RNDr. Jan Tumajer, Ph.D.

Research Associate in WorkingGroup of Dendroecology

Co-PI of institutional project Natural and anthropogenic georisks (operational programme JAC Excellent Research)

Academic and research positions

Charles University, Faculty of Science, Department of Physical Geography and Geoecology

• Since 10/2021
• Research fellow, Research Assistant

University of Greifswald,  Institute of Botany and Landscape Ecology

• 2/2020 – 10/2021
• Post-Doctoral Researcher

IFER – Institute of Forest Ecosystem Research, Jílové u Prahy

• 2/2014 - 9/2019
• Independent researcher

Research interests

I apply tree rings and wood formation monitoring to study past environmental conditions and their effects on the growth and fitness of woody plants. Specifically, my research interest is the climate-growth interaction on fine temporal scales. During my previous research, I acquired experience with analyzing direct data about intra-annual growth dynamics recorded by dendrometers (Tumajer et al. 2022: New Phytologist; Tumajer et al. 2024: Scientific Reports) and xylogenesis monitoring (Tumajer et al. 2021: Agricultural and Forest Meteorology). To overcome limitations given by the lack of long (multidecadal) xylogenesis and dendrometer datasets, I apply process-based models of wood formation to better understand long-term trends in cambial kinetics and phenology under the ongoing climate change. In my recent works, I i) verified the intra-annual precision of the widely applicable Vaganov- Shashkin model and ii) applied the model in large-scale studies involving multiple species to assess the effects of climate change on cambial phenology and kinetics. For i) we were able to prove, that the Vaganov-Shashkin model provides a reliable approximation of spring growth phenology but not autumn phenology in temperate (Tumajer et al. 2021: Frontiers in Plant Science), boreal (Tumajer et al. 2023: Science of the Total Environment), and Mediterranean ecosystems (Tumajer et al. 2022: Agricultural and Forest Meteorology). For ii) we showed that dry regions experience significant shifts of growth phenology due to climate change but cold regions rather show variation in summer growth kinetics during the last decades (Tumajer et al. 2023: Global Change Biology). We also documented the remarkable plasticity of simulated growth phenology and kinetics in response to climate change for geographically widespread species, e.g. the most widespread woody plant Juniperus communis (Tumajer et al. 2021: Global Ecology and Biogeography). The results based on both empirical and modelling approaches contribute to understanding the observed responses of woody-species-dominated biomes across the globe to climate change and improve forecasts of their carbon sequestration capacity.

A full list of publications is available through my ResearchGate or ORCID.

Main projects

(Only projects as PI or co-PI are listed)

• 24-11757S - Quantifying the effects of phenology, growth rate, and growth occurrence for annual wood formation (PI, Funded by the Czech Science Foundation, 01/2024-12/2026)
• PRIMUS/24/SCI/004 - Using dendrometers and modeling to quantify effects of phenology, growth rate, and growth occurrence for wood formation (PI, Funded by Charles University Programme PRIMUS, 01/2024-12/2027)
• CZ.02.01.01/00/22_008/0004605 - Natural and anthropogenic georisks (co-PI, Johannes Amos Comenius Programme, 04/2024-06/2028)

Awards

• Alexander von Humboldt Foundation - Fellowship for post-doctoral researchers (02/2020-10/2021, Dendrogreif group at University Greifswald - prof. M. Wilmking)
• Faculty of Science Deans' awards for excellent PhD students (2018) and excellent early-career researchers (2022)

Teaching

• Ecology (for geographers)
• Dendrochronology
• Applied landscape ecology
• R and Python in Geosciences (in English)
• Forest geography (in English)
• Selected Chapters from Physical Geography and Geoecology (in English)