PROJECT DESCRIPTION
BACKGROUND
Hundreds of years ago the landscape in what is now the German-Dutch border area looked very different. Sweeping expanses of 'useless' mire and fen rimmed the southern edges of the north German plains, a trap for the unwary, such as the Roman soldiers enticed into these wastes by their Teuton opponents. Centuries later doom would befall the habitats and species of this peculiar landscape when the descendants of these ancient tribes sought to civilise their wilderness through intense peat digging and massive drainage. Remnants of these once extensive mires still occur in the Netherlands and in the Borken district (Nordrhein-Westfalen). On the German side, the nature reserves Amtsvenn/Hündfelder Moor and Zwillbrocker Venn/Ellwicker Feld together constitute the last reasonably-sized fen and mire complex of Nordrhein-Westfalen. In spite of massive human influence, their raised bog relicts still consist of thick peat strata in places. The heaths and bogs are a refuge for many ground-nesting birds, which can no longer adjust to the very intensely used farmland around. They are also staging points along European flyways. Species like crested newt, corncrake, bluethroat and nightjar as well as cotton grass and bogmosses find shelter here, but ruff and whinchat have disappeared for the time being as a result of the impact from human land use.
OBJECTIVES
The project builds on previous conservation work undertaken here and on the lengthy experience acquired by the Zwillbrock biological station. First of all, the dessication process of the peat bogs needs to be stopped. Extensive renaturalisation measures to preserve and restore raised bog relicts with their characteristic range of species will be carried out. Water levels will be raised and their fluctuations dampened so that a true bog hydrology would be restored, which should also have positive effects on nutrient cycles. The removal of trees and the interconnection of wetlands by this LIFE (Nature) project is expected to create large coherent blocks of habitat, improving the conditions for species once occurring here. Many waders such as common snipe, lapwing and black-tailed godwit should in future also feel at home again.
RESULTS
The LIFE project addressed two distinct ecosystems within the SPA Moore und Heiden des westlichen Münsterlandes: 1. degraded bogs and associated habitats (heaths), where desiccation and succession were the leading threats. Planned actions were removal of birch succession followed by rehumidification. Sites: Amtsvenn, Hündfelder Moor, Zwillbrock Venn Results: - Topographic survey of Amtsvenn/Hündfelder Moor, showing exact location of the dams (over 500). No detailed topographic maps existed of the drainage ditches, contours etc before the project began. The survey discovered that topography was more uneven than expected so that about 220 ha of the Moor was technically feasible for rehumidification – the rest was too high relative to the average level of the ground. - 42.8 ha land purchased to add to land already in public ownership. For some sections, owners did not want to sell but gave their permission for rehumidification. Removal of 77.7 ha of birches as a necessary preliminary measure and to reduce water loss through evapotranspiration. - 11.7 ha of birch left standing to enhance the habitat restoration work by providing suitable habitat for Caprimulgus europaeus, leaving nuclei which can develop into bog woodland (habitat 91D0) and creating buffer zones along the margins of the rehumidification area. - Follow-up work was done to counteract shoots and suckers from the stumps of the birches cut down: part by hand (inaccessible areas) but most by intensive grazing by sheep. For this grazing, one area of 8 ha had to be fenced in and the levels of several tracks into the bog had to be raised and culverts installed to keep abreast of rising water levels. - Technically, the strategy used to rehumidify the degraded bogs was to close individual drainage ditches, as prior experience had shown that mire regeneration (Sphagnum growth) begins in such closed ditches with higher water levels and expands from there. Instead of oakwood, which eventually rots, polyethylene was used for the dams. With a motor saw, slits were cut in the banks of the ditch and then polyethylene plates were pressed down by an excavator, which scooped up peat from the ditch to cover the top of the plate. Besides these small dams, of which 545 were built, long peat dykes were laid down to stop diffuse outflow from areas where there were no distinct ditches (total length of these dykes 870 metres). Together these measures rehumidified an area of 216 hectares in one coherent block. Because of the uneven topography within the degraded bog, rehumidification had to be done in small-scale compartments, and was not homogeneous, but a patchwork of higher/drier and lower/wetter areas. I.e. a diversity in ecotones was achieved. 2. wet grasslands, important habitats for meadow-breeding birds such as Limosa limosa, Gallinago gallinago, Numenius arquata, Motacilla flava, Saxicola rubetra etc, but much reduced in surface area and surrounded by intensive farmland. High land rents because of the intensive farming of housed livestock, make agri-environmental measures financially unattractive for farmers. Planned action: purchase of arable land, conversion to wet grassland and lease-back to farmers with management prescriptions. Sites: Ellewicker Feld, Ammeloer Venn Results: - and purchase was done via a rural land consolidation procedure and 37.5 ha was acquired, closing gaps between land already owned by public authorities or foundations and adding sections around the edges of existing core zones. The coherent blocks thus created increase the total area of the wet grassland by 20-25%. After harvesting maize and other crops from the land acquired, it was sown with grass seed supplied by the beneficiary. - Rehumidification works: on 7.45 ha, drains were destroyed, on 7.22 ha, drains were closed and on the rest existing drains were equipped with controllable outlets or adjustable culverts (9 in total). This will allow water level to be kept high in spring and early summer (to improve the breeding success of meadow birds), and to be lowered later on during the season, when the meadows need to be accessed with heavy machinery for the mowing of the grass. - By project end, 7 farmers interested in using this new wet grassland had already been found, for 30 ha together. Most of the work in the field was done by local firms, using labourers who knew the mires well. The beneficiary considers that consequently their relationship to the work was more personal and they could consider future improvements to the site’s flora and fauna as something they had contributed to, acting as multipliers in favour of conservation among the local population. In addition to the site-based actions, the project produced the following horizontal outputs: - A 2-day seminar on bog restoration was held on April 19th and 20th 2002. Ca. 50 people attended the workshop, mostly from Germany and the Netherlands, including LIFE-Nature beneficiaries from projects dealing with peat-bog restoration. The seminar led to a 172 page book for professionals called ‘Naturschutz in Moor und Heide’. - A project folder about the restoration actions on the Amtsvenn-Hundfelder Moor, a booklet about birds occurring in the SPA and a project web-site were produced. - An observation tower and information panels were erected, complementing other visitor infrastructure financed with INTERREG support. - A LIFE exhibition presenting the results of the project was installed at the Zwillbrock visitor centre. It includes an electronic touch screen with a choice of pathways. Choosing the ‘LIFE’ option, for instance, yields a series of screens which explain LIFE in general, the project, the continuation of the project after LIFE. - To allow monitoring of the water level, 30 water gauges were installed and a special hydrological examination was done in part of the Hundfelder Moor, which proved that the measures were indeed stabilising water levels. - Habitat mapping to give baseline data for the development of the 9 habitat types listed on Annex I of the Habitats Directive which occur in the project area and are affected by the project actions. During the project, a plan to extract salt from underneath the project area was assessed for its impact on the Natura 2000 area and its consequences for the work cofiannced by LIFE. The LIFE project created two full-time temporary jobs: a project coordinator, and a second shepherd to manage the sheep used for the intensive grazing of birch shoots, both hired for the entire duration of the project.