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With pests and climate change in mind, Finland’s forest legislation was mended

The Forest Damage Prevention Act of Finland focuses on maintaining the good health and growing conditions of forests. The act’s regulations are therefore pre-emptive: their purpose is to prevent large-scale forest damage, especially those caused by pest insects. The regulations targeting insect damage must, however, be continuously updated, as many pest insects are benefitting from ongoing climate change. Pest insects are key species in the creation of dead wood, however, so the law must always strike a balance between the prevention of major pest outbreaks and the necessary formation of key elements of forest diversity, such as deadwood.  

Spruce bark beetle had advanced – the law was outdated

The spruce bark beetle (Ips typographus) is currently the most severe pest of spruce in Europe. In Finland, a key element of the related law is to maintain the spruce bark beetle populations at a low level. The species reproduces very efficiently in any fresh and damaged spruce roundwood it can find in the forest, whether fallen by storm, or cut and stacked by a harvester.

The law thus mandates that all harvested or damaged spruce roundwood must be removed from the forest before the next generation of beetles growing under the bark emerges and spreads into the surrounding forest. The fixed dates of when this is to be done were, however, falling behind. Researchers studied weather conditions over a 20-year period, combined them with local data on bark beetle damage and population levels, and concluded that there were areas where the law was more often failing than functioning: the next generation of beetles had already matured and left the spruce logs before the logs were removed from the forests. 

Research met practice as the new law came into order

In March 2021, the findings, along with the research-based recommendations were compiled in a detailed report and sent to the Ministry of Forestry and Agriculture: the dates by which spruce roundwood is to be removed must be changed, and the removal must happen earlier. The researchers also made a separate cost analysis, showing that any costs to logistics due to the changed will be minuscule, especially if compared to a case where a non-functioning law results in more bark beetle damage. After hearings, discussions, and rounds of comments, the new law came into order on 1st January, 2022, with changes following those recommended by research. 

“This was a nice example of how research was taken into practice. In this case it was also encouraging for the future, as we know that the situation regarding forest damage is changing rapidly”, commented Tiina Ylioja and Markus Melin, the principal investigators of the project. 

Risk of bark beetle damage was reduced – for now

While the new law will reduce the risk of damage caused by storing harvested or damaged roundwood, the situation must be continuously followed, as climate change is proceeding rapidly, especially in the boreal zone. Yet, it is equally important to always consider the balance between preventing pest outbreaks and maintaining the natural cycle of tree mortality and a continuous flow of dead wood. 

“After all, if we strip our forests of their dead wood or diversity, the damage will be more severe than climate change or any pest could ever do”, Melin continued. 

Takarajoja kuusipuutavaran kuljettamiseen pois metsistä oli aikaistettava, jotta tukkien kaarnan alla kasvavat kirjanpainajat eivät ehdi levitä ympärysmetsiin.

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