Réserve naturelle régionale du pré des Nonnettes: Geographic Atlas of a Northern French Nature Reserve

The landscape of the pré des Nonnettes has been shaped by human activity for centuries. The meadow is part of the Marais du Vivier, a low-lying wetland area whose ponds historically served as fish ponds, or viviers, for the nearby Abbey of Marchiennes. This monastic management established the open, periodically mown character of the site long before any formal conservation framework existed.

By the late twentieth century, regional scientists had come to view the pré des Nonnettes as a rare and threatened habitat. Its combination of botanical interest, breeding bird populations, and invertebrate fauna led to its inclusion in numerous regional scientific inventories. In recognition of these values, the commune classified the site as a réserve naturelle volontaire on 25 September 1990, giving it a first formal layer of protection.

The site's current status dates from 29 April 2008, when the Conseil régional du Nord-Pas-de-Calais formally designated it as a réserve naturelle régionale. The classification was granted for an initial period of twenty years and placed the reserve under the management of the Parc naturel régional Scarpe-Escaut, integrating the site more fully into the regional protected area network of the Scarpe valley.

The reserve occupies a low-lying position within the broader Marais du Vivier, an alluvial valley formed by the lower Scarpe river. The terrain is flat and waterlogged, shaped by centuries of pond management and meadow use rather than dramatic topography. The openness of the surrounding wetland gives the site a quiet, expansive character in a region otherwise dominated by agriculture and small towns.

Within the Marais du Vivier, the pré des Nonnettes represents a particularly open and traditional landscape element. The reserve is essentially a piece of wet hay meadow embedded in a wider wetland mosaic that includes ponds, marshy fringes, riparian woodland, and poplar plantations. This combination of low-intensity open ground and adjacent wetter, more vegetated habitats creates clear landscape contrasts at a very local scale, even though the elevation changes are minor.

The site is one of the last examples of a traditional fauche, or hay meadow, in this part of the Scarpe valley. Most of the historically comparable meadows have either been drained, ploughed, or converted to other uses. The persistence of an open, regularly mown sward here is the key visual and ecological signature of the reserve, and it strongly influences what visitors experience when walking the site's interpretive trail.

Ecologically, the pré des Nonnettes belongs to the alluvial wetland systems of the lower Scarpe. Although the reserve itself is small, it sits within a much larger wetland complex of roughly 400 hectares of varied biotopes, a scale that gives local ecological processes more space to operate than the protected perimeter alone would suggest.

The reserve's vegetation reflects a long history of traditional mowing on wet, nutrient-rich alluvial soil. Open hay meadow dominates the core of the site, while the edges grade into reed- and sedge-dominated marsh, pond margins, and patches of wet woodland and poplar plantation. The mix of open and more vegetated habitats produces a structured mosaic that supports both meadow-dependent species and those tied to taller, wetter vegetation.

Particular botanical interest comes from species such as Achillée sternutatoire and Pigamon jaune, which are considered characteristic of the site's traditional meadow character. The maintenance of an open sward through annual mowing is central to preserving these plant communities, which would otherwise be shaded out by scrub or replaced by more intensive grassland.

The animal life of the reserve is shaped by the interplay of open wet meadow, marsh, and pond habitats. Birds are the most visible component of the fauna and include a suite of species associated with marshland and damp meadows. Among the breeding and visiting birds documented on the site are the Gorgebleue à miroir, Rousserolle effarvatte, Locustelle tachetée, Bruant des roseaux, Bruant jaune, and the Busard des roseaux, a raptor closely tied to reedbed and marsh environments.

The invertebrates of the site are also notable. The reserve hosts 25 recorded species of dragonflies, a remarkably high count for such a small area and one that reflects the diversity of still-water habitats within and around the meadow. Seven species of orthopterans have also been recorded, completing the picture of a meadow that supports a broad grassland and marsh invertebrate community.

Together, the bird and invertebrate richness gives the pré des Nonnettes an ecological profile that punches well above its weight by area, and underlines why the site has been included in numerous regional scientific inventories over the decades.

The pré des Nonnettes is significant from a conservation perspective because it preserves a habitat type, a wet hay meadow, that has largely disappeared from the lower Scarpe valley. Its designation as a régional nature reserve reflects both the rarity of the habitat mosaic it contains and the unusually high species density recorded within its modest surface area.

The reserve forms part of a broader cluster of wetland protections in the Scarpe valley, working alongside sites such as the RNR de la tourbière de Vred and the RNN de la tourbière alcaline de Marchiennes. Together, these reserves protect complementary elements of the region's peatland and marsh heritage, and the pré des Nonnettes contributes the traditionally managed open meadow component of this network.

Management is led by the Parc naturel régional Scarpe-Escaut in partnership with local naturalist associations, hunting organizations, and scientific institutions. Active stewardship focuses on maintaining the open meadow structure through traditional mowing, conserving the wetland mosaic, and sustaining favorable conditions for the site's characteristic plant, dragonfly, and breeding bird communities.

The reserve carries a strong, if understated, cultural dimension rooted in the medieval landscape of the Scarpe valley. The wet meadow it protects was historically part of the viviers, or fish ponds, operated by the Abbey of Marchiennes, and the open character of the site is a direct legacy of that monastic land management.

This continuity between centuries-old land use and present-day conservation gives the pré des Nonnettes a recognizable identity within its region. The maintenance of hay-cutting practices, in cooperation with local stakeholders including hunting societies, embeds the reserve in the rural rhythms of Marchiennes and the surrounding communes, rather than separating it as a purely natural enclave.

The reserve's strongest qualities are its combination of small size and concentrated biodiversity. Within roughly 17 hectares, the site preserves a traditional wet hay meadow, a rich dragonfly assemblage of 25 species, a documented orthopteran community of 7 species, and a breeding bird list that includes marsh specialists such as the Busard des roseaux and the Gorgebleue à miroir.

Its location within the Marais du Vivier and proximity to neighboring peatland and marsh reserves also enhance its value, allowing the pré des Nonnettes to function as the open meadow component of a larger wetland conservation network in the lower Scarpe valley.

The reserve is designed around the seasonal cycle of a traditional wet hay meadow. Late spring and early summer are typically the most rewarding periods for the breeding birds of the marsh and meadow, while the dragonfly community is most active during warm, settled weather from late spring through summer. Visitors interested in the meadow's botanical interest, including Pigamon jaune, will generally find the most expressive displays of meadow vegetation in late spring and early summer, when the sward is at its richest before the annual cut.

The site's interpretive Circuit des Oiseaux trail offers a structured way to experience these seasonal variations, and visiting on a calm day tends to bring out the best of the site's bird and dragonfly activity.