Have European forests grown older or are they actually getting younger?

Europe’s forests have changed drastically since the 1950s when forest and land use management caught up with the effects of the World War II. The forest area increased by 30% between 1950 and 2000 as low productive agricultural lands were abandoned and many countries were carrying out active afforestation. Today, forest management is very much in the focus of attention especially in the light of increasing the use of forest biomass for energy.

One of the most common perceptions has been – until now – that European forests were young after the World War II due to the extensive cuttings carried out following the war. But were our forests really younger then? A group of international scientists have now compiled detailed information from historic forest inventories to reconstruct forest age class structure changes from 1950 to 2010. The results are partly surprising, because the average age of forests today is actually a few years lower than in 1950. The share of old forests declined quite strongly from 1950 to 1980, when the average age was at its minimum. Only after 1980 there has been a slight increase in the share of older forests.

The scientists used an innovative combination of inventory data and backcasting to reconstruct and map the forest age class structure from 1950 to 2010. This information is now used in the GHG-EUROPE project to improve the representation of forest management history in biogeochemical simulation models that are run to study the human influence on the greenhouse gas (GHG) fluxes of European land use systems.

What do these results tell us about past forest management? The results now show that since the 1950s, our forests became younger – but at the same time they gained in growing stock and stored more carbon. This means that the old forests that were cut in the 1950–1970s probably looked different from old forests today: they were less dense and probably less uniform in age than the typical conifer stands that replace them. The full article "Reconstructed forest age structure in Europe 1950-2010" by Terhi Vilén and others has been published in Forest Ecology and Management and is available at the journal website.