Temperature and fuel availability control fire size/severity in the boreal forest of central Northwest Territories, Canada

QUATERNARY SCIENCE REVIEWS

卷:250

Article

Gaboriau, Dorian M.^1,2  Remy, Cecile C.³  Girardin, Martin P.^4,5  Asselin, Hugo^1,4  Hely, Christelle^2,6,7  Bergeron, Yves^4,7  Ali, Adam A.^2,7 

[1] Univ Quebec Abitibi Temiscamingue, Sch Indigenous Studies, 445 Blvd Univ, Rouyn Noranda, PQ J9X 5E4, Canada

[2] UMR 5554 CNRS IRD Univ Montpellier EPHE, Inst Sci Evolut, 2 Pl Eugene Bataillon, F-34095 Montpellier, France

[3] Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA

[4] Univ Quebec Montreal, Ctr Forest Res, POB 8888,Stn Ctr Ville, Montreal, PQ H3C 3P8, Canada

[5] Canadian Forest Serv, Nat Resources Canada, Laurentian Forestry Ctr, 1055 Rue PEPS,POB 10380, Quebec City, PQ G1V 4C7, Canada

[6] PSL Univ, Ecole Prat Hautes Etud, Paris, France

[7] Univ Quebec Abitibi Temiscamingue, Forest Res Inst, 445 Blvd Univ, Rouyn Noranda, PQ J9X 5E4, Canada

关键词: Large wildfires;    Charcoal;    Pollen;    Fire size;    Lake sediments;    Vegetation dynamics;    Climate change;    Holocene;   

DOI  :  10.1016/j.quascirev.2020.106697

来源: Elsevier

【 摘 要 】

The north-central Canadian boreal forest experienced increased occurrence of large and severe wildfires caused by unusually warm temperatures and drought events during the last decade. It is, however, difficult to assess the exceptional nature of this recent wildfire activity, as few long-term records are available in the area. We analyzed macroscopic sedimentary charcoal from four lakes and pollen grains from one of those lakes to reconstruct long-term fire regimes and vegetation histories in the boreal forest of central Northwest Territories. We used regional estimates of past temperature and hydrological changes to identify the climatic drivers of fire activity over the past 10,000 years. Fires were larger and more severe during warm periods (before ca. 5000 cal yrs. BP and during the last 500 years) and when the forest landscape was characterized by high fuel abundance, especially fire-prone spruce. In contrast, colder conditions combined with landscape opening (i.e., lower fuel abundance) during the Neoglacial (after ca. 5000 cal yrs. BP) were related with a decline in fire size and severity. Fire size and severity increased during the last five centuries, but remained within the Holocene range of variability. According to climatic projections, fire size and severity will likely continue to increase in central Northwest Territories in response to warmer conditions, but precipitation variability, combined with increased abundance of deciduous species or opening of the landscape, could limit fire risk in the future. Crown Copyright (C) 2020 Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free