Freshwater Systems & Catchment Flux - CIREE
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Aerial orthomosaic of braided subarctic river channels cutting through snow-covered boreal forest

Freshwater Systems & Catchment Flux

Multi-decadal tracking of thermal regime shifts, active-layer thaw, and solute transport across subarctic braided river networks.

Theme
Environment
Location
Mackenzie Basin Field Corridor (61°18'N 120°34'W)
Timeframe
2021 — 2027
Status
Active Long-Term Hydrometric Array
01

The question

How do anomalous spring thermal pulses and accelerated permafrost thaw transform carbon solute mobilization and benthic macroinvertebrate drift in subarctic catchments?

Initiated in 2021, the Freshwater Systems investigation tracks biogeochemical fluxes across subarctic drainage networks. By integrating autonomous hydrometric loggers with high-frequency dissolved organic matter spectrofluorometry, our research team isolates the chemical signature of thawing active layer soils before nutrients reach downstream lacustrine sinks.

The multi-year dataset bridges catchment-scale hydrologic modeling with benthic biodiversity surveys, providing public resource agencies with predictive models for post-breakup water chemistry.

02

The place

Mackenzie Basin Field Corridor (61°18'N 120°34'W)

61.3058° N, 120.5739° W

The Mackenzie Basin Field Corridor spans 380 km of unregulated boreal braided channels, characterized by permafrost discontinuous zones, steep glaciofluvial banks, and extreme seasonal thermal variability ranging from -42°C in January to +28°C in July.

Field journal, waterproof notebook and water sampling vials resting on a wooden dock
03

Methods

How the evidence was gathered, step by step.

  1. 01

    High-frequency acoustic Doppler current profiling (ADCP)

  2. 02

    Excitation-emission matrix spectrofluorometry of organic carbon

  3. 03

    Continuous optical dissolved oxygen and temperature telemetry

  4. 04

    DNA metabarcoding of benthic macroinvertebrate drift assemblages

04

People

05

Outcomes

Preliminary synthesis across four hydrologic cycles indicates that early-season thermal pulses trigger a 34% increase in aromatic carbon mobilization, preceding the peak hydrograph by up to nine days. These findings have been integrated into regional watershed advisory models and published in the Journal of Hydrological Ecology.

06

Publications and citations

Journal article2025

Thermal stratification and nutrient pulses during unseasonal snowmelt in subarctic river basins

Dr. Elena Rostova, Dr. Marcus Vance, Prof. T. K. Bergmann

Journal of Hydrological Ecology, Vol. 48(3), pp. 182–199

Cite as

Rostova, E., Vance, M., & Bergmann, T. K. (2025). Thermal stratification and nutrient pulses during unseasonal snowmelt in subarctic river basins. Journal of Hydrological Ecology, 48(3), 182-199.

DOI (opens in a new tab)Read online (opens in a new tab)
07

Field media

01Braided Tributary Network During Spring Break-UpCIREE UAV Survey Unit / Mackenzie Corridor
02Autonomous Acoustic Doppler Profiling in High FlowCIREE Hydrometry Working Group
03Common Kingfisher (Alcedo atthis) Along Riparian Feeding ReachCIREE Ecological Survey / Canon 500mm f/4 IS II
Old-growth conifer forest canopy emerging through low morning mountain fog

Next chapter

Forest Ecology & Canopy Buffering