International Journal of Wildland Fire International Journal of Wildland Fire Society
Journal of the International Association of Wildland Fire

Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

Different Historical Fire - Climate Patterns in California

Jon Keeley , Alexandra Syphard

Abstract

There are five important lessons on fire ─ climate relationships in California 1) Seasonal variations in temperature have had minimal control on area burned in the lower elevation mostly non-forested landscapes. 2) Temperature has been a significant factor in higher elevation montane forests, however, it varied with season; winter showed no significant effect, whereas spring and summer temperatures were determinants of area burned. 3) Precipitation is a controller of fires in forests, with drier years resulting in greater area burned on most USFS lands in the state, but the effect of current year precipitation was decidedly less on lower elevation Cal Fire lands. 4) In grass-dominated foothills the magnitude of prior year rainfall was positively tied to area burned in the following year, and we hypothesize that this is tied to greater fuel volume in the year following high rainfall. 5) The strongest fire ─ climate models were on USFS lands in the Sierra Nevada Mountains, and these explained 42 – 52% of the variation in area burned, however the models changed over time with winter and spring precipitation being the primary drivers in the first half of the 20th century, but replaced by spring and summer temperatures after 1960.

WF16102  Accepted 26 February 2017

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