TY  - JOUR
PY  - 2012//
TI  - Control of the multimillennial wildfire size in boreal North America by spring climatic conditions
JO  - Proceedings of the National Academy of Sciences of the United States of America
A1  - Ali, Adam A.
A1  - Blarquez, Olivier
A1  - Girardin, Martin P.
A1  - Hély, Christelle
A1  - Tinquaut, Fabien
A1  - El Guellab, Ahmed
A1  - Valsecchi, Verushka
A1  - Terrier, Aurélie
A1  - Bremond, Laurent
A1  - Genries, Aurélie
A1  - Gauthier, Sylvie
A1  - Bergeron, Yves
SP  - 20966
EP  - 20970
VL  - 109
IS  - 51
N2  - Wildfire activity in North American boreal forests increased during the last decades of the 20th century, partly owing to ongoing human-caused climatic changes. How these changes affect regional fire regimes (annual area burned, seasonality, and number, size, and severity of fires) remains uncertain as data available to explore fire-climate-vegetation interactions have limited temporal depth. Here we present a Holocene reconstruction of fire regime, combining lacustrine charcoal analyses with past drought and fire-season length simulations to elucidate the mechanisms linking long-term fire regime and climatic changes. We decomposed fire regime into fire frequency (FF) and biomass burned (BB) and recombined these into a new index to assess fire size (FS) fluctuations. Results indicated that an earlier termination of the fire season, due to decreasing summer radiative insolation and increasing precipitation over the last 7.0 ky, induced a sharp decrease in FF and BB ca. 3.0 kyBP toward the present. In contrast, a progressive increase of FS was recorded, which is most likely related to a gradual increase in temperatures during the spring fire season. Continuing climatic warming could lead to a change in the fire regime toward larger spring wildfires in eastern boreal North America.<p />  <p>Language: en</p>
LA  - en
SN  - 0027-8424
UR  - http://dx.doi.org/10.1073/pnas.1203467109
ID  - ref1
ER  -