The Triad framework seeks to balance the economic and ecological functions in forested landscapes by combining intensively, extensively, and unmanaged areas, assuming a higher support to biodiversity in extensively rather than in intensively managed forests. We quantified the effects of Triad zoning on biodiversity in (sub)montane eutrophic European beech forests. Using a European-wide multitaxon database and a "virtual" landscape approach (i.e., by resampling empirical data), we evaluated how the proportion of Triad management categories affected the landscape-level species diversity of birds, saproxylic beetles, vascular plants, epiphytic bryophytes, lichens, and wood-inhabiting fungi, as well as multitaxonomic diversity. The results varied greatly among taxonomic groups. Multitaxonomic diversity peaked in landscapes composed of 60% unmanaged and 40% intensively managed forests. While intensive management can benefit some taxa through the creation of open habitats, unmanaged forests are the backbone of biodiversity conservation, underlining the need to safeguard the remaining old-growth forests under natural dynamics, and to extend the current area of unmanaged forests in Europe. Extensive forest management, however, did not contribute to biodiversity conservation as expected. As withdrawing such a high proportion of European forest landscapes from management is unfeasible given the increasing demand for timber, efforts are needed to increase the presence of structural features supporting biodiversity into extensively managed forests.

Botany and Forest Ecology University of Applied Forest Sciences Rottenburg 72108 Germany

Council for Agricultural Research and Economics Research Centre for Forestry and Wood Arezzo 52100 Italy

Department of Biological and Environmental Science University of Jyväskylä Jyvaskyla 40014 Finland

Department of Botany and Zoology Faculty of Science Masaryk University Brno 60200 Czech Republic

Department of Botany Faculty of Science University of South Bohemia České Budějovice 37005 Czech Republic

Department of Environmental Biology Sapienza University of Rome Rome 00185 Italy

Department of Environmental Systems Science Institute of Terrestrial Ecosystems ETH Zürich Zürich 8092 Switzerland

Department of Forest Ecology Czech University of Life Sciences Prague 16500 Czech Republic

Department of Forestry and Renewable Forest Resources University of Ljubljana Ljubljana 1000 Slovenia

Ecological Services Hořovice 26801 Czech Republic

Forest Ecosystems Research Unit Nogent sur Vernisson 45290 France

Forest Entomology Swiss Federal Institute for Forest Snow and Landscape Research Birmensdorf 8903 Switzerland

Habitat Dynamics Swiss Federal Institute for Forest Snow and Landscape Research Birmensdorf 8903 Switzerland

Institute of Botany of the Czech Academy of Sciences Průhonice 25243 Czech Republic

Institute of Evolutionary Ecology and Conservation Genomics University of Ulm Ulm 89081 Germany

Institute of Plant Sciences University of Bern Bern 3013 Switzerland

Mountain Ecosystem and Society Laboratory Grenoble 38402 France

Ornithology Natural History Museum Vienna 1010 Austria

Research Institute on Terrestrial Ecosystems National Research Council Florence 50019 Italy

School of Resource Wisdom University of Jyvaskyla Jyvaskyla 40014 Finland

Silviculture and Forest Ecology of the Temperate Zones University of Göttingen Göttingen 37077 Germany

Terrestrial Ecology Research Group Department of Life Science Systems School of Life Sciences Technical University of Munich Freising 85354 Germany

Zobrazit více v PubMed

Seibold S., et al. , Arthropod decline in grasslands and forests is associated with landscape-level drivers. Nature 574, 671–674 (2019). PubMed

Nagel T. A., et al. , Evaluating the influence of integrative forest management on old-growth habitat structures in a temperate forest region. Biol. Conserv. 216, 101–107 (2017).

Barredo J., et al. , Mapping and Assessment of Primary and Old-Growth Forests in Europe (Publications Office of the European Union, 2021).

Blattert C., et al. , Climate targets in European timber-producing countries conflict with goals on forest ecosystem services and biodiversity. Commun. Earth Environ. 4, 1–12 (2023).

Gregor K., et al. , Reconciling the EU forest, biodiversity, and climate strategies. Glob. Change Biol. 30, e17431 (2024). PubMed

Commission European, EU Biodiversity Strategy for 2030: Bringing Nature Back into Our Lives. European Commission: Directorate-General for Environment (Publications Office of the European Union, 2021).

Commission European, A Sustainable Bioeconomy for Europe: Strengthening the Connection Between Economy, Society and the Environment—Updated Bioeconomy Strategy. European Commission: Directorate-General for Research and Innovation (Publications Office of the European Union, 2018).

Bouget C., Lassauce A., Jonsell M., Effects of fuelwood harvesting on biodiversity — a review focused on the situation in Europe1This article is one of a selection of papers from the International Symposium on Dynamics and Ecological Services of Deadwood in Forest Ecosystems. Can. J. For. Res. 42, 1421–1432 (2012).

Winkel G., Ed., Towards a Sustainable European Forest-Based Bioeconomy: Assessment and the Way Forward (European Forest Institute, 2017).

Eyvindson K., et al. , High boreal forest multifunctionality requires continuous cover forestry as a dominant management. Land Use Policy 100, 104918 (2021).

Nolet P., Kneeshaw D., Messier C., Béland M., Comparing the effects of even- and uneven-aged silviculture on ecological diversity and processes: A review. Ecol. Evol. 8, 1217–1226 (2018). PubMed PMC

Schall P., et al. , The impact of even-aged and uneven-aged forest management on regional biodiversity of multiple taxa in European beech forests. J. Appl. Ecol. 55, 267–278 (2018).

Kuuluvainen T., et al. , Natural disturbance-based forest management: Moving beyond retention and continuous-cover forestry. Front. For. Glob. Change 4, 629020 (2021).

Duflot R., Fahrig L., Mönkkönen M., Management diversity begets biodiversity in production forest landscapes. Biol. Conserv. 268, 109514 (2022).

Gossner M. M., et al. , The importance of heterogeneity revisited from a multiscale and multitaxa approach. Biol. Conserv. 166, 212–220 (2013).

Hilmers T., et al. , Biodiversity along temperate forest succession. J. Appl. Ecol. 55, 2756–2766 (2018).

Felipe-Lucia M. R., et al. , Multiple forest attributes underpin the supply of multiple ecosystem services. Nat. Commun. 9, 4839 (2018). PubMed PMC

Sabatini F. M., et al. , Trade-offs between carbon stocks and biodiversity in European temperate forests. Glob. Change Biol. 25, 536–548 (2019). PubMed

Seymour R. S., Hunter M. L. Jr., “Principles of ecological forestry” in Maintaining Biodiversity in Forest Ecosystem, Hunter M. L., Ed. (Cambridge University Press, 1999), pp. 22–61.

Messier C., et al. , Triad zoning in Quebec: Experiences and results after 5 years. For. Chron. 85, 885–896 (2009).

Betts M. G., et al. , Producing wood at least cost to biodiversity: Integrating Triad and sharing–sparing approaches to inform forest landscape management. Biol. Rev. 96, 1301–1317 (2021). PubMed

Himes A., Betts M., Messier C., Seymour R., Perspectives: Thirty years of triad forestry, a critical clarification of theory and recommendations for implementation and testing. Forest Ecol. Manage. 510, 120103 (2022).

Larsen J. B., et al. , Closer-to-Nature Forest Management (European Forest Institute, 2022).

Blattert C., et al. , Enhancing multifunctionality in European boreal forests: The potential role of Triad landscape functional zoning. J. Environ. Manage. 348, 119250 (2023). PubMed

Côté P., et al. , Comparing different forest zoning options for landscape-scale management of the boreal forest: Possible benefits of the TRIAD. Forest Ecol. Manage. 259, 418–427 (2010).

Harris S. H., Betts M. G., Selecting among land sparing, sharing and triad in a temperate rainforest depends on biodiversity and timber production targets. J. Appl. Ecol. 60, 737–750 (2023).

Tittler R., Filotas É., Kroese J., Messier C., Maximizing conservation and production with intensive forest management: It’s all about location. Environ. Manage. 56, 1104–1117 (2015). PubMed

Tollefson J., Controversial forestry experiment will be largest-ever in United States. Nature 594, 20–21 (2021). PubMed

Schall P., et al. , Can multi-taxa diversity in European beech forest landscapes be increased by combining different management systems?. J. Appl. Ecol. 57, 1363–1375 (2020).

Burrascano S., et al. , Where are we now with European forest multi-taxon biodiversity and where can we head to? Biol. Conserv. 284, 110176 (2023).

Sabatini F. M., et al. , Where are Europe’s last primary forests?. Divers. Distrib. 24, 1426–1439 (2018).

Ram D., Lindström Å., Pettersson L. B., Caplat P., Forest clear-cuts as habitat for farmland birds and butterflies. For. Ecol. Manage. 473, 118239 (2020).

Seibold S., et al. , Microclimate and habitat heterogeneity as the major drivers of beetle diversity in dead wood. J. Appl. Ecol. 53, 934–943 (2016).

Heinrichs S., et al. , Landscape-scale mixtures of tree species are more effective than stand-scale mixtures for biodiversity of vascular plants, bryophytes and lichens. Forests 10, 73 (2019).

Naaf T., Wulf M., Effects of gap size, light and herbivory on the herb layer vegetation in European beech forest gaps. Forest Ecol. Manage. 244, 141–149 (2007).

Vogel S., et al. , Diversity and conservation of saproxylic beetles in 42 European tree species: An experimental approach using early successional stages of branches. Insect Conserv. Divers. 14, 132–143 (2021).

Bruun H. H., Heilmann-Clausen J., What is unmanaged forest and how does it sustain biodiversity in landscapes with a long history of intensive forestry?. J. Appl. Ecol. 58, 1813–1816 (2021).

Paillet Y., et al. , Quantifying the recovery of old-growth attributes in forest reserves: A first reference for France. Forest Ecol. Manage. 346, 51–64 (2015).

Gossner M. M., et al. , Current near-to-nature forest management effects on functional trait composition of saproxylic beetles in beech forests. Conserv. Biol. 27, 605–614 (2013). PubMed

Aszalós R., et al. , Natural disturbance regimes as a guide for sustainable forest management in Europe. Ecol. Appl. 32, e2596 (2022). PubMed

Nagel T. A., et al. , Can triad forestry reconcile Europe’s biodiversity and forestry strategies? A critical evaluation of forest zoning. Ambio 54, 632–641 (2024), 10.1007/s13280-024-02116-2. PubMed DOI PMC

Puettmann K. J., et al. , Silvicultural alternatives to conventional even-aged forest management - What limits global adoption? For. Ecosyst. 2, 8 (2015).

Commission European, Guidelines on Closer-to-Nature Forest Management. European Commission: Directorate-General for Environment (Publications Office of the European Union, 2023).

Uhl B., Schall P., Bässler C., Achieving structural heterogeneity and high multi-taxon biodiversity in managed forest ecosystems: A European review. Biodivers. Conserv. 34, 3327–3358 (2024), 10.1007/s10531-024-02878-x. DOI

Messier C., et al. , For the sake of resilience and multifunctionality, let’s diversify planted forests!. Conserv. Lett. 15, e12829 (2022).

Duflot R., Eyvindson K., Mönkkönen M., Management diversification increases habitat availability for multiple biodiversity indicator species in production forests. Landsc. Ecol. 37, 443–459 (2022).

Bundeswaldinventur Ergebnisdatenbank—Federal forest inventory results database. https://bwi.info/ [Accessed 14 November 2024].

Forest management. MZe. https://mze.gov.cz/public/portal/en/mze/publications/publications-forest [Accessed 14 November 2024].

Fulvio F. D., et al. , Impact of the EU biodiversity strategy for 2030 on the EU wood-based bioeconomy. Glob. Environ. Chang. 92, 102986 (2025).

Peura M., et al. , Cost-effective biodiversity protection through multiuse-conservation landscapes. Landsc. Ecol. 39, 48 (2024).

Fahrig L., et al. , Is habitat fragmentation bad for biodiversity?. Biol. Conserv. 230, 179–186 (2019).

Mikolāš M., et al. , Protect old-growth forests in Europe now. Science 380, 466–466 (2023). PubMed

Kotiaho J. S., Mönkkönen M., From a crisis discipline towards prognostic conservation practise: An argument for setting aside degraded habitats. Ann. Zool. Fenn. 54, 27–37 (2017).

Triviño M., et al. , Enhancing resilience of boreal forests through management under global change: A review. Curr. Landscape Ecol. Rep. 8, 103–118 (2023), 10.1007/s40823-023-00088-9. DOI

Konczal A. A., Derks J., Koning J. H. C., Winkel G., Integrating nature conservation measures in European forest management—An exploratory study of barriers and drivers in 9 European countries. J. Environ. Manage. 325, 116619 (2023). PubMed

Burrascano S., et al. , Handbook of field sampling for multi-taxon biodiversity studies in European forests. Ecol. Indic. 132, 108266 (2021).

Chamberlain S. A., Szöcs E., taxize: taxonomic search and retrieval in R. F1000Res. 2, 191 (2013). PubMed PMC

Kindt R., WorldFlora: An R package for exact and fuzzy matching of plant names against the World Flora Online taxonomic backbone data. Appl. Plant Sci. 8, e11388 (2020). PubMed PMC

Trentanovi G., et al. , Words apart: Standardizing forestry terms and definitions across European biodiversity studies. For. Ecosyst. 10, 100128 (2023).

Bohn U., et al. , Map of the natural vegetation of Europe. (www.synbiosys.alterra.nl/eurovegmap) (Federal Agency for Nature Conservation (BfN), Landwirtschaftsverlag, 2004).

Hofmeister J., et al. , Shared affinity of various forest-dwelling taxa point to the continuity of temperate forests. Ecol. Indic. 101, 904–912 (2019).

Blasi C., et al. , Multi-taxon and forest structure sampling for identification of indicators and monitoring of old-growth forest. Plant Biosyst. 144, 160–170 (2010).

Sabatini F. M., et al. , One taxon does not fit all: Herb-layer diversity and stand structural complexity are weak predictors of biodiversity in Fagus sylvatica forests. Ecol. Indic. 69, 126–137 (2016).

Allan E., et al. , Interannual variation in land-use intensity enhances grassland multidiversity. Proc. Natl. Acad. Sci. 111, 308–313 (2014). PubMed PMC

Chao A., Chiu C.-H., Jost L., Unifying species diversity, phylogenetic diversity, functional diversity, and related similarity and differentiation measures through hill numbers. Annu. Rev. Ecol. Evol. Syst. 45, 297–324 (2014).

Wood S. N., Generalized Additive Models: An Introduction with R (Chapman and Hall/CRC, ed. 2, 2017).

Oksanen J., et al. , vegan: Community Ecology Package (Version 2.6-4, R package, 2022). http://CRAN.R-project.org/package=vegan.

Duflot R., Schall P., Heinrichs S., Sustainable forest planning: assessing biodiversity effects of Triad zoning based on empirical data and virtual landscapes. Zenodo. 10.5281/zenodo.16611858. Deposited 30 July 2025. PubMed DOI PMC

Sustainable forest planning: Assessing biodiversity effects of Triad zoning based on empirical data and virtual landscapes