Iza Murzynowska

Les forêts primaires sont rares en Europe occidentale, en particulier en Suisse, du fait d'un long historique de pratiques agricoles et de gestion forestière. Afin de favoriser les processus naturels, des réserves forestières sans intervention humaine ont été créées. Le Parc naturel du Jorat, établi en 2021, en est un exemple. Un inventaire réalisé durant l'hiver 2021/22 a permis de
documenter l'état initial des forêts du parc. Les résultats révèlent une forêt encore fortement influencée par la gestion passée, avec une prédominance de conifères et une faible quantité de bois mort au sol par rapport à d'autres réserves suisses. A l'avenir, la forêt devrait évoluer vers un état plus naturel, avec une composition en espèces plus naturelle et des quantités plus importantes de bois mort.

Primary forests are rare in Western Europe, particularly Switzerland, due to a long history of agricultural practices and forest management. In order to promote natural processes, forest reserves without human intervention have been created. The Jorat Nature Park, established in 2021, is an example. An inventory carried out during the winter of 2021/22 made it possible to document the initial state of the park's forests. The results reveal a forest still strongly influenced by past management, with a predominance of conifers and a low quantity of dead wood on the ground compared to other Swiss reserves. In the future, the forest is expected to evolve towards a more natural state, with a more natural species composition and greater amounts of deadwood.
 

The Jorat is one of the largest continously forested areas in the Swiss Plateau. On a forested area of 778 ha, the Parc Naturel du Jorat (PNJ), a periurban parc, has been established in 2022. To document the initial state of the forest within the perimeter of the PNJ, a sample plot inventory (SPI) was carried out on 132 sample plots (SP) in winter 2021/22. The aim was to describe the condition and development of the forest structure and to compare it with the results of previous sample inventories in the same area carried out in 1994 and 2004. This report presents the results and interprets them in the context of research results from natural and virgin forests. The analysis is based on the two zones (core and buffer) of the PNJ. [...]