| In 1994 and 1995 a remapping of 80 plant species of interest has been carried out in the marsh and fen nature reserve De Wieden (province of Overijssel). Species were mapped in a grid of 100m by 100m squares. Their occurrence and distribution were compared to those of the preceding mapping, which took place in 1982 and 1983. A number of marsh species ( Calla palustris, Hottonia palustris, Myriophyllum verticillatum, Ranunculus lingua and Stratiotes aloides) have increased, possibly due to a different management of the ditches. The Berne-Convention species Liparis loeselii was found in 104 (against 41) plots, probably a real increase. Within quagfens, Carex pulicaris, Cladium mariscus, Dactylorhiza incarnata and Scorpidium scorpioides have decreased.... |
