Tejshree Tiwari

I work on developing biogeochemical models and coordinating projects at the Department of Forest Ecology and Management, SLU. My research explores the interconnected biological, chemical, and physical processes that drive carbon, nutrient, and water cycling in boreal ecosystems, with a focus on the Krycklan catchment. I specialise in translating complex mechanistic understanding into conceptual models to simulate energy flow, nutrient cycling, and hydrologic routing across heterogeneous landscapes.

My work examines how climate extremes—such as droughts and floods—reshape biogeochemical dynamics, with a focus on dissolved organic carbon, cations, anions, stable isotopes, and water fluxes. A central theme of my research is scaling: linking plot-scale processes to large catchment responses and identifying the transformation zones that influence water quality and ecosystem function along the way. I combine field measurements, long-term monitoring, and mechanistic and conceptual models to investigate energy flow, nutrient cycling, and hydrologic routing across heterogeneous landscapes.

Key Research Themes:

1. Biogeochemical Processes and Carbon Cycling

• Tiwari, T., RA Sponseller, H. Laudon. The emerging role of drought as a regulator of dissolved organic carbon in boreal landscapes. Nature Communications 13 (1), 5125, 2022.

• Ågren, AM., I Buffam, DM Cooper, T Tiwari, CD Evans, H Laudon. Can the heterogeneity in stream dissolved organic carbon be explained by contributing landscape elements? Biogeosciences 11 (4), 1199-1213, 2014.

• Tiwari, T., H. Laudon, K. Beven, AM. Ågren. Downstream changes in DOC: Inferring contributions in the face of model uncertainties. Water Resources Research 50 (1), 514-525, 2014.

• Tiwari, T., RA Sponseller, H Laudon. Contrasting responses in dissolved organic carbon to extreme climate events from adjacent boreal landscapes in Northern Sweden. Environmental Research Letters 14 (8), 084007, 2019.

2. Modeling and Conceptual Frameworks

• Tiwari, T., I Buffam, RA Sponseller, H Laudon. Inferring scale-dependent processes influencing stream water biogeochemistry from headwater to sea. Limnology and Oceanography 62 (S1), S58-S70, 2017.

• SK Oni, T Tiwari, MN Futter, A Ågren, C Teutschbein, J Ledesma, … New Insights into Fluvial Carbon Responses to Future Forest Management and Climate Change Obtained from Multi-Scale Modelling of Biogeochemical Processes. AGU Fall Meeting Abstracts, 2014.

• Tiwari, T. Conceptualizing catchment processes affecting stream chemistry: From basic understanding to practical applications. Department of Forest Ecology and Management, SLU, 2015.

• Tiwari, T., H Laudon, A Ågren. An interdisciplinary approach on the controls of stream biogeochemistry in a mesoscale catchment—A journey from the landscape sources to the outlet. EGU General Assembly Conference Abstracts, 2013.

3. Hydrology, Climate Impact and Catchment Processes

• Tiwari, T., H Laudon. Trends in hydroclimate extremes: How changes in winter affect water storage and baseflow. Hydrology and Earth System Sciences 29 (17), 4055-4071, 2025.

• Tiwari, T., RA Sponseller, H Laudon. Extreme climate effects on dissolved organic carbon concentrations during snowmelt. Journal of Geophysical Research: Biogeosciences 123 (4), 1277-1288, 2018.

• Tiwari, T., F Lidman, H Laudon, W Lidberg, AM Ågren. GIS-based prediction of stream chemistry using landscape composition, wet areas, and hydrological flow pathways. Journal of Geophysical Research: Biogeosciences 122 (1), 65-79, 2017.

• Laudon, H., T Tiwari. The Krycklan Catchment Study: A unique infrastructure for field-based research on hydrology, ecology and biogeochemistry. Swedish University of Agricultural Sciences, 2025.

4. Land Use, Forest Management, and Ecosystem Impacts

• Tiwari, T., J Lundström, L Kuglerová, H Laudon, K Öhman, AM Ågren. Cost of riparian buffer zones: A comparison of hydrologically adapted site‐specific riparian buffers with traditional fixed widths. Water Resources Research 52 (2), 1056-1069, 2016.

• SK Oni, T Tiwari, JLJ Ledesma, AM Ågren, C Teutschbein, J Schelker, … Local- and landscape-scale impacts of clear-cuts and climate change on surface water dissolved organic carbon in boreal forests. Journal of Geophysical Research: Biogeosciences 120 (11), 2402-2426, 2015.

• Tiwari, T. An investigation of the hydrological potentials of an ancient Greek city, Palairos. 2009.

My work in environmental analysis combines field measurements, laboratory chemistry, and modeling to understand how carbon, nutrients, and water move through boreal landscapes. I integrate soil and water data with hydrological and biogeochemical models to link local processes to catchment-scale ecosystem responses and inform sustainable management.

As coordinator for the Krycklan Catchment, I am responsible for data management, ensuring high-quality datasets through standardized cleaning protocols. These data, including climate measurements from Svartberget, are curated and shared on the SITES portal, supporting open-access research and facilitating large-scale analyses. This role ensures that our long-term monitoring programs generate reliable, consistent, and usable datasets for studying environmental change in northern landscapes.

Coordinator of the PhD course “Watershed Ecology and Biogeochemistry”, offered through the Krycklan Catchment Study, which provides advanced training in field methods, data analysis, and ecosystem modeling for northern landscapes.

Krycklan Catchment Study

A long-term research site for hydrology, biogeochemistry, and ecosystem processes, providing valuable data on nutrient cycling, carbon storage, and forest management impacts.