natur&ëmwelt;
Luxembourg has what is known as a Temperate Climate in which winters are generally mild and summers comparatively cool, with rainfall that can be high; its flora and fauna have thrived in and adapted to this climate over the centuries and millennia, with ongoing challenges due to pollution and recent climate change, as well as the introduction of non-native species, resulting in disruptions to the norm.
Nevertheless, with various initiatives and organisations helping the ecosystem and habitat, including sustainability and re-wilding, there is a lot happening in nature across the Grand Duchy.
Chronicle.lu has teamed up with natur&ëmwelt (the non-profit organisation (naturemwelt), the foundation (Hëllef fir d'Natur) and the Wildlife Care Centre (Flegeestatioun)) for a series of articles on Luxembourg's fauna in which we look at various mammals, birds, insects, amphibians and aquatic animals, as well as touching on vanishing species returning to Luxembourg, focussing on their lifestyle and habitat, including when and where to observe them.
No. 28 in this series focuses on Conzefenn.
The Conzefenn site, located at the northern tip of the Grand Duchy, is a vital oasis spanning 13.92 hectares managed by the foundation. It presents a rich mosaic of wetlands along the Fennbaach and Kailsbaach streams, which feed the Weiswampach artificial lakes. This "-fenn" landscape (marsh or peat bog) underscores the essential role these muddy terrains play in water retention and biodiversity support.
From Ecological Battlegrounds to Sanctuaries
Conzefenn is primarily renowned for its rare remnants of acid grassland habitats, featuring Nardus stricta and, most notably, the Mountain Arnica (Arnica montana). These delicate ecosystems were threatened by eutrophication stemming from excessive agricultural runoff. Through the LIFE-Nature Arnikawiesen project, direct action was taken: for instance, by restoring alluvial bottoms following the removal of inappropriate spruce trees, this has enabled the Arnica population to thrive once again, demonstrating the impact of scientific intervention.
Nature's Service: The Hydrological Role of Tree and Canopy
Every tree acts as a universe, beginning with its crucial role in the water cycle. The forest soil functions as a natural sponge, capable of retaining about twice as much water as agricultural soil; this capacity effectively prevents floods and ensures the summer supply to groundwater tables. The absorbed water then travels up the trunk to the canopy. The canopy utilises this water for biomass production but also evaporates a significant portion, especially during heatwaves, thereby acting as a natural air conditioner that creates a cooler, moister microclimate.
Exceptional Biodiversity: Flora and Fauna as Success Stories
The success of the restoration is evident in the return of emblematic species, including the actively protected Silver-washed Fritillary (Boloria selene), whose caterpillars exclusively rely on local violet species for sustenance. Furthermore, the site harbours the only known Luxembourg population of the English Gorse (Genista anglica), a small, spiny shrub. The site's remarkable biological richness was also confirmed by the late bryologist Jean Werner, who documented 84 moss species, including ten different types of Sphagnum, the peat-building mosses.
Visitor Information: Experiencing Conzefenn
To fully appreciate this sensitive natural area, specific precautions are advised. While general access is permitted, visitors must remain on the marked trails to avoid disturbing the fragile habitats, particularly the delicate grasslands and peat bog areas. The best time to observe the Mountain Arnica in bloom is typically from late spring through early summer. As the area is inherently wet, always wear waterproof walking boots. For an in-depth experience, the Hëllef fir d’Natur Foundation sometimes organises guided tours focusing on the restoration projects and specific biodiversity; check the foundation’s schedule for upcoming dates.
