Having flowers on the dikes instead of grass is not only better for the dikes and the natural environment, but it is also better for mankind, claims ecologist Hans de Kroon. Rather than merely seeing Dutch dikes as a barrier against water, his ‘Future Dikes’ research project seeks to view them as an essential part of our natural landscape, which we can also enjoy. ‘When you cycle past the floral dikes, you can see people enjoying them.’ “We’ve known for around 10-15 years that a diverse natural landscape full of different types of flowers and grasses has positive effects on the roots of these flowers and grasses. The more diverse the plants, the stronger their roots and this, in turn, leads to stronger topsoil. Theoretically, this principle also applies to dikes.” This is good news not only for the dikes, but also for the insects that visit the flowers and grasses. “The Netherlands has around 360 species of wild bees, and a large number of these are rare. We’ve already seen about a third of these species on our dikes, which is quite a lot.”Flood trialsWithin the Future Dikes project, De Kroon and a number of colleagues are investigating whether floral vegetation actually make dikes safer, what the best vegetation is and what these floral dikes mean for the insect community. In one of the studies, the scientists wanted to see if the floral dikes could withstand flooding. “We exposed a floral dike to the ultimate stress test during the flood trials. In this type of trial, a huge splash of water is thrown over a dike and you keep watching to see if the dike collapses. It usually doesn’t take that long before the top layer is stripped off and a huge crack appears. We carried out these trials on six test surfaces, but they were indestructible. The moment of failure never came. After three days of dousing the surfaces with water, we ultimately quit what we were doing. And I accepted this outcome with a big smile on my face,” says De Kroon.Elongated structuresThe choice of dikes was not coincidental. De Kroon: “Dikes are interesting because they’re elongated structures. We have around 17,000 kilometres of dikes in the Netherlands; of this distance, the primary flood defence system that keeps our feet dry is around 3,700 kilometres long. The other dikes are embankments that do not primarily serve as a flood defence. The main dikes meander through the landscape and could subsequently function as the main arteries along which the insects move.” The dikes are connected to each other; they form a network. They are almost like ecoducts for insects. “We’ve seen that the dikes aren’t just being used as some fancy bus lane by insects where they hop on and off, we’ve also seen that there are villages on these dikes where insects are able to develop. The use of floral dikes consequently creates a very vital community for both plants and bees, for example.”Ground rulesThe objective of the Future Dikes project is to see the Netherlands’ main dikes covered with flowers instead of grass. “The ideal scenario involves floral dikes, unless... As far as we’re concerned, this should be one of the ground rules for dike management. The development management will be slightly different - it might be a bit more complicated - but through this project we aim to provide enough evidence to show that this will work. Many of the water authorities are already quite excited, and the Delta Programme Commissioner is also an advocate.”Flower XHappy dikes, happy vegetation and happy bees. And as an added bonus: happy people. “We’ve always viewed nature as though it owes us something: it should be purifying our water, or we should be getting something out of it. That’s obviously not a bad thing, but it does mean that we’re putting a strain on these systems. In the last few years, more and more people have been saying that nature conservation is also important for our well-being.”“Nature is an essential part of our environment. It is part of us. It’s a well-known fact that green surroundings are better in all respects: people recover faster and are less likely to get sick, for example. And you might ask whether ‘Flower X’ is really necessary, but I’d never ask you if you really needed your little finger, would I? That would be absurd, because it’s a part of you. Flower X is also part of the whole picture. If we’re not surrounded by nature and the biodiversity that comes with it, then something is wrong. That’s what I hear when I’m down among the flowers on the dike: I hear people literally saying that the flowers are making a valuable contribution.”You have a part to playOur society is facing major challenges. Radboud University wants to contribute to a healthy, free world with equal chances for everyone. With 'Je bent nodig' (You have a part to play), Radboud University aims to reach people who want to contribute to that goal. Would you like to actively contribute or read more about sustainability in our education and research? Visit www.jebentnodig.nl for more information.The Future Dikes research project is now about halfway through. Additional funding is needed for the next few years. If you would like to make a contribution, Click here for more information.Photo: Karsten Russ