Sentier de découverte de la réserve de Chalmessin

Short tour of the reserve: 2.1 km
Grand tour of the reserve: 3 km

Created in 1993, the Chalmessin nature reserve is a natural treasure in the middle of the woods. Its 124 hectares, managed by the Conservatoire d'Espaces Naturels de Champagne-Ardenne, are home to one of the most remarkable tufa marshes on the Langres plateau. Since the last ice age, 8,000 years ago, very specific conditions have enabled this narrow valley to preserve a typically mountain fauna and flora. The discovery trail is open all year round, or guided tours are available on request.
The 124-hectare Chalmessin Nature Reserve is home to one of the most remarkable tufa marshes on the Langres Plateau. Completely enclosed within the forest, it is located at the bottom of a valley known as Combe Forquot or Vallée des Goulottes, which forms the upper Tille valley.
Since the last ice age, 8,000 years ago, very specific conditions, and in particular a cold climate, have enabled this narrow valley to preserve a typically mountain flora and fauna. The eminent Haut-Marne botanist Pierre Fournier wrote 70 years ago that it froze in the coombs of the Langres plateau at least once a month, even in July and August! The Langres plateau is the region of France where this type of marsh is most common. This small natural region has all the elements needed to create these marshes: a limestone subsoil, a cold climate and a dense network of waterways.
Of the hundred or so tufa marshes on the Langres plateau, the Chalmessin marsh is one of the best preserved. Most of these marshes were drained in the 1950s and attempts were made to afforest them.
The Chalmessin Nature Reserve is part of a network of around thirty protected areas on the Langres plateau, including 25 tufa marshes of the same type (as well as several marshes in the nearby Côte d'Or). As such, it plays a fundamental role in the conservation of the genetic heritage of species that are often rare or relict, and which are adapted to this type of environment.