Generally a higher waterlevel reduces peat mineralization and therefore influences also the nutrient availability. The measures to rise the waterlevel should be defined in respect to the hydrological diversity of mires, namely the waterquality and the present trophic status. The closing of drainage ditches holds only ground- and rainwater in the wetland and is probably only slightly connected with an higher nutrient input. This measure is suitable to restorate nutrient-poor groundwater fed spring or percolation fens in areas with an high groundwater discharge. Inundation is often only possible with nutrient rich water from neighbouring ditches or rivers and is therefore connected with an high nutrient input.
Inundation is the best method to rise the water level permanent to the surface.
The Fuhlensee area is a small nature reserve of 46 hectares located in the Weichselian moraine landscape. The terrestrialization fen is fed with base-rich groundwater. At present, eutrophic Alnus and Phragmites peat occur in the active terrestrilization zone, the 'higher' parts are covered with low humified, mesotrophic brownmoss peat. Today only a small meadow of 3 hectares is used for agriculture. This meadows shows a high diversity of different typical Calthion communities such as Angelico-Cirsietum, Juncus subnodulosus association or even mesotrophic Sphagnum dominated Carex rostrata stands.