Gilbert Projer

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. [...]

Forests dominated by European beech (Fagus sylvatica L.) are among both the most widespread in Europe and the most intensely exploited globally. One of the largest remnants of unmanaged beech forests in Europe is the Uholka‐Shyrokyi Luh forest in Transcarpathia, Ukraine, covering 8,800 ha of primeval forest. In 2000, a permanent forest plot of 10 ha has been established in the Uholka massif. All living and dead trees with a diameter at breast height (DBH) ≥ 60 mm were identified to species, DBH measured, stems tagged and mapped. Since then, the plot has been remeasured in 2005, 2010, and 2015. In total, 4,820 individual trees were measured with 14,116 individual measurements throughout all four inventories. In spring 2018, an Airborne Laser Scan was carried out, covering the Uholka‐Shyrokyi Luh forest. This data set allows us to derive a high‐resolution digital elevation model (DEM) of the plot area. European beech covers a share of ≈ 95% of the basal area (BA) of all living stems. While BA was relatively stable throughout all inventories (≈ 38 m²/ha), the number of stems increased considerably between 2010 and 2015 from 290 to 430 stems/ha. Additionally, the proportion of beech stems decreased from 95% in 2010 to 86% in 2015. The continuity of the share of beech on BA and the decrease in number of stems can be traced back to disturbance events, which led to an increase of more light demanding species in the recruitment but did not alter the distribution of BA as these small trees contribute very little to BA. The data set allows for important insights into the development and the spatial and temporal dynamics of primeval beech forests. It can be used to quantify the demographic processes growth, mortality, and recruitment, and to study inter‐ and intraspecific effects on demographic rates, stand structure, and species composition. No copyright or proprietary restrictions are associated with the use of this data set other than citation of this Data Paper.