Surface CO₂ Exchange Dynamics across a Climatic Gradient in McKenzie Valley: Effect of Landforms, Climate and Permafrost ...

• Main Authors: Startsev, Natalia, Bhatti, Jagtar S., Jassal, Rachhpal S.
• Format: Text
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2019
• Subjects: Mackenzie Valley; Peat; Peat plateau; permafrost; Subarctic
• Online Access: https://dx.doi.org/10.14288/1.0379044; https://doi.library.ubc.ca/10.14288/1.0379044

Northern regions are experiencing considerable climate change affecting the state of permafrost, peat accumulation rates, and the large pool of carbon (C) stored in soil, thereby emphasizing the importance of monitoring surface C fluxes in different landform sites along a climate gradient. We studied surface net C exchange (NCE) and ecosystem respiration (ER) across different landforms (upland, peat plateau, collapse scar) in mid-boreal to high subarctic ecoregions in the Mackenzie Valley of northwestern Canada for three years. NCE and ER were measured using automatic CO₂ chambers (ADC, Bioscientific LTD., Herts, England), and soil respiration (SR) was measured with solid state infrared CO₂ sensors (Carbocaps, Vaisala, Vantaa, Finland) using the concentration gradient technique. Both NCE and ER were primarily controlled by soil temperature in the upper horizons. In upland forest locations, ER varied from 583 to 214 g C·m⁻²·year⁻¹ from mid-boreal to high subarctic zones, respectively. For the bog and peat ...