Blog 3 – Dynamic dunes

… or the lack of them. That and they causes and consequences will be the topic of this blog.

Last blog ended with me arriving in Denmark, and the expectation of some more dunes. And dunes I got! After a day and a half I left the Waddensea behind me, and truly arrived at the North Sea. The absence of dikes was a blessing. But dunes can also be pretty endless. They have some more variation. Forests, heather, beach, and sandy as we known them. Up to Skagen, I cycled mainly amongst dunes. And therefore it seems the perfect topic of this blog.

I might not go into much detail in this blog, because everytime I plan to write, I run into another cyclist and we start chatting and time flies by… So, here goes. With another promise that the next blog will be within a week.

Rudbøl to Frederikshavn

Day 13 – 70 km to Ribe – Beautiful rolling countryside with blue sky and fields of gold. Gravel roads are interesting to ride one. Ribe itself is a nice old village. Reminded me somewhat of Den Burg (Texel).

Day 14 – 86 km to Henne – The weather turned grey. But it suited the landscape. Fields of heather, some lakes ad some coniferous forests.

Day 15 – 75 km to Vedersø Klit – Day started nice, and for the first time in a while: no headwind! But as soon as I arrived truly in the dunes, it started raining again. In front of me the sky was blue, behind me the sky was blue, but an eternal raincloud hung over me. Even when I stopped for some pancake. The small gravel cycling paths are terrible for your bike when everything is wet. Everything was covered in a layer that stuck like clay.

Day 16 – 10 km on a rest day – With everything wet and my mood turning as grey as the clouds the day before, I took a day off. Cycled to the beach to step into the North Sea for the first time this trip and cycled to the forest to have some lunch and listen to the birds. And some practical stuff. Getting laundry done and all my gear sorted and dry again.

Day 17 – 93 km to Svankær – The campsites are a bit expensive in Denmark, so I started using the Shelter app. After cycling along the dunes and some fjords for a day, I ended up on a shelter spot in a forest. The nice thing: the family already there had the campfire going. The bad thing: mosquitoes…

Day 18 – 82 km to Thorup – Another beautiful day among dunes and forests. And ending on a shelter spot in a forest, with a campfire.

Day 19 – 109 km to Thornby – Yet another beautiful day among dunes and forests. This time also ON the beach. And ended up, again, on a shelter in a forest, with a campfire. And met up there with another cyclist I met earlier in Germany.

Day 20 – 87 km to Hulsig, including Skagen and back – The plan was to ride with the other cyclist to Hirthals. But as soon as we left the forest, I saw quite a lot of birders. Cirl bunting (Cirlgors, check!) and possibly (Roodkopklauwier). After 55 km along dunes and forests dropped all my stuff at a campsite and cycled to Skagen and back. Since this was the route anywaym it seemed a bit redundant to cycle those extra 30 km with luggage.

Day 21 – 37 km to Frederikshavn and the ferry to Sweden – I finished the North Sea coast in Denmark, so it’s time to cross over to Sweden. It was a cycling highway from the campsite to Frederikhavn. The official North Sea Cycle Route does continue for another 250 km to Grenå, but I’ll skip the last part.

Of sand, sea and wind

Similar to salt marshes, dunes are a result of the inflow of sediment and the trapping by plants. But the sand, coming from the sea, is more affected by wind than the smaller sediment of salt marshes. The wind determines the directionality of drifting dunes. With on average wind from th southwest, dunes can slowly drift to the northeast.

While dunes are initially created by grasses trapping the sediment, a diverse array of plant species and associated fauna will arrive. This takes time. Unlike salt marshes, dunes are not nutrient rich. On top of that, water is not retained and the sun on the sand makes everything extremely hot. Additionally, sand caught in the wind is always creating dynamics in which vegetation can get covered up again. It is tough to grow in the dunes, which make the flora and fauna living there also vulnerable to changes.

When sand threatens

Of course, dynamic dunes may also cause problems. These problems are based on a human interests. It is only when drifting sand threatens to engulf building, or cover roads, that it is considered a threat. There are basically three options when this happens, and all three I have come across on journey in Denmark.

The first option is to let nature do its thing. This happened to the 14th century church south of Skagen. In the 19th century it was decided that the church could no longer be protected against drifting sand. The church was closed, partly demolished, and washed white to serve as a beacon for seafarers. To my mind, humans are not very good at abandoning their structures. Currently, the option to let the dunes roam free is not the go-to option.

The second option is a very temporary option. I suppose this has also been attempted for the church in the previous example. You can simply shove the sand to the side, as demonstrated on the road to Hvide Sande. However, the sand will continue to drift.

So, there is a third option: stopping the sand from drifting. The fixation of the dunes is done by planting Marram grass (Helm). As this is the main plant in the dunes to trap sand anyway, it seems like a simple solution. But the fixation of dunes has also other consequences.

When sea and wind threaten

Historically, the dunes would move more “land inward” whem sea levels rose. When they are fixed, this is no longer possible. As a result, wind and wave action during storms may erode the dunes. Small cliff formattions will occur, and the beaches become smaller. To keep the beeches sandy, the Dutch and the Belgian use sand suppletion. Sand from deeper in the North Sea is added to the beach. The Danish have another solution. They use piers to trap some sand.

If a row of dunes is small, it might even be broken through with a severe storm. In Denmark there is one specific point where this may occur. At Ferring is the former connection to the Nissum fjord. The conection to the sea now lays way further north at Thybøron. But this former fjord-entrance is vulnerable in a similar way that seadykes can break through. The houses right behind the dunes… I wouldn’t want to live there during a severe winter storm!

When mankind threatens

The threats of sand, sea and wind are usually threats to man-built structures or argriculture. However, mankind may be a larger threat to dunes.

In entering Denmark, I hoped to see beautiful dynamic dunes. I had heard that Denmark had some of Europes most impressive dunes. I was disappointed. I’ve seen a total of 2 sand dunes. One of which was landinward… Almost the entire coastal dune line was completely covered with vegetation. Only where people crossed the dunes to go to the beach was sand visible.

Besides the absence of dune dynamics, I was somewhat surprised by the vast number of holiday houses built throughout the dunes. The houses themselves are not that big, but the are spread out quite a bit. If all the houses were more clustered, that would lead to larger “untouched” areas of dunes, more suitable for birds for instance.

Across the water

After cycling the entire west coast of Denmark, to Skagen, where the North Sea meets the Skagerak, I was convinced I would see more natal dunes than in Belgium or the Netherlans. Buy arriving in Skagen and seeing almost all the tourist in Denmark combined trying to reach the tip of Skagen, I was actually very disappointed. The absence of dynamic dunes as well as the immense tourism made me ready to leave Denmark behind and start another chapter of this journey.

In a way I am excited to go to Sweden. The country where I had a wonderful summer working in 2011. But also the country where Greta Thurnberg comes from. An inspiration to fight for climate justice. Sweden, here I come!