De duinen

Soms zijn ze dor, koud en winderig, soms zijn ze weelderig, warm en in bloei, maar altijd zijn de duinen adembenemend mooi!

Als er iets natuurlijks is in dit land dat niet werd gecreëerd door God maar door Hollanders, dan zijn dat de duinen, die langs de gehele westkust van Nederland strekken van Cadzand in Zeeland tot aan Den Helder in Noord-Holland en de Waddeneilanden. Voor het grootste gedeelte bestaan ze uit een smal strookje land slechts een paar kilometer breed, maar bij Bergen worden ze ineens breder en vormen ze een van de omvangrijkste kust-duingebieden van Europa, die wel 5 kilometer landinwaards reiken tot Schoorl.

Not only do the dunes become broader at Bergen, the composition of the sand changes, too. South of Bergen aan Zee, the sand has a blonde colour and is rich in calcium and iron oxide. To the north, the sand is a paler, whitish grey and contains far less calcium. It is believed that this is because the southern sand was deposited by the Rhine river and the northern sand comes from seabed that Rhine deposits haven’t reached.

The lovely little Burnet Rose

The difference can also clearly be seen by looking at the vegetation: less calcium means more acidic and suitable for heathland plants like crowberry and common heather which you’ll find north of Bergen aan Zee only; more calcium and other nutrients in the sands to the south means the dunescape is more lush and much greener, with a greater variety of plant life, including wild flowers like the pretty burnet rose.

Dogger, Jan Pocellis (1627)

The dunes as we see them today are referred to as young dunes and are only about 1,000 years old. The story begins at the end of the last ice age, however, about 18,000 years ago when an ice cap covered much of northern Europe. As the huge amounts of ice started to melt, the cap gradually receded to reveal land where the North Sea now is. Named after the 17th century Dutch fishing boats called Doggers, Doggerland was mostly tundra and connected the east coast of the British Isles to the Netherlands. North Sea fishermen have caught plenty of evidence in their nets over the years of habitation, both animal and human. But sea levels rose still further, and all that remains today is Dogger Bank, a sandbank about 100 km off the coast of England that features on BBC radio’s famous shipping forecast.

As Doggerland was gradually swallowed up by the North Sea and the northwest of Europe flooded, tides and currents deposited sand to form beach ridges west of and in the coastal region of what is Holland today. The sea level rose so fast during this period, about a meter per century, that the ridges disappeared as readily as they appeared, but by about 4,800 B.C. as the rate of sea-level rise decreased to a more moderate 15 centimetres every 100 years and the sea reached its most easterly point, they had joined together to form a continuous coastline. Sand continued to be brought by the sea and whipped up by the wind and the ensuing dunes grew seaward as far as ten kilometres.

The beach ridges were dry and there’s evidence of pre-historic settlements, but not much can be easily seen of them today. Many towns in Holland are built on them, though, like Alkmaar, and Bergen is built on three smaller beach ridges. The oldest relic found here is a burial urn that dates to approx. 2000 B.C. and can be admired at ‘t Sterkenhuis.

If you thought that sandbanks and beaches are dunes, too, then you’re absolutely right. Tidal currents bring sand to the beaches and shallow waters of the coast because the incoming tide is stronger than the outgoing tide and therefore more sand is brought to the coast than is taken away. As this sand piles up on the seabed, it eventually clears the waterline to form a sandbank. When it dries, the wind blows the sand over the top part of the bank, where it settles on the leeward side (out of the wind). As this process continues over time, the bank grows and moves in the direction of the prevailing wind, which around Bergen’s waters is southwesterly. The photograph above (credit: Kevin Mansell) shows Noorderhaaks sandbank between Den Helder on the mainland and Texel, the first of the Frisian, or Wadden Islands. Formed where the incoming tide from the west meets the outgoing tide from the Wadden Sea in the east, Noorderhaaks stands about 1.5 m above sea level at high tide (although northwesterly storms submerge it) and covers an area of approx. 5 km². It’s moving eastwards at a rate of about 100 m per year and is expected, like a number of other documented sandbanks in the past centuries, to reach and become part of Texel at some time in the future. A fantastic satellite image time-lapse showing the movement of the bank between 1984 and 2017 can be viewed on Wikipedia.

As climate change slowed, then, the coastline of Holland became more stable and settled towards the position it’s in now. The earliest maps of the region are Roman and show that in about 50 B.C. the North Holland peninsula was still very much a part of Fisia and its coast lay a few kilometres farther west than it does today. Winds and the sea’s currents eroded the beach ridges, but at the same time, the prevailing winds blew the sand inland. The result of this play reminiscent of cat and mouse is that the coastline moved eastward and the dunes on it grew broader and taller. By about 1600, we had the young dunes you see today and it is around then that they became a true pillar of Dutch water management, which they still are today.

The dunes at Bergen belonged to the Lord of Bergen, who extended hunting and other rights as he saw fit. But the dunes were a much more barren landscape than they are now, and dunes being dunes, they still liked to wander. After a heavy storm, and we get at least two or three a year, it wasn’t unheard of for houses and farms on the edge of the dunes to be completely buried in sand. The solution was to plant trees and lots of marram grass, which helps to keep the sand in its place. Over the centuries, lots of money has been spent keeping the dunes in check, and it’s an ongoing project.

Other than sand for construction and clean drinking water (used to make beer, especially in Haarlem), the economic value of the dunes was generally limited to rabbits, which had to be hunted anyway because they damaged the dunes, and timber. The end of the 18th century, however, saw the emergence of coastal, spa-like holidays and Mayor Van Reenen of Bergen and his wife Marie Amalie Dorothea van Reenen-Völter saw an opportunity and took the initiative to build a small village in the dunes on the coast. Bergen aan Zee was born and Bergen’s tourist industry was a fact.

It’s a wonderful walk from Bergen to Bergen aan Zee through the dunes. It takes about two hours (or as long as you like) and you’ll enjoy a unique experience. I suggest you start at Duinvermaak and simply follow the signposts. If you stray off the main paths and are worried you’re lost, find a high spot and look for a tower – it’s Huize Glory in Bergen aan Zee. Also, at any time after midday, simply keep the sun on your right as you walk and you’ll inevitably get back to (the road to) Bergen.

Go for a walk south of the Zeeweg and you’re likely to come face to face with Highland cattle imported from the Scottish Highlands (as with all Scots, leave them alone and they’ll leave you alone, but if you go anywhere near their calfs, you’re likely a goner) and ponies imported from Exmoor, England. They’ve been introduced here to compensate for the dwindling rabbit population as a result of diseases such as myxomatosis and RHD. Numbers have fallen 90% and without the rabbits, there is nothing to eat the grasses and shrubbery in the dunes, which were becoming overgrown. The big grazers now keep the undergrowth in check.  It’s a mighty sight to see them roaming about!



Photography: Robin Glendenning, Kevin Mansell, Rijksmuseum.