Seasonal Dynamics of Dominant Macrophyte Community Seed Banks in a Yangtze River-Connected Floodplain Wetland: Implications for Restoration

Background

Seed banks play a crucial role in population replenishment, community succession, and ecosystem resilience. In floodplain wetlands, seed banks may display seasonal dynamics that are influenced by seasonal flooding and temperature; however, seasonal dynamics remain poorly understood.

Location

Two dominant macrophyte communities in the Dongting Lake wetlands, China.

Methods

We investigated seed-bank densities, vertical distributions, and species richness of two dominant macrophyte communities in the Dongting Lake wetlands during November 2017 (after flooding), January (winter), March (spring), and May 2018 (before flooding).

Results

Carex and Miscanthus community seed-bank densities peaked in May (15,307 and 17,330 individuals/m², respectively), decreased from November to March, and were the lowest in January (440 and 627 individuals/m², respectively). Carex and Miscanthus community seed-bank densities declined rapidly with soil depth during May from 13,414 and 16,535 individuals/m² in the 0–5 cm soil layer to 254 and 42 individuals/m² in the 10–20 cm soil layer, respectively. The species richness of Carex and Miscanthus community seed banks peaked during May (7 and 8 species, respectively). However, species similarity with extant communities was low (0.23 and 0.27, respectively).

Conclusions

The results of this study emphasize the significance of seasons and stratification in the utilization of soil seed banks for floodplain wetland restoration. Supplementary measures such as bud banks and introduced seedlings should be adopted for the successful restoration of macrophyte communities because of the low density and richness of perennial species in seed banks.