Floristic composition and species richness of soil seed bank in three abandoned rice paddies along a seral gradient in Gwangneung Forest Biosphere Reserve, South Korea

Background We sought to understand the relationship between the seed bank and vegetation in abandoned rice paddies in South Korea, in order to guide management of these sites. We investigated the floristic composition and species richness of the soil seed bank and ground vegetation in former paddies along three seral gradients (wet meadow, young forest, and mature forest) in Gwangneung Forest Biosphere Reserve. Results Seed bank samples contained 59 species, of which the dominant families were Cyperaceae, Gramineae, and Polygonaceae. Species richness and seedling density (59 taxa and 19,121 germinants from all samples) were high. Carex spp. (11, 921 germinants) were the dominant taxa. The species composition in the seed bank changed gradually as the land transitioned from wet meadow to mature forest. Sørensen’s index of similarity between above- and below-ground vegetation was 29.3% for wet meadow, 10.8% for young forest, and 2.1% for mature forest. Germinant density also declined, with 10, 256 germinants for wet meadow, 6445 germinants for young forest, and 2420 germinants for mature forest. Conclusions Changes in aboveground environment and life history traits such as amphicarpic plants, likely affect the composition of soil seed bank species. Abandoned paddy fields may be good sites for restoration of wetland forest and conservation of wetland habitat. Some intervention may be required to promote the recovery of a natural species assemblage.