So says an old German proverb. From a forestry point of view, however, this cannot be left uncommented.
Everyone has the images of the Upper Lusatian forests in mind. And it is not just here, but all over Germany, that the terrible sight haunts us:
Entire forests and stretches of land criss-crossed by deep snow, cut down or partially cleared. What remains are cold, barren expanses that give pause for thought and raise many questions. Why have the forests of Upper Lusatia been so badly affected? Will the forest recover? And why is the bark beetle not the real problem?
It is difficult to find suitable answers to these questions. But we would also like to do our part to come a step closer to solving these problems. That's what we want to do with this page.
We want to help educate, inform and raise awareness of the explosive nature of this issue.
On this page we would like to provide you with information on the subject of "Bark beetles in the forests of Upper Lusatia".
We also provide information graphics, contacts of experts and useful information and links.
What you should know
Not all bark beetles are the same
The bark beetles (lat.: Scolytinae) are a subfamily of weevils (Curculionidae) between 0.7 - 12 mm in size. There are about 6000 species worldwide. The best known species in this country is probably the book printer (lat.: Ips typographus). This is not only known to forest owners in Saxony, but also causes headaches throughout Germany. Its preferred prey is mainly the spruce forests of Germany. However, the animals can also be found in forest areas in other Central European countries.
Habitat and reproduction of beetles
There are different species of bark beetle and each has its own preference for species and part of the tree. However, the way of life is quite similar for all of them. Once the beetles have found and flown to a suitable breeding site, they bore or eat their way into their preferred part of the plant, where the female finally lays her eggs. The hatching larvae then nibble their way into the brood chamber. Once they are fully grown, they bore their way out and leave the host tree in search of a reproductive partner and a new host tree.
What drives the bark beetle
Very few species of bark beetle attack healthy trees. In the vast majority of cases, the tree's own defenses (e.g. resin flow) are too strong for the beetles. They therefore attack dying or diseased trees instead. These are then referred to as weak parasites or secondary pests.
In rarer cases, however, the beetles also seek out healthy trees. The starting point for this is a very high number of beetles that have been able to develop in large numbers in a large breeding area. These include above all litter and broken wood, but also dry-stressed spruce trees with limited defenses.
Why some forests are more affected
To answer this question, you have to go a little further and take a closer look at the forests in question. You will quickly notice that most forests have not grown naturally in the way they are composed. Even decades ago, the native mixed forests were increasingly planted with spruce. The reason for this is the relatively rapid growth of spruce. This was particularly useful as rapid reforestation could be used to counteract the massive loss of forest areas (mine wood, firewood, smelting) that had been caused by mining since the Middle Ages. Many forest areas also had to pay tribute to the economic circumstances of history, such as the world war reparations or the self-sufficiency efforts of the GDR regime. Reforestation with pine and spruce forests was intended to reduce the loss of forest areas.
However, spruce trees pose one problem in particular: they require a lot of water as their roots run shallowly under the ground and therefore have no access to the water in deeper layers of soil. Of course, this does not apply to all spruce trees, as they can develop a good sinker root system in a suitable location. However, in the event of prolonged drought and a lack of precipitation, many shallow-rooted trees are weakened by water shortages and are more susceptible to infestation by pests such as the bark beetle. However, bark beetle infestations in the Tatra Mountains and the Alps show that this is also a natural process. However, the increasing climatic conditions are causing problems for all tree species.
What needs to be done if a section of forest has been colonized by the bark beetle
Forest owners and forestry companies are working hard to repair the damage in the forests as best they can.
The following measures can be taken to this end:
- Recognize infestation in good time, before the new generation of beetles emerges
- Cut down the infested tree immediately and remove it or store it at least 500 m away from the forest
- Alternatively, render the beetle brood harmless on site using suitable methods (e.g. by debarking)
- Otherwise, concentrate the infested trees locally and render them harmless there using suitable methods
- Within the framework of integrated pest management, there are various methods for neutralization
The forest BEFORE the bark beetle infestation
The mixed forests of Upper Lusatia are characterized above all by a unique diversity in the vertical cross-section. For example, the forest areas around the Muskauer Heide in the north of Upper Lusatia are primarily characterized by pine trees, although not always of natural origin. This is mainly due to the mostly predominant sand and gravel layers. The counterpart is formed by the spruce forests in the south of Upper Lusatia, which are mostly artificially induced. While the shallow-rooted trees often thrive naturally in mountainous regions, they were also planted in flatter areas due to their rapid growth in order to boost timber production in the region. Nevertheless, beautiful deciduous and mixed forests can still be found here and there.
The forest WITH bark beetle infestation
If an area is infested by the bark beetle, entire parts of the forest are often affected. The shallow-rooted spruce forests in particular find it very difficult to defend themselves against the insects during long periods of drought. As they develop very quickly and then swarm, it is rare to see only individual groups of trees infested, even though this was not uncommon until a few years ago. However, it is always important to mention that the bark beetle is not a new phenomenon. Rather, it is due to the long dry summers that the animals find it relatively easy to overcome the trees' natural defense mechanisms. In addition, there are structural problems in particular: small-scale, fragmented ownership structures and the differentiated commitment of forest owners to combating infestation are contributing to the current situation.
The forest AFTER the bark beetle infestation
Once the forest has been cleared of bark beetle infestation, it takes a long time for it to fully recover. It is also important to mention here that the bark beetle has always existed and that there has always been a natural selection of diseased and weakened trees. On the one hand, this ensures a progressive diversity of plant species and, on the other, a change in forest areas. Furthermore, a forest will never be complete without bark beetles. Like most other insects, it is part of a healthy and living forest.
As bad as the cuts are, forest owners can also see them as an opportunity to restore biodiversity and diversity. Irrespective of this, the German forests continue to be under enormous pressure from the changing climate. Regular and long periods of drought will continue to pose a threat to native flora that should not be underestimated.
Sachsenforst has produced a leaflet on correct behavior in the forest. Among other things, the following details are requested:
1. enjoy nature with all your senses. Avoid noise. Protect the forest and nature in your own interest and for those who come after you.
2. litter does not belong in nature, is harmful to animals and encourages parasites, pests and diseases. Plan your visit so as to avoid litter and take everything you bring back with you.
3. natural areas always have an owner. This owner designs and manages the areas and makes them available for recreation. Remember that people work in the forest. Therefore, forestry work, obstacles, uneven paths or vehicles should always be expected on a tour through the forest.
These and other rules of conduct can be found in the current information sheet from Sachsenforst and can be downloaded.
Your contacts for further information on bark beetles
Saxony Forestry
Sachsenforst is a decentralized state enterprise under the supervision of SMEKUL. Its core tasks are, for example , to provide comprehensive advice and support for private and corporate forest owners and to ensure the management of Saxony's state forest in twelve forest districts. It is also the higher forest & hunting authority, the office for large protected areas and the competence center for forests and forestry.
Contact:
Staatsbetrieb Sachsenforst
Bonnewitzer Str. 34
01796 Pirna OT Graupa
03501 - 542 319
sbs.presse@smekul-sachsen.de
https://www.sbs.sachsen.de/
Upper Lusatia forest district
The Upper Lusatia forest district covers almost 25% of Saxony's forests and extends over the largest areas of the districts of Bautzen and Görlitz. Here, district managers provide advice and support to private forest owners.
Contact:
Forstbetrieb Oberlausitz
Paul-Neck-Straße 127
02625 Bautzen
03591 - 2160
oberlausitz.poststelle@smekul.sachsen.de
https://www.sbs.sachsen.de/
Saxony Forest Owners Association
The Sächsischer Waldbesitzerverband e.V. (Saxon Forest Owners' Association) is a professional association representing the interests of around 85,000 municipal, private and church forest owners in Saxony and has set itself the goal of safeguarding the inviolability of the forest, the freedom of its management and the right to self-administration.
To this end, it advises and supports its members on a wide range of forestry issues and provides information material, sample presentations and forms. A regularly published members' magazine is also offered.
Contact:
Sächsische Waldbesitzerverband e.V.
Pienner Straße 10
01737 Tharandt
035203 - 39820
wbv.sachsen@gmail.com
https://www.waldbesitzerverband.de/index.php
German Hiking Association (DWV)
The German Hiking Association, founded in 1883, is an umbrella organization of 57 regional member organizations with around 500,000 members.
According to its own figures, the association devotes around 1/7 of its working time to nature conservation alone.
Contact:
German Hiking Association
Kleine Rosenstr. 1-3
34117 Kassel
0561 - 938 730
info@wanderverband.de
https://www.wanderverband.de/
Forest Foundation for Saxony
Established in 1996 by the Free State of Saxony, the foundation not only aims to increase the proportion of forest in Saxony and to ensure that forests are as close to nature as possible, but above all to protect the forest ecosystem in Saxony.
Its main tasks consist of planning, coordinating and implementing forest enhancement projects as well as advising municipal and private owners. It also raises awareness through exhibitions, specialist lectures and public planting campaigns.
Contact:
Stiftung Wald für Sachsen
04416 Markkleeberg
0341 - 309 080
waldstiftung@wald-fuer-sachsen.de
https://mehr-wald-fuer-sachsen.de/
FAQ
Will the forest recover?
This question is not easy to answer. Although foresters and forest owners have been working for many years to increasingly diversify forests and avoid monocultures, forest change is a very lengthy process that can take several generations of trees. In addition, progress and developments are made more difficult or hindered by the influence of climate change, for example due to longer or more frequent periods of drought.
What impact does this have on me as a hiker?
As a hiker and nature lover, you have to get used to the images of bare and partially deforested areas for the time being. Even if the forest owners and foresters are working hard to repair the damage, it will still take some time for the forest to regenerate.
It is also possible that heavy machinery will be used to clear the damage more quickly, which could then affect the hiking trails. We ask for your understanding in view of the tense situation.
Why is there still so much wood in the forest?
There can be various reasons for this. If the deadwood is still lying untouched in the forest, it could be because it has been left in place for ecological reasons. This is usually not a problem, as the beetles have already flown out to look for a new host tree. The remaining dead wood can serve as a habitat for birds, insects and fungi.
If there are already felled trees in the forest, it is quite possible that forest owners will temporarily store the wood with the required minimum distance due to lack of time or space.
Why are the forests of Upper Lusatia more affected than others?
The forests of Upper Lusatia are characterized above all by the intensive afforestation with spruce in the last hundred years. Spruces are characterized by fast growth and low demands on their environment. However, as shallow-rooted trees, they are heavily dependent on rainwater as they do not have a deep root system to reach water from deeper layers of soil. If there are longer or more frequent dry periods, the spruces are weakened and more susceptible to diseases and pests.
When is the bark beetle "in season"?
Like most cold-blooded animals, bark beetles also retreat in winter and spend the cold months in the shelter of the trees. From around 16°C air temperature and dry weather, the beetles fly out again. Within a dry and warm year, the bark beetles can breed up to three generations.
