Effects of flooding on the germination of seed banks in the Nansi Lake wetlands, China

Abstract

The soil seed bank potentially is one of the important components of the regeneration of a wetland. To understand the effects of flooding on the germination of seed banks in wetlands, we simulated three hydrologic regimes in a seed bank germination experiment. Soil samples were collected from four communities in the Nansi Lake wetlands in Shandong Province, China. The temporal dynamics, species abundance, and number of seedlings were determined and analyzed statistically at the species and community levels. The results showed that flooding can delay seed emergence and suppress terrestrial plant emergence. Soil seed banks from different communities exhibited different responses to flooding, highlighting the role of species-specific flooding tolerance. These results also suggest that the species composition of emergent community types in shallow lake shore and humidogene forest characterized by shallow water tables would change drastically after Nansi Lake was impounded as a reservoir for China's South-to-North Water Transfer Project. Finally, based on the temporal dynamics of seed emergence, we suggest that emergence experiments be conducted over a longer period to avoid missing some species in the wetland soil seed bank.