Seed Banks of a Lakeshore Wetland, Gahai Lake

We selected 22 sample sites from four plots to determine the characteristics of seed banks of an alpine meadow in a lakeshore wetland,Gahai Lake in Tibetan plateau.The results show that seed banks were composed of 37 species,13 families,and 34 genera,while the above-ground species were comprised of 31 species,17 families,and 29 genera.The average seed density of the seed banks was 7400 seeds/m²,which were mainly annual species.Unlike the seed bank species,the above-ground species were mainly composed of perennials.These results are in accordance with the trait of an alpine meadow.The vertical distribution of seed banks showed great correlation among different layers.The density of the surface layer was significantly higher than the deeper ones.The life form of species in Gahai wetland was affected by the water depth: with increasing water depth,species life form changed from mesophyte with its indicator Aconitum gymnandrum to submerged ones with Batrachium bungei.Our study indicates that seed banks of Gahai likely buffered distribution from restored degraded wetland,while the hydrology had to be taken into account.As for the target species,whether they are absent in the seed bank is essential for restoration.