Folia Forestalia Polonica Feed

The condition of forest soils in central and northern Poland in the decade 2007–2017 based on selected indicators

Tue, 17 Mar 2026 00:00:00 GMT

The aim of the study was to assess the condition of forest soils in central and northern Poland in 2007–2017. The study areas were located in eight forest districts, namely, Białowieża, Chojnów, Łąck, Gdańsk, Krotoszyn, Krucz, Strzałowo and Suwałki. In 2007 and 2017, soil samples were taken from the organic layer (O) and five mineral layers (M): 0–5, 5–10, 10–20, 20–40 and 40–80 cm deep. Physicochemical analyses of the soil were carried out on the appropriately prepared samples (i.e., drying, sieving, grinding), that is, granulometric composition, pHCaCl2 in a solution of 0.01 mol CaCl2·dm-3, organic carbon content (TOC), total nitrogen content (TN), exchangeable acidity (Hw) and the content of basic and acidic cations in a solution of 0.1 M barium chloride at pH 8.1. In addition, the sum of cations (SBC), the cation exchange capacity (CEC), the saturation of the basic complex (BS%) and the sum of basic cations (SBC : Al) were determined. The soils analysed were characterised by an extreme and strong acid reaction (pHCaCl2: 2.75–4.60). Regardless of time, the highest TOC content in the closed layer was found in the Krotoszyn forest area under the Quercus robur L. on the Stagnosol soil and the lowest in the Strzałowo forest area under the Pinus sylvestris L. stands on the Halpc Luvisol soil. The TOC content in the mineral layers was low regardless of the location and year of investigation and was similar in the analysed soils. Most of the forest soils analysed were poor sites and soils from sands with low alkaline cation content (SBC<5.0), sorption capacity (CEC) and saturation of the alkali-sorption complex (BS < 20%).

Dynamics of surface fuel accumulation in Scots pine (Pinus sylvestris L.) forests of green zones of the cities of Kyiv and Kharkiv

Tue, 17 Mar 2026 00:00:00 GMT

The aim of this study was to investigate the dynamics of forest fuel accumulation in relation to fire hazard in the green zones forests of Kyiv and Kharkiv cities. The research employed analytical–calculative, monitoring and generalising methods to assess the formation and accumulation of forest fuels and to provide practical recommendations. The results identified key factors influencing the accumulation of surface forest fuels within these urban forests. In Kyiv’s green zone, pine stands growing under the most widespread forest site conditions (B2–3: fresh and moist subor types), the total litter load (in absolutely dry condition) ranged from 8.1 to 46.0 t/ha, with litter layer thickness varying between 2.1 and 8.1 cm. In Kharkiv’s green zone forests, significantly higher fuel loads were recorded, ranging from 15.6 t/ha in young pine stands to 60.0 t/ha in mature and overmature forests. A litter stock modelling approach was applied to estimate the accumulation of forest litter and duff in the periurban forests of Kyiv and Kharkiv using the conversion coefficients (Rv) derived from empirical stand parameters (DBH, density and age). The models demonstrated high accuracy (R2 = 0.75–0.98) and confirmed that the highest surface fuel accumulation in pine stands occurs at 60–75 years. It was confirmed that pine stands in Kharkiv’s green zones growing under fresh subor conditions accumulate 22.8% more surface fuels. The difference in normalised mean values was statistically significant (tst = –1.89, tcrit = 1.69; p = 0.03).

Decrease in forest above-ground biomass in war-damaged forests of Ukraine: A case study using GEDI, Sentinel-2 data, and the GEE platform

Tue, 17 Mar 2026 00:00:00 GMT

Armed conflict leads to significant disturbances in forest ecosystems, resulting in structural degradation and biomass loss. In eastern Ukraine, forested areas have been directly affected by military activities since 2014, with intensified disturbances after 2022. This study assesses changes in forest Above-Ground Biomass (AGB) in selected war-affected areas of Luhansk Oblast using spaceborne LiDAR data from the Global Ecosystem Dynamics Investigation (GEDI) and multispectral imagery from Sentinel-2 processed within the Google Earth Engine (GEE) platform. GEDI Level 4A biomass products were used as reference AGB data to train regression models based on Sentinel-2 spectral bands and vegetation indices. Separate models were developed for three forest polygons (Kuzmyne, Metolkine and Bobrove test sites). The results show strong relationships between GEDI reference AGB and Sentinel-based predictions (R2 = 0.715 for Kuzmyne, 0.704 for Metolkine and 0.720 for Bobrove test sites). The models demonstrate consistent biomass underestimation in high-AGB stands, suggesting structural simplification in damaged forests. The study confirms that combining GEDI and Sentinel-2 data provides a reliable approach for biomass monitoring in conflict-affected regions where field measurements are unavailable. Further analysis showed that average Normalized Difference Vegetation Index (NDVI) values decreased from 0.67–0.71 in 2020 to 0.22–0.24 in 2022 and remained at similarly low levels (approximately 0.24) until 2025 at the Kuzmyne and Metolkine test sites. In contrast, a decrease in NDVI was already detected in 2021 at the Bobrove test site. This early decrease is associated with the shelling of the region by Russian-backed armed groups since late 2020, which caused large-scale forest fires and extensive destruction of vegetation. Overall, this study highlights the significant potential of integrating GEDI and Sentinel-2 data to reliably estimate forest AGB under extreme conditions caused by military conflict. The proposed approach is a valuable tool for monitoring and assessing forest ecosystem degradation in hard-to-reach or high-risk regions and can contribute to planning for forest ecosystem recovery after war.

Reconstructing the origin of silver fir (Abies alba Mill.) stands in the Białowieża Forest

Tue, 17 Mar 2026 00:00:00 GMT

The Białowieża Forest, one of the largest and best-preserved forest complexes in Europe, is located outside the continuous distribution range of silver fir (Abies alba). The area hosts several artificial stands of this species, including old stands that are in good condition. The aim of this study was to reconstruct their origin and establishment conditions. In the Polish part of the Białowieża Forest, 13 sites with the presence of silver fir were identified and described, including 9 old stands. These sites share three key features: anthropogenic origin, generally minimal human intervention in their growth and development after establishment, and location outside the continuous distribution range of the species. Analyses of dendrometric traits showed that many trees reach parameters comparable to those observed under optimal conditions within the natural distribution range of silver fir. Historical reconstruction suggests that the stands most likely originated from direct seeding on clear-cuts created during intensive logging by The Century European Timber Corporation Ltd. in the interwar period (1924–1929). Based on silvicultural, historical and ecological arguments, it appears highly unlikely that silver fir planting stock was produced and used at that time in the Białowieża Forest. The hypothesis proposed here assumes that silver fir seeds were sown under the developing canopy of secondary-succession pioneer species. The surviving old trees and their progeny show a high degree of adaptation to the continental climate of north-eastern Poland. The origin of these stands should be further verified by comparative genetic studies of silver fir populations in Europe and Poland.

Silvicultural and economic aspects of forest regeneration in the Eastern Polissya Region of Ukraine

Tue, 17 Mar 2026 00:00:00 GMT

The scope of forest regeneration (including reforestation and afforestation) in Eastern Polissya of Ukraine has been defined. Forest regeneration is carried out primarily through artificial methods. Based on an analysis of the growth of experimental forest stands, key indicators for types of forest stands have been developed: main and accompanying tree species, mixing schemes, initial density, planting technology, and the frequency and number of tending operations. Successful natural regeneration of valuable species on areas after clear cutting occurs in seed years following prior soil mineralization (on 50–60% of the plot area). According to comparative analysis, measures to promote natural regeneration of Scots pine (Pinus sylvestris L.) on fresh areas after clear cutting are 1.8 times more effective than creating artificial stands.

Botanical and mycological research of the Bielański Forest (Central Poland) during the twentieth century and current times

Fri, 12 Dec 2025 00:00:00 GMT

The Bielański Forest is one of the most valuable remnants of natural vegetation in Warsaw, being the subject of research since the 18th century. This article presents the research on vegetation cover and mycobiota of the Forest, conducted in the 20th century and to the present. The studies are discussed chronologically and divided by the biota of fungi and lichens, the flora of bryophytes and vascular plants, plant communities, veteran trees, and the issues of protecting these resources. The scope and completeness of the research results are discussed, particularly in the context of the forest’s conservation status. Significant differences in the completeness of data were found between the individual groups of living organisms discussed. The identification of the vascular flora and plant communities is relatively complete, both in terms of historical and contemporary data. The assessment of the forest’s conservation based on these components shows that it is a site that has undergone profound and unfavorable changes. The forest’s flora includes common species, while the rare species are only locally rare. The identification of the bryophyte resources is similar to that of the vascular flora. Additionally, this group includes species considered as relics of primeval forests. The current state of knowledge about mycobiota resources is unsatisfactory. It requires compilation, analysis, and publication of existing data. A thorough assessment of the contemporary fungal biota would be useful, allowing for the identification of its changes in relation to historical data. It is also worthwhile to continue the relatively recent research on the lichen biota. The state of the fungal and lichen biota, despite existing deficiencies, currently gives an image of the relatively best condition of the Forest. The knowledge of the ancient trees and deadwood in the Bielański Forest is quite good, but it is worth supplementing it with, for example, maps showing their distribution. In future mycobiota studies, it would also be worthwhile to pay special attention to epiphytic and saproxylic microhabitats. The Bielański Forest also offers opportunities for historical research. Based on the species found here over nearly three centuries, it is possible to describe the forest’s transformations resulting from the conditions in which it functioned.

Do private forest owners in Poland recognise Natura 2000 areas?

Fri, 12 Dec 2025 00:00:00 GMT

Private forest owners in Poland, like those in many other European Union countries, should be viewed as a diverse social group. Due to the size and diversity of private forest owners, one of the most effective ways to understand and categorise them is by examining their values, opinions, views and intentions. The analysis aimed to investigate differences between three respondent groups, distinguished by their level of knowledge about Natura 2000 sites. The research was conducted using the Computer-Assisted Personal Interview method, employing a standardised interview questionnaire that included both content questions and respondent metrics. Three levels of knowledge among respondents were identified: those who said they knew about Natura 2000 sites and correctly defined them (labelled as ‘experts’ – 397 respondents, 39.6%), those who knew what Natura 2000 sites were but did not confirm their knowledge with the correct definition (labelled as ‘amateurs’ – 224 respondents, 22.4%) and those who admitted they did not know what Natura 2000 sites were (labelled as ‘laypeople’ – 382 respondents, 38.0%). Forest owners can be considered a homogeneous group regardless of their knowledge of Natura 2000 sites, and awareness campaigns or financial support can be directed the same way across all groups. Irrespective of how forest owners were categorised, no differences were found in their approaches to types of services, forest functions, time spent on training topics or the tax amounts allocated. Controlling forest pests remains the most critical area of support for private forest owners.

The economic aspect of establishing fire breaks along public roads and reducing the losses caused by forest fires

Fri, 12 Dec 2025 00:00:00 GMT

One of the most important forest management activities in fire protection is the establishment and maintenance of different types of fire belts depending on the threat, including the numerous belts along public roads. The role of fire belts is primarily to limit the possibility of fire spread and to facilitate firefighting by the emergency services. The article presents the results of an economic analysis of the maintenance of fire belts along public roads by the State Forests and clearing of the area of forest materials that pose a particular fire risk. The economic calculation of the establishment and maintenance of fire belts and clearing along public roads to reduce the damage caused by fires is based on analyses of the following: the occurrence of forest fires along public roads, damage caused by forest fires along public roads, the costs of establishing and maintaining type A belts and clearing along public roads. The analyses presented have shown that maintaining type A fire belts and 30-m-wide fire belts with cleared terrain in accordance with current regulations is not rational and justified. The current practice of creating these fire belts does not bring the expected effects in terms of a significant improvement in forest fire safety, which makes it necessary to reflect on their justification and adaptation to actual needs. The losses caused by fires along roads amounted to PLN 814 thousand, while the costs of carrying out these activities totalled PLN 35.84 million. If we compare the losses caused by fires along roads with the costs of establishing and maintaining fire belts and cleaning up, we can see that the losses are more than 40 times lower than the costs incurred, which raises serious doubts about the rationality of the activities carried out and their effective impact on increasing fire safety in forest areas.

Health condition and features of growth of age-old oak forests of natural origin

Fri, 12 Dec 2025 00:00:00 GMT

The purpose of the work was to carry out comprehensive studies of the components of old oak forest stands to assess their health condition and growth characteristics. The research methodology involved obtaining biometric data, agrochemical properties of the soil and health characteristics of the stands. On four trial plots with an area of 7.5 ha, biometric indicators of 794 old oak trees were measured, and their distribution was carried out according to the degree of weakening and damage by phytopathological signs. The average age of the stands, which ranges from 200 to 214 years, was determined experimentally. Productivity of old oak stands ranges from 429 to 510 m3/ha. The results of the study showed that stands have different levels of resistance to the influence of harmful factors, such as rot, wood-destroying fungi, transverse oak cancer, frostbite and hollows in the trunk. Changes in climate, droughts, hydrological regime, invasions of leaf-gnawing pests and pathogens, etc. contributed to the weakening of old trees in different periods. The novelty of research is the development of a classification by growth and development of age-old oak stands of natural origin. A complete description of all components of the stands is given. The best soilimproving properties were found in the plot of 204-year-old stand, with available undergrowth of up to 20,000 units/ha and a litter stock of 7,984 kg/ha compared to the site where the undergrowth was up to 5,500 units/ha with a litter stock of 6,873 kg/ha. Therefore, the obtained data can be useful for monitoring the condition of oak stands, making decisions on the optimization of forestry measures in aged oak forests, managing forest resources effectively, preserving the biodiversity of the national forest fund and developing strategies for forest adaptation to climate change and other threats.

Plants, fungi, and invertebrates of Northern red oak (Quercus rubra L.) experimental stands in Rogów Arboretum (Poland)

Fri, 12 Dec 2025 00:00:00 GMT

This paper gives a survey of biodiversity of Northern red oak (Quercus rubra L.) stands in Rogów Arboretum on the background of environmental data. Northern red oak is found throughout much of the eastern United States and southeastern Canada and occurs on sites with a wide variety of soil types and topographic positions. In Poland, it is considered an invasive plant, dangerous to the native flora. During the study, 36 taxa of vascular plants, mosses, and liverworts; 40 taxa of fungi; and 112 taxa of invertebrates were found.

Controlled burning as an active method of protecting heathlands – methodology of the procedure

Fri, 12 Dec 2025 00:00:00 GMT

Heathlands in Poland are valuable natural habitats, which have been included in the Natura 2000 network, among others. These communities often occurred on military training grounds. Abandonment of their utilisation and the lack of factors inhibiting the succession of woody vegetation have led to the overgrowth of heathlands, their degradation and loss of biodiversity. Active nature conservation is essential for the preservation of these ecosystems. Traditional methods, such as mowing or grazing, are often inadequate or too expensive. Controlled burning can be used as an effective and cost-efficient alternative to stop succession processes and preserve valuable heathlands. To organise burning properly, the right time for burning must be chosen, taking into account both meteorological and natural conditions. During the burning operations, safety and adequate equipment and qualifications of those carrying out and coordinating the activities are crucial. Environmental monitoring carried out after the burning operations showed a high capacity for vegetative regeneration of heather and no negative impact of the treatment on the biodiversity of flora and fauna associated with the heath habitat.

Silvicultural characteristics of medieval 40–50-year-old stands of pedunculate oak in Bilohrudivsky Forest

Fri, 12 Dec 2025 00:00:00 GMT

The forest dacha Bilohrudivsky Forest was an educational and scientific production department of the Main School of Horticulture, now Uman National University of Horticulture, located in Uman District of Cherkasy Region in the Central Forest-Steppe Zone of Ukraine, near the northeastern outskirts of the city of Uman. The area of the forest dacha is 473.7 ha. Based on the materials of forest management and our experimental studies, we analysed the distribution of forest vegetation by dominant species, as well as oak plantations by origin, forest types, age groups, growth classes, fullness and stem wood reserves. The dynamics of the main taxonomic indicators of medieval oak cultures are presented. Indicators of the use of forest vegetation potential by oak plantations of artificial origin in the most common forest type – fresh hornbeam oak forest (D2-hD) – were determined. According to the research, oak forests are the most common, accounting for 81.6% of the total area covered by forest vegetation. It was found that young trees account for 16.7% of the total area, that is, plantations under 20 years old. Medieval plantations account for the largest share – 68.0% of the total area. The smallest share is occupied by ripening (7.1%) and ripe and overripe (8.2%). Among oak forests, artificial plantations of the I, Ia, and II classes of growth, which have a completeness of 0.7 and 0.9 units, significantly prevail in terms of area. The age structure of oak forests is unbalanced, with a predominance of middle-aged plantations, which account for 68% of the area. In the second half of the 20th century, the agrotechnological methods of creating cultures of pedunculate oak in the Bilohrudivsky Forest were reduced to three options, namely soil cultivation was carried out by cutting furrow to a depth of 30 cm by a mechanised method with a PKL-70 plough, followed by a two-fold loosening of the furrow ridges with a KLB-1.7 disc harrow into a plough ridge and breakdown in an aggregate with an MTZ-80 tractor; soil cultivation was carried out by cutting furrow by a mechanised method with a PKL-70 plough to a depth of 30 cm; soil cultivation was carried out according to the agrotechnological method in the form of lowering stumps to ground level in a strip 2–2.5 m wide, and then soil cultivation for forest crops on log cabins was carried out by cutting furrow to a depth of 30 cm with a mechanised forest plough PKL-70 and passing a cultivator KLB-1.7 for two to three times into the plough ridge in an aggregate with a tractor MTZ-80. It was found that the soil cultivation methods used in establishing forest cultures in 40–50-year-old plantations did not impact their productivity. The main feature of forest crops is untimely felling, which has led to the emergence of complex plantations in some neighbourhoods with a share of low-productive trees of natural origin such as hornbeam, sharp-leaved maple, small-leaved linden and a low share of pedunculate oak in artificial plantations. Proposals for implementing appropriate forestry measures to optimise the age structure, increase the productivity of oak plantations and enhance their important ecological and protective functions are presented.

The impact of participation in Forestry Students’ Scientific Association of Warsaw University of Life Sciences on professional and personal development of students

Fri, 12 Dec 2025 00:00:00 GMT

This study aims to evaluate the impact of students participation in the Forestry Students’ Scientific Association (FSSA) at the Warsaw University of Life Sciences on their professional and personal development. The research was based on empirical data collected through an anonymous online survey of 28 questions conducted among former and current members of the Association. A total of 263 correctly completed questionnaires were qualified for analysis. The data were processed using statistical methods, including the chi-squared test to assess the significance of differences in multiple-choice responses, and the Mann–Whitney test to examine the relationship between the level of respondents’ engagement and the outcomes of their development. The results indicate that participation in FSSA significantly fosters professional and soft skills development. The most frequently reported outcomes included fieldwork skills (86%), teamwork abilities (78%), specialized forestry knowledge (66%), and public speaking skills (62%). Furthermore, 82.5% of respondents considered the competencies acquired through the Association useful in their professional work, with 44.9% rating them as highly significant. Nearly half of the respondents declared that the experience gained FSSA was an asset during their recruitment processes. A strong relationship was observed between the level of involvement in the Association activities and both the scope of competencies acquired and their applicability in professional practice (p ≤ 0.001). Activities identified as having the greatest developmental impact included participation in field research and scientific conferences, as well as preparing presentations and research projects. The findings confirm that activities in FSSA integrate theoretical knowledge with research and social practice, thereby implementing the concept of learning by doing. Participation in activities of the Association contributes to multidimensional professional and personal growth, enhancing graduates’ competitiveness in the labor market. These results highlight the need to support students’ scientific associations as an effective component of academic education and as an example of innovative teaching methods applicable at other levels of education.

Responses of Ginkgo biloba to water stress

Fri, 12 Dec 2025 00:00:00 GMT

The research paper deals with the adaptability of Ginkgo biloba L. and its growth and physiological responses under conditions of water scarcity. We hypothesised that under conditions of water scarcity, Ginkgo would use adaptive mechanisms that would allow it to manage water efficiently and, at the same time, survive the dry season. Two experimental variants were set up with plants in the juvenile stage of ontogeny with differentiated irrigation. In the control variant, the soil substrate was saturated with water to 70% of the field’s water capacity. The water saturation of the substrate of the stressed plants was 40%. The differentiated irrigation regime was introduced at the beginning of June and maintained until the beginning of September. The results of three years of research were evaluated. Based on the results, we can conclude that Ginkgo biloba has an exceptional ability to protect the water content of the leaves under conditions of water shortage, which probably allows it to survive a prolonged period of drought. However, the survival strategy of the lack of water leads to a significant limitation of the growth of the whole plant, including the root system.

Botanical and mycological research in Bielański Forest in Warsaw (central Poland) during the 19th century

Sun, 14 Sep 2025 00:00:00 GMT

The Bielański Forest in Warsaw is one of the most valuable natural areas in central Poland. Its royal ownership and the presence of the Camaldolese monastery helped it to maintain high naturalness by the late 18th century. This study presents research carried out in the Bielański Forest, on vascular plants, mosses, lichens, fungi and slime moulds in the 19th century. The initiators of research in the first half of the 19th century were M. Szubert and shortly thereafter W. Jastrzębowski. The first data were published in the second half of the century by, among others, K. Majewski, F. Karo and J. Rostafiński. The majority of research from the Bielański Forest was published in Polish scientific journals Pamiętnik Fizyjograficzny and Wszechświat, established in the 1880s. At that time, on the initiative of T. Chałubiński, studies of bryophytes and lichens began, carried out by K. Filipowicz, S. Dawid, J. Steinhaus, and F. Błoński, who also researched vascular plants and fungi. Fungi were also studied by S. Chełchowski, slime moulds by J. Aleksandrowicz and J. Rostafiński, and vascular plants by F. Kamieński, H. Cybulski, and K. Łapczyński, who as the first noticed the impoverishment of the Bielański Forest flora. Our analyses allowed us to establish that of the 45 species of vascular plants reported from Bielany by Rostafiński (1872), about 50% of the taxa had not been observed by the 1920s, and nearly 67% by the end of the 20th century. Of the group of 14 species listed by Rostafiński and currently considered as endangered or protected, Kobendza (1929) listed only one. Of the 26 species listed by Błoński (1892), nearly 54% had disappeared by the end of the 20th century. From the group of 30 species of macrofungi recorded at the end of the 19th century, considered now as endangered, only 6 taxa were recorded a century later.

The effects of post-hurricane forest regeneration methods on soil carbon and nutrient content

Sun, 14 Sep 2025 00:00:00 GMT

The aim of the study was to show the effects of different methods of soil preparation for planting forests in post-hurricane areas on the levels of organic carbon and nutrients needed to rebuild the forest ecosystem. The study was conducted in the forest district of Runowo (Toruń) in the Kujawsko-Pomorskie region. In 2022, experimental plots were established in the areas after the hurricane in 2017, that is, 1. prepared area (ploughing + planting); 2. prepared area [ploughing (furrows) + planting]; 3. unprepared area (without ploughing) + planting; 4. unprepared area (without ploughing + natural regeneration) and 5. control area – forest. The soil samples were taken in spring (April) 2024 from the organic layer (O) on the objects (4 and 5) and layers (0–5, 5–10, 10–20 and 20–40 cm) on all objects. The soil samples were analysed for granulometric composition (using the laser diffraction method), hydrolytic acidity (Hh) and exchangeable acidity (Hw) (titrimetric methods) and for pH in a solution of 0.01 mol CaCl2 dm−3. The contents of Corg and NTot were determined by high-temperature combustion with TCD detection. The total content of Ptot, Ktot, Mgtot, Catot, Natot was determined after mineralisation in HCl and HNO3 acids (1:3), and the content of cations (Ca2+, Mg2+, K+, Na+, H+, Al3+) was determined in a solution of 0.1 mol BaCl2·dm−3 by inductively coupled plasma optical emission spectrometry. It was found that the content of Corg and nutrients was significantly higher in the objects where no agricultural treatments were carried out, that is, 4 (‘natural regeneration’) and 5 (forest), compared to the objects where cultivation was carried out (sites 1, 2, 3). Positive Spearman rank correlations were found between Corg content and Ntot and cation exchange capacity (CEC) and between Ntot and CEC and sum of the base cations. The method of soil preparation for planting forests in post-hurricane areas affected carbon accumulation and availability of nutrients for forest ecosystem regeneration.

Potentially invasive fungal pathogens in forests of Nepal

Sun, 14 Sep 2025 00:00:00 GMT

Potentially invasive fungal pathogens of tree species in Nepal were isolated and identified in this study. A survey was conducted throughout the country, and the infected parts of different host trees were cultured in potato dextrose agar medium to isolate the pathogenic fungi. Altogether, 10 fungal pathogens were identified as causing foliar and trunk diseases. Two of the pathogens, Nectria sp. (stem canker) and Phytophthora alni subsp. alni (bleeding canker), were reported from the stems and trunks of Alnus nepalensis and Shorea robusta, respectively. The pathogens Neonectria neomacrospora (needle cast), Aureobasidium apocryptum (anthracnose), Golovinomyces cichoracearum (powdery mildew), Calonectria reteaudii (blight), Dothistroma septosporum (needle cast), Calonectria indusiata (spot), Olivea tectonae (rust) and Rhytisma acerinum (tar spot) were isolated from the foliar part of the host trees Abies spectabilis, Acer laevigatum, Alnus nepalensis, Eucalyptus camaldulensis, Pinus roxburghii, Rhododendron arboreum, Tectona grandis and Toona ciliata, respectively. These species could be the potential invasive forest pathogens in Nepal. An effective long-term future plan needs to be developed for managing these forest diseases to maintain the forest health of the country.

The insular distribution of beech forests in Romania – reminiscent of the glacial period induced by genetic and ecological plasticity

Sun, 14 Sep 2025 00:00:00 GMT

We attempt to explain the presence of the genus Fagus outside its usual climate range. We provide information regarding the evolution of beech wooded areas in the context of climate change, as well as on the morphological variability and the genetic and ecological plasticity. In Romania, five study zones were selected that were found to be in extra range, with each area having 1–3 plots. The following parameters were identified for each area: number of the plots, surface of each plot, altitude, exposure, soil type, participation of beech in the composition of the forest, average age, average diameter measured at arm height (HDB, average height, and flora type. The climatic and bioclimatic indices were computed along with indices that describe particularities of Fagus species based on air temperature and precipitation data for the period 1901–2020. All 17 plots present in 5 mature forests are located at an altitude of less than 250 m above sea level. The average age of the beech is over 100 years, the oldest being about 170 years. The structure of the forests is the result of the pedo-climatic conditions. In the context of climate change, as well as the ecological plasticity, the morphological variability of species in the genus Fagus offers this genus the opportunity to adapt to new pedo-climatic conditions and to expand the range of some thermophilic beech species.

Age trends in the effectiveness of some ecosystem services provided by poplar cultivars in the Western Forest Steppe of Ukraine

Sun, 14 Sep 2025 00:00:00 GMT

The article presents the results of a long-term study on an experimental plantation of four poplar cultivars (‘Canadian-Balsamic’, ‘Druzhba’, ‘Tronko’, and ‘Strilopodibna’) at 7, 9, and 15 years of age. The plantation was established near Ternopil, the city in western Ukraine. Under conditions of natural thinning, the average survival rate of the poplar cultivars decreased linearly (R2 = 0.995) from 83.5% on a 7-year-old plantation to 32.5% on a 15-year-old plantation. The average stem wood stock of all poplar cultivars on the plantation increased over the 8-year period (from 7 to 15 years), rising from 108.3 to 134.5 m3·ha−1. However, the growth dynamics of individual cultivars varied. At 7 years of age, the Strilopodibna poplar exhibited slightly lower growth rates in both height and diameter than the other cultivars and had the smallest stem wood stock (93 m3·ha−1). However, due to a lower natural tree loss rate, it ranked first in productivity by the age of 15, nearly doubling its stem wood stock to 171 m3·ha−1 over the 8-year period. The study has also shown that all poplar cultivars on the experimental plantation have a high potential for generating various ecosystem services, including CO2 sequestration, oxygen production, and energy biomass generation. However, the trends in both average annual values and current changes in the provision of these ecosystem services vary among cultivars. Similar to the trends observed in stem wood accumulation, the average annual volumes of ecosystem services for the poplar cultivar ‘Strilopodibna’ declined at a significantly lower rate than those of ‘Druzhba’, ‘Canadian-Balsamic’, and ‘Tronko’. At the same time, the current change in ecosystem service provision for ‘Strilopodibna’ at ages 9 and 15 remained positive and relatively high, whereas for the other cultivars, it was low and often negative. Based on these findings, the results of the study suggest that the optimal maturity age of the analyzed poplar cultivars, based on their maximum efficiency in ecosystem service generation, is less than 7 years.

Ecological and trophic determination of the ontogenesis in vitro plants of the genus Betula

Sun, 14 Sep 2025 00:00:00 GMT

A comprehensive assessment was conducted to identify the features of decontamination formation, morphogenesis of primary explants of birch genus plants and their regeneration at the stages of obtaining aseptic culture, multiplication and induction of rhizogenesis. According to the ‘step-by-step’ principle, the following were selected: the best age of explant donors and the conditions of their cultivation, namely, a depository with diffused lighting and fungicidal and bactericidal protection. The effectiveness of the use of Blanidas 300 as a decontaminant was substantiated. The peculiarities of the trophic determination of plant objects by artificial nutrient media with different compositions of mineral elements were established. The effect of phytotoxicity caused by excess nitrogen in the Morayshire and Skoog nutrient medium and excess sulphur in the Lloyd-McCone (WPM) artificial nutrient medium was established. The effect of pH on the availability of elements of mineral nutrition was revealed; the peculiarities of heterotrophic nutrition were investigated; the determinants at the stages of rhizogenesis and adaptation were identified; and the peculiarities of the ontogenesis of plant objects were determined. For effective decontamination and improvement of the regeneration process of primary explants, it is advisable to use one-year-old juvenile donors, grown under diffused lighting in depository conditions and with a system of compatible fungicidal and bactericidal measures. Based on experimental data, the expediency of the principle of using the main and unloading nutrient media is substantiated.