Taking Stock – Vegetation and Climate Present Challenges
BY NIEVES FERNANDEZ-ANEZ AND FRIDA VERMINA PLATHNER
According to the World Meteorological Organization, the last eight years are on track to be the eight hottest on the books. The MetOffice predicts that 2023 will be one of the hottest years on record. This increase in temperature has been predicted for fire seasons for the last several years. However, if we look back at the data, in July 2022 the surface air temperature anomaly in comparison with the average between 1991 and 2020 was lower in the Scandinavian peninsula; this contrasts with the temperature increase that was observed for other months in that year (June and August included).
The Scandinavian peninsula presents several difficulties when predicting fire behaviour due to the variability of vegetation types, involving three main fire scenarios. First, heather and grass are predominant fire carriers on the west coast; these fuels are sensitive to moisture content, easily losing water and becoming fire prone when rainfall is reduced. These fuel types constitute the largest hazard to health and the built environment in Sweden and Norway, with a spike in injuries and damage during winter and spring. Rainfalls are frequent at the coast of both countries while the interior is drier. In recent years, northern countries have become wetter with more precipitation, but at the same time, the periods without precipitation have been longer in Norway and parts of Sweden, providing longer dry periods that can trigger fires in vegetation. These dry periods are more common during winter and spring, and these months are the most dangerous regarding fires in heather and grass. Mature conifer production forest is the main stand type in the border between both countries, as well as the entire inland of Sweden. The general lack of ladder fuels makes crown fires in this region rare; instead, the fire is carried by the continuous cover of feather mosses. Northern and mid-boreal forests are more sensitive to summer weather compared to southern/nemo-boreal forests due to a more closed canopy in the south, shielding the surface fuel moisture from evaporating. This means there could be some divergence between future fire regimes in the Nordic region, even with similar changes in climate.
Finally, the North is known by the peat forming its soil structure. Zombie fires (smouldering fires, essentially flameless forms of combustion) inside the Arctic circle are attracting attention nowadays as a clear representation of the new scenarios caused by climate change.
One of the main forest fire-related activities that needs to be mentioned is prescribed fire, with significant differences between Sweden and Norway. In Sweden, prescribed fires are mainly carried out by large forestry companies for environmental certification and by the county administrative boards, however anyone is allowed to perform burning activities with the permission of the landowner, unless a local fire ban has been invoked (typically when FWI exceeds 17). Norway has implemented new policies controlling prescribed fire; firefighters, stakeholders and researchers work together to ensure that prescribed burns take place in a safe way and that there are no out-of-control fires.
Norway is known for having good forest fire preparedness. Local farmers and volunteers are an invaluable resource in the forest fire context. The fire season is framed by a general campfire ban from April 15 to Sept. 15, when it’s illegal to light campfires or barbecues in or near forests or other open land. Norway does not have specific resources for forest fires, but the Norwegian Directorate for Civil Protection is responsible for a management support group formed by 13 fire chiefs that can be contacted to support the use of a helicopter when it is needed. On the equipment side, Norway does not own helicopters for fire fighting, but has an agreement with a private helicopter company. Normally, a helicopter is centrally located in the eastern part of Norway, and the number of helicopters can be increased, as well as their locations. In contrast, after the 2014 and 2018 high-profile fires in Sweden overwhelmed suppression capacities, national efforts have been made to take prevention actions, including a program for helicopter and fixed-wing suppression support as well as updates in the Swedish Civil Protection Act that demand co-operation between rescue services at the level of command and control; this has led to more prompt requests for aerial support when weather conditions are unfavorable. Yet, despite increased capacity at national and regional levels, concern is growing over the shortage of part-time rescue personnel in rural areas.
Sweden and Norway are starting to face new challenges that are expected to worsen in the coming years but are learning from recent incidents. There is a significant need for specific support and resources focused exclusively on forest fires that so far has not been implemented.
ABOUT THE AUTHORS
Nieves Fernandez-Anez has been an associate professor at the Western Norway University of Applied Sciences since 2018. Before that, she did her PhD at Universidad Politecnica de Madrid and worked as a postdoctoral researcher at Imperial College, London. Her research interests are focused on the study of flammability and fire behaviour of organic materials, both in their natural form and transformed to reutilise them. Currently, she leads a project focused on the prediction of spread of wildfires in Scandinavian vegetation, and a working group on modelling fire behaviour in the WUI, both funded by the Norwegian Research Council. Fernandez-Anez also leads a working group on the COST Action Firelinks.
Frida Vermina Plathner is with the Department of Fire Technology, RISE Research Institutes of Sweden. Her research interests are wildfire behaviour in boreal Europe, fuel modelling, and forest and garden features as passive wildfire protection systems. She is currently doing her postdoc on Swedish forest fuels for the Swedish Civil Contingency Agency.
