| The ‘Amsterdamse Waterleidingduinen’ is a dune area near Haarlem in the calcareous Dune district. Since 1851 it is the water catchment area of Amsterdam. Due to the lowering of the groundwater level the moist dune slacks have disappeared gradually. Since 1957 infiltration of water from the river Rhine takes place for the water supply of Amsterdam. This water, rich in nutrients, causes among others a ruderal vegetation of high forbs and poor in species instead of the former species-rich dune slack vegetation. Since about 1970 locally a divergent vegetation is developing. In the so-called Groot Zwarteveld not only dune slack species have established, but also a number of species characteristic for dunes poor in lime and nutrients: Empetrum nigrum, Erica... |
