Global warming could increase climatic instability and large wildfire activity in circumboreal regions, potentially impairing both ecosystem functioning and human health. However, links between large wildfire events and climatic and/or meteorological conditions are still poorly understood, partly because few studies have covered a wide range of past climate-fire interactions. We compared palaeofire and simulated climatic data over the last 7000 years to assess causes of large wildfire events in three coniferous boreal forest regions in north-eastern Canada. These regions span an east-west cline, from a hilly region influenced by the Atlantic Ocean currently dominated by Picea mariana and Abies balsamea to a flatter continental region dominated by Picea mariana and Pinus banksiana. The largest wildfires occurred across the entire study zone between 3000 and 1000 cal. BP. In western and central continental regions these events were triggered by increases in both the fire-season length and summer/spring temperatures, while in the eastern region close to the ocean they were likely responses to hydrological (precipitation/evapotranspiration) variability. The impact of climatic drivers on fire size varied spatially across the study zone, confirming that regional climate dynamics could modulate effects of global climate change on wildfire regimes.
Institut de recherche sur les Forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, Canada;Institut des Sciences de l’Évolution—Montpellier, UMR 5554 CNRS-IRD-Université Montpellier-EPHE, Montpellier, France;Author to whom any correspondence should be addressed.;Institut de recherche sur les Forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, Canada;Institut des Sciences de l’Évolution—Montpellier, UMR 5554 CNRS-IRD-Université Montpellier-EPHE, Montpellier, France;École Pratique des Hautes Études, PSL Research University, Paris, France;Département de Géographie, Université de Montréal, Montréal, QC, Canada;GEOTOP—Geochemistry and Geodynamics Research Center, Université du Québec à Montréal, Montréal, QC, Canada;Institut de recherche sur les Forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, Canada;Centre d’Étude de la Forêt, Université du Québec à Montréal, Montréal, QC, Canada;Département de géographie and Centre d’études nordiques, Université Laval, Québec, QC, Canada;Institut de recherche sur les Forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, Canada;Institut des Sciences de l’Évolution—Montpellier, UMR 5554 CNRS-IRD-Université Montpellier-EPHE, Montpellier, France
Recommended Citation:
Cécile C Remy,Christelle Hély,Olivier Blarquez,et al. Different regional climatic drivers of Holocene large wildfires in boreal forests of northeastern America[J]. Environmental Research Letters,2017-01-01,12(3)