No great increase in forest harvesting in Europe

“We were very surprised. That such a big and sudden change could happen without anyone noticing was totally unexpected,” says Johannes Breidenbach, who was the lead author of the study

“The EU’s forest policy should be based on accurate and reliable figures. I don’t think you should harvest more than is necessary, but you shouldn’t refer to figures that aren’t correct either.”

The article in Nature is based on satellite-based forest maps. Researchers from Norway, Sweden, Finland and Switzerland, combined the satellite-based maps with observations from the Swedish and Finnish national forest inventories. The national forest inventories are measurements of forests across the country and have been carried out for more than 100 years in Norway, Sweden and Finland.

Their results showed that the results in the Nature article could not be correct.

“The huge increase was quite simply a side effect caused by the method of identifying harvesting areas having improved since 2015,” explains Breidenbach.

The researchers compared the satellite maps with more than 120,000 observations of forest on the ground, and the results showed that it was not the harvesting that had increased at all, but rather the ability of satellite imaging to detect harvesting. The measurements on the ground, in the forest, carried out by field workers of the Finnish and Swedish national forest inventories in the years before and after 2015 showed the actual harvesting, and it had not increased dramatically after 2015.

“Satellite images are a useful tool, but it’s always important to calibrate the satellite images with thorough recordings on the ground, in the forests where the trees grow,” concludes Breidenbach.