Post-fire forest management methods in Sweden: Societal perception and biological aspects

Sammanfattning: With an increasing global temperature, at rates twice as fast as the global average in the northern boreal forests, an increasing wildfire frequency is to be expected. Previous studies have shown that forest areas in Eurasia with high risk of wildfires today are expected to more than double in size in the following 30 years. This will have a great impact on the fire regime, biodiversity, economic and social quality as well as ecosystem services between forest and society in these areas. Sweden is one of many countries at risk, with forest cover being 60% of the country's total land cover. Furthermore, the forest products industry accounts for between 9-12% of Swedish industry’s total employment, exports, sales and added value. It is needless to say that the Swedish population is largely dependent on the forest and will be affected by these altered fire regimes on an biological and social level. However, little research has been done on the societal perceptions of wildfires and different post-fire forest management methods in the country. Furthermore, knowledge about societal perceptions in combination with biological aspects of different post-fire forest management options is of great interest. In this study, I analyzed vegetation data from five boreal forest sites in the Ljusdal fire complex, where 9500 hectare of forest burned down during the summer season 2018. I analyzed the vegetation cover based on fire intensity and the post-fire forest management method that was applied. Moreover, I also conducted a survey in order to gain perspective of the Swedish population's perceptions of wildfires and the forest management methods that could be realized after a wildfire. The results showed that vascular plant cover was significantly different between sites that had been affected by different degrees of fire severity as well as different post-fire forest management methods. Three years after the fire, the vascular plant ground cover and naturally generated pine seedling number was the highest at both of the unlogged fire-severity sites in contrast to the salvage-logged sites. However, the pine-seedlings proved slightly taller at the salvage-logged sites than at the unlogged sites. Regarding the societal perceptions, a small majority of participants prefered salvage-logging (42,4%) over leaving the forest unlogged (39,9%). There also proved a relationship between forest ownership and logging method, where people who own forest were more inclined to pick salvage-logging as the prefered post-fire forest management option. If forest owners as well as people with interest in forests were made aware of the forest soil properties potentially being negatively altered many decades post disturbance, their opinion might prove different. After all, leaving a forest unlogged might lead to a higher economical- and biological value than that which would be provided short-term by salvage-logging. Furthermore, a lot of the time, money and energy of forest owners could be spared since less interaction would be necessary and equal, if not higher, forest value would be achieved.