Mosaic-management in the Middel- en Oostduinen

Dynamic Dunes Oktober 2015Marten Annema

Contents of my presentation

• Area

• Ambition

• Management

• Results

Rotterdam

Goeree-Overflakkee

Middel- en Oostduinen

Dune area 205 hectare (mainly grey dunes)Water collection area (sandbed <4 meter)Lime poor to calcareousMany gradients in short distance

Middelduinen

Oostduinen

Many gradients in a short distance

Problem

• Dessication of vulnerablevegetation

• Shrub- and grassencroachment

• Water supply

• Draining neighbourhood

• Eutrophication:

by infiltration water

by N-deposition

• lack of management

• collapse of rabbitpopulation

Ambition of recovery management

• Restoration of grey dunes and

duneslacks

• Sufficient drinkwater for the area

• No sand drift on large scale

Restoration- and management measures Middel- en Oostduinen

Restoration measures Management measures

Mowing frequency Middel- en Oostduinen

We learned:Dry, undisturbed, dune vegetationsonly need grazingCalcareous dune slacks need (first 20 years?) extra mowing

Relation red-list species vascular plants and management measures

Mozaïc management leads to a quick return of typical species, even in an intensively usedwater supply area

Question:

Do decalcified dune slacks need

sod-cutting every 40 years?

Statement:

Large scale management leeds to the samebiodiversity as mosaic management,

it only lasts

longer.