Because the Council of State (RvS) disapproved of Dutch policy on reducing nitrogen emissions, thousands of construction projects are at stake. A committee will probably advise the cabinet next week on how the projects can proceed. What kind of damage does nature actually cause nitrogen?
Sighing Lex Querelle looks into the distance. The forester of Natuurmonumenten stands on the edge of a lawn in the Brabant nature reserve the Kampina. "In 2009 this was still heather, but in ten years it has only become grass. In a relatively short time the heath disappeared here."
The cause of that grassification? The precipitation of nitrogen in the nature reserve. "Nitrogen is actually a fertilizer," explains Querelle. "If you want to grow grass, you scatter nitrogen. That grass will get really tall and dark green very quickly."
On the contrary, heather thrives in nutrient-poor conditions. But because of the large amount of nitrogen that settles on the heathlands, the heath is overgrown by grasses and other plants that grow fast.
In the Netherlands, 118 of the 160 Natura 2000 areas suffer from nitrogen. This is achieved in various ways. For example, vehicles and industry emit nitric oxide. In agriculture, nitrogen is released via ammonia, which in turn is released from the evaporation of manure. Nitrogen oxide and ammonia eventually end up in the ground again, which has a major impact on nature.
77Why does nitrogen cause so many problems in the Netherlands?
A hundred years ago you found heather almost everywhere
Almost 200 kilometers to the north in National Park Dwingelderveld in Drenthe, the same can be seen. You will find grass where the purple heather once bloomed. "It is a shame that we cannot go back in time a hundred years, because then you saw heath almost everywhere outside the villages," says Arnout-Jan Rossenaar, ecologist at Staatsbosbeheer. "It's the only thing that normally grows on this soil."
When Rossenaar walks into the adjacent forest, he points to the blackberries, ferns and nettles. "Plants that all grow extra fast because of the fall in nitrogen and that suppress less species of nutrients," he explains.
On the edge of the forest, where a farmer is currently mowing the grass, it is even more visible. "Look, he probably got a little shot in fertilizing his pasture," says Rossenaar, pointing to a large bunch of nettles.
A large bunch of nettles on the edge of a field. (Photo: NU.nl/Job van der Plicht)
"Heather wants poor conditions"
In addition to the fertilizers and exhaust gases displacing heaths, heaths also make people lazy. Querelle walks through a piece of heather that looks like a blanket of fabric over it. "Drought stress" is his conclusion.
"The heather wants poor conditions. But if nutrient-rich nitrogen falls over it, the heath will be spoiled, with the result that the heath system of the heath keeps getting smaller," explains the forester. "The plant also survives with shorter roots, because suddenly there is all food in the area. But during dry periods such as last year and this year, the plant is no longer able to find sufficient moisture due to the shortened roots and dies."
The gray heather that died due to drought stress. (Photo: NU.nl/Job van der Plicht)
The moor is a gray, dead plain
It is a sad sight to see not one or a few, but hundreds and perhaps thousands of gray, dead heather plants. Insects barely fly around and there is almost no life on the arid plain.
A little further on, Querelle walks to a dead tree. It turns out to be an oak. Also died as a result of nitrogen, but then again through a different process. "Nitrogen that settles in the soil leads to an acidification process," the forester knows. This is a chemical reaction, but in summary it means that fungi around the roots of the tree die. The tree needs these fungi to be able to absorb nutrients from the soil. Because the fungi also kill the roots of the tree, the tree dies.
"Every tree has different types of fungi around its roots. The fungi of oak cannot tolerate nitrogen, but those of pines, for example, are less troubled by it," Querelle explains. "We not only see oaks dying in Brabant, but also in the Veluwe and in Drenthe."
Bird species and insects disappear
That species disappear and are added is a natural process in itself and does not have to be bad at all, says Querelle. "But the pace at which it is now is shocking. Take the oak, for example. It moved north from the Mediterranean twenty years ago. The oak took a long time. And now, in ten or twenty years, they die that time is too short for new species to replace those trees. "
With the dying of the oaks, but also, for example, the heather plants, the other species that live around it disappeared and benefited from the disappeared trees or plants. Querelle: "All sorts of mushrooms, mosses, wild bees and other insects go away in one fell swoop. Birds, such as the robin and the tree lark, are also seen less and less."
Ten years ago the heather was still flourishing here. The plant has since been replaced by grass species. (Photo: NU.nl/Job van der Plicht)
"It remains green to the eye, but nature is completely dead"
Rossenaar sees that the butterfly species of heather blue and cranberry blue are being observed less and less by the displacement of the heath, that animals can no longer survive in increasingly acidifying ponds and that beetles are disappearing.
The ecologist calls it a "fast food culture" in which only a limited number of species can survive. "Is that bad?" He asks aloud. "When you go on vacation, you come for local eating habits and regional specialties, among other things. You don't go on vacation to eat at a fast-food restaurant, you can do that everywhere. That's how nature works. The special things disappear and the nitrogen surplus is partly responsible for that. "
"To the eye it remains green, but it is completely dead", Querelle concludes. "It becomes quiet on the heath. In fact, it is already quiet."
See also: Cabinet has solution for nitrogen ruling, projects may have resumed