PNNL

Arjun Chakrawal is a soil scientist with a PhD in physical geography from Stockholm University. He is currently a postdoctoral research associate at the Environmental Molecular Sciences Laboratory (EMSL), contributing to the Molecular Observation Network and Small Business Innovation Research (SBIR) led by Subsurface Insights (in collaboration with Dr. John Bargar at Pacific Northwest National Laboratory). Before joining EMSL, Chakrawal was a postdoctoral researcher at Stockholm University in Manzoni Lab and contributed to the European Research Council (ERC)-funded SMILE project. Chakrawal’s research has focused on theoretical advancements in modeling organic matter decomposition, exploring the upscaling of decomposition kinetics; integrating carbon, nitrogen, and energy flows in microbial metabolism; and applying eco-evolutionary approaches to model decomposition dynamics using optimal control theory. In this current role, his research focuses on the utilization of high-resolution Fourier-transform ion cyclotron resonance and solid-state ¹³C nuclear magnetic resonance techniques to characterize soil organic matter composition and its integration into process-based biogeochemical models used for predicting carbon exchange fluxes from soils. On the SBIR side, he contributes to a large team of researchers working on open source development of data fusion and analysis tools to enable machine learning for systems biology.

Chakrawal’s recent work, “Modelling optimal ligninolytic activity during plant litter decomposition,” has been recognized through a commentary by S. Shao and B. N. Sulman, “Eco-evolutionary insights into microbial litter decomposition,” published in New Phytologist.

Chakrawal serves as a guest editor for Soil Biology and Biochemistry and provides mentorship to aspiring undergraduates in India, promoting career development in the field of geoscience.

• Eco-evolutionary processes
• Biogeochemical cycle modeling
• Plant–soil–microbe interactions
• Data–model integration for parametrization and validation
• Optimization, optimal control, and machine learning

• PhD in physical geography, Stockholm University
• Erasmus Joint Master’s Degree Program in Groundwater and Global Change - Impacts and Adaptation
• BSc and MSc in Earth and environmental science, Indian Institute of Science

• Guest editor for Soil Biology and Biochemistry special issue, “Linking carbon and energy fluxes in soil – from resources to consumers and back again”
• Active reviewer for Soil Biology and Biochemistry, European Journal of Soil Science, Geoderma, Nature Ecology & Evolution, Geoscientific Model Development, Biogeochemistry
• “Thermodynamics of microbial growth,” Instituto Gulbenkian de Ciência (IGC), Portugal (virtual event, 15 Nov 2021)
• “Bioenergetic approaches in soil systems,” DFG (German Research Foundation) priority programme Soil Systems: Systems ecology of soils (virtual event, 6 Oct 2022)
• Contributed lecture to Soil Systems summer school on Modeling in biothermodynamics and systems ecology

• Editor’s choice paper in Soil Biology and Biochemistry
• Outstanding Student Poster and PICO (OSPP) Award, EGU 2019, European Geosciences Union, 2019
• News article “New formula provides key to predicting microbial growth”

2024

• Chakrawal A., B. D. Lindahl, O. Qafoku, and S. Manzoni. 2024. “Comparing Plant Litter Molecular Diversity Assessed from Proximate Analysis and ¹³C NMR Spectroscopy.” Soil Biology and Biochemistry 197: 109517. https://doi.org/10.1016/j.soilbio.2024.109517
• He X., E. Abs, S.D. Allison, F. Tao, Y. Huang, S. Manzoni, and R. Abramoff, et al. 2024. "Emerging multiscale insights on microbial carbon use efficiency in the land carbon cycle." Nature Communications 15. PNNL-SA-209252. doi:10.1038/s41467-024-52160-5