Approaches to Forest Restoration in Disaster Clearings
Extensive clearings resulting from wind and bark beetle disturbances present significant challenges for forest restoration in the Czech Republic. Due to highly variable ecological conditions, reliance on a single restoration method is not suitable. Consequently, forestry practices increasingly advocate for a diverse set of procedures that integrate artificial and natural restoration, enabling adaptive responses to specific local habitat conditions.
Photo: clearing after bark beetle disaster, author Jan Řezáč
Researchers from VÚLHM, v. v. i., and Mendel University in Brno concentrated on forest restoration in areas affected by disasters. They conducted this research as part of the project NAZV QL25020059, titled “Ongoing Bark Beetle Disaster in the Czech Republic as a Starting Point for Adaptation of Forests and the Forestry Sector to Climate Change and Development of Resilience to Future Disaster Situations.” Their findings were published in the article “Assessment of forest regeneration approaches following large-scale disturbance clearings” (Vyhodnocení různých postupů obnovy lesa na kalamitních holinách), which appeared in the journal Reports of Forestry Research, Volume 4, 2025.
To assess the initial development of a calamity clearing using combined restoration methods, scientists selected the Heraltice permanent research area (TVP). This site was established in the fall of 2019, located at an altitude of 600–620 meters above sea level. The clearing initially covered approximately 40 hectares in 2020; however, due to the gradual expansion and interconnection of individual clearings, it has now developed into a continuous area of about 200 hectares.
Photo: A clearing overgrown with grass and blackberries, author Jan Řezáč
In 2024, following five growing seasons since the establishment of the areas, we evaluated the presence of all forestry-significant tree species found in those areas. The evaluation also included individuals from artificial regeneration. Part of this assessment involved calculating the costs associated with securing the cultivation based on different regeneration methods and selected tree species.
The traditional one-time artificial regeneration of extensive clearings, which has been predominantly used so far, requires a significant amount of planting material, advanced technology, and careful work organization. Furthermore, the need for repeated improvements and subsequent care for these cultures increases the overall costs of achieving a secured forest stand, which negatively impacts the economics of forest establishment.
An even greater concern is that these regeneration techniques can lead to the creation of large-scale, even-aged stands. Such stands may struggle to maintain adequate stability and vitality in the face of global climate change and the associated risks of recurring natural disasters.
The primary objective of restoration should be to create mixed stands that feature a finely structured mix of a diverse range of tree species, fulfilling the desired functions of the forest.
Photo: Clearing overgrown with natural birch regeneration, author Jan Řezáč
Combined restoration can be highly effective from both economic and biological perspectives. However, it is crucial to consider the varying natural conditions so that the methods used are tailored to the specific ecological parameters of the clearing being restored.
The results of the experiment demonstrate that employing different restoration procedures on large areas affected by calamity can lead to more stable, functionally valuable, and economically efficient forest stands.
Traditional methods of artificial regeneration for target broadleaf tree species, such as beech and oak, are generally reliable in achieving the desired species composition. However, their high costs and the need for planting materials limit their widespread use.
An effective alternative is combined regeneration, which involves planting fewer tolerant species along with promoting natural regeneration. This approach significantly reduces costs, accelerates the regeneration process, and fosters the development of spatially and species-diverse stands that are better suited to adapt to climate change.
A key area for future research is optimizing the parameters of combined regeneration across different habitat conditions. This includes selecting appropriate tree species, determining the optimal number of trees to plant, and assessing the potential for natural regeneration.
Photo: A group of larches on a disaster clearing overgrown with birch, author Jan Řezáč
Alternative tree species mixtures, such as cherry and birch, offer a viable solution for habitats with limited natural regeneration potential. However, they require timely educational interventions.
Our scientists’ findings align with international trends that emphasize the importance of combining natural and artificial processes, using high-quality planting material, regulating light and competitive conditions, and effectively protecting young trees from predators. ¨
These principles should be integrated into forestry practices as the foundational pillars of forest regeneration after disasters. By utilizing the ecological potential of the habitat, we can accelerate forest regeneration while enhancing long-term stability, ecological functionality, and economic sustainability.
The paper “Assessment of forest regeneration approaches following large-scale disturbance clearings” (Vyhodnocení různých postupů obnovy lesa na kalamitních holinách) can be downloaded here.
Authors: Jan Leugner, Petr Bureš, VÚLHM, v. v. i., VS Opočno, Jakub Černý, VÚLHM, v. v. i., VS Opočno, Mendelova univerzita v Brně, e-mail: leugner@vulhmop.cz
Prepared by Jan Řezáč based on the original, e-mail: rezac@vulhm.cz