Scientists discovered 11,410 species of fungi in the soil of calamity clearings
Habitat trees, whether living or dead, often consist of large, old trees and decaying wood. These trees provide a natural habitat for various organisms, including fungi and endangered species. Additionally, they positively impact the microclimate of the area by creating shade and reducing wind speed, which contributes to the restoration and stability of the forest ecosystem. The decaying wood also enriches the soil with essential nutrients.
Photo: Norway spruce attacked by honey fungus and red-belted bracket, author Jan Řezáč
Scientists studied the diversity of fungi in habitat trees, dead wood, and soil while working on a project to restore calamity clearings near the municipalities of Račín and Nové Veselí in the Žďár nad Sázavou district. These areas had experienced damage from spruce stands destroyed by bark beetles in recent years.
The researchers focused on fungi and the symptoms of their activity, particularly wood rot, found on selected habitat trees and on dead wood in brushwood piles and mounds. They also documented the presence of other fungi. When it was not possible to identify the fungi directly in the field, the team collected samples from trunks, branches, or bark containing fruiting bodies or other parts of the fungi and conducted laboratory identifications.
Photo: Left – Hairy bracket (Trametes hirsuta) on the sycamore maple; right – honey fungus (Armillaria sp.) on the black alder, Račín, author František Lorenc
The researchers collected soil samples from a total of thirty locations, including the organic horizon, where decaying plant material accumulates, and the mineral horizon at a depth of 0-10 cm. At each sampling location, they recorded various characteristics, including the presence of clearance or vegetation, as well as the amount and type of brushwood and weeds.
Using DNA analysis, the scientists identified the species of fungi present in the collected soil samples. Each species was then classified into the appropriate ecological group: mycorrhizal fungi, fungi that decompose dead wood, fungi that cause plant diseases, and other types.
On the habitat trees, primarily wood-destroying fungi were observed. The most common species included the honey fungus on spruce trees and on broadleaf trees, the red-belted bracket on spruce and pine, the pine heart-rot on pine, and the splitgill mushroom on birch. Additionally, in the habitat branches, the maple tar spot disease was prevalent, leading to the appearance of noticeable black spots on the leaves.
On the dead wood, which was mainly composed of Norway spruce, the most common fungus identified was the pith fungus, characterized by its inconspicuous black coatings. Other notable fungi included the false chanterelle and the purlepore bracket associated with fir trees. Overall, many of the abundant species found on the dead wood were wood-decaying fungi.
Photo: Left – candlesnuff fungus (Xylaria hypoxylon) on dead wood, Nové Veselí; right – beech woodwart (Hypoxylon fragiforme) on a broken branch of European beech, Račín, author František Lorenc
Among the mycorrhizal fungi that form a mutually beneficial symbiosis with tree roots, the most common include the brown roll-rim, the bay bolete, and the red-cracking bolete. Most of these mycorrhizal fungi produce distinctive fruiting bodies during wet weather, many of which are harvested by mushroom pickers.
Overall, the presence of fungi is significantly influenced by the type of tree and whether it is alive or dead wood, while variations between different locations are minimal.
Scientists discovered 11,410 species of fungi in the soil using DNA analysis. The predominant types were ascomycetes, a diverse group of fungi, and stamenospores, which are primarily traditional fungi characterized by tubular or scaly caps.
From an ecological perspective, various groups of fungi that decompose dead plant material and other organisms are most commonly found in the soil. The highest diversity of fungal species is observed in the organic horizon.
Photo: White rot on a broken branch of European beech, Račín, author František Lorenc
The proportion of fungi in the soil that cause plant diseases was low. Among these, the most prevalent was Nectria rammulariae, the causative agent of bark cancer in certain tree species, particularly in areas with brushwood or wood chips. In several instances, the causative agents of root rot from the genus Fusarium were also identified, typically found in areas with dense weeds. Additionally, there were occasional reports of Neonectria major, which causes plant cancer, as well as pine needle-cast fungus and fungi Heterobasidion parviporum.
From a forestry perspective, this condition does not pose a threat to forest stands. Therefore, the restoration of areas affected by calamities can proceed without the need for extraordinary measures to combat fungal pathogens.
Based on the results obtained, scientists recommend planting a greater diversity of tree species, preserving habitat trees, and leaving some dead wood in the stands (such as brushwood on mounds or in piles) to enhance the diversity of fungi.
More detailed information about the results of the mushroom assessment can be found in the article “LORENC F., BALDRIAN P., 2025: Houby na habitatových stromech, mrtvém dřevě a v půdě na kalamitních holinách (Fungi on habitat trees, dead wood, and soil in calamity clearings). Lesnická práce 104(4), pp. 220-221 (28-29).”
Details about the calamity clearing restoration project are available on the VÚLHM website here.
Contact for more information: Ing. František Lorenc, Ph.D., VÚLHM, v. v. i., e-mail: lorenc@vulhm.cz