Abstract: With major dikes in Poyang Lakeside as a case study, aboveground vegetation was investigated by means of route surveying and quadrate method in different typical dikes. Soil seed banks were investigated with quadrate method on dikes where aboveground vegetation was sampled, and germination method was used to identify density of seed banks. Our objective was to determine the characteristics of aboveground vegetation and their relationships with soil seed banks. The results showed that the aboveground vegetation was composed of 106 species in 89 genera of 36 families in the study area. The main families are Gramineae, Compositae and Euphorbiaceae. The species life of aboveground vegetation is mainly composed of herbaceous species. Moreover, plant diversity and soil bank density followed the order of paddy soil＞construction trash＞mountain clay. The soil seed bank density of planting grass pattern at 0~10 cm depth was significantly less than that of natural recovery mode, which had the greater aboveground plant diversity. Soil seed density was significantly (P<0.05) correlated with the ground vegetation species, Simpson index, Shannon-weiner index and Pielou evenness index, and also significantly (P<0.01)correlated with the ground vegetation density and importance value, while had no significant correlation with Margalef abundance index. Therefore, there were mutual impacts between aboveground vegetation and soil seed bank density in different typical dikes. The relationships have played a key role in strengthening and eliminating dangers of embankment engineering.

Key words: plant diversity, soil seed bank, different reinforcing materials, dike, Poyang Lakeside