Why Réserve naturelle régionale du Ried de Sélestat, l'Ill*Wald stands out
The Ill*Wald is particularly known for being one of the largest alluvial floodplain forests in France, set within the broader Grand Ried wetland landscape of Alsace. Its combination of oak, ash, and alder woodland with a dense and constantly shifting river network gives it a striking landscape identity, shaped each year by winter flooding from the Ill and its tributaries. The reserve is also renowned for its phreatic springs, whose remarkably stable water temperature sustains a unique aquatic environment distinct from the main river. Wildlife-wise, it harbors what is considered France's largest wild population of fallow deer, alongside European beaver, a rich birdlife of 141 species, and 32 dragonfly species, making it a focal point for floodplain ecology in northeastern France.
Réserve naturelle régionale du Ried de Sélestat, l'Ill*Wald history and protected-area timeline
The territory of the present reserve, like the rest of the Grand Ried, was historically dominated by vast marshes. Only during the medieval period did permanent agricultural exploitation take hold, gradually shaping the semi-bocage landscape of meadows, canals, woodland, and hedgerows that still characterizes the area. For centuries, the floods of the Illwald and the cultivated land around Sélestat were closely intertwined: seasonal inundations formed part of the town's natural defenses, while hay and timber from meadows and forest supported the local economy.
The post-war spread of maize cultivation in the second half of the 20th century profoundly disrupted this balance, contributing to the loss of reedbeds, herb-rich pastures, and hedgerows across the Ried. At Sélestat, conservation concerns emerged in 1989 with the reconversion of former maize fields back into herb-rich grasslands. On 13 March 1995, at the initiative of the municipality and with the agreement of 93 landowners, the Réserve naturelle volontaire de l'Illwald was officially created, gathering some 2,000 hectares of land, including 1,500 hectares of continuous forest and 500 hectares of wet meadows.
In February 2013, the voluntary reserve was upgraded to the status of a regional nature reserve (Réserve naturelle régionale) for a renewable 25-year term. The reclassification followed a request from the city of Sélestat and gathered the support of more than 80 private landowners, cementing the Ill*Wald's long-term role in protecting one of France's most notable alluvial floodplain forests.
Réserve naturelle régionale du Ried de Sélestat, l'Ill*Wald landscape and geographic character
The Ill*Wald occupies a wide, flat stretch of the Alsatian Rhine graben, where the plain narrows and the Grand Ried broadens. Elevations are unusually uniform, sitting between roughly 166 and 170 meters above sea level. The reserve takes the shape of an irregular triangle covering nearly the entire southeastern half of the Sélestat commune, bordered to the northwest by the town's built-up area and crossed by a departmental road that links Sélestat to the Rhine plain.
Geologically, the area belongs to the Rhine graben, a vast tectonic trench sunk during the Eocene and filled during the Oligocene and Quaternary with marine, lacustrine, and fluvial deposits. The Illwald's substrate is dominated by Holocene alluvial sands and silts, occasionally interrupted by gravelly deposits, with no calcareous component. This soft, flood-derived material, combined with the shallow groundwater, produces the unstable, waterlogged soils that shape both forest composition and meadow patterns.
The defining visual impression of the reserve is one of alternating woodland, wet meadow, marsh, and open water. Dense alluvial forest borders an intricate web of channels and ditches, including the well-known Oberriedgraben, the Grosschluth, and the Schiffwasser. Pebble banks surface in some of the excavated channels, while reedbeds, tall-herb fens, and isolated willows along the ditches break the forest canopy. In winter, the rising Ill and rising groundwater transform much of this mosaic into a temporary shallow lake before the waters slowly recede.
Réserve naturelle régionale du Ried de Sélestat, l'Ill*Wald ecosystems, habitats, and plant life
The Ill*Wald safeguards a remarkable mosaic of more than 30 habitat types, ranging from alluvial forest and meadows to marshlands and aquatic environments. This habitat richness reflects the tight interplay between river flooding, groundwater conditions, and the legacy of long-standing human land use in the Grand Ried.
In the forest, the wettest zones are dominated by alder, with ash, oak, and elm taking over where soils are slightly drier. More than 35 species of trees and shrubs have been recorded in the Illwald, surpassing the diversity of nearby Vosges forests, though slightly below that of the Rhine-side forest on the Île de Rhinau. The shrub layer includes hazel, dogwood, hawthorn, guelder rose, blackthorn, and spindle, while the herb layer features large sedges, meadowsweet, wild garlic, and yellow false buttercup, alongside the invasive Himalayan balsam. The understory is also home to more than 80 species of higher fungi.
Open habitats cover a wide ecological gradient. Dry meadows, very local in the reserve, can host upright brome and orchids, while moderately moist meadows feature autumn crocus and tall oat-grass; moister ones are marked by meadow brome, Yorkshire fog, and abundant meadowsweet; the wettest meadows support meadow foxtail, tubular water-dropwort, and marsh ragwort. Reedbeds, sedge beds, and tall-herb fens add a further layer of botanical diversity, supported by rare species such as purple small-reed, marsh fern, marsh ragwort, and various protected plants. Aquatic habitats range from cold, clear phreatic streams rich in pondweed species to nutrient-laden branches of the Ill covered in duckweed and water crowfoot.
Réserve naturelle régionale du Ried de Sélestat, l'Ill*Wald wildlife and species highlights
The reserve is especially notable for two flagship mammal species. The fallow deer herd, introduced in the 19th century by the Rohan family, has become fully wild and is believed to be the most important truly wild fallow deer population in France, with around 300 individuals recorded in 2019. The European beaver is also established along the Ill's branches and the quieter watercourses, where its dam- and lodge-building leaves a visible mark on the riparian landscape.
Birdlife is particularly rich, with 141 species recorded across the reserve, including waders and wetland raptors such as the Eurasian curlew and the marsh harrier. The mosaic of reedbeds, wet meadows, and alluvial woodland provides both breeding grounds and seasonal stop-over habitat. Amphibians and reptiles are represented by 14 species, among them the yellow-bellied toad, a species of conservation interest. Dragonflies are exceptionally diverse for an inland site, with 32 recorded species, reflecting the range of water temperatures and flow conditions across the reserve's streams and stagnant water bodies.
Réserve naturelle régionale du Ried de Sélestat, l'Ill*Wald conservation status and protection priorities
The Ill*Wald plays a key role in conserving the Grand Ried floodplain, one of the most distinctive wetland landscapes of the Upper Rhine. By protecting a continuous block of alluvial forest together with associated meadows, reedbeds, marshes, and aquatic habitats, the reserve sustains functional ecological processes, including seasonal flooding, groundwater-surface water exchange, and natural river dynamics that much of the surrounding plain has lost.
Beyond habitat protection, the reserve preserves a large set of species and habitats of European and national importance. The alder-ash swamp woodland is classified as a priority habitat at the European level, while a range of protected plant species, including meadow small-reed, meadow grape-fern, and several rare graminoids and legumes, find refuge in the meadows and fens. The reserve also hosts one of France's most significant truly wild fallow deer populations, a unique conservation inheritance.
Management responsibility sits with the commune of Sélestat, working in close partnership with the regional council, neighboring municipalities, and more than 80 private landowners. Addressing the long-term impacts of historical channelization and drainage, particularly on the phreatic system, is a central conservation concern, complemented by work to control invasive species such as Himalayan balsam and to maintain the open meadow habitats that depend on traditional wet-mowing practices.
Réserve naturelle régionale du Ried de Sélestat, l'Ill*Wald cultural meaning and human context
The Ill*Wald is deeply intertwined with the history of Sélestat. For centuries, the fluctuating rhythm of the Ill shaped both the town's defenses and its economy: seasonal floods helped shield the medieval settlement, while the surrounding meadows and the Illwald provided hay and timber. The name itself reflects this cultural layering, since "wald" denotes forest and "Ill" the river in regional usage, and "ried" comes from the Old Alemannic word for reeds, underscoring the long coexistence of human communities and wetland ecosystems.
The asterisk in Ill*Wald is a deliberate symbolic choice, representing the close interactions between water, marsh, meadow, and forest, as well as the strong human imprint on the site including past drainage, channelization, and changes in agricultural practice. After the Second World War, the spread of maize cultivation transformed much of the Ried, and the reserve's creation in 1995 marked a marked shift back toward valuing traditional grasslands and the historic links between the town and its floodplain.
Top sights and standout views in Réserve naturelle régionale du Ried de Sélestat, l'Ill*Wald
The Ill*Wald's standout qualities begin with its sheer scale: among the five largest regional nature reserves in France, it protects a vast and rare continuous block of alluvial forest in the heart of Alsace. Its habitat mosaic of more than 30 distinct types, from alder-ash swamp woodland to wet meadows, reedbeds, and phreatic streams, gives it an unusually rich ecological identity.
Equally distinctive is its wildlife heritage, in particular the long-established wild fallow deer herd, a thriving beaver population, a bird checklist of 141 species, and a remarkable 32 dragonfly species. The dynamic interplay between the Ill's branches and the cold, stable phreatic springs creates a hydrological landscape that is both visually striking and scientifically important, while the reserve's accessibility from Sélestat and its interpretation trail "L'Ill aux trésors" make it a notable example of a floodplain protected area closely tied to the urban and cultural life of a neighboring town.
Best time to visit Réserve naturelle régionale du Ried de Sélestat, l'Ill*Wald
The character of the Ill*Wald shifts dramatically with the seasons, and the timing of a visit strongly influences what visitors experience. In winter and early spring, the Ill and its tributaries swell, and large portions of the Ried, including forest edges and meadows, are regularly inundated. These annual floods are essential to the floodplain's ecology but can also limit access to some paths, so visiting in this period requires flexible expectations and attention to water levels.
Late spring and early summer offer a particularly rewarding combination of conditions, with high water levels gradually receding, lush vegetation at its most expressive, meadows coming into flower, and active birdlife alongside the start of the dragonfly season. Late summer and autumn allow quieter exploration of the forest interior and the many small channels, when the rich fungal flora of the Illwald becomes more visible. Throughout the year, fog and low cloud are frequent in the Rhine graben, lending the reserve a soft and atmospheric quality, while the stable phreatic springs keep some watercourses remarkably cold even in midsummer.
