Silva Fennica : quarterly issues : 38(3) : sa383253.htm

Markku Larjavaara, Timo Kuuluvainen, Heidi Tanskanen & Ari Venäläinen. 2004.

Variation in forest fire ignition probability in Finland

Silva Fennica 38(3): 253–266

We examined climate-caused spatio-temporal variation of forest fire ignition probability in Finland based on empirical ignition experiments and 37 years of meteorological data from 26 meteorological stations scattered across Finland. First, meteorological data was used in order to estimate the variation in forest fuel moisture content with the model of the Finnish forest fire risk index. Second, based on data from empirical ignition experiments, fuel moisture content was linked with forest fire ignition probability. In southern Finland average forest fire ignition probability typically peaks in late May and early June, whereas in the northern part of the country the peak occurs at the end of June. There was a three-fold difference in the average annual ignition probability between the north-eastern part (3%) and south-western part of the country (9%). The observed differences in fire ignition probability suggest that the characteristics of the natural fire regime also vary considerably in the southern versus the northern part of the country.

ignition, forest fuel moisture, forest fire, fire regime

University of Helsinki, Dept of Forest Ecology, FI-00014 University of Helsinki, Finland. E-mail

Received 21 July 2003 Accepted 4 June 2004
ISSN 0037-5330

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