Global Ecology and Conservation (Aug 2022)
Grassland legacy remaining in vegetation and seedbank species diversity: Evaluation in abandoned grasslands and plantation forests
Abstract
Species-rich semi-natural grasslands have been drastically transformed into agricultural areas, plantation forests, and abandoned grasslands worldwide. Grassland legacy—the impacts of a past grassland-use history on biological communities—is often detected in clear-cut forests that were formerly grasslands. This study assessed whether grassland plant species remain in the standing vegetation and soil seedbanks in transformed former grasslands. We surveyed standing vegetation and soil seedbanks in four land-use types with a grassland history (i.e., managed grassland, abandoned grassland, evergreen plantation, and deciduous plantation) and compared plant species richness and species composition among them. Grassland species remained but had lower species richness in abandoned grasslands and plantations, particularly of evergreen trees, than in standing vegetation in managed grasslands. The grassland species richness of seedbanks was significantly lower in abandoned grasslands than in managed grasslands. There were no differences in grassland species richness or the number of individuals in seedbanks among the other land-use types. The grassland species composition differed between standing vegetation and seedbanks regardless of land use, and the grassland species composition of standing vegetation in managed grasslands clearly differed from that of the other land-use types. Additionally, exotic species appeared in both the standing vegetation and seedbanks of managed and abandoned grasslands but not in those of plantations. Thus, our study detected grassland legacy in both standing vegetation and soil seedbanks, with variations depending on diversely transformed land uses, although the presence of grassland specialist species seemed to be limited. These results highlight the potential importance of plantation forest management for grassland restoration and the risk of exotic plant establishment associated with abandoned grassland restoration.
