Threats in the project area

Threat 1: Over fertilization and acidification
Threat 2: Loss of habitat due to lack of adequate management
Threat 3: Dehydration
Threat 4: Disturbance by recreational pressure
Threat 5: Presence of invasive alien species
Threat 6: Decrease in persistence (shelf life) of the seed bank
Threat 7: Lack of social support and socio-economic embedding

Threat 1: Over fertilization and acidification
The heathland habitats and inland dunes in the project area are struggling with an unwanted enrichment and acidification by nitrogen, phosphorus and sulfur.
This is mostly caused by atmospheric deposition (air pollution by nearby agriculture, industry and traffic). The enormous enrichment of the poor heathland ground and inland dunes causes unwanted and accelerated grass growth. This causes purple moor grass to dominate and the biodiversity to decline. Tackling the causes of atmospheric deposition is not an aim of the project. However, extra measures such us cutting sods, grazing, mowing and chopping can prevent heathland habitats from becoming overgrown with grass.

Another problem is the direct runoff of fertilizer-enriched surface water from the agricultural enclave “Steertse Heide” (Flanders) to Groote Meer (Netherlands).


On the attached map we can see that the western part qualifies for weakly buffered pool (i.e. a pool rich in plant and animal species) but the eastern part does not qualify (anymore). This can also be noted by the roughness of the eastern part. Currently this part serves as buffer and purification for the western part. For this reason in summer 2014 a dam was constructed between the eastern and western part. This way the western part can be prevented from becoming too rough and losing its typical flora. During the project, a purification plant will be built to clean the fertilizer-rich water from Steertse Heide to the correct quality. At the same time, agricultural land will be bought (at a faster pace) on Flemish side to slow down and stop intensive agriculture and fertilization. Both actions are intended to get the water quality back to the desired levels for weakly buffered pools. At that point the eastern part can be cleaned (at a later stage) and the dam between the two parts can be removed.

Threat 2: Loss of habitat due to lack of adequate management:
Until 2009, Mont Noir and Stappersven/De Nol were privately owned. Management of these parts was aimed at maintaining and expanding the wooded surface and not at the important habitats such as inland dunes, dry and wet heathland. Alignment with the surrounding lots and other owners was not an issue.This way small remnants of land dunes and wet heath were completely isolated, threatening a number of species.
During this project open areas will be enlarged and connected with each other.
A similar situation can be found between Steertse Heide (B) and Groote Meer (NL). The presence of privately owned parcels prevented connection and the realization of an ecological connection zone. Purchase of these isolated parcels will enable to connect the desired open habitats.
The fire of 25 and 26 May 2011 illustrated once again the importance of corridors to connect areas, allowing species to better spread and that way be less vulnerable for calamities as these.

Threat 3: Dehydration
Because of a lack of high water levels, Groote Meer is for 80% (or 385.000 m3) dependent on the rich surface water from the agricultural enclave Steertse Heide. This water supply mainly takes place in fall/winter (Artesia 2012). The water is currently inadequate to maintain the weakly buffered character of the western part of Groote Meer. The construction of a purification plant should change this situation and will hopefully allow us to supply Groote Meer with sufficient ‘clean’ water. Downsizing water collection in Flanders and the Netherlands should also cause an increase in soil water.

Threat 4: Disturbance by recreational pressure
For as long as we know, visitors have been present in the whole project area. The image of Kalmthoutse Heide and the until recently inaccessible area surrounding Stappersven attract a lot of visitors. Lack of recreational measures such as paths, watchtowers, look- out points, … cause damage to important natural values such as wood lark (Lullula arborea) and European nightjar (Caprimulgus Europeaus)- companions in the open area, but also disruption of honey buzzard (Pernis apivorus) nests. It is important that this project solves these issues by constructing a watchtower and look- out platform.

Threat 5: Presence of invasive alien species
The most threatening invasive alien species of the project area are black (American) cherry (Prunus serotina) and Pontic rhododendron (Rhododendron ponticum). American oak (Quercus rubra) is also largely present. These species are a threat to all heath and similar habitats. Invasive alien species are also responsible for loss of quality of the dryer wood habitat. This quality loss impacts species such as black woodpecker (Dryocopus martius) and honey buzzard (Pernis apivorus). Fighting these invasive alien species will be done throughout the whole area.

Threat 6: Decrease of persistence (shelf life) of the seed bank
The stock of germ potential (living) seeds of heath and related habitats in the entire project area is decreasing. The limited shelf life is illustrated by research of ‘de Blust, G. & Slootmaekers M. red. (2004). Natuurbeheer, Davidsfonds, 452pp’. This could cause a loss of heath and related habitatsin the entire project area. That is why the project will create circumstances suitable for the present seeds to germinate.

Threat 7: Lack of social support and socio-economic embedding
With the previous Life project (HELA project 2006-2011) we have noticed that offering accessible information about nature in general and more specifically about the results of management as it is carried out, resulted in greater involvement. Not only with the specialized nature lover but also with the regular visitors and inhabitants. Informing all ‘civilians’ is a necessity to create a broader support. This will contribute importantly to the socio-economic embedding of the border park in its totality.