp., and Haloragis micrantha occurred commonly in the soil samples from the areas where the seepage marsh existed in the past. In contrast, seedlings of many recoded species including Eriocaulon nudicuspe and Moliniopsis japonica did not occur. Similarly, from the existing seepage marsh samples, germinated species comprised only a few of the species growing there. Although more detailed investigation is needed, our findings suggest that certain species of wet grassland on seepage marshes form a soil seed bank for a long time even after the disappearance of the vegetation; however, this is not the case for all species.
