Hengstberg

Hengstberg is a strict biological reserve (réserve biologique intégrale) set in the heart of the Northern Vosges, within the commune of Reipertswiller in the Bas-Rhin department, inside the Northern Vosges Regional Nature Park. Covering just under 100 hectares around a 372-metre hill, it was designated a protected area in September 2006 as part of the Ingwiller state forest. This is a place where nature has been left to write its own story, undisturbed for over two decades.

Why was a reserve created here specifically?

Hengstberg stands out among the biological reserves of the Vosges massif for its unusually high proportion of birch trees. This is no coincidence — it is a direct legacy of the Second World War. In January 1945, fierce fighting broke out in the immediate vicinity of the hill between American and German forces during the German Nordwind offensive. Phosphorus munitions destroyed and burned large stretches of forest. On the scorched ground, birch — a pioneer species that rapidly colonises exposed, nutrient-poor soil — was the first tree to take hold.

What can visitors see in the forest today?

More than twenty years of uninterrupted natural succession have turned the reserve into a living laboratory of forest regeneration. The birch woodland is gradually giving way to beech, the climate-appropriate climax species for this type of habitat in the Northern Vosges. A distinctive sight throughout the reserve is dead and dying birch trunks covered in bracket fungi, clear evidence that the shift from birch to beech forest is well under way. Few places offer such a direct, visible chronicle of a forest healing itself — from meadow, through pioneer scrub, to mature broadleaf woodland.

What protection status does the site hold?

As a réserve biologique intégrale, Hengstberg carries the highest level of protection applied within French state forests, equivalent to IUCN category Ia, reserved for strictly protected areas where natural processes unfold entirely free of human intervention. No timber is harvested here, and dead wood is left in place, providing habitat for insects, fungi and birds associated with decaying wood. The reserve also forms part of the wider Vosges du Nord–Pfälzerwald transboundary biosphere reserve, which includes core, buffer and transition zones.

Can you visit, and what should you know beforehand?

Hiking trails cross the reserve, including a popular route running from Reipertswiller directly into the Hengstberg reserve, well known among hikers exploring the Northern Vosges. Even though the trails are open to the public, the area retains strict protected status, so visitors are encouraged to stay on marked paths and leave the surrounding vegetation and deadwood undisturbed.

Frequently asked questions

Where exactly is Hengstberg located? In the commune of Reipertswiller, Bas-Rhin department, within the Ingwiller state forest, at the heart of the Northern Vosges.

Why are there so many birch trees in the reserve? They are a legacy of the destruction caused by fighting in January 1945 — the ground burned by phosphorus munitions was first colonised by birch, a pioneer species.

Since when has the area been protected? The reserve was established in September 2006.

Can the reserve be explored on foot? Yes, hiking trails lead into the area, including one starting from Reipertswiller, popular with visitors touring the Northern Vosges.