Seed germination experiments were conducted on the soils collected in the hydro-fluctuation beltalong the old channel of Jiyun River.The soil seed bank composition

species diversity

and their similarityand spatial distribution were discussed.Overall

16species including 4species of chenopodiaceae and 5species of asteraceae

belonging to 8families and 15genera

were identified in the soils.Species relative abundance and density distribution of the soil seed bank differed in topographic positions

in a descending order asheavily flooded area>incidentally flooded area>frequently flooded area.The Shannon-Wiener index andthe Margalef Richness Index decreased with water levels

while ecological dominance and Pielou evenness index showed an opposite trend.The seed bank also varied spatially.The 0-5cm layer was the richest in allthree areas in terms of seed number

with a quantity of 623per m2.Meanwhile

the seed numbers differedsignificantly in the three areas;the seed number of heavily flooded area was 253and 353per m2 more thanthat of the incidentally flooded area and frequently flooded area.