## 3 Possibilities for Mitigating the Fire Disaster Risk
### Calluna Dominated WUI Fire Risk  
Land-use adaptation can help mitigate WUI fire risk under current and future climate scenarios. The Atlantic heathlands of north-western Europe, from Portugal to the Arctic Circle, are part of an ancient cultural landscape that originated soon after the introduction of livestock husbandry. Anthropogenic fire regimes were used to increase pasture value and livestock production [38]. This has changed much during the past decades and most of the _Calluna vulgaris_ heath has been left unmanaged. In these unmanaged old _Calluna_ stands, the biomass accumulates, and the lower canopy consists mainly of dead branches [39] which dry very quickly [37,40]. Compared to young stands, much more intense fires are therefore experienced in 50+ years old stands currently representative for the coastal areas of Norway south of the Polar Circle [41]. Additionally, unmanaged Norwegian heathlands gradually develop a vegetation composition where e.g., juniper, pine and spruce increase in abundance. The highly flammable resinous juniper foliage contributes significantly to the fire prone biomass [42]. In coastal Norway, the _Calluna_ stands were previously covered by snow during the winter months. However, as a result of global warming, this has changed through the last decades. For long periods during the recent winters, the ground has been snow-free, rendering the wildland susceptible to ignition and fire spread. A lack of land management (prescribed burning (PB) and  
Figure 3: (**a**) Location of the Laerdalsoyri town fire, January 18–19, 2014 [4,6] (1) and location of the recent largest WUI fires in Norway, i.e., Flatanger 15 km\({}^{2}\) (1500 ha), 28–31 January, 2014 (2), Froya 10 km\({}^{2}\) (1000 ha), 30–31 January, 2014 [4,37] (3) and Sokndal 7 km\({}^{2}\) (700 ha), 24–27 April, 2019 (4), which all started in and developed through old _Calluna_ dominated coastal heathland. (**b**) Location of Norway in Europe.  
grazing) in combination with climate changes therefore causes increasing concern, evidenced by the severe Flatanger wildfire January 2014 [37].  
This is not just a modern European problem. The 1949 Mann Gulch fire, MT, USA, made immortal in the book \"Young men and fire\" by [PERSON] [43], was to a large extent a result of recent land-management changes. The area was a national park where herbivores were excluded the preceding year, resulting in waist high cured grass that supported dangerously rapid fire spread, killing 12 smokejumpers and one ranger.  
Reestablishing PB with e.g., 10-20 years rotations and grazing can greatly reduce the WUI fire risk in _Calluna_ dominated landscapes [44, 45]. However, new and targeted prescribed burning regimes may be required in future climates, creating both new needs and opportunities for societal benefits in linking fire risk and land-use management science. This is also important regarding protection of cultural heritage buildings, e.g., remotely located Norwegian stave churches [46], exposed to potential wildfires.  
Current warning systems do not predict cold climate wildfire risk. Previously developed wildfire warning models, e.g., the Canadian Forest Fire Weather Index (FWI) system, work very well for the fuel and temperature envelopes they are designed for. However, these models are not able to predict _Calluna_ heathand sub-zero temperature fire risk. They do not predict the humidity levels in the lower canopy dead fuel [39], which has a significant bearing on the fire spread through a moisture content threshold [47]. Fundamental drying models are therefore required, but are not available today.