The bark beetle disaster affected surrounding states in 2023

In 2023, the large-scale overgrowth of bark beetles on spruce trees in the Central European region, which includes Austria, the Czech Republic, Germany, Poland, and Slovakia, showed “uneven stagnation.” Overall, the amount of infested material remained approximately the same as in 2022, totalling around 30 million cubic meters.

The situation varied among individual countries. Only the Czech Republic and Poland reported a decrease in infestation levels. In the Czech Republic, this decline was primarily due to the extremely high infestation levels observed in previous years, while Poland’s decrease was attributed to an already generally low level of infestation.

In contrast, Slovakia, Austria, and Germany saw an overall increase in the volume of bark wood in 2023. Germany recorded the highest increase, rising from approximately 16 million m³ to over 18 million m³. Slovakia experienced a slight year-on-year increase, moving from 1.8 million m³ to around 2 million m³. Similarly, Austria’s bark wood volume grew marginally from 3.7 million m³ to 3.9 million m³.

In 2023, the Czech Republic and Germany remained the most affected countries by the bark beetle disaster. Of the approximately 30 million cubic meters of bark beetle-infested wood reported in the entire Central European region, these two countries accounted for around 23 million cubic meters, which is over three-quarters of the total volume. Notably, nearly 60% of the forest stands in both countries are comprised of spruce.

Germany

In Germany, approximately 18 million cubic meters of bark beetle material were recorded in 2023, an increase from around 16 million cubic meters in 2022. The situation showed significant regional variability, with the highest amounts of bark beetle damage reported in Thuringia (around 6 million cubic meters affecting about 200,000 hectares of spruce forests), Baden-Württemberg (approximately 2 million cubic meters over an area of 450,000 hectares), and North Rhine-Westphalia (almost 2 million cubic meters across 250,000 hectares of spruce forests), in addition to damage in Bavaria.

In the two federal states bordering the Czech Republic, Bavaria and Saxony, the situation regarding forest infestation differs significantly. In Bavaria, there has been an increase in infestation, rising by more than one-third to approximately 6.3 million cubic meters in 2023, up from around 4 million cubic meters in 2022. This data comes from about one million hectares of spruce forests. In contrast, Saxony has experienced a notable decrease in infestation, with a drop of more than half, recording approximately 0.3 million cubic meters in 2023, down from around 0.7 million cubic meters in 2022. This figure pertains to an area of less than 0.2 million hectares of spruce forests.

The values reported for bark beetle infestations are alarmingly high at both local and regional levels. In Bavaria and the nearby region of Thuringia, 2023 is considered the worst year on record, with bark beetle wood volumes reaching maximum levels in both areas.

Overall, Germany has become the most infested country by spruce bark beetles in Central Europe in the year 2023. The recorded infestation level is 6.7 m³ per hectare of spruce stands, while the Czech Republic ranks second with an infestation level of 3.8 m³ per hectare.

Austria

In Austria, reports indicate that the bark beetle situation slightly worsened in 2023, with approximately 3.9 million cubic meters of infested material recorded nationwide, compared to around 3.7 million cubic meters in 2022. The most serious issues are occurring in the Alpine regions of East Tyrol and Carinthia, where there has been a consistent year-on-year increase in the volume of infested materials, although the increase is not as dramatic as that seen in 2021 and 2022.

Slovakia

The bark beetle crisis in Slovakia has remained relatively stable or has seen a slight increase in recent years. In 2023, approximately 2 million cubic meters of spruce trees were attacked, up from about 1.8 million cubic meters in 2022.

The slowing rate of this infestation is largely due to the fact that most available spruce forests are now located at higher altitudes. In these areas, the more favorable weather conditions of the past two years have had a positive impact, preventing a rapid escalation of bark beetle outbreaks.

However, long-term efforts to control the bark beetle populations have been significantly hindered by legal constraints related to nature protection. These regulations effectively limit the practical options for forest management across large areas of protected mountainous regions.

Poland

In Poland, the bark beetle infestation situation remains highly favorable. In 2023, the total recorded infestation was approximately 0.5 million cubic meters, a decrease from about 0.75 million cubic meters in 2022. This positive development can largely be attributed to the effective management of local forestry resources, as around 80% of all forests are overseen by state forest authorities, which are well-equipped in terms of legal, organizational, capacity, and personnel aspects.

Note: Data on the occurrence of harmful factors for 2023 have been sourced from the latest issue of the Forest Protection Bulletin for Slovakia and Poland (ZOL, vol. 27/2024, pp. 1-88). For German-speaking countries, the information is drawn from the annual review, Waldschutz – Waldschutzsituation 2023/24, which is published in the German federal forestry magazine AFZ Der Wald (AFZ Der Wald, 9/2024, pp. 1-71).

Prepared based on data from the publication “Forest Protection Report, Supplement 2024,” which can be downloaded here.

Processed by Jan Řezáč, VULHM, v. v. i., email: rezac@vulhm.cz

Illustrative photo: Spruce stands affected by bark beetle