Has timber harvesting in Europe increased in recent years? Yes, say researchers from various countries, but nowhere near as much as a study on “Abrupt increase in harvested forest area in Europe after 2015” published in Nature in the summer of 2020 claims. In a new study, a European team including Prof. Dr. Jürgen Bauhus, Chair of Silviculture and Prof. Dr. Marc Hanewinkel, Chair of Forest Economics and Forest Planning at the University of Freiburg, Germany, shows that the timber harvest has increased by only 6 percent in recent years, not 69 percent as previously postulated. The erroneous analysis was due to an increase in the sensitivity of the underlying satellite data. In addition, the earlier publication had mistakenly classified some forest areas affected by natural disturbances as timber harvest, explain the authors of the current study, which has now also appeared in Nature.
For the study at that time, the authors had used satellite data to observe the change in the forested area. Based on the data, they had concluded that timber harvesting in European forests had increased by 69 percent as of 2016. The team from the European Commission’s Joint Research Centre (JRC) suggested that this increase was due to growing demand for timber, which was driven by the European Union’s (EU) bioeconomy and bioenergy policies. The publication sparked significant scientific and political debate, as the timing of the study’s release coincided with deliberations by the EU Parliament and Council on the EU’s post-2020 forest strategy.
In the study just published, 30 researchers from 13 European countries prove that the results and conclusions of the JRC study were incorrect: They claim that the analysis on large forest losses was mainly due to methodological errors. One of the errors in the JRC study, the authors of the current study explain, was that it underestimated how satellite-based imagery and the methods used to analyze it have improved over time. At the same time, there have been changes in forests due to natural disturbances, such as drought, storm and bark beetle damage, that were often incorrectly reported as timber harvests in the JRC study.
Many studies on forest conditions addressed to policy makers and society are based on data from remote sensing methods. Therefore, Dr. Marc Palahí, Director of the European Forest Institute in Joensuu in Finland, who led the new study, emphasizes: “In the future, forest data should be evaluated more carefully. A wide range of methodological issues and factors must be taken into account. This requires increased cooperation between the European Commission and Member States to enable better-informed, forest-related policymaking.”
More intensive timber harvesting is not to be criticized in general, says Hanewinkel: “If you look at what has happened in the last three years, it would have made much more sense – not only from an economic point of view – to use larger quantities of the dead trees as part of a planned forest restoration. During this period, around 30 million cubic meters of wood were left in the forests in Germany because they could no longer be used economically due to disturbances such as storms. To a larger extent, however, this was high-quality construction timber. Such a situation does not make sense, not only from an economic point of view.”
Bauhus does not share the conclusion of the criticized 2020 study that timber harvesting at such a high level as they describe would severely impair the EU vision of forest-based climate protection after 2020: “The actual harvesting volumes in Europe are not a matter of concern. At present, significantly less wood is harvested in the EU than grows back, so that the wood stocks in European forests have steadily increased. The study also ignored the fact that efficient use of the harvested wood also provides climate protection functions, especially if wood use is geared towards longevity and multiple use. The climate protection performance of forests is not threatened by sustainable timber harvesting, but by increasing disturbances caused by climate change. Therefore, policymakers should push to meet climate mitigation targets and adapt forests to unavoidable climate change.”
Palahí, M., Valbuena, R. et al. (2021): Concerns about reported harvests in European forests. In: Nature. DOI: 10.1038/s41586-021-03292-x