POTENTIAL FOR THE DEVELOPMENT OF MARSH VEGETATION FROM THE SEED BANK AFTER A DRAWDOWN

In the inundated part of the Oostvaardersplassen, a marsh in The Nethe rlands, most of the emergent vegetation disappeared due to herbivory a nd erosion, resulting in a shallow lake. The emergent vegetation was s uccessfully re-established by means of a drawdown. A comparable floode d marsh was studied to describe its seed bank and to find out if it wa s possible to make an accurate prediction of the vegetation developmen ts after a drawdown based on the Van der Valk model on succession in w etlands. Two different zones could be distinguished in the lake. These differed mainly in the number of seeds found, not in the species comp osition of their seed banks. The short-term prediction that Typha lati folia would become dominant did not always match the actual pioneer ve getation that developed, several different communities developed from similar seed banks. The long-term prediction, that Phragmites australi s would become dominant after four years of drawdown, was fulfilled.