To date, only 2% of European forests are left to natural dynamics, without human intervention. Part of the forest area is subject to intensive management to meet the growing demand for timber, with significant consequences for forest biodiversity. There is also extensive forest management which, in addition to timber production, includes biodiversity conservation and ecosystem services, such as carbon storage for climate change mitigation.

These three different management approaches are present in varying proportions in different European countries, but the outcome of this distribution in terms of biodiversity conservation is unknown. An international research team led by Sapienza University, the German University of Göttingen and the Finnish University of Jyväskylä used a large European database containing detailed information on various taxonomic groups, including birds, beetles, plants, lichens and fungi, to understand what the optimal combination of management approaches for biodiversity conservation in European beech forests might be.

Based on the data collected, the researchers developed ‘virtual forest landscapes’ divided into three management categories, modelling the effects on the diversity of different taxonomic groups.

This method made it possible to create landscapes in which the proportions of extensive, intensive and unmanaged forests vary, and to explore their effects on biodiversity.

The original data, collected from nine sites in France, Germany, Italy and the Czech Republic, were classified according to forest management categories: intensive (clear-cutting, i.e. all or almost all trees in an area), non-intervention (no cutting in recent decades) and extensively managed forests (partial cutting and dominated by native tree species).

Researchers determined that multi-taxonomic diversity was highest in landscapes composed of 60% untouched forests and 40% intensively managed forests, while extensively managed forests contributed little to species diversity.

For this reason, the authors suggest focusing not only on increasing the percentage of unmanaged forests, but also on improving the ecological performance of extensive management, making its structure as similar as possible to that of forests where no intervention takes place, for example by creating a mosaic of forest areas with varying degrees of tree cover and maintaining large old trees and dead wood.

‘Naturally dynamic forests remain an important reference point from which to learn how to manage the forests from which we harvest timber in a sustainable manner, i.e. by ensuring their environmental functions,’ emphasises Sabina Burrascano of Sapienza University of Rome.

The study was funded by the EU Horizon 2020 Framework Programme through COST, the German Research Foundation (DFG) and the Kone Foundation (Finland).

References: Duflot et al “Sustainable forest planning: assessing biodiversity effects of Triad zoning based on empirical data and virtual landscapes,” (PNAS) (2025). DoI: https://doi.org/10.1073/pnas.2512683122