Banking on the past: Seed banks as a reservoir for rare and native species in restored vernal pools

Soil seed banks serve as reservoirs for future plant communities, and when diverse and abundant can buffer vegetation communities against environmental fluctuations. Sparse seed banks, however, may lead to future declines of already rare species. Seed banks in wetland communities are often robust and can persist over long time periods, making wetlands model systems for studying the spatial and temporal links between above- and belowground communities. In a recent study in AoB PLANTS, Faist et al. found that the belowground community in the soil seed bank of restored ephemeral wetlands (vernal pools) in California’s Central Valley, USA, has been less invaded by exotic plants and is a reservoir for rare and native plant species. They also found that seed bank community structure most closely resembled the aboveground community structure from five to eight years prior to seed bank sampling rather than more recent years. The maintenance of rare and native plant species in soil seed banks, even while aboveground vegetation communities are being invaded by exotic plants, is an exciting finding with important implications for management and restoration efforts in annual plant communities.