Wildfires change summertime dissolved organic matter in boreal headwater streams
Abstract
Boreal forests export large amounts of terrestrial carbon into downstream waters as dissolved organic material (DOM), but how increasing wildfire frequency affects this flux remains understudied. If more DOM is exported from land into water after wildfire and/or this DOM is more readily transformed by microbes, the net loss of carbon from terrestrial ecosystems after wildfire may be greater than currently estimated. Here we investigated how wildfire changes DOM exported from boreal forests into headwater streams in northwestern Ontario, Canada over a summer growing season. We compared the concentration and molecular composition of DOM between 10 recently burned and 10 undisturbed catchments using optical spectroscopy and ultra‐high‐resolution mass spectrometry. We found a 29% increase, on average, in DOM concentrations in the streams of burned catchments in August only. DOM in burned …
abstract: “Boreal forests export large amounts of terrestrial carbon into downstream waters as dissolved organic material (DOM), but how increasing wildfire frequency affects this flux remains understudied. If more DOM is exported from land into water after wildfire and/or this DOM is more readily transformed by microbes, the net loss of carbon from terrestrial ecosystems after wildfire may be greater than currently estimated. Here we investigated how wildfire changes DOM exported from boreal forests into headwater streams in northwestern Ontario, Canada over a summer growing season. We compared the concentration and molecular composition of DOM between 10 recently burned and 10 undisturbed catchments using optical spectroscopy and ultra‐high‐resolution mass spectrometry. We found a 29% increase, on average, in DOM concentrations in the streams of burned catchments in August only. DOM in burned …” authors:
- E_Matula
- E_Emilson
- E_Smenderovac
- Jeremy A Fonvielle
- E_Freeman
- Andrew J Tanentzap featured: false projects: [] publication: ‘Journal of Geophysical Research: Biogeosciences’ publication_short: '' publication_types:
- “2” date: ‘2025-11-01T00:00:00Z’ publishDate: ‘2026-01-02’ title: ‘Wildfires change summertime dissolved organic matter in boreal headwater streams’ url_pdf: “https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2025JG008980" url_source: “https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2025JG008980"
Erin Matula
M.Sc. Student, Trent University
I grew up in the middle of the northwoods of Wisconsin following my silviculturalist mom around on her field days which utterly convinced me ecology was the only path for me. I just graduated from Northern Michigan University in Marquette, MI with a B.S. in Environmental Science with a Water Resources Concentration. During my undergrad, I was a reserach assistant at the University of Wisconsin-Madison Center for Limnology Trout Lake Station with Susan Knight and Gretchen Gerrish and the Lac du Flambeau Band of Lake Superior Chippewa on a wild rice phenology project. Now, I’m starting my M.Sc. at Trent University in January working with boreal systems, fire ecology, and eddy flux.
Erik J.S. Emilson
Research Scientist, Watershed Ecology Team Lead, Associate Editor CJFR
I am interested in how forests support freshwater ecosystem services. My research combines microbial and molecular approaches to undertand how forest productivity and disturbances affect ecosystem functions in headwater streams and lakes.
Emily Smenderovac
Watershed Ecologist
Trained in microbial ecology and bioinformatic analysis of community datasets.
