Dr. Jonas Hagge

Curriculum vitae



Postdoc at the department for Forest Nature Conservation, Georg-August-University Göttingen



Member of scientific staff of Bavarian Forest National Park, Department for Nature Conservation and Research



PhD at the Department of Animal Sciences, Chair of Zoology, Entomology working group, Technical University of Munich. Drivers of saproxylic biodiversity and prospects for conservation (supervised by Prof. Dr. Roland Gerstmeier and Prof. Dr. Jörg Müller). Passed with highest distinction, “summa cum laude”



Master of Science - Environmental Geography: Systems, Processes, and Interactions, Philipps-Universität Marburg. Thesis: “Forest structure and temperature drive colour lightness of beetles” (supervised by Prof. Dr. Lukas Lehnert and Prof. Dr. Thomas Nauss). Grade 1.0



Master of Science - Biodiversity and Conservation, Philipps-Universität Marburg. Thesis: “The Carabus wagae complex: phylogeography of a trans-Tibetan ground beetle species group” (supervised by Dr. Joachim Schmidt, Dr. Lars Opgenoorth and Prof. Dr. Roland Brandl). Grade 1.0



Bachelor of Science - Biology, Philipps-Universität Marburg. Thesis: “Migratory behaviour determines avian fruit colour preferences” (supervised by Dr. Jörg Albrecht, Prof. Dr. Nina Farwig and Prof. Dr. Roland Brandl). Grade 1.3

Research interest

  • Integrative forest nature conservation approaches
  • Ecology and biodiversity of deadwood depended (saproxylic) species
  • Biodiversity friendly pest management
  • Ecological processes and interactions (e.g., nutrient cycling, trophic interactions)
  • Joint approaches combining ecological, economic and social aspects
  • Species monitoring concepts and conservation strategies
  • Restoration ecology
  • Biogeography

  • Current projects

    BioHolz deadwood experiment

    BioHolz deadwood experiment

    In an experimental approach at several sites across Germany we investigated the spatial arrangement of different deadwood types on biodiversity of saproxylic species. The different spatial arrangement (i.e., aggregated and distributed) effect microclimatic conditions at the forest stand level and for the single deadwood objects. By creating standing deadwood (i.e. snags) and lying deadwood we can compare differences between these two types of deadwood resource for saproxylic biodiversity and for ecological processes. Next to basic ecological understanding of drivers for forest biodiversity the experiment allows us to study different types of disturbance patterns and deadwood retention types. Also, potential questions of forest restoration and management options of deadwood enrichment can be addressed within the project and may provide practical implication for forest nature conservation.

    See the virtual reality (360°) video: https://www.youtube.com/watch?v=bLcM3grLJeY

    Biodiversity friendly pest management

    Biodiversity friendly

    In trees weakened by natural disturbances, the population density of bark beetles can greatly increase, which leads to extensive outbreaks and high economic damaged in forestry. Nevertheless, conservationist are aware of the high value of natural disturbances for restoring more natural forests from former plantations and promoting biodiversity. Salvage logging of bark beetle invested areas is also applied in protected areas but decrease biodiversity of forest biodiversity. Alternative management strategies to handle naturally disturbed forests in protected areas and beyond are urgently required. Here bark gouging provides one new biodiversity friendly management option, particular for protected areas.

    English publication about bark-gouging: https://doi.org/10.1111/conl.12615

    Deutsche Publikation zum Rindenstreifen:



    Trait database for saproxylic beetles

    Trait database

    The use of functional traits provides mechanistic insights into community functioning and assembly processes and allows a generalization across scales. Morphological traits (i.e., traits measurable at the species level) have the advantage of being measurable using standardized protocols. However, with the exception of body size, studies of morphological traits and a standardized protocol for saproxylic beetles are lacking. Therefore, I initiated a framework to compile a morphological trait database of saproxylic beetles. The measurement protocol consists of 38 morphological traits per species, including body size and shape (body length, body height, elytra length), locomotion (wing area, leg length), foraging (in-lever length, jar length) and sensory organs (eye area, antenna length, hairiness). The saproxylic trait database provides a standardized resource that can be combined with sampled community data from survey and experimental studies to obtain mechanistic insights into community functioning and assembly processes.

    Associate Editor for

    Reviewer for

    • Biodiversity and Conservation
    • Ecology and Evolution
    • European Journal of Forest Research
    • Forest Ecology and Management
    • Insect Conservation and Diversity
    • Scientific Reports
    • Journal of Environmental Management



    Hagge, J., Müller, J., Birkemoe, T., Buse, J., Christensen, R.H.B., Gossner, M.M., Gruppe, A., Heibl, C., Jarzabek‐Müller, A., Seibold, S., Siitonen, J., Gonçalo Soutinho, J., Sverdrup‐Thygeson, A., Thorn, S., Drag, L., (2021). What does a threatened saproxylic beetle look like? Modelling extinction risk using a new morphological trait database. J. Anim. Ecol. 1365-2656.13512. https://doi.org/10.1111/1365-2656.13512


    Müller, J., Ulyshen, M., Seibold, S., Cadotte, M., Chao, A., Bässler, C., Vogel, S., Stengel, E., Hagge, J., Weiß, I., Baldrian, P., Tláskal, V., & Thorn, S. (2020). Primary determinants of communities in deadwood vary among taxa but are regionally consistent. Oikos, (in press). https://doi.org/10.1111/oik.07335

    Thom, D., Sommerfeld, A., Sebald, J., Hagge, J., Müller, J., & Seidl R. (2020). Effects of disturbance patterns and deadwood on the microclimate in European beech forests. Agricultural and Forest Meteorology, 291, 108966. https://doi.org/10.1016/j.agrformet.2020.108066


    Hagge, J., Bässler, C., Gruppe, A., Hoppe, B., Kellner, H., Krah, F., Müller, J., Seibold, S., Stengel, E., Thorn, S. (2019). Bark coverage shifts assembly processes of microbial decomposer communities in dead wood. Proceedings of the Royal Society B, 286, 20191744

    Hagge, J., Müller, J., Bässler, C., Biebl, S.S., Brandl, R., Drexler, M., Gruppe, A., Hotes, S., Hothorn, T., Langhammer, P., Stark, H., Wirtz, R., Zimmerer, V., & Mysterud, A., (2019). Deadwood retention in forests lowers short-term browsing pressure on silver fir saplings by overabundant deer. Forest Ecology and Management, 451, 117531. https://doi.org/10.1016/j.foreco.2019.117531

    Richter, T., Jestädt, K., Leitl, R., Linner, J., Müller, J., & Hagge, J. (2019). Roost tree selection of the barbastelle bat (Barbastella barbastellus) in the Bavarian Forest National Park and an evaluation of sampling methods. Nyctalus, 19, 270-284.

    Biedermann, P. H. W., Müller, J., Grégoire, J.-C., Gruppe, A., Hagge, J., Hammerbacher, A., Hofstetter, R., Kandasamy, D., Kolarik, M., Kostovcik, M., Krokene, P., Sallé, A., Six, D. L., Turrini, T., Vanderpool, D., Wingfield, M., & Bässler, C. (2019). Bark beetle population dynamics in the Anthropocene: challenges and solutions. Trends in Ecology and Evolution, 34, 914–924. https://doi.org/10.1016/j.tree.2019.06.002

    Hagge, J., Abrego, N., Bässler, C., Bouget, C., Brin, A., Brustel, H., Christensen, M., Gossner, M. M., Heilmann-Clausen, J., Horak, J., Gruppe, A., Isacsson, G., Köhler, F., Lachat, T., Larrieu, L., Schlaghamersky, J., Thorn, S., Zapponi, L., & Müller, J. (2019). Congruent patterns of functional diversity in saproxylic beetles and fungi across European beech forests. Journal of Biogeography, 46, 1054–1065. https://doi.org/10.1111/jbi.13556

    Hagge, J., Seibold, S., & Gruppe, A. (2019). Beetle biodiversity in anthropogenic landscapes with a focus on spruce plantations, Christmas tree plantations and maize fields. Journal of Insect Conservation, 23, 565–572. https://doi.org/10.1007/s10841-019-00146-w

    Hagge, J., Leibl, F., Müller, J., Plechinger, M., Soutinho, J. G., & Thorn, S. (2019). Reconciling pest control, nature conservation and recreation in coniferous forests. Conservation Letters, 12, e12615. https://doi.org/10.1111/conl.12615


    Albrecht, J., Hagge, J., Schabo, D., Schaefer, H. M., & Farwig, N. (2018). Reward regulation in plant–frugivore networks requires only weak cues. Nature Communications, 9, 4838. https://doi.org/10.1038/s41467-018-07362-z

    Seibold, S.*, Hagge, J.*, Müller, J., Gruppe, A., Brandl, R., Bässler, C., & Thorn, S. (2018). Experiments with dead wood reveal the importance of dead branches in the canopy for saproxylic beetle conservation. Forest Ecology and Management, 409, 564–570. https://doi.org/10.1016/j.foreco.2017.11.052

    * These authors contributed equally to this study.

    Articles in non-peer-reviewed journals

    Richter, T., & Hagge, J. (2020): Stolpersteine bei der telemetrischen Quartiererfassung von Fledermäusen. ANLiegen Natur, 42, 1– 4, (online preview)

    Richter, T., & Hagge, J. (2020): Quartiererfassung von Fledermäusen anpassen. Naturschutz und Landschaftsplanung, 52, 161.

    Hotes, S., Hagge, J., Härtl, F., Sacher, P., Simons, N. (2019): Biodiversitätsstrategien in Wäldern: Das BioHolz-Projekt. AFZ-DerWald, 16, 16–20.

    Hagge, J., Leibl, F., Müller, J., Plechinger, M., & Thorn, S. (2019). Streifenförmige Entrindung bekämpft Buchdrucker in bereits befallenen Fichten. ANLiegen Natur, 41, 157–162.

    Hagge, J., Simons, N., Weisser, W. W., Thorn, S., Seibold, S., Gruppe, A., & Müller, J. (2018). Biodiversity and ecosystem services in forest - the ‘BioHolz’ project. 5th European Congress of Conservation Biology. doi.org/10.17011/conference/eccb2018/107379

    Thorn, S., Müller, J., Hagge, J., & Becka, P. (2018). Drázkování – cesta k zachování druhové rozmanitosti. Šumava, Jaro, 10–11. ISSN: 0862-5166

    Gossner, M., Hagge, J., & Seibold, S. (2017). Lamprodema maura (FABRICIUS, 1803) – Erstnachweis für Deutschland aus dem Nationalpark Bayerischer Wald (Heteroptera: Rhyparochromidae, Megalontini). Nachrichtenblatt der Bayerischen Entomologen, 66, 93–97.

    Hagge, J. (2016). Atmung bei aquatischen Käfern: Lebensweise und morphologische Anpassungen bei Schilfkäfern Donacia (Coleoptera: Chrysomelidae). Naturkundliche Beiträge des DJN, 38, 1–3.