Sengeløse Mose

What secrets lie beneath the surface of Sengeløse Mose? This bog, stretching almost two kilometers, holds a history as rich and layered as the peat that once filled its depths. Sengeløse Mose, nestled amid fields and encroaching development near Copenhagen, is a hidden gem. It’s part of a string of bogs known as the Vestegnens mosses or “Sengeløse ring”. Sengeløse Mose, once a source of peat during and after wartime, is now a vital habitat and corridor for wildlife. Imagine the slow transformation of this landscape. At the end of the Ice Age, Sengeløse Mose was a lake. Over millennia, it gradually filled, evolving into the low bog we see today. The bog’s unique ecosystem is due to calcium-rich mussel shells in its soil. These shells support specialized plant communities like chalk meadows and fens. Sengeløse Mose, unfortunately, shows signs of human impact. Houses stand within its boundaries. Some areas are entirely cultivated. Yet, pockets of valuable chalk-influenced habitats remain, with meadows, grasslands, and natural forest-like stands. These areas, particularly one north of Sengeløse Å known as “Kalkoverdrevet” (the chalk meadow), host rare and endangered plants. Think of the delicate eng-ensian, a red-listed species, or the unique hybrid creeping x rosemary willow. Other notable plants include the lance-leaved helleborine, marsh helleborine, heartgrass, willow-leaved elecampane, dwarf thistle, tufted hair-grass, and devil’s-bit scabious. Once, the elegant rank starwort graced this area, but it’s feared to be lost. In the western part of the bog, rich fens flourish with species like the frog orchid, curved sedge, marsh valerian, and black willow. However, these resilient plants face challenges like ammonia pollution from agriculture, overgrowth, and changes in groundwater levels. Sengeløse Mose has seen significant changes over time. Once a more open area grazed by livestock and harvested for hay, its water level has lowered due to peat digging and water extraction. Kalkoverdrevet, a dry meadow over chalky soil, tells a poignant story. During World War II, the area, belonging to Katrinebjerg Estate, was completely stripped of its peat, exposing the underlying marl layers. Interestingly, there are credible accounts of the rust-leaved knautia, a plant known from the nearby Vasby Mose, also growing here after the war. Sengeløse Mose derives its name from the large village of Sengeløse, once an independent municipality. The name means “the dwellers by the lake’s meadow”. Sadly, the bog is now under threat from encroachment. Grazing areas have diminished, and only a quarter of the natural area is currently grazed. Despite the challenges, there’s hope for Sengeløse Mose. Efforts are underway to create accessible paths and expand conservation efforts. So, as you stand at the edge of Sengeløse Mose, remember the layers of history beneath your feet. From Ice Age lake to vital habitat, from wartime peat source to a refuge for endangered plants, this quiet bog whispers stories of resilience and change.