Citation

Wang X, Parisien MA, Flannigan MD, Parks SA, Anderson KR, Little JM, Taylor SW. Glob. Chang. Biol. 2014; 20(8): 2518-2530.

Affiliation

Department of Renewable Resources, University of Alberta, 751 General Service Building, Edmonton, T6G 2H1, AB.

Copyright

(Copyright © 2014, John Wiley and Sons)

DOI

10.1111/gcb.12590

PMID

24700739

Abstract

Given that they can burn for weeks or months, wildfires in temperate and boreal forests may become immense (eg 10(0) - 10(4) km(2) ). However, during the period within which a large fire is "active", not all days experience weather that is conducive to fire spread; indeed most of the spread occurs on a small proportion (e.g. 1 ~ 15 days) of not necessarily consecutive days during the active period. This study examines and compares the Canada-wide patterns in fire-conducive weather ('potential' spread) and the spread that occurs on the ground ('realized' spread).

RESULTS show substantial variability in distributions of potential and realized spread days across Canada. Both potential and realized spread are higher in western than in eastern Canada; whereas potential spread generally decreases from south to north, there is no such pattern with realized spread. The realized-to-potential fire spread ratio is considerably higher in northern Canada than in the south, indicating that proportionally more fire-conducive days translate into fire progression. An exploration of environmental correlates to spread show that there may be a few factors compensating for the lower potential spread in northern Canada: a greater proportion of coniferous (i.e., more flammable) vegetation, lesser human impacts (i.e. less fragmented landscapes), sufficient fire ignitions, and intense droughts. Because a linear relationship exists between the frequency distributions of PSD and SD in a fire zone, it is possible to obtain one from the other using a simple conversion factor. Our methodology thus provides a means to estimate realized fire spread from weather-based data in regions where fire databases are poor, which may improve our ability in predicting future fire activities. This article is protected by copyright. All rights reserved.

Language: en