Olson et al. (2025) Long‐Term Stream Chemistry Patterns in a Boreal Watershed Underlain With Discontinuous Permafrost

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Journal of Geophysical Research Biogeosciences
• Year: 2025
• Date: 2025-11-29
• Authors: K. L. Olson, Jeremy B. Jones
• DOI: 10.1029/2025jg009126

Research Groups

Caribou Poker Creeks Research Watershed, Alaska, USA

Short Summary

This study investigated over 20 years of stream chemistry and climate trends in boreal catchments with varying permafrost extents to understand how altered flowpaths and climate change affect solute transport. It found significant declines in dissolved organic carbon (DOC) and partial pressure of carbon dioxide (pCO₂) in sub-catchments with higher permafrost extent, with moisture and discharge being key abiotic drivers.

Objective

• To evaluate long-term patterns (over 20 years) in dissolved inorganic carbon (DIC, pCO₂), dissolved organic carbon (DOC), nitrogen (dissolved organic nitrogen, NO₃⁻), geochemical solutes (Ca²⁺, Mg²⁺, SO₄²⁻), and discharge to determine how altered terrestrial flowpaths and climate change-related trends in temperature and precipitation have transformed solute transport in high-latitude watersheds during the ice-free season.

Study Configuration

• Spatial Scale: Multiple catchments within the Caribou Poker Creeks Research Watershed, with permafrost extents ranging from 4% to 53%.
• Temporal Scale: Over a 20-year period, focusing on long-term trends during the ice-free season.

Methodology and Data

• Models used: Thiel-Sen analysis, mixed effects model.
• Data sources: Long-term stream chemistry measurements (DIC, pCO₂, DOC, DON, NO₃⁻, Ca²⁺, Mg²⁺, SO₄²⁻), discharge measurements, and climate trends (temperature, precipitation).

Main Results

• Significant declines were observed in dissolved organic carbon (DOC) ranging from -109.0 to -169.9 μg L⁻¹ yr⁻¹ and partial pressure of carbon dioxide (pCO₂) at -24.1 ppmv yr⁻¹ in sub-catchments with higher permafrost extent.
• The catchment with the highest permafrost extent exhibited the most pronounced changes, contrasting with fewer or opposite trends in catchments with lower permafrost extent.
• Model results indicated that moisture conditions and discharge are significant abiotic factors (p < 0.05), particularly influencing changes in organic solutes.

Contributions

• Provides a long-term (20+ years) analysis of stream chemistry and climate trends in boreal permafrost catchments, demonstrating the differential impact of permafrost thaw on solute transport based on permafrost extent.
• Quantifies the importance of abiotic factors like moisture and discharge in regulating organic solute dynamics in high-latitude headwater streams under a changing climate.
• Highlights the potential consequences of permafrost thaw for in-stream communities and downstream solute yields.

Funding

Not specified in the abstract.

Citation

@article{Olson2025LongTerm,
  author = {Olson, K. L. and Jones, Jeremy B.},
  title = {Long‐Term Stream Chemistry Patterns in a Boreal Watershed Underlain With Discontinuous Permafrost},
  journal = {Journal of Geophysical Research Biogeosciences},
  year = {2025},
  doi = {10.1029/2025jg009126},
  url = {https://doi.org/10.1029/2025jg009126}
}