Onderzoeksoutput: Boek/rapport › Rapporten van het Instituut voor Natuur- en Bosonderzoek
|Uitgeverij||Instituut voor Natuur- en Bosonderzoek|
|Status||Gepubliceerd - 2008|
|Naam||Rapporten van het Instituut voor Natuur- en Bosonderzoek|
|Uitgeverij||Instituut voor Natuur- en Bosonderzoek: Brussel|
The military areas of Camp Beverlo and Helchteren Shooting Range in the province of Limburg, together with the neighbouring brook valleys and forests, are among the most important core areas for biodiversity in Flanders. During the 20th century, the historical heathland landscape outside of the military grounds was dramatically changed by the expansion of building sites, industrial areas and road infrastructure, and by forest planting on nutrient-poor soils. Agricultural intensification has resulted in a strong decrease in nature values on arable land and in brook valley grasslands, especially from the fifties on.
Within the military areas, however, vast heathlands, sand dunes and forests have remained. These areas also serve as important infiltration zones for the neighbouring brook valleys. Thanks to the extensive land use the hydrological relations between the valleys and neighbouring plateaus have remained intact to an important extent. As a result, very rare, groundwater-dependent biotopes of oligotrophic to mesotrophic conditions can still be found in the brook valleys. On the basis of these ecological values both military areas and the surrounding forests and valleys were designated as special protection areas of the Bird and Habitat Directives.
The delineation as Bird Directive Area was based mainly on Annex I breeding birds of heathland and marshes, as well as migratory species like Common Crane and Hen Harrier. Species of vast, open heathlands (Black Grouse, Montague’s Harrier, Short-eared Owl, Golden Plover, Tawny Pipit), however, have declined strongly or have disappeared altoghether from the area since its delineation. This goes hand in hand with a decline in habitat quality due to grassing over, afforestation, and disturbance. In addition, agricultural intensification in neighbouring feeding areas has had a negative impact on species like Short-eared Owl, Black Grouse and Montague’s Harrier. The conservation status of breeding birds of marshy areas and brook valleys (Great Bittern, Spotted Crake, Corncrake, Red-backed Shrike) is also generally worrying. The reasons are the increasing afforestation of marshes on the one hand, and agricultural intensification on the other. Species of forests (Black Woodpecker, Honey Buzzard) or of transitions from forest to heathland (European Nightjar, Wood Lark) remain stable or are even on the increase.
The delineation as Habitat Directive Area was mainly based on habitats like sand dunes, dry and wet heathlands, fens and their accompanying Large White-faced Darter, oak woods with birch, stream valleys with alluvial forests, semi-natural grasslands, peat bogs, and meadowsweet communities. The Zwarte Beek is also important for European Brook Lamprey.
On the basis of the declared area, both special protection areas are of major importance in Flanders for the conservation of heathlands, land dunes, fens, peat bogs, Nardus grasslands and oligotrophic alluvial forests. Even on a European level these military areas and their surrounding brook valleys are very important for the habitats of land dunes, heath and alluvial alder forests. The conservation status of most habitats is currently not good. The main reasons are grassing over and afforestation of heathlands and sand dunes, and the eutrophication and acidification of fens, also causing the disappearance of good habitats for Large White-faced Darter. On the Helchteren Shooting Range, the falling groundwater level seriously threatens the conservation of wet heathlands, fens and peat bogs. Peat bog habitats and semi-natural grasslands have suffered greatly from the absence of the historical hay land use. Some of these hayfields were transformed into more productive but ecologically less valuable fields or grasslands. Other hay meadows evolved into underwood, scrub and forest. Habitats of dry deciduous woods are largely poorly developed: their relatively young age and the dominance of planted conifers result in a relatively poor structure and little dead wood. The presence of exotic species like Black Cherry and Northern Red Oak is also an important problem.
In order to preserve and develop the nature values in the special protection areas, an ecological vision was created. It is based on the following issues: