RT Journal Article
T1 Fire as a removal mechanism of pyrogenic carbon from the environment: effects of fire and pyrogenic carbon characteristics
A1 Doerr, Stefan H.
A1 Santín, Cristina
A1 Merino García, Agustín
A1 Belcher, Claire M.
A1 Baster, Greg
K1 Black carbon
K1 Boreal forest
K1 Carbon balance
K1 Charcoal
K1 Charcoal reflectance
K1 Wildfire
K1 Management burn
K1 Thermal analysis
AB Pyrogenic carbon (PyC, charcoal) is produced during vegetation fires at a rate of ~116–385 Tg C yr−1 globally. It represents one of the most degradation-resistant organic carbon pools, but its long-term fate and the processes leading to its degradation remain subject of debate. A frequently highlighted potential loss mechanism of PyC is its consumption in subsequent fires. However, only three studies to date have tested this hypothesis with reported losses of <8–37%, with the effects of PyC chemical characteristics and fire conditions on PyC loss in wildfires remaining unexplored. To address this, we placed materials with different degrees of thermal and chemical recalcitrance (A: wildfire charcoal, B: slash-pile charcoal, C: pine wood and D: cedar wood) on the ground surface just prior to a high-intensity and a low-intensity boreal forest wildfire. Mass losses were highly variable and dependent on fire- and sample characteristics. Mass losses across both fires (as % of dry weight) were for A: 66.5 ± 25.2, B: 41.7 ± 27.2, C: 78.2 ± 14.9, and D: 83.8 ± 18.9. Mass loss correlated significantly with maximum temperature (Tmax) recorded on sample surfaces (r = 0.65, p = 0.01), but only weakly (r = 0.33) with time >300°C. Mass losses also showed a significant negative correlation (r = −0.38, p = 0.05) with thermal recalcitrance (T50) determined using Differential Scanning Calorimetry (DSC) and Tmax with charcoal reflectance (Ro) determined after the fires (r = 0.46, p = 0.05). Losses in the high-intensity fire were significantly higher (p = 0.05) than in the low-intensity fire, but the latter had a higher rate of conversion of fuel to PyC. Our results demonstrate that exposure to fire can indeed be a significant removal mechanism for PyC that remains exposed on the ground after a previous fire. The losses found, however, are likely to represent an extreme upper range as most PyC produced in a fire would not remain exposed on the ground surface by the time the next fire occurs. Our data also demonstrate, for real wildfire conditions, the (i) contrasting resistance of different PyC types to combustion and (ii) contrasting net PyC losses between different fire intensities. The DSC and reflectance (Ro) results support the usefulness of these analyses in reflecting thermal degradation resistance and temperature exposure under actual wildfire conditions
PB Frontiers Media
YR 2018
FD 2018
LK http://hdl.handle.net/10347/22290
UL http://hdl.handle.net/10347/22290
LA eng
NO Doerr SH, Santín C, Merino A, Belcher CM and Baxter G (2018) Fire as a Removal Mechanism of Pyrogenic Carbon From the Environment: Effects of Fire and Pyrogenic Carbon Characteristics. Front. Earth Sci. 6:127. doi: 10.3389/feart.2018.00127
NO Fieldwork and sample analysis was supported a Leverhulme Trust grant to SD (RPG-2014-095) and a European Research Council Starter Grant ERC-2013-StG-335891-ECOFLAM to CB. During manuscript preparation, SD was supported by a Leverhulme Trust Fellowship (RF-2016-456\2) and CS by a Sêr Cymru Fellowship co-funded by European Union’s Horizon 2020 research and innovation programme (Marie Skłodowska-Curie grant agreement No 663830) Special thanks go to Westly Steed and the Department of Environment and Natural Resources, Government of the Northwest Territories, Canada for supporting the field work Thanks also the staff of FPInnovations, Alberta Environment and Sustainable Resource Development and the residents of Fort Providence for their support during fieldwork
DS Minerva
RD 24 abr 2026