Peter Hajek

Functional biodiversity of forests

Tree diversity, traits and ecosystem resilience

Biodiversity-driven stability of forest ecosystems

From traits to ecosystems: Forest responses to climate stress

Mechanisms of forest resilience under climate extreme

Publikationen

Sasaki T, […], Hajek P, […], Eisenhauer N (2026) Biodiversity effects under climate extremes intensify with aridity in grasslands but not forests. Nature Ecology & Evolution https://www.nature.com/articles/s41559-026-03130-1

Kunert N, Ehrmann J, Gebhard S, Hofmann S, Zimmermann G, Hajek P (2026) Temperate tree species show cross-tolerance to heat, drought, and late spring-frost stress. New Phytologist (http://doi.org/10.1111/nph.71277)

Kunert N, Münchinger I, Hajek P (2026) Turgor loss point explains climate‐driven growth reductions in trees in Central Europe (2026-04-17). Plant Biology (https://doi.org/10.1111/plb.13687)

Jensen J, Bauhus J, Beyer F, Hajek P, Saito D, Scherer-Lorenzen M, Serrano-León H, Weih M (2026) Tree species diversity drives above‐ground carbon sequestration through light‐related trait shifts. Functional Ecology (http://doi.org/10.1111/1365-2435.70320)

Jactel H, Pluchard E, Schillé L, Plat N, Jouveau S, Rivoal J-B, Hajek P, Fründ J, Scherer-Lorenzen M (2026) Experimental evidence of reduced Ips typographus damage in mixed spruce plantations. Journal of pest science (https://doi.org/10.1007/s10340-025-01995-y)

Bourdin A, Augusto L, Joly F-X, Bres C, Chahine T, Guillemot J, Hajek P, Jactel H, Jensen J, Mereu S, Muys B, Ponette Q, Sandén H, Parker W C, Paquette A, Messier C, Robin A, Scherer-Lorenzen M, Serrano-León H, Weih M, Castagneyrol B, Bakker M R, Fanin N (2025) Context dependency of tree diversity effects on standardized substrates decomposition: Role of tree functional composition, mycorrhizal type and climatic conditions. Journal of Ecology (https://doi.org/10.1111/1365-2745.70189)

Werner R, Jensen J, Fransson P, Baum C, Sandén H, Rewald B, Godbold D L, Mayer M, Guillemot J, Robin A, Brancalion P H S, Koricheva J, Ponette Q, Muys B, Verheyen K, Scherer-Lorenzen M, Bauhus J, Beyer F, Hajek P, Jactel H, Weih M (2025) Effects of Tree Species Richness on Topsoil Carbon and Fungal Diversity in European Planted Mixed Forests are Modulated by Environmental Conditions. Geoderma (https://doi.org/10.1016/j.geoderma.2025.117591)

Serrano-León H, Blondeel H, Glenz P, Steurer J, Schnabel F, Baeten L, Guillemot J, Martin-StPaul N, Skiadaresis G, Scherer-Lorenzen M, Bonal D, Boone M, Decarsin R, Druel A, Godbold DL, Gong J, Hajek P, Jactel H, Koricheva J, Mereu S, Ponette Q, Rewald B, Sandén H, van den Bulcke J, Verheyen K, Werner R, Bauhus J (2025) Global Change Biology 31:9, (https://doi.org/10.1111/gcb.70394)

Mosig et al. (2025) – deadtrees.earth — An open-access and interactive database for centimeter-scale aerial imagery to uncover global tree mortality dynamics.Remote Sensing of Environment (https://doi.org/10.1016/j.rse.2025.115027)

Jensen J, Blondeel H, Guillemot J, Schnabel F, Serrano-León H, Auge H, Baeten L, Barsoum N, Bauhus J, Baum C, Bermudez R, Beyer F, Brancalion P, Cavender-Bares J, Eisenhauer N, Felton A, Ferlian O, Fiedler S, Gebauer T, Godbold D L, Hajek P, Hall J S, Hölscher D, Jactel H, Kreft H, Lapadat C, MacLaren C, Martin-StPaul N, Meredieu C, Mereu S, Messier C, Montgomery R A, Muys B, Nock C A, Parker J D, Parker W C, Paterno G B, Perring M P, Ponette Q, Potvin C, Reich P B, Rentch J, Rewald B, Robin A, Scherer-Lorenzen M, Sandén H, Sinacore K, Standish R J, Stefanski A, Verheyen K, Williams L J, Weih M (2025) Diversity in resource use strategies promotes productivity in young planted tree species mixtures. Global change biology (https://doi.org/10.1111/gcb.70493)

Jactel H, Pluchard E, Schillé L, Plat N, Jouveau S, Rivoal J-B, Hajek P, Fründ J, Scherer-Lorenzen M (2025) Experimental evidence of reduced Ips typographus damage in mixed spruce plantations. Journal of Pest Science

Déziel M, Schoenig D, Sousa-Silva R, Searle E B, Parker W C, Cavender-Bares J, Mereu S, Scherer-Lorenzen M, Nock C A, Messier C, Reich P, Stefanski A, Dong N, Hajek P, Gravel D, Paquette A (2025) Resolving the effects of functional traits on tree growth rates: The influence of temporal dynamics and divergent strategies by leaf habit. Journal of Ecology  (https://doi.org/10.1111/1365-2745.70151)

Zheng L, Ibáñez I, Williams L J, Zhu K, Serrano-León H, Jensen J, Eisenhauer N, Verheyen K, Scherer-Lorenzen M, Schnabel F, Kreft H, Guerrero-Ramírez N R, Hölscher D, Paterno G B, Irawan B, Ponette Q, Messier C, Paquette A, Stefanski A, Mereu S, Bauhus J, Hajek P, Nock C A, Cavender-Bares J, Parker W C, Quosh J, Ferlian O, Auge H, Potvin C, Yan E, Yang B, Zhang L, Zhao Z, Sinacore K, Hall J S, Guillemot J, Robin A, Brancalion P H S, Sundawati L, Reich P B (2025) Neighbourhood diversity increases tree growth in experimental forests more in wetter climates but not in wetter years. Nature Ecology & Evolution (https://doi.org/10.1038/s41559-025-02805-5)

Williams L J, Kovach K R, Guzmán Q J A, Stefanski A, Bermudez R, Butler E E, Coq–Etchegaray D, Glenn-Stone C, Hajek P, Klama J, Medlyn B E, Messier C, Moradi A, Paquette A, Park M H, Scherer-Lorenzen M, Townsend P A, Reich P B, Cavender-Bares J, Schuman M C (2025) Tree diversity shapes the spectral signature of light transmittance in developing forests. Ecology (https://doi.org/10.1002/ecy.70032)

Bier-Schorr L, Gräser V, Scherer-Lorenzen M, Hajek P & Kurz P (2024) – Enhancement of the Plant-Accessible Phosphate Fraction in Sewage Sludge Ashes by Na+ or K+ Addition Prior to Combustion. ChemSusChem (http://doi.org/10.1002/cssc.202401744)

Decarsin R, Guillemot J, le Maire G, Blondeel H, Meredieu C, Achard E, Bonal D, Cochard H, Corso D, Delzon S, Doucet Z, Druel A, Grossiord C, Torres-Ruiz J M, Bauhus J, Godbold D L, Hajek P, Jactel H, Jensen J, Mereu S, Ponette Q, Rewald B, Ruffault J, Sandén H, Scherer-Lorenzen M, Serrano-León H, Simioni G, Verheyen K, Werner R, Martin-StPaul N (2024) – Tree drought–mortality risk depends more on intrinsic species resistance than on stand species diversity. Global change biology (https://doi.org/10.1111/gcb.17503)

Kunert N, Münchinger I, Hajek P (2024) – Turgor loss point explains climate-driven growth reduction in trees in Central Europe. Plant Biology (http://doi.org/10.1111/plb.13687)

Luo S, Schmid B, Hector A, Scherer-Lorenzen M, Verheyen K, Barsoum N, Bauhus J, Beyer F, Bruelheide H, Ferlian O, Godbold D, Hall J S, Hajek P, Huang Y, Hölscher D, Kreft H, Liu X, Messier C, Nock C, Paquette A, Parker J D, Parker W C, Paterno G B, Reich P B, Rewald B, Sandén H, Sinacore K, Stefanski A, Williams L, Eisenhauer N (2024) – Mycorrhizal associations modify tree diversity−productivity relationships across experimental tree plantations. New Phytologist (https://doi.org/10.1111/nph.19889)

Jing X, Baum C, Castagneyrol B, Eisenhauer N, Ferlian O, Gebauer T, Hajek P, Jactel H, Muys B, Nock C, Ponette Q, Rose L, Saurer M, Scherer-Lorenzen M, Verheyen K, Van Meerbeek K (2024) – Leaf isotopes reveal tree diversity effects on the functional responses to the pan-European 2018 summer drought. New Phytologist (https://doi.org/10.1111/nph.19931)

Zheng, L, Barry, K, Guerrero-Ramírez, N R, Craven, D, Reich, P B, Verheyen, K, Scherer-Lorenzen, M, Eisenhauer, N, Auge, H, Barsoum, N, Bauhus, J, Hautier, Y, Bruelheide, H, Cavender-Bares, J, Dolezal, J, Zhao, Z, Fagundes, M, Ferlian, O, Fiedler, S, Forrester, D, Ganade, G, Gebauer, T, Haase, J, Hajek, P, Hector, A, Herault, B, Holscher, D, Hulvey, K, Irawan, B, Jactel, H, Koricheva, J, Kreft, H, Lanta, V, Leps, J, Mereu, S, Messier, C, Montagnini, F, Mörsdorf, M, Müller, S, Muys, B, Nock, C A, Paquette, A, Parker, W, Parker, J, Parrotta, J, Paterno, G, Perring, M, Piotto, D, Polley, H, Ponette, Q, Potvin, C, Quosh, J, Rewald, B, van Ruijven, J, Standish, R, Stefanski, A, Sundawati, L, Tilman, D, Urgoiti, J, Williams, L, Wilsey, B, Yang, B, Zhang, L, Godbold, D, Sandén, H, Ebeling, A, Schmid, B, Fischer, M, Yang, Y, Kotowska, M, Palmborg, C (2024) – Effects of plant diversity on productivity strengthen over time due to trait-dependent shifts in species overyielding. Nature Communications 15, 2078 (https://doi.org/10.1038/s41467-024-46355-z)

Kurjak D, Petrík P, Konôpková AS, Link RM, Gömöry D, Hajek P, Liesebach M, Leuschner C, Schuldt B (2024) Inter-provenance variability and phenotypic plasticity of wood and leaf traits related to hydraulic safety and efficiency in seven European beech (Fagus sylvatica L.) provenances differing in yield. Annals of Forest Science (https://doi.org/10.1186/s13595-024-01227-w)

Depauw, L, De Lombaerde, E, Dhiedt, E, Blondeel, H, Abdala-Roberts, L, Auge, H, Barsoum, N, Bauhus, J, Chu, C, Damtew, A, Eisenhauer, N, Fagundes, MV, Ganade, G, Gendreau-Berthiaume, B, Godbold, D, Gravel, D, Guillemot, J, Hajek, P, Hector, A, Hérault, B, Jactel, H, Koricheva, J, Kreft, H, Liu, X, Mereu, S, Messier, C, Muys, B, Nock, CA, Paquette, A, Parker, JD, Parker, W C, Paterno, G B, Perring, M P, Ponette, Q, Potvin, C, Reich, PB, Rewald, B, Scherer-Lorenzen, M, Schnabel, F, Sousa-Silva, R, Weih, M, Zemp, DC, Verheyen, K and Baeten, L (2024) Enhancing tree performance through species mixing: Review of a quarter‑century of TreeDivNet experiments reveals research gaps and practical insights. Current Forestry Reports (https://doi.org/10.1007/s40725-023-00208-y)

Hajek P, Mörsdorf M, Kovach KR, Greinwald K, Rose L, Nock CA, Scherer-Lorenzen M (2023) Quantifying the influence of tree species richness on community drought resistance using drone-derived NDVI and ground-based measures of Plant Area Index and leaf chlorophyll in a young tree diversity experiment. European Journal of Forest Research (https://doi.org/10.1007/s10342-023-01615-3).

Münchinger I, Hajek P, Akdogan B, Caicoya AT, Kunert N (2023) Leaf thermal tolerance and sensitivity of temperate tree species are correlated with leaf physiological and functional drought resistance traits. Journal of Forestry Research (https://doi.org/1/s11676-022-01594-y).

Kunert N & Hajek P (2022) Shade-tolerant temperate broad-leaved trees are more sensitive to thermal stress than light-demanding species during a moderate heatwave.Trees, Forests and People 9: 100282 (https://doi.org/10.1016/j.tfp.2022.100282)

Hajek P, Link RM, Nock C, Bauhus J, Gebauer T, Gessler A, Kovach K,  Messier C, Paquette A, Saurer M, Scherer-Lorenzen M, Rose L, Schuldt B (2022) Mutually inclusive mechanisms of drought-induced tree mortality. Global change biology 28(10), 3365-3378. (https://doi.org/10.1111/gcb.16146).

Kunert N, Hajek P, Hietz P, Morris H, Rosner S, Tholen D (2021) Summer temperatures reach the thermal tolerance threshold of photosynthetic decline in temperate conifers. Plant Biology. (https://doi.org/10.1111/plb.13349)

Berthelot S, Frühbrodt T, Hajek P, Nock C, Dormann C, Bauhus J,  Fründ J (2021) Tree diversity reduces risk of bark beetle infestation for preferred conifer species, but increases risk for less preferred hosts. Journal of Ecology, 109: 2649– 2661.

Schuldt B, Buras A, Arend M, Vitasse Y, Beierkuhnlein C, Damm A, Gharun M, Grams T, Hauck M, Hajek P, Hartmann H, Hiltbrunner E, Hoch G, Holloway-Phillips M, Körner C, Larysch E, Lübbe T, Nelson D, Rammig A, Rigling A, Rose L, Ruehr N, Weiser F, Werner C, Wohlgemuth T, Zang C, Kahmen A (2020) A first assessment of the impact of the extreme 2018 summer drought on Central European forests. Basic and Applied Ecology, 45, 86-103.

Grass I, Meyer S, Taylor P, Foord S, Hajek P, Tscharntke T (2018) Pollination limitation despite managed honeybees in South African macadamia orchards. Agriculture, Ecosystems & Environment, 260, 11-18.

Hajek P, Kurjak D, von Wühlisch G, Delzon S, Schuldt B (2016) Intraspecific variation in wood anatomical, hydraulic and foliar traits in ten European beech provenances differing in growth yield. Frontiers in Plant Science 7, 791.

Hajek P, Seidel D, Leuschner C (2015) Mechanical abrasion, and not competition for light, is the dominant canopy interaction in a temperate mixed forest. Forest Ecology and Management, 348, 108-116.

Hajek P, Leuschner C, Hertel D, Delzon S, Schuldt B (2014) Assessing the trade-offs between xylem hydraulic properties, wood anatomy and yield in Populus. Tree Physiology, 34(7), 744-756.

Hajek P, Hertel D, Leuschner C (2013) Root order- and root age-dependent response of two poplar species to belowground competition. Plant and Soil, 377(1), 337-355.

Hajek P, Hertel D, Leuschner C (2013) Intraspecific variation in root and leaf traits and leaf-root trait linkages in eight aspen demes (Populus tremula and P. tremuloides). Frontiers in Plant Science, 4, 415.

Poster

Matevski D, Glatthorn J, Hajek P, Fründ J (2025) Spatial scale dependence of tree functional diversity effects on herbivory. 54th GfÖ Annual Meeting
Würzburg, Germany

Decarsin R,  Guillemot J, Cochard H, Corso D, Delzon S, Torres-Ruiz J-M, Jactel H, Meredieu C, Mereu S, Rewald B, Hajek P, Bauhus J, Scherer-Lorenzen M, Doucet Z, Achard E, Serrano-León H, Ponette Q, Le Maire G, Martin-StPaul N (2022) Tree species diversity effects on hydraulic safety margins. 5^th Xylem International Meeting, University of Würzburg

Kurjak D, Sliacka-Konôpková A, Petrik P, Hajek P, Schuldt B (2022) Xylem anatomy explains intraspecific variability of Ψ₅₀ and d¹³C in European beech provenances 5^th Xylem International Meeting, University of Würzburg

Williams L, Villanueva RB, Butler E, Cavender-Bares J, Couture J, Hajek P, Klama J, Kovach K, Messier C, Moradi A, Paquette A, Park M, Reich P, Rice K, Scherer-Lorenzen M, Schuman M, Stefanski A, Townsend P, Wang Z (2022) Light as a resource, stressor and cue in mediating diversity-productivity relationships in forests. Earth and Space Science Open Archive [online] URL: http://www.essoar.org/doi/10.1002/essoar.10509969.1

Preise/Awards

Helmut-Lieth-Preis für Umweltforschung 2022; Stifter: Albert-Ludwigs-Universität Freiburg Köperschaftsvermögen

Laufende Projekte

Die 9 Universitäten des Landes Baden-Württemberg präsentieren 99 Projekte für eine postfossile Zukunft. Siehe: 99 Projekte und https://uni-freiburg.de/99projekte/(20.07.2926).

Forschungsprogramm „Mit Innovationen den ökologischen Landbau gemeinsam stärken“ Ministerium für Wissenschaft, Forschung und Kunst Baden-Württemberg (MWK) – „PHÖNIX – Phosphor-Recyclingdüngemittel im Ökologischen Landbau: Nachhaltige Integration und Kreislaufwirtschaft mit P-XTRACT“ (01/2026-12/2028)

badenova Innovationsfonds (10/2025-09/2028) „Vom Klärschlamm zum Pflanzendünger – Phosphorrecycling aus Klärschlammasche“ 

Eva-Mayr-Stihl Stiftung (2024-2028) „Effektivität von Mischbeständen und Durchforstung zur Anpassung an Klimaextreme“

International Diversity Experiment Network with Trees IDENT and network of tree biodiversity experiments TreeDivNet

Global Archive for 3D Forest Data (3Dtrees.earth)
3Dtrees.earth is a collaborative platform where data holders can upload, visualize and share high-quality 3D forest data — and receive predictive insights in return. The Freiburg IDENT site contributes to the growth of this global archive by connecting datasets across regions and disciplines , enabling deeper understanding of forest structure, growth, and change at scale. See https://3dtrees.earth/datasets/969

Abgeschlossene Projekte

P-XTRACT Regionale Klärschlammverwertung mit integrierter Phosphorrückgewinnung

Lehre

BSc.-Studiengang Biologie

• Vertiefungsmodul Geobotanik (WiSe)
• Projektmodul Geobotanik (WiSe)

 MSc.-Studiengang Biologie

• Wahlmodul Pflanzenökologie und Ökosystemfunktionen (SoSe)
• Wahlmodul Ur-/Primärwaldexkursion, Slowakei (SoSe)
• Schwerpunktmodul II Ökologie und Evolutionsbiologie: Experimente in Evolutionsbiologie und funktioneller Ökologie (WiSe)

Master of Education (M.Ed.) Biologie

• Freilandökologie (SoSe)
• Ökologische Perspektiven einer nachhaltigen Entwicklung (SoSe)