
Kajar Köster
Associate Professor
Interactions of ecological disturbances and atmosphere.
Department of Environmental and Biological Sciences, Faculty of Science, Forestry and Technology
Research interests: Disturbances (fire, wind, reindeer grazing, insects, etc.) and biogeochemistry, carbon dynamics, greenhouse gas emissions, pyrogenic matter formation and post-fire transport (by water), post-disturbance changes in biogeochemical processes, etc.
My research deals with questions how the northern ecosystems respond to climate change, the changes in land-use, and the changes in disturbance dynamics. My current research focusses on how northern ecosystems respond to changes in fire dynamics and other disturbances, and what are the consequences on the formation of greenhouse gas, volatile organic compound, pyrogenic carbon, and soot emissions. The research uses a wide scope of measurements with extensive field-based measurements including experimental and natural fires and detailed process-level studies on the effects of fires on the formation of particles using the existing laboratories in UEF. The work will link disturbance related studies to plant ecology, biogeochemistry and atmospheric sciences, and will improve predictions of ecosystem responses to a changing climate, and helps to understand possible tipping points in the environment (e.g. transitions of ecosystems from carbon sinks to carbon sources).
Research groups
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Biogeochemistry research group 01.01.1993 -
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ECOSERV – Ecosystem Services and Climate Change Research Group 01.04.2025 -
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Plant Ecology
Projects
Publications
29/29 items-
Short-term effects of low-intensity surface fires on dissolved organic matter from boreal forest soils
Rebiffé, Mathilde; Kohl, Lukas; Köster, Egle; Keinänen, Markku; Berninger, Frank; Köster, Kajar. 2025. Journal of soils and sediments. [Epub ahead of print 21 May 2025]: 1-20 A1 Journal article (refereed), original research -
Soil microhabitat conditions drive post-fire ecosystem multifunctionality changes in forests recovering from prescribed burning
Han, Yu; Köster, Kajar; Dou, Xu; Yu, Cheng; Wang, Jianyu; Ding, Yiyang; Wang, Yusong; Hu, Tongxin. 2025. Plant and soil. [Epub ahead of print 05 June 2025]: 1-14 A1 Journal article (refereed), original research -
The role of pyrogenic carbon addition after wildfires in the boreal forest of China: Impact on plant–soil–microbial ecological stoichiometry
Dou, Xu; Wang, Jianyu; Köster, Kajar; Yu, Cheng; Ren, Yuexiao; Sun, Long; Hu, Tongxin. 2025. Geoderma. 455: A1 Journal article (refereed), original research -
Accessing the Low-Polar Molecular Composition of Boreal and Arctic Peat-Burning Organic Aerosol via Thermal Analysis and Ultrahigh-Resolution Mass Spectrometry: Structural Motifs and Their Formation
Schneider, Eric; Neumann, Anika; Chacón-Patiño, Martha L; Somero, Markus; Ruppel, Meri M; Ihalainen, Mika; Köster, Kajar; Sippula, Olli; Czech, Hendryk; Rüger, Christopher P; Zimmermann, Ralf. 2024. Journal of the american society for mass spectrometry. 35: 1713-1725 A1 Journal article (refereed), original research -
Effects of biochar on soil carbon pool stability in the Dahurian larch (Larix gmelinii) forest are regulated by the dominant soil microbial ecological strategy
Huang, Mingzhou; Hu, Tongxin; Wang, Jianyu; Ding, Yiyang; Köster, Kajar; Sun, Long. 2024. Science of the total environment. 951: A2 Review article, Literature review, Systematic review -
Enhancing boreal forest resilience: A four-year impact of biochar on soil quality and fungal communities
Liao, Yang-chun-zi; Pu, Hong-xiu; Jiao, Zi-wen; Palviainen, Marjo; Zhou, Xuan; Heinonsalo, Jussi; Berninger, Frank; Pumpanen, Jukka; Köster, Kajar; Sun, Hui. 2024. Microbiological research. 283: A1 Journal article (refereed), original research -
Organic soil greenhouse gas flux rates in hemiboreal old-growth Scots pine forests at different groundwater levels
Samariks, Valters; Kenina, Laura; Istenais, Nauris; Ozolins, Kristaps; Koster, Kajar; Jansons, Aris. 2024. European journal of forest research. [Epub ahead of print 25 April 2024]: 1-12 A1 Journal article (refereed), original research -
Post-fire soil carbon emission rates along boreal forest fire chronosequences in northwest Canada show significantly higher emission potentials from permafrost soils compared to non-permafrost soils
Köster, Kajar; Aaltonen, Heidi; Köster, Egle; Berninger, Frank; Pumpanen, Jukka. 2024. Frontiers in ecology and evolution. 2023; 11: . 1331018 A1 Journal article (refereed), original research -
Post-fire soil greenhouse gas fluxes in boreal Scots pine forests–Are they affected by surface fires with different severities?
Köster, Kajar; Kohli, Juliana; Lindberg, Henrik; Pumpanen, Jukka. 2024. Agricultural and forest meteorology. 349: A1 Journal article (refereed), original research -
Prescribed burning alters soil microbial community structure by changing soil physicochemical properties in temperate forests of northern China
Hu, Tongxin; Han, Yu; Köster, Kajar; Wang, Jianyu; Hu, Haiqing; Dou, Xu; Sun, Long; Ding, Yiyang. 2024. Journal of forestry research. 35: A1 Journal article (refereed), original research