Guidance Dunes: Drying up and Rewetting

Index section Dunes: Drying up and Rewetting

• The dark green fritillary and water draw-down in the dunes
• Birds of reed vegetation and the rewetting of the dunes

Introduction

Until about 1900 there were large damp areas in the dunes. In many locations these disappeared in the first half of the twentieth century, largely as a result of the abstraction of groundwater for drinking water. This drying up of habitats caused dune slack vegetation and its associated butterflies to dwindle.

The abstraction of water from the dunes was superseded by allowing river water to percolate through the dunes. This has led to more open water in the dunes and to the emergence of reed vegetations and their associated birds. The nutrient-rich water also encouraged rank vegetation to develop in the wetter parts of the dunes: species such as great hairy willowherb and nettle have invaded, ousting rare species such as grass of parnassus. Since the 1980s the inflow of nutrients has abated, because the water supply company purifies the river water before pumping it into the dunes.

Thanks to nature restoration projects the area of dune slack vegetation is increasing again. A good example is the Moksloot area on Texel.

Relevant sections and indicators in the Environmental Data Compendium

• Heathland in Brabant is suffering from water draw-down
• Heathland and fens: water draw down and acidification
• Forest and woodland: water draw down and acidification