In mature age, red oak production of wood is bigger, if compared with sessile oak and pedunculate oak
Since the first half of the 19th century, forest owners and foresters have aimed to enhance forest productivity and economic efficiency. To achieve this, they began using certain exotic tree species, primarily focusing on growth rates and volume production. Over time, they also considered other principal factors in forestry and economics, such as adaptability to Central European conditions and wood quality.
Photo: Mature red oak stand, Central Bohemia, author Jan Řezáč
Due to significant changes in climatic conditions, there is a growing emphasis on resilience to the current climate and its health impacts. One tree species that has proved the ability to withstand these ongoing climate changes in the Czech Republic is the red oak. This species has a shorter growing season compared to our native oaks and produces valuable wood for various applications.
Red oak (Czech abbreviation DBC) is native to the eastern and central United States and extends into southern central Canada. It was introduced to Europe around the year 1700, initially being used in castle gardens and parks. Over time, it gradually spread throughout western and central Europe, colonizing parts of Belgium, Germany, and Poland. In some instances, it has become an invasive species.
Photo: Young read oak in the fence, Central Bohemia, author Jan Řezáč
In European forests, red oak primarily grows on the edges of forest stands, where there is ample light. This light availability is crucial for sufficient tannin production in the wood, which are key factors for the species’ survival and longevity.
In the Czech Republic, red oak covered approximately 6,000 hectares in 2010, with a total stock of 900,000 cubic meters. Currently, red oak occupies about 6,719 hectares in Czech forests, which is 0.25% of the total forest area. Its total stock has increased to 1,493,000 cubic meters, being 0.21% of the overall wood stock in Czech forests.
The average age of DBC trees is approximately 53 years. The highest representation of this tree species is found in the forests of Prague, accounting for 3.12%, while the Central Bohemian region has 0.75%. The forests in Prague also have the oldest average age for DBC trees at 62 years, while the Moravian-Silesian region has the youngest average age at 46 years.
In the Czech Republic, there has been minimal attention given to the DBC species and its role in forestry. There is a significant lack of knowledge about the production properties and the evaluation of certain quality metrics related to DBC in the country.
Photo: High-quality red oak stand with minimal herbaceous layer, TZP Hraběšín (Lesy Orlík), author F. Beran
Therefore, the staff of the Department of Biology and Breeding of Forest Trees at VÚLHM, v. v. i., established 34 permanent experimental trials (hereinafter referred to as TZP) with DBC from 2013 to 2023. These trials were set up in eleven natural forest areas (PLO). The largest number of trials, numbering nine, is in PLO 10, Středočeská pahorkatina, where approximately one-third of all red oak stands in the Czech Republic can be found. The other most numerous TZP were established in PLO 17 Polabí, PLO 7 Brdská vrchovina, and PLO 6 West Bohemian vrchovina.
By evaluating these tree growth performance indices (TZP), scientists gained insights into the growth of red oak stands. They summarized their findings in the paper titled “Production capabilities of red oak (Quercus rubra L.) on different habitats in Czech forests“ („Produkční schopnosti dubu červeného na různých stanovištích v českých lesích“) which was published in the journal Reports of Forestry Research4/2024. This article was created as part of the project QK22020045 „Potenciál geograficky nepůvodních druhů dřevin v lesním hospodářství ČR “(“Potential of Geographically Non-Native Tree Species in the Forest Management of the Czech Republic”).
It has been found that when comparing production capabilities, red oak at an older age (stockwood) achieves significantly higher values than native oak species.
(The high forest is the final growth phase of a forest, characterized by a mean nominal thickness of 20 cm or more and an age exceeding 50 years).
Photo: Young stand of red oak, Central Bohemia, author Jan Řezáč
The health status of the red oak trees was assessed as excellent in all monitored areas. Natural regeneration of diameter at breast height (DBC) occurs in these locations; however, the often-mentioned ability of aggressive spontaneous rejuvenation was not significantly observed here.
Red oak is a fast-growing tree species in its youth, producing high-quality trunks. It has lower soil requirements and shows rapid growth in nutrient-rich habitats.
Smaller habitat demands allow for broader usage, including in areas that are more challenging to afforest. Conceptual training can help keep the quality and health of stands at the desired level until they reach their maturity age, which should be at least one hundred years for this tree species. Starting from the fifth age class, it is advisable to gradually thin the stands of red oak.
Red oak has the potential to diversify the tree species composition of our forests because it thrives well in current climatic conditions and can withstand climatic extremes such as drought and temperature fluctuations.
Photo: Mature stand of red oak, Central Bohemia, author Jan Řezáč
The results suggest that red oak may serve as a viable alternative to native oak species in areas with low precipitation, particularly in regions where native oaks have historically experienced high mortality rates and poor growth.
Given its biological and production advantages, along with lower habitat requirements, red oak could potentially be applied in lower forest vegetation levels.
Opinions on the use of red oak in our forests vary widely. On one hand, some express concerns about its invasiveness and the negative impact it may have on native herbaceous communities. On the other hand, research has proven its benefits in improving poor habitats, its good production capabilities, and its potential to adapt to climate change. The authors emphasize that finding a viable compromise solution for cultivating this tree species should rely on well-established knowledge. Therefore, it is important to continue exploring the use of non-native tree species.
The paper titled “Production capabilities of red oak (Quercus rubra L.) on different habitats in Czech forests“(„Produkční schopnosti dubu červeného na různých stanovištích v českých lesích“) can be downloaded here.
Authors: František Beran, Martin Fulín, Jaroslav Dostál, VÚLHM, v. v. i., e-mail: fulin@vulhm.cz
Prepared following original by Jan Řezáč, VÚLHM, v. v. i., e-mail: rezac@vulhm.cz