Should Kalmthout sacrifice a landmark American oak to protect its heath?

Flemish nature managers have ring-barked a prominent American oak on the Kalmthout Heath, leaving the tree to die as part of efforts to protect the reserve’s open heathland. The intervention, reported by De Standaard and Het Nieuwsblad in late August, has angered local residents and drawn objections from Kalmthout Mayor Lukas Jacobs

The dispute concerns more than one old tree. It exposes a difficult choice in Flemish nature policy: whether managers should preserve a familiar landscape feature valued by visitors or remove a non-native tree that competes with a protected habitat. For people who know the heath through walks, childhood outings and family photographs, the oak is an individual place with a history. For the Agency for Nature and Forests, or ANB, it is also part of a wider ecological process that can gradually turn open heath into woodland.

ANB spokesperson Frank Van Swalm told Het Nieuwsblad that the American oak had recently begun producing seedlings. He argued that unmanaged tree growth would eventually transform the Kalmthout Heath into forest. Ring-barking — removing a strip of bark around the trunk to interrupt the movement of water and nutrients — kills a tree gradually and can leave standing dead wood for insects, fungi and other wildlife. The reporting does not establish precisely when the work was carried out or how long the tree will remain standing.

Jacobs, who is both Kalmthout’s mayor and chair of the cross-border Grenspark Kalmthoutse Heide, represents the opposing local view. De Standaard reported that he and residents were unhappy that a conspicuous, culturally familiar tree had been condemned. Their objection is not necessarily a rejection of heathland restoration; it is a demand for proportionality and for managers to explain why this specimen could not be treated as an exception.

The ecological case rests on the unusual vulnerability of heath. Unlike a mature woodland, healthy heathland depends on nutrient-poor soils, open sunlight and continuing intervention to prevent grasses, shrubs and trees from taking over. The Flemish government’s official Natura 2000

American oak, Quercus rubra, was introduced from North America and planted widely in European forests. Research published by Belgium’s Institute for Nature and Forest Research, INBO, describes how its broad leaves can form a thick, slowly decomposing litter layer that suppresses ground vegetation. The Grenspark’s own conservation programme identifies American oak among the non-native plants threatening heath and related habitats and has previously set a target of removing invasive alien trees and shrubs across 60 hectares on the Flemish side.

That does not make every American oak ecologically identical or require every specimen in Belgium to be destroyed. The species is not simply interchangeable with the organisms on the EU list of invasive alien species, which carries specific legal restrictions. Here, the relevant European connection is the habitat: the Kalmthout Heath forms part of the Natura 2000 network and extends into the Netherlands, where De Zoom and the Brabantse Wal have complementary conservation objectives. Decisions on the Belgian side can therefore affect a cross-border ecological system, even though this particular tree remains a Flemish management matter rather than an EU institutional decision.

Climate stress sharpens the argument. ANB’s conservation documents say woodland can increase evaporation in this sandy landscape, while the official habitat plan identifies drying as a central problem. Yet the sight of a large tree being deliberately killed during dry periods can feel counter-intuitive to the public. That tension is precisely why communication matters: carbon storage, shade and emotional attachment are real benefits, but they do not automatically outweigh the needs of a scarce open habitat at every location.

The immediate outcome appears settled because ring-barking is intended to be irreversible, although ANB has not publicly specified when the tree will die or whether safety considerations will eventually require its removal. The larger question is whether the agency and Kalmthout municipality will agree on clearer consultation before similarly visible interventions. The oak may be lost, but the public trust surrounding the heath’s long-term management is still open to repair.