MEASURES TO DEVELOP A RICH-FEN WETLAND LANDSCAPE WITH A FULL RANGE OFSUCCESSIONAL STAGES

Species-rich plant communities characteristic for succession from meso trophic open water to fen are very rare in The Netherlands. These vege tation types used to occur in turf ponds in the low lying peatland are a, created by pear dredging and filled with water due to seepage of me sotrophic, well-buffered groundwater. One of the goals of the National Nature Policy Plan is to create new opportunities for the initial ter restrialization communities through ecological engineering, e.g., rest oration and creation of open water habitats. Restoration of the abioti c conditions in acidified floating fen communities is only possible by a combined measure of removal of the Sphagnum-layer and superficial d rainage of surplus rain water. New turfponds have been excavated. This study showed that the abiotic conditions (i.e., water depth and water chemistry) are favorable for the development of aquatic communities c haracteristic of mesotrophic conditions. The aquatic plant species fou nd in the new ponds also point in this direction, e.g., Chara major an d Ch. delicatula are very abundant as are seven Potamogeton species. I t is concluded that a constant discharge of groundwater and a good con nectivity between the ponds and the existing remnants of plant communi ties desired in the area are essential for the conservation and develo pment of these species-rich plant communities.