Wellier Schleife/Staustufe Landesbergen Nature Reserve and Protected Weser River Valley Landscapes

The landscape protected in Wellier Schleife/Staustufe Landesbergen was substantially shaped in the late 1950s and early 1960s, when the Staustufe Landesbergen was constructed along the Weser in 1959 and 1960. This infrastructure project transformed an existing meander or side channel into the Wellier Schleife, an oxbow arm disconnected from the main river above the weir and only loosely reconnected below it through a sill.

More than three decades later, on 11 April 1996, the area was formally placed under nature conservation protection as the Naturschutzgebiet Wellier Schleife/Staustufe Landesbergen, designated with the code NSG HA 177. The reserve was recognised as ecologically valuable both for its newly formed oxbow habitats and for its position within the wider Weser floodplain. It was also integrated into larger European conservation frameworks, primarily as part of the EU Bird Protection Area "Wesertalaue bei Landesbergen" and partly within the Habitats Directive site for pond bat waters near Nienburg.

Since its designation, the reserve has been cared for under the oversight of the Landkreis Nienburg/Weser as the responsible lower nature conservation authority, with the Nienburg district association of the Naturschutzbund Deutschland (NABU) contributing to its on-the-ground stewardship.

The landscape of Wellier Schleife/Staustufe Landesbergen is defined by the interplay between a regulated river and the quieter waters left behind by that regulation. The central feature is the Wellier Schleife, the oxbow arm of the Weser that was created when the Staustufe Landesbergen was built; above the weir, this old channel sits apart from the Weser as a semi-isolated water body, while below the weir a shallow sill maintains a partial connection.

Around the Schleife, low-lying riverbanks and the broader floodplain of the Middle Weser shape the terrain, with elevation in the reserve ranging from roughly 25 to 30 meters above sea level. Much of the land between the oxbow and the present Weser channel is flat agricultural country, today mostly used for arable farming. Two former gravel pits, now open water bodies linked to the Schleife, introduce additional shoreline and pit-lake character into the area.

The reserve also incorporates a portion of the island lying between the lock and weir of the Staustufe Landesbergen, sitting within the engineered infrastructure of the waterway. Adjoining the gravel pits are patches of grassland that soften the boundary between open water, former extraction sites, and the cultivated floodplain, creating a mosaic of water, wetland edge, meadow, and farmland typical of the Middle Weser valley.

The reserve's ecological identity revolves around the Wellier Schleife and its associated shoreline and floodplain habitats. The oxbow arm and its banks form the core near-natural ecosystem that protection efforts focus on, combining slow-moving or still freshwater with fringing wetland vegetation characteristic of the Middle Weser.

The mosaic extends beyond the water itself. Former gravel pits, now hydraulically connected to the Schleife, contribute additional standing-water and shore habitats, while adjacent grassland patches provide open terrestrial habitat that complements the wetter zones. The wider floodplain, although largely under arable cultivation, retains the spatial structure of a typical Weser valley landscape, with cultivated land, meadows, standing water, and riparian features in close proximity.

At a broader scale, the area is recognised as part of the EU Birds Directive site "Wesertalaue bei Landesbergen", placing the nature reserve within a larger network of habitats important for birds of the Weser floodplain. A smaller portion of the protected area also falls within the Habitats Directive area "Teichfledermaus-Gewässer im Raum Nienburg", highlighting the importance of its water bodies for pond bat populations alongside their broader ecological role.

The Wellier Schleife/Staustufe Landesbergen reserve is most strongly associated with birds of the Weser floodplain, as the site forms a substantial part of the EU Bird Protection Area "Wesertalaue bei Landesbergen". The combination of open water in the oxbow and former gravel pits, fringing shoreline vegetation, adjacent grassland, and the broader cultivated floodplain provides a range of habitats used by waterway and farmland bird species typical of the Middle Weser.

Alongside its bird significance, part of the reserve overlaps with the Habitats Directive site "Teichfledermaus-Gewässer im Raum Nienburg", meaning that the connected water bodies of the Schleife and the gravel pits also contribute to habitat for pond bats in the Nienburg area. The mix of open water, dead-wood and shoreline edges within and around the former gravel pits likely supports bat foraging and commuting, as well as a wider community of wetland-associated invertebrates and other fauna typical of similar Middle Weser sites.

The reserve's central conservation goal is the preservation and development of the near-natural ecosystem of the Wellier Schleife and its shores, anchoring habitat protection for what is essentially a human-influenced but ecologically valuable Weser oxbow. By formally protecting the Schleife, its banks, the land between the old arm and the current river, and part of the Staustufe island, the designation safeguards a coherent floodplain unit rather than an isolated patch.

Recognition at the European level further strengthens the site's conservation profile. The bulk of the reserve is part of the EU Birds Directive protection area "Wesertalaue bei Landesbergen", anchoring it in the network of important bird areas along the Weser. A smaller portion lies within the Habitats Directive area "Teichfledermaus-Gewässer im Raum Nienburg", giving the connected water bodies an explicit role in bat conservation.

On the ground, protection has been in force since 11 April 1996 under the Natura 2000 framework's domestic implementation, and stewardship is shared between the Landkreis Nienburg/Weser as the responsible lower nature conservation authority and the Nienburg district association of NABU, linking formal oversight with active local conservation engagement.

The reserve protects a human-engineered yet ecologically valuable oxbow of the Weser, the Wellier Schleife, created by the 1959/1960 construction of the Staustufe Landesbergen and subsequently brought under formal nature protection in 1996. Its 278 hectares combine still and slow-moving water, shoreline habitats, former gravel pits, grassland, and arable floodplain within a single, coherent Middle Weser landscape.

Its integration into the EU Bird Protection Area "Wesertalaue bei Landesbergen" and partial overlap with the Habitats Directive site for pond bat waters near Nienburg place it firmly within the wider Lower Saxon conservation network, while the unusual mix of working farmland, gravel-pit lakes, and an oxbow arm gives the site a distinctive cultural-ecological character shaped by both river engineering and active land use.