University of Michigan
Department of Ecology and Evolutionary Biology

Large forest regions in Canada are apparently about to experience rapid change. Based on models, scientists can now show that there are threshold values for wildfires just like there are for epidemics. Large areas of Canada are apparently approaching this threshold value and may in future exceed it due to climate change.

As a result both the area burnt down annually and the average size of the fires would increase, according to Professor Mercedes Pascual, Richard Zinck, former visiting research investigator, and their colleague at the Helmholtz Centre for Environmental Research (UFZ), Volker Grimm. Their findings were published in the December issue of the journal The American Naturalist. The strategies for combating wildfires in large parts of Canada should therefore be reconsidered.

Small changes in the fire propagation parameters have a great impact on the size of the fires. Gradual changes, such as those which can be expected due to climate change, can therefore result in an abrupt and sharp increase in the size of the fires.

The scientists were also interested in the parallels with disease propagation. Prevention strategies, which reduce combustible material, are in a way similar to the vaccinations which are used against the spread of diseases such as the measles. Here too there is a threshold value above which a disease spreads and below which it falls. Other modelers from the UFZ were therefore able to turn this theoretical threshold value into a practical value. With foxes it was shown that only 60 per cent had to be vaccinated against rabies in order to successfully combat the disease. The scientists therefore hope to find out more in future studies which cover both disciplines.

The research was widely covered by the media. Helmholtz Centre for Environmental Research – UFZ press release

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