Why do we cut down trees in the Sonian Forest?

Why chop down healthy trees? This is a question that is often put to the managers and forest wardens in the Sonian Forest. The answer is simple: trees are only chopped down if there are good reasons to do so.


© Sophie Vercammen

Valley of the Drowned Children

Concealed within the Sonian Forest, there is an exceptional nature reserve that is referred to as the Vallei van de Verdronken Kinderen (Valley of the Drowned Children). This damp, wooded valley is a paradise for rare plant and animal species. The tufted duck and the Alpine newt and the protected European bitterling are completely at home in this setting. The numerous springs are also the perfect home for bitter field cress and branched bur-reed. The team from Leefmilieu Brussel ensures that the lush, unique natural environment is maintained. That is why, for example, they remove exotic plants and clear the ponds.

Our forefathers also regarded the valley to be a paradise. At the interchange of the Tumuliweg and Tweebergenweg, you can find two tumuli and the remains of a 5,000-year-old neolithic settlement on both sides of the Tweebergenweg. But in order to ensure heritage is retained as effectively as possible, sometimes major interventions are required. Frederik Vaes from Leefmilieu Brussel: “We chop down thick, unstable beech trees because they could easily fall during stormy weather and their huge roots could disrupt the original soil profile. In the past, fallen trees have seriously damaged the earth and the remains of the neolithic site.”

One-off activity

Felling the beech trees give Scots pine, birch and heather a much better chance to grow. “Coniferous trees, birch and oak are much more stable and can withstand stormier weather. The Scots pine and heather also protect the ground. They acidify the subsurface, ensuring earthworms and other soil animals do not root around in the soil. This allows the soil profile to remain intact”, explains Frederik Vaes.

Leefmilieu Brussel stresses that this is a one-off activity. “In the future, we will only chop down a few trees or a group of trees so that the woodland can gradually regenerate.”

Safe to the other side

Soon, the view on both sides of the Brussels Ring will change entirely. Between Groenendaal and Waterloo, work is taking place on an ecoduct. This is part of the European LIFE+ OZON project, that is tackling the fragmentation of the Sonian Forest. The first stone was laid on 26 September 2016 and the project should be completed by the end of 2017. Steven Vanonckelen, project leader of LIFE+ OZON from the Agency for Nature and Forestry: “The ecoduct will allow animals to safely cross to the other side. In order to ensure that they do not wander onto the motorway, we are installing an eco-grid over a distance of 25 km. This is 2m high fencing that will be placed along the R0 and E411 motorways. Trees will have to be sacrificed in order to install the eco-grid. Simultaneously, it is an opportunity to create a wide forest edge. We are thus fulfilling the European Nature Targets that we set in the context of Natura 2000. We will plant shrubs in their place which will create the ideal habitat for many woodland residents.”

For more information on the Life+ Ozone-project, see here