In the northwest corner of Nationaal Park Zuid-Kennemerland (a Nature 2000 area) lies a restful bit of nature with great potential for dynamic dune development. After years of talks with stakeholders, nature organisations and specialists, a plan was realised to revitalise this area of dunes: project Northwest nature core.
Most of the habitats are threatened. The main cause is reduced dynamics of the dunes, and, as a consequence, increased speed of succession. Blowing dunes, planting of forests, a decline in the number of rabbit and the rapid expansion of exotic shrubs and trees (e.g. black cherry, Prunus serotina, andwhite poplar, Populus alba) are important factors in the succession of the dunes. Dunes need to be dynamic to stay alive.
Project Northwest nature core strives to get the dunes moving again. In the first row of dunes from the sea/beach, called the zeereep, five trenches are made to let the wind from the sea into the dune area. The slopes of the dunes lying behind these gaps are made bare. Grasses, shrubs and part of their root systems are removed to give the blowing wind maximum space to move the sand from the slopes. The lime rich sand from the slopes and from the base of the dunes is blown over the top of the dunes and forms new habitat for the special dune plants, allowing the dunes to rejuvenate.
Project Northwest nature core was executed in two stages. Stage 1 took place between October 2011 and March 2012, Stage 2 between September 2012 and March 2013. In Stage 1 the grasses, shrubs and some of their root systems were removed from two dune slopes. The soil was used to make a nearby deep lake shallower. In Stage 2 the same sequence took place with three other dunes.
Over 140,000 m³ of sand
Between October 2012 and March 2013 the actual digging of the five wind trenches in the zeereep was done. Over 140,000 m³ of sand were displaced and used to raise the beach of nearby Zandvoort (100,000 m3) and for building an ecoduct east of Zandvoort. The ecoduct connects two large dune areas: the Amsterdamse Waterleidingduinen and Nationaal Park Zuid-Kennemerland. The remaining 20,000 m3 were stored and in 2017 will be used to build a second ecoduct lying inside Nationaal Park Zuid-Kennemerland.
The project is financed with contributions from the European Commission and Provincie Noord-Holland. Nationaal Park Zuid-Kennemerland lies between the cities of IJmuiden, Haarlem and Zandvoort and measures 3800 hectare. PWN Water Supply Company North Holland is responsible for project Noordwest nature core.
Project 'Klein Doornen' is a part of the Dutch Dune Revival (LIFE 09 NAT/NL/000418 actie C13) and was finished in 2015. This dune area was used to gain groundwater until 2000. The natural groundwaterlevel is now slowly restoring as well as it's nature values.