Hydrologic and Landscape Controls on Dissolved Organic Matter Composition Across Western North American Arctic Lakes

Authors

Martin R. Kurek, Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL, USA
Fenix Garcia-Tigreros, School of Environmental and Forest Sciences, University of Washington, Seattle, WA, USA
Kimberly P. Wickland, United States Geological Survey, Water Resources Mission Area, Boulder, CO, USA
Karen Frey, Clark UniversityFollow
Mark M. Dornblaser, United States Geological Survey, Water Resources Mission Area, Boulder, CO, USA
Robert G. Striegl, United States Geological Survey, Water Resources Mission Area, Boulder, CO, USA
Sydney F. Niles, National High Magnetic Field Laboratory Ion Cyclotron Resonance Facility, Tallahassee, FL, USA
Amy. M. McKenna, National High Magnetic Field Laboratory Ion Cyclotron Resonance Facility, Tallahassee, FL, USA
Pieter J.K Aukes, Department of Earth & Environmental Studies, University of Waterloo, Waterloo, ON, Canada
Ethan D. Kyzivat, Department of Earth, Environmental & Planetary Sciences, Institute at Brown for Environment & Society, Brown University, Providence, RI, USA
Chao Wang, Department of Earth, Marine and Environmental Sciences, University of North Carolina, Chapel Hill, NC, USA
Tamlin M. Pavelsky, Department of Earth, Marine and Environmental Sciences, University of North Carolina, Chapel Hill, NC, USA
Laurence C. Smith, Department of Earth, Environmental & Planetary Sciences, Institute at Brown for Environment & Society, Brown University, Providence, RI, USA
Sherry L. Schiff, Department of Earth & Environmental Studies, University of Waterloo, Waterloo, ON, Canada
David Butman, School of Environmental and Forest Sciences, University of Washington, Seattle, WA, USA
Robert G. M. Spencer, Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL, USA

Document Type

Article

Abstract

Northern high-latitude lakes are hotspots for cycling dissolved organic carbon (DOC) inputs from allochthonous sources to the atmosphere. However, the spatial distribution of lake dissolved organic matter (DOM) is largely unknown across Arctic-boreal regions with respect to the surrounding landscape. We expand on regional studies of northern high-latitude DOM composition by integrating DOC concentrations, optical properties, and molecular-level characterization from lakes spanning the Canadian Taiga to the Alaskan Tundra. Lakes were sampled during the summer from July to early September to capture the growing season. DOM became more optically processed and molecular-level aromaticity increased northward across the Canadian Shield to the southern Arctic and from interior Alaska to the Tundra, suggesting relatively greater DOM incorporation from allochthonous sources. Using water isotopes (δ¹⁸O-H₂O), we report a weak overall trend of increasing DOC and decreasing aromaticity in lakes that were hydrologically isolated from the landscape and enriched in δ¹⁸O-H₂O, while within-region trends were stronger and varied depending on the landscape. Finally, DOC correlated weakly with chromophoric dissolved organic matter (CDOM) across the study sites, suggesting that autochthonous and photobleached DOM were a major component of the DOC in these regions; however, some of the northernmost and wetland-dominated lakes followed pan-Arctic riverine DOC-CDOM relationships, indicating strong contributions from allochthonous inputs. As many lakes across the North American Arctic are experiencing changes in temperature and precipitation, we expect the proportions of allochthonous and autochthonous DOM to respond with aquatic optical browning with greater landscape connectivity and more internally produced DOM in hydrologically isolated lakes.

Publication Title

Global Biogeochemical Cycles

Publication Date

1-2023

Volume

37

Issue

1

ISSN

1944-9224

DOI

10.1029/2022GB007495

Keywords

Arctic regions, Alaska, Canadian Shield, dissolved organic matter, wetlands, lakes, landscapes, growing season

Repository Citation

Kurek, Martin R.; Garcia-Tigreros, Fenix; Wickland, Kimberly P.; Frey, Karen; Dornblaser, Mark M.; Striegl, Robert G.; Niles, Sydney F.; McKenna, Amy. M.; Aukes, Pieter J.K; Kyzivat, Ethan D.; Wang, Chao; Pavelsky, Tamlin M.; Smith, Laurence C.; Schiff, Sherry L.; Butman, David; and Spencer, Robert G. M., "Hydrologic and Landscape Controls on Dissolved Organic Matter Composition Across Western North American Arctic Lakes" (2023). Geography. 562.
https://commons.clarku.edu/faculty_geography/562