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

R Rémi Duflot (Department of Biological and Environmental Science, University of Jyväskylä) S Steffi Heinrichs (Silviculture and Forest Ecology of the Temperate Zones, University of Göttingen) L Lorenzo Balducci (Department of Environmental Biology, Sapienza University of Rome) F Francesco Chianucci (Council for Agricultural Research and Economics (CREA)—Research Centre for Forestry and Wood) J Jeňýk Hofmeister (Department of Forest Ecology, Czech University of Life Sciences) Y Yoan Paillet (Mountain Ecosystem and Society Laboratory (Lessem), Université Grenoble Alpes, National Research Institute for Agriculture, Food and Environment (INRAE)) G Giovanni Trentanovi (Research Institute on Terrestrial Ecosystems, National Research Council) F Frédéric Archaux (Forest Ecosystems Research Unit (EFNO), National Research Institute for Agriculture, Food and Environment (INRAE)) S Steffen Boch (Habitat Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research (WSL)) C Christophe Bouget (Forest Ecosystems Research Unit (EFNO), National Research Institute for Agriculture, Food and Environment (INRAE)) D Daniel Dvořák (Department of Botany and Zoology, Faculty of Science, Masaryk University) M Markus Fischer F Frédéric Gosselin (Forest Ecosystems Research Unit (EFNO), National Research Institute for Agriculture, Food and Environment (INRAE)) M Marion Gosselin (Forest Ecosystems Research Unit (EFNO), National Research Institute for Agriculture, Food and Environment (INRAE)) M Martin M. Gossner (Forest Entomology, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL)) E Eva Holá (Department of Botany, Faculty of Science, University of South Bohemia) J Jan Hošek (Ecological Services) K Kirsten Jung (Institute of Evolutionary Ecology and Conservation Genomics, Department of Biology, Ulm University) Z Zdeněk Palice (Institute of Botany of the Czech Academy of Sciences) S Swen C. Renner (Ornithology, Natural History Museum) W Wolfgang W. Weisser (Terrestrial Ecology Research Group, Department of Life Science Systems, School of Life Sciences, Technical University of Munich) T Thomas A. Nagel S Sabina Burrascano (Department of Environmental Biology, Sapienza University of Rome) P Peter Schall (Silviculture and Forest Ecology of the Temperate Zones, University of Göttingen)

Abstract

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.

Article Details

Volume / Issue Vol. 122, Issue 39
Published September 30, 2025
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (24)

R

Rémi Duflot

Department of Biological and Environmental Science, University of Jyväskylä

S

Steffi Heinrichs

Silviculture and Forest Ecology of the Temperate Zones, University of Göttingen

L

Lorenzo Balducci

Department of Environmental Biology, Sapienza University of Rome

F

Francesco Chianucci

Council for Agricultural Research and Economics (CREA)—Research Centre for Forestry and Wood

J

Jeňýk Hofmeister

Department of Forest Ecology, Czech University of Life Sciences

Y

Yoan Paillet

Mountain Ecosystem and Society Laboratory (Lessem), Université Grenoble Alpes, National Research Institute for Agriculture, Food and Environment (INRAE)

G

Giovanni Trentanovi

Research Institute on Terrestrial Ecosystems, National Research Council

F

Frédéric Archaux

Forest Ecosystems Research Unit (EFNO), National Research Institute for Agriculture, Food and Environment (INRAE)

S

Steffen Boch

Habitat Dynamics, Swiss Federal Institute for Forest Snow and Landscape Research (WSL)

C

Christophe Bouget

Forest Ecosystems Research Unit (EFNO), National Research Institute for Agriculture, Food and Environment (INRAE)

D

Daniel Dvořák

Department of Botany and Zoology, Faculty of Science, Masaryk University

M

Markus Fischer

F

Frédéric Gosselin

Forest Ecosystems Research Unit (EFNO), National Research Institute for Agriculture, Food and Environment (INRAE)

M

Marion Gosselin

Forest Ecosystems Research Unit (EFNO), National Research Institute for Agriculture, Food and Environment (INRAE)

M

Martin M. Gossner

Forest Entomology, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL)

E

Eva Holá

Department of Botany, Faculty of Science, University of South Bohemia

J

Jan Hošek

Ecological Services

K

Kirsten Jung

Institute of Evolutionary Ecology and Conservation Genomics, Department of Biology, Ulm University

Z

Zdeněk Palice

Institute of Botany of the Czech Academy of Sciences

S

Swen C. Renner

Ornithology, Natural History Museum

W

Wolfgang W. Weisser

Terrestrial Ecology Research Group, Department of Life Science Systems, School of Life Sciences, Technical University of Munich

T

Thomas A. Nagel

S

Sabina Burrascano

Department of Environmental Biology, Sapienza University of Rome

P

Peter Schall

Silviculture and Forest Ecology of the Temperate Zones, University of Göttingen