The nitrogen ruling offers hope for this vulnerable nature reserve

He has not yet read the court’s ruling in full, but the fact that the government must put more effort into reducing nitrogen in vulnerable nature reserves seems good news to the forester from Overijssel. “We have been working here for a long time to protect the raised bog. With internal measures. If we ensure that less nitrogen ends up here, it will be an external measure from which this area will certainly benefit,” says Henk-Jan van der Veen, forester and ecologist at Staatsbosbeheer.

The fog has lifted, the sun is making weak attempts to break through the gray cloud cover. Silence reigns over the Engbertsdijkvenen, one of the last remaining remnants of the raised moor landscape of the Netherlands, near Kloosterhaar, not far from the German border. A vast landscape, protected under the European Natura 2000 regime, covering eleven hundred hectares. It is difficult not to see the beauty of this landscape, with the treeless plains, the pools in which water peat moss forms here and there, with vipers, cranes and a great diversity of dragonflies. Yet this raised bog would have looked even better with less nitrogen.

Nitrogen is a kind of pokon

Just think: raised bogs thrive in what ecologists call a nutrient-poor environment, an area where rainwater cannot escape, pure rainwater without fertilizers, without many minerals. On the other hand, with the presence of nitrogen in the Engbertsdijk peat bogs from “a sum” of agriculture, industry and traffic, other plants and trees receive the food that allows them to flourish and thus outcompete the original peat moss. “Think of nitrogen as a kind of pokon,” says Van der Veen. “The microenvironment is changing. This causes the vegetation to change. Grass will grow, strawberry, and trees like birches.” The ranger spreads his elbows and says: “They widen and push away the peat moss.”

The fact that there is a “nitrogen blanket” over the rare raised bog area is old news. For years, Staatsbosbeheer has been trying to combat the loss of the area, with varying degrees of success. Van der Veen: “In the Netherlands, when it comes to raised bogs, it is always half a step forward and then another step back.” The ranger peers across the plain, pointing to the “core area”; the last remaining part of the Engbertsdijk moors, which still has five meters of thick raised bog. In other parts of the area the raised bog is much less thick. Van der Veen: “The goal is of course to let the raised peat grow again by one millimeter per year. But in practice the growth is marginal. We are satisfied if the peat does not dry out and is oppressed by other species.”

We are satisfied if the peat does not dry out and is oppressed by other species

Without intervention, the process of ‘mineralization’ would continue in the Engbertsdijk peat bogs and the entire area would suffer from ‘forestation’. Quays were constructed in the area as early as the 1960s and 1970s to preserve pure rainwater during the ever-increasing desiccation, often a result of drainage from agriculture and other human activity in the area. The peat embankments turned out not to be completely capable of this. “They are porous, cracks appear,” says Van der Veen. Since around the turn of the century, Staatsbosbeheer has started to reinforce a number of quays with sand and loam, five meters high. Staatsbosbeheer also has small trees cut down every year to give the peat moss more space. Here and there are groups of birches and pines. “But we leave them alone, they grow on high sand heads.”

Pill for headache

The fact that the court ruling may actually result in less nitrogen being released into the Engbertsdijk fens is a sign for forester Van der Veen that this nature may turn out well “in the long term”. That would be more than just treating the symptoms, such as sawing away saplings, it could remove the real cause. “It’s like a headache. You can take a pill against that. But you may also discover that perhaps you are working too hard, and that you should work a little less.” And besides, he says: a raised peat area like this also stores a lot of CO₂ on.

The area still has large, extensive lakes. That is hopeful, and actually a small miracle after several years of prolonged periods of drought. Of course, this also has a lot to do with the abundant rain that has fallen in the Netherlands over the past year and a half – a blessing for raised bogs. “Look, you see some peat moss growing there again,” the ranger points enthusiastically to some greenery in the water.

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