Naturpark Holsteinische Schweiz: Mapping the Protected Glacial Landscapes of Schleswig-Holstein

The park is especially known for its remarkable density of lakes, including the Großer Plöner See, which is the largest, deepest, and most island-rich lake in Schleswig-Holstein and is internationally important for waterbirds. Several of the state's most nutrient-poor lakes greater than 50 hectares, including the Suhrer See, Schöhsee, Stocksee, Schluensee, and Selenter See, lie within the park. It is also recognized for its characteristic combination of glacial landforms, traditional Knick hedgerows, deciduous beech forests, and restored peatlands such as the Tarbeker Moor. The park's distinctive mix of lakes, hills, and mosaic farmland makes it a defining landscape of the broader Holsteinische Schweiz holiday region.

The Naturpark Holsteinische Schweiz was established through the founding of the supporting association Verein Naturpark Holsteinische Schweiz in 1986. Its members are the districts, municipalities, and cities within the park area, making it a cooperatively run cross-district protected landscape rather than a single-site reserve.

Some of the most significant conservation chapters within the park relate to its peatlands. The Tarbeker Moor, until the twentieth century part of a much larger raised bog formed in a glacial meltwater channel, was drained and partially cultivated before industrial peat extraction began in the 1950s and continued on a large scale until the late 1980s. After extraction ended, the area was deliberately allowed to develop back into a growing, peat-producing moor for nature conservation rather than being converted back to farmland. The most important step was raising the water table again, a measure that has since allowed many bog-specific and fen-specific species to return, including 57 documented breeding bird species.

In the Heidmoor near Seedorf, rewetting measures and the establishment of large-scale, low-intensity cattle grazing have rebuilt open wet habitat for meadow-breeding birds. Across the park, the association has also worked to maintain the traditional Knick hedgerow network, encourage semi-open grazing landscapes using hardy old cattle and horse breeds, and set aside areas of natural forest, such as the Dodauer Forst and the area around the Ukleisee, where woodland communities can develop without human intervention.

The landscape of Naturpark Holsteinische Schweiz is a textbook example of a young moraine region. The Weichselian glaciation left behind a patchwork of low hills and broad meltwater channels, in some of which rivers and streams still flow today. The hills and the lake basins together create the characteristic alternation of elevated ridges and water-filled depressions that defines the Holsteinische Schweiz region as a whole.

Water is the most visible element of the scenery. The park encompasses roughly 200 lakes and a dense network of flowing waters. The 68-kilometer Schwentine rises in the Bungsberg area, threads its way through numerous lakes in deeply incised stream gorges, and eventually reaches the Kieler Förde. The largest single body of water is the Großer Plöner See, with nearly 3,000 hectares, which is also the deepest and most island-rich lake in Schleswig-Holstein. Other notable lakes include the Selenter See, the Suhrer See, the Schöhsee, the Stocksee, and the Schluensee, the last five of which are also the state's most nutrient-poor lakes in the size class above 50 hectares.

Land use has shaped the rest of the scenery. Around two-thirds of the park is farmland, mostly cropland, while the remaining open countryside is a checkerboard of meadows, Knick hedgerows, and small woodlands. Forest covers about 16 percent of the area, distributed across the Bungsberg area, the Dodauer Forst, and other wooded ridges that break up the agricultural plain. The highest point in the park region, the Bungsberg, anchors the eastern edge of the landscape and offers some of the most sweeping views across the lake country.

Ecologically, the park is defined by a closely woven mosaic of aquatic, wetland, woodland, and cultural habitats. Its roughly 200 lakes range from large, biologically productive waters like the Großer Plöner See to small, nutrient-poor forest and kettle lakes, providing a remarkable gradient of freshwater conditions within a relatively small area. Glacial meltwater channels host streams and bogs, while peatlands such as the Tarbeker Moor and the Heidmoor carry the ecological imprint of the last ice age.

The forests of the park cover roughly 16 percent of the area, an unusually high figure for the region, and are dominated by European beech. Oak, ash, sycamore and Norway maple, small-leaved lime, hornbeam, and birch occur in smaller proportions, and overall the share of broadleaf forest is significantly higher than that of coniferous forest. Spring-flowering woodland species such as wood anemone, hollow corydalis, and cowslip appear in many stands. On periodically flooded sites along the larger lakes, alder-dominated swamp forests have developed, including notable stands near the Prinzeninsel and around the small islands in the Großer Plöner See. Designated natural forest areas, where woodland can develop without human intervention, exist in the Dodauer Forst and around the Ukleisee.

Outside the forests, the park's traditional cultural landscape supports its own rich ecology. Knicks, the regionally characteristic hedgerows, host an estimated 7,000 animal species, mostly insects, which in turn feed a wide community of songbirds, small mammals, and the hazel dormouse. Semi-open grazing landscapes, in which hardy traditional cattle and horse breeds graze at low density, recreate a savanna-like mix of pasture, shrubs, and scattered trees in several parts of the park, including areas around the Großer Plöner See, the Barkauer See, the Middelburger Seen, and the Kasseedorfer Teiche nature reserve. Altogether, the interplay of water, woodland, bog, and traditionally managed farmland gives the park an unusually varied ecological profile for a region so heavily shaped by agriculture.

The park's wildlife profile is dominated by its importance for birds. The Großer Plöner See, with its many islands, is a habitat of international significance for breeding, roosting, and migrating birds. Greylag geese breed on the islands, and white-tailed eagles maintain nesting territories there. The five most nutrient-poor larger lakes host particularly sensitive waterbird communities. In the rewetted peatlands, meadow and bog-breeding species have returned in considerable numbers; the Heidmoor supports skylark, quail, whinchat, meadow pipit, curlew, and yellow wagtail, while the Tarbeker Moor has recorded 57 breeding bird species, including lapwing, garganey, red-necked grebe, little ringed plover, wood lark, and crane.

The Knick hedgerow network supports an additional layer of birdlife, including yellowhammer, lesser whitethroat, Eurasian blackcap, song thrush, European robin, chiffchaff, and dunnock, along with insectivorous mammals such as hedgehogs, common and pygmy shrews, and the hazel dormouse. Old overstorey trees in mature Knicks, especially large oaks, are ecological hotspots in their own right, with more than 400 animal species recorded on individual trees.

Larger and more charismatic species also feature prominently in the park's wildlife identity. The association has highlighted a wide range of them through its annual Naturpark-Tier des Jahres program, which since 2003 has focused public attention on species such as the white-tailed eagle, crane, Eurasian eagle-owl, red kite, European otter, kingfisher, grass snake, natterjack toad, and tree frog, as well as less conspicuous inhabitants such as the banded demoiselle, water shrew, and common shelduck. This long list underlines the variety of animal life that the region's forests, lakes, moors, hedgerows, and grasslands can support.

The conservation significance of Naturpark Holsteinische Schweiz lies largely in maintaining a working cultural landscape that still contains the ecological traces of the last ice age. The park is not a single strict nature reserve but a large, multi-use landscape in which the protection of lakes, peatlands, hedgerows, and forests is balanced with agriculture, forestry, and local community life. At this scale, the park plays a crucial role in safeguarding the connectivity between habitats across three districts.

Two peatland restoration efforts stand out. The Tarbeker Moor, once heavily exploited for industrial peat extraction, has been deliberately converted back to a growing bog through rewetting, and now functions as a refuge for high-bog and low-bog species as well as for waterbirds. The Heidmoor has been restored through rewetting paired with extensive cattle grazing, creating wet meadow habitat for ground-nesting birds. Together, these projects demonstrate how former extraction and drainage sites can be brought back into ecological use.

Beyond peatlands, the park supports conservation in several other ways. The traditional Knick hedgerows are protected and maintained as wildlife corridors and refuges for thousands of species. Semi-open grazing landscapes with hardy traditional breeds are encouraged as a tool for maintaining biodiverse, structurally rich pasture. Natural forest reserves, such as the Dodauer Forst and the area around the Ukleisee, are set aside to allow woodland communities to evolve without human interference. The annual Naturpark-Tier des Jahres campaign links public attention to species-level conservation themes, ranging from keystone raptors such as the white-tailed eagle and red kite to amphibians, dragonflies, and bats.

The Holsteinische Schweiz, in both its broader regional sense and as a nature park, has long been a recognized holiday and recreation area in northern Germany. Its name evokes a comparison with Swiss landscapes, referring to the rolling hills and lake-dotted scenery of the young moraine. The park therefore sits at the heart of a regional identity that has historically combined small agricultural communities, market towns such as Plön and Eutin, and lake-based summer recreation.

The Knicks are perhaps the most visible expression of the region's cultural landscape. These traditional hedgerows, formed by centuries of field clearance and management, are not only ecological features but also a recognized part of Schleswig-Holstein's agricultural heritage, shaping how the land is divided and used. Their maintenance within the park is therefore both a cultural and an ecological act.

The towns of Plön and Eutin also contribute a deeper historical and cultural layer. As former residences and seats of Holstein nobility, and as centers of schooling and culture, they link the park's natural landscape to a longer story of how the region has been shaped, inhabited, and enjoyed over the centuries. The supporting association itself, with members drawn from the districts, municipalities, and cities of the park, reflects a model of conservation governance that is embedded in local civic life.

Naturpark Holsteinische Schweiz is anchored by the Großer Plöner See, the largest, deepest, and most island-rich lake in Schleswig-Holstein and a site of international importance for breeding and migrating birds. Several of the state's cleanest and most nutrient-poor larger lakes, including the Suhrer See, Schöhsee, Stocksee, Schluensee, and Selenter See, also lie within its borders.

Equally distinctive are its restored peatlands. The Tarbeker Moor, once an industrial peat-extraction site, is now a rewetted bog with 57 recorded breeding bird species, while the Heidmoor combines rewetting with extensive cattle grazing to maintain wet meadow habitat. The traditional Knick hedgerow landscape, running through roughly two-thirds of the park's agricultural land, gives the countryside its finely textured appearance and supports thousands of species.

The park is also notable for its network of protected and semi-natural habitats: natural forest reserves in the Dodauer Forst and around the Ukleisee, semi-open grazing landscapes managed with hardy traditional breeds, and the iconic Bungsberg at the eastern edge. Together, these features make the park a compact showcase of the lake, hill, and hedgerow country that defines eastern Schleswig-Holstein.

Spring is a particularly rewarding time to experience the park's deciduous forests, when wood anemones, hollow corydalis, and cowslip create a rich ground layer beneath the beech canopy. Late spring and early summer also bring active bird life to meadows, hedgerows, and lake edges, with breeding waterbirds on the larger lakes and ground-nesting species in the wet peatland areas.

Summer is the traditional season for lake-based recreation in the Holsteinische Schweiz, when boat trips on the Großer Plöner See and walks along lake-shore and stream-gorge paths are most inviting. Autumn offers quieter conditions, colorful deciduous woodland, and good opportunities for observing wetland and meadow wildlife, while winter highlights the stark glacial landforms, frozen lake fringes, and open skies over the surrounding countryside. Across all seasons, the combination of low light, water surfaces, and gently rolling terrain gives the park a calm, distinctly northern character.