It is getting worse

The Czech think tank Czech Forest developed a forecast which assumes a further worsening of the bark beetle calamity in most areas. The main reasons for this are an extreme increase in the infestation rate of stocks, a weakening of spruce stocks due to the lack of rainfall and bottlenecks in control. Nevertheless, it is realistic to effectively limit the calamity in many areas thereby creating the necessary conditions for a natural regeneration.

Doubling from year to year

Since 2015, the volume of beetle-damaged wood has roughly doubled every year, and since 2018, it has exceeded regular harvest (usually 16 million m³). Last year, total harvest (regular harvest and damaged wood) amounted to around 27.5 million m³, of which 7.5 million m³ might not have been removed from forests in time.

More than 30 million m³ this year

In view of the nationwide beetle infestation and many other factors, such as the uncontrolled spread of bark beetles in the Ceské Švýcarsko National Park, the Czech Forest members assume that a total of more than 30 million m³ of stocks are going to be infested in 2019. Since 2015, more than 40 million m³ of beetle-damaged wood have been harvested. The actual volume is likely to be even higher since beetle-infested trees have not been reported as such.

Lagging behind the beetle

For a few years already, the infestation rate, the size of the cultivated areas and their staff have made it impossible to identify all infested trees in time. The capacities for reforestation are also limited (According to LOS VÚLHM, only 20% of the beetle-infested areas were completely cleared of the infested wood in 2018).

Half of damage due to ownership structures

Almost 20% of Czech forests belong to small forest owners (406,000 owners), of which 96% own forests which extend on less than 5 hectares. The economic situation of these small forest owners, insufficient capacities and information deficits pose risks. Inadequate forest protection measures facilitate the spread of parasites. Up to 50% of forest owners do not have the capacity to process the damaged wood in good time or they even lack the necessary knowledge. In the Czech Republic, limiting the spread of bark beetles will probably only be successful at higher altitudes and on large forest properties. Political and legal measures can help forest owners, but they have only a negligible impact on slowing the disaster.

Enormous infestation rate

In many beetle regions, a simple rule of thumb applies: A tree which is infested in spring causes up to ten newly infested trees (assuming there are two generations each year). If one applies this to the 6 million m³ of beetle-infested trees (average trunk volume 1 m³) which were not harvested in 2018, up to 60 million m³ of previously unaffected wood could be infested in 2019. The Czech sawmills can take around 11 million m³ per year. According to Czech Forest, exports to neighboring countries are becoming increasingly difficult, as these countries are affected by beetle infestations as well. It is becoming increasingly difficult for small forest owners to sell smaller quantities of wood, which makes them even less motivated to take real forest protection measures. The moisture deficit remains. However, studies show that trees return to their physiological optimum after several years of periods of intense heat. Freezing winters have a major impact on the mortality of bark beetles when temperatures are close to -20 ° C. Meteorologically, last year was more favorable than 2018 (later start of swarming and only two generations, more precipitation in some areas). Nevertheless, the beetle population grew again in 2019.

Reduction in growing stock since 2018

Up until 2018, Czech forestry could be regarded as sustainable because logging was lower than growth despite various catastrophic events (growth: approx. 25 million m³/year). In the future, growth will concentrate on young and deciduous forests. The volume of log wood will soon be limited. Forest owners are also very likely to record negative operating results in the next forty years.