According to a new analysis, forest loss in Germany is significantly greater than previously assumed. From January 2018 to April 2021, trees were destroyed on an area of around 501,000 hectares – that corresponds to almost five percent of the entire forest area, announced the German Aerospace Center (DLR) after evaluating satellite data. That is considerably more than previously thought. The cause is “above all the unusually strong heat and drought periods in these years, which in turn have favored the infestation by harmful insects.”
The DLR research group at the Earth Observation Center (EOC) in Oberpfaffenhofen used images from the satellite to precisely quantify the loss of trees Sentinel-2 the European earth observation program Copernicus and the US satellite Landsat-8. The data showed that central Germany with its coniferous forests is mainly affected – from the Eifel to the Sauerland, the Harz Mountains and the Thuringian Forest to Saxon Switzerland. North Rhine-Westphalia alone has lost more than a quarter of its spruce forests within three years, and in some districts it was even more than two thirds.
The trees have either died or fallen victim to large-scale emergency felling. “Clear cuttings are often the last measure in the event of a massive pest infestation – in the case of spruce – to deprive the bark beetle of food and thus prevent it from spreading further,” said DLR. While deciduous trees often recover from an insect infestation, this is often not the case for conifers. However, not only spruce forests are affected by the consequences of the drought. “Our analyzes show that oak, beech and pine, the most common tree species in Germany alongside spruce, also show severe damage. The same applies to rarer species such as sycamore or larch,” said Frank Thonfeld from the EOC. The damage in recent years is “unprecedented”.
The satellite data also shows the extent of storm events in eastern Bavaria, Saxony-Anhalt and Saxony. The current storm situation over Germany will probably lead to wood having to be removed in many places, according to the forecast.
The remote sensing experts evaluated a total of more than 20,000 data sets for their forest situation report. Conclusion: “It may take even longer for the forest ecosystem to recover. It is therefore urgently necessary for Germany and Europe to take efficient measures to protect the forests quickly. Satellite-based earth observation can provide researchers and decision-makers with a data basis for this.”
Comprehensive forest information is important for forestry in order to map tree species, differentiate causes of damage and prevent negative developments through early detection. Earth observation satellites provide the necessary spatial and temporal resolution. Nevertheless, the findings from the satellite images have not yet been fully exploited by the authorities.