PROJECT DESCRIPTION
BACKGROUND
The colloquial term 'ven' in Flemish refers to oligotrophic aquatic habitats which originated when peat extraction created depressions reaching down to the sand or clay subsoil, in which small lakes ('vennen') formed. These lakes were traditionally used for extensive fish farming among others, and were often temporarily drained to be used as arable land. In their shallow water a species-rich vegetation, thriving in a context low on nutrients, developed (Litorella uniflora, Isoetes lacustris, Luronium natans, etc). Around these fen-lakes, small-scale agriculture shaped heaths and mat grasslands. Traditional agriculture ceased in the 20th century, which led to a degeneration of these habitats. In addition, large areas were drained and planted with pine, in order to supply pit poles for the upcoming coal mines nearby. Fish farming gradually became more intensive. The most recent development was that ever more maize was being planted in the surrounding area and the number of pigs was growing exponentially; the disposal of their manure was having some very pernicious effects. The two project subsites, the Vennen near Turnhout and the Maten near Genk, were brought under legal protection quite a while ago but the designated nature reserves were much too small to safeguard the oligotrophic aquatic habitats occurring there.
OBJECTIVES
The objective of this LIFE-Nature project was to secure oligotrophic lakes, wet heathlands and related habitats in the two project sub-sites: the "Vennengebied" (Turnhout)and "De Maten" (Genk). In the sub-site "Vennengebied Turnhout", the project would focus on the development of a comprehensive management plan. Oligotrophic lake restoration will only work if the surroundings are also drawn into the restoration plan, because, to keep the lakeshores sandy and therefore devoid of nutrients, enough sunlight and wind need to reach them. Next, to restore the oligotrophic lakes, mat grassland and heaths, 45 ha of land would be purchased and thoroughly modified: lake bottoms experimentally dredged of sediment and - to foster the regeneration of heath - pine forests chopped down and the topsoil stripped off. Fences were to be installed to start up a grazing management to allow these habitats to develop further. Homeless people from a refuge near the subsite would be involved in the restoration work. In the sub-site "De Maten", Natuurpunt also aimed to restore oligotrophic lakes, Nardus grasslands and wet heaths. Here the main action would be to repair the dikes separating the lakes and to restore Nardus grassland. Finally, the beneficiary planned several public relations actions with the aim to promote a more sustainable land-use around these sensitive areas.
RESULTS
The project met its targets, and even exceeded some. The most tangible results were: - a management plan for entire Turnhoutse Vennen subsite - 48.35 ha of land purchased (target 45.0) - trees cut over 22.6 ha of land to restore heaths and Nardus grassland (target 14 ha) - sods stripped over 4.5 ha to restore heaths - 5.1 km of dyke repaired around the ponds in De Maten subsite - experimental excavation of a 0.25 ha former ‘ven’ (= oligotrophic pond) - experimental excavation of part of shores of an oligotrophic lake - experimental silt removal from the bottom of an oligotrophic pond, 1.5 ha - fencing of blocks of land acquired, followed by intensive initial management (a regime of mowing and grazing) to kick off restoration towards heathland habitats - 32 information panels for visitors to the two subsites - 2 information folders for visitors and locals (one per subsite, 50,000 copies each) Note that the two subsites present quite different pictures. At De Maten the beneficiary already controlled most of the land. Consequently, site restoration predominated here: the system of dykes which contains the chain of oligotrophic ponds making up De Maten, was falling into disrepair and LIFE allowed the whole system to be thoroughly and systematically restored (5.1 km of dykes treated). In addition, over 8 ha of Nardus grassland overgrown with shrubs was restored. In the other sub-site “Turnhouts Vennengebied”, the beneficiary only controls a small part of the land. LIFE-Nature did allow this managed area to increase by 40% thanks to the land purchase it cofinanced. However, at the end of the project hydrological impacts and increased nutrient input from intensive agriculture in the vicinity still affected the site. Nevertheless, the restoration of the land purchased via LIFE (clearing afforested areas, the removal of the enriched topsoil through sod cutting and, where necessary, restoration of the original micro-topography) indicated a trend shift, away from the intensive production-oriented land use. This provided the targeted biotopes the necessary “oxygen” to survive in the otherwise suffocating environment. Encouraging is that during the project, the competent Flemish authority for nature, AMINAL-afdeling Natuur, began its own programme of land purchase and site restoration in the Turnhouts Vennengebied. Both bodies (AMINAL and Natuurpunt) are continuing their efforts after the LIFE project. Besides the habitats, for which an ex ante monitoring was done during the project (with follow-up monitoring foreseen after LIFE by the beneficiary), some Annex I bird species are also benefiting directly from the restoration measures. For instance, the bittern (Botaurus stellaris) with 3 breeding pairs in the Maten, and the little bittern (Ixobrychus minutus). Socially interesting was the involvement in biotope management of homeless people who are given shelter by a charity home near the Turnhouts Vennengebied. For future recurring management of the Turnhouts Vennengebied, at project end the beneficiary was planning to set up an employment scheme for socially disadvantaged people.