Between plain and mountain, these three sites with rare and fragile biodiversity have become a nature reserve

In Bas-Rhin, between Obernai and Rosenwiller, a new nature reserve was created on June 21. The Nature Reserve of the dry hills of Bischenberg, Immerschenberg and Holiesel will ensure the long-term protection of the rare and fragile environments that compose it.

In the Bischenberg forest, located in the town of Bischoffsheim (Bas-Rhin), no trees have been felled since 2014. A decision by local elected officials to preserve this 54 hectare forest, so useful to their village. “We don’t want there to be any interventions in this forest given the services it provides to the population”declares Christian Braun, deputy mayor of Bischoffsheim. “In cases of extreme heat, as we have experienced in recent years, […] it has an air conditioning effect which is very appreciated.”

Above all, this forest is unique in its kind. It is made up of downy oaks, a southern species, which survives thanks to the limestone soil and the almost Mediterranean climate of the Vosges foothills. Transforming the forest into a nature reserve was the logical continuation of the municipality's preservation efforts.

Today, the three hills reserve, created in June 2024, is spread over three municipalities: Bischoffsheim, Obernai and Rosenwiller, for a total area of ​​97 hectares. Thirty-five years after the creation of the Erstein forest nature reserve, the very first in Alsace, this reserve becomes the 15th in the region.

Like the Bischenberg forest, each site has rare natural spaces in Alsace.

The dry calcareous lawns (which grow on calcareous soil) of Immerschenberg are another example. “These are environments in which we will find biodiversity which is specific [au piémont vosgien] and which is particularly rich, with a large number of species now threatened. As well among plants as among insects or fauna”explains Luc Dietrich, mission manager of regional nature reserves.

If the Vosges foothills are conducive to the development of this type of natural space, it is also very favorable to the cultivation of vines. This is why it is rare today to find this type of environment in Alsace, and it is essential to protect it.

Concretely, the nature reserve status assigned to these three hills will protect them in the long term against urbanization and agricultural exploitation. As Muriel Diss-Schott from the Alsace Conservatory of Natural Spaces recalls, “These sites have been protected for a while thanks to local policies. […] But the nature reserve status really gives them a protective status, with regulation and inherent police power.”

Thus, in addition to the bans on building and carrying out work, the status of a nature reserve also implies restrictions for walkers. Stay on the trails, do not pick up anything, keep dogs on a leash and respect the tranquility of the area. Breaches may be fined.