Does it make sense to manage birch stands?
Silver birch is the most common tree species that naturally establishes itself in areas created after disturbances in spruce stands throughout much of Central Europe. These spontaneously formed stands exhibit considerable variability in their structure, which in turn affects their productivity. The origin of these stands influences their variability, habitat, stand condition, and weather conditions, particularly during the initial phases of restoration. The structure of these stands is a fundamental factor for their economic utilization and the necessary silviculture management that follows.
Birch is a typical pioneer tree species known for its rapid growth during its early years. It quickly reaches its maximum height, thickness, and volume, but has a short lifespan. Generally, after reaching 50 years of age, birch trees start to exhibit rot in their wood, and by around 80 years, they typically die. Birch trees have high light requirements, which leads to the formation of birch stands that are usually uniform and exhibit significant self-thinning.
The properties of birch make it economically attractive, particularly in specific situations and suitable habitats. For instance, birch is well-suited for extensive calamity clearings, as its production is comparable to that of other tree species, especially when grown in shorter rotations on soils rich in water and nutrients.
Additionally, birch stands allow a significant amount of light to penetrate, which, along with their positive impact on soil health, microclimate, and water balance, makes this tree species highly desirable for creating preparatory stands.
In addition to the structure of the stand, the development of spontaneously formed stands depends on the owner’s requirements, the company’s guidelines, and the socio-economic context.
Like naturally or artificially regenerated stands, spontaneously formed stands can also be managed through grazing or selective methods. The effectiveness of these management methods can be assessed based on the intensity of the management practices employed.
Scientists from VÚLHM, v. v. i., the Opočno Research Station, and Mendel University in Brno are jointly addressing the issue of cultivating spontaneously formed birch stands.
In their latest study, they focused on a specific spontaneously formed birch stand and developed various cultivation models for its further development. These models were designed based on different management intensities and economic methods used.
The results of their research were published in the paper “Pěstební východiska a modely pro spontánně vzniklý březový porost – objekt Losí” („Silviculture frameworks and models for spontaneously regenerated silver birch stand – plot “Losí“) which appeared in the journal Zprávy lesnického výzkumu (Reports of Forestry Research), in the issue 4/2024.
The paper was created during the implementation of projects NAZV No. QK22020008, titled „Komplexní vyhodnocení plnění produkčních a mimoprodukčních funkcí lesa u porostů přípravných dřevin“(Comprehensive evaluation of the fulfilment of production and non-production functions of the forest in stands of preparatory tree species), and QK21010198, titled „Adaptace lesního hospodářství pro udržitelné využívání přírodních zdrojů“(Adaptation of forest management for sustainable use of natural resources).
The scientists selected a stand locally known as “Losí,” located in PLO 16 – Českomoravská Vrchovina, for their study. This stand covers an area of approximately 3.6 hectares. As of the initial survey conducted in the summer of 2022, when the stand was 22.5 years old, no cultivation interventions had been carried out. The owner is currently considering how to proceed with the
The height of the birch tree species, measuring 21 meters, indicates that this location is one of high quality. Overall, the site, which is the focus of interest, is considered suitable for further cultivation of birch trees. The current condition of the stand highlights the urgent need for educational intervention.
Research scientists have developed a total of ten thinning models for the stand, each varying in management intensity and the economic methods employed. The SWOT analysis created for these models can help the owner make informed decisions regarding the future direction of the stand. In conclusion, the scientists have conducted a thorough assessment of various approaches to management intensities.
0 – passive
The advantages of using a passive management approach primarily revolve around the anticipated increase in biodiversity. This model may be appealing to landowners, particularly driven by enthusiasm or when financial subsidies are available. It is especially suitable for owners who are not heavily reliant on the forest for material benefits, as well as for those who own large expanses of land. Along with forgoing wood production, there is a risk associated with the potential danger posed by the uprooting of dying trees.
1 – extensive
The extensive approach is often linked to a farmer’s understanding of the forest, focusing on the direct use of its production function or specific requirements for forestry (value production). This approach provides a broad range of applications for the wood production function of the forest stand. Its effectiveness is, however, limited by the successful spontaneous (natural) regeneration that follows.
2 – standard
Various partial models and their variants are available for this level of management, differing in economic approaches and cultivation practices. Standard intensity models rely on fully utilizing wood production, which is diversified according to potential economic objectives, and predominantly involve artificial regeneration, although always on a comprehensive scale (refer to the selection model). Incorporating a combined model within this standard intensity helps address some of the limitations associated with the individual models.
3 – intensive
The intensive approach primarily focuses on wood production. However, applying this method rigidly—such as rejecting preparatory tree species—can result in the complete degradation of the ecosystem. To prevent this, artificial regeneration should utilize a broader range of tree species and impose strict care requirements for subsequent growth.
4 – combined
A combined approach balances the strengths and weaknesses of individual methods, optimizing the needs of the company or owner. However, rapid changes in forest requirements can undermine the effectiveness of this model.
The paper “Pěstební východiska a modely pro spontánně vzniklý březový porost – objekt Losí“ („Silviculture frameworks and models for spontaneously regenerated silver birch stand – plot “Losí“) can be downloaded here.
Authors: Antonín Martiník, Mendelova univerzita v Brně, Lesnická a dřevařská fakulta, e-mail: antonin.martinik@mendelu.cz; Jiří Souček, VÚLHM, VS Opočno
Prepared in accordance with the original by Jan Řezáč, FGMRI (VÚLHM, v. v. i.), e-mail: rezac@vulhm.cz
Illustrative photos: Examples of birch forest stands