A bstract 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, pH CaCl2 in a solution of 0.01 mol CaCl 2 ·dm -3 , organic carbon content (TOC), total nitrogen content (TN), exchangeable acidity (H w ) 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 (pH CaCl2 : 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%).

A bstract 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.

A bstract 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.

Abstract 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.

Abstract 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.

Abstract The research conducted on the occurrence of fungal diseases in forest nurseries in Poland from 2012 to 2021 revealed significant insights. The study focused on tracking the trend in the change of disease areas and providing a comprehensive summary of each disease in terms of symptoms, host plants, and weather conditions. The findings highlighted the critical role of forest nurseries in rearing and producing tree seedlings for reforestation, emphasizing the need to limit pathogen spread to ensure the production of healthy and resistant seedlings. The analysis identified the most common fungal diseases, such as powdery mildew, needle-cast of pine, and their impact on various tree species. The study also emphasized the influence of climatic conditions on the development and spread of these diseases. Additionally, the research underscored the importance of adhering to hygiene rules, using high-quality seeds, and providing proper irrigation, aeration, fertilization, and weed control to mitigate the influence of abiotic factors on forest nurseries. The data from the annual monitoring of forest nurseries indicated a decreasing trend in the damaged area caused by pathogens, although the occurrence of diseases varied in intensity, potentially related to weather conditions. Overall, the study provided valuable insights into the incidence of fungal diseases in forest nurseries and highlighted the significance of monitoring and addressing these diseases to ensure sustainable forest management.

Abstract Effective management of forest ecosystems requires accurate predictions of damage by ungulates, a challenge particularly acute in the Kyiv Polissya. This study aims to identify key drivers of ungulate browsing intensity and compare the effectiveness of the random forest model (RFM) and generalized linear model (GLM) in forecasting damage to young forests. We analysed field data from three experimental enterprises in the Kyiv region, covering a combined area of 71.4 thousand hectares and involving 275 experimental plots. The study identified ungulate population density as the most influential factor affecting browsing intensity, surpassing variables such as tree age, tree species ratio and forest type. In comparing models, RFM demonstrated superior predictive accuracy over GLM, highlighting its effectiveness in forecasting damage to young forests. The study highlights how machine learning enhances the accuracy of ecological predictions and underscores the significance of selecting variables thoughtfully during model development. The findings point to the need for flexible forest management strategies focused on regulating wild ungulate populations and protecting young forests.

Abstract Assessing the condition of plants in an urban landscaping is a necessary component of monitoring urban ecosystems. Studying how the sensitivity of plants to stressful conditions and the influence of many factors on their growth and development is important for determining the suitability of using plants for urban improvement. The purpose of this study was to identify the impact of stress factors on the growth and development of Ligustrum vulgare L. (commonly called privet). The research was conducted in the city of Kyiv, where the plants are affected by significant vehicle traffic, intense insolation or excessive shade, and mechanical traumatization of plants due to plant trimming. Shoots of Ligustrum vulgare L. of different ages and under different growing conditions were used for the analysis. The research used methods of morphometry, chromatographic profiling of secondary metabolites, and statistical data processing. To analyze the morphogenesis of annual shoots, the Gaussian model was used, which accurately (R2 > 0.90) describes their growth processes. The model coefficients were used for a comparative assessment of the growth dynamics of Ligustrum vulgare L. shoots depending on the growing conditions and plant care. Correlation analysis also allowed for the identification of potential connections between the growth model coefficients and certain phenolic synthesis products. It was found that the plant trimming leads to an increase in the length of the shoots and accelerated growth of the side shoots. The obtained results may indicate that phenolic compounds, in particular chlorogenic acid, directly or indirectly affect the regulation of growth and development of shoots of Ligustrum vulgare L. in response to stress factors, such as mechanical injury. The content of chlorogenic acid positively correlates with the increase in the length of internodes, which indicates its possible role in morphogenesis. It has been established that the profiles of phenolic substances allow identification of Ligustrum plants at the species level. Principal component analysis (PCA) and cluster analyses showed that the phenolic profiles of plants depend on their growing conditions and the urban environment. The study confirms the importance of plant trimming for stimulating plant growth. The significant adaptation potential of Ligustrum vulgare L. plants confirmed the suitability of their use in urban environments.

Abstract The forest fires constitute a major danger for the forests in the Western Algerian region. They are caused by a combination of several factors, particularly climatic and anthropogenic, which are often amplified by the composition of vegetation that is considered highly flammable during the dry season. The priority for action to deal with this phenomenon is to strengthen monitoring resources and apply preventive silvicultural measures to avoid the outbreak of fires, without forgetting efforts to educate and raise public awareness. A systematic examination of data retrieved from the General Forests Directorate of Forest Fires stretching between 2003 and 2017 reveals the spatiotemporal, spatial and temporal evolution of fires in the Western Algerian region. The statistical approach applied in this study allowed us to identify the periods in which our forests are mostly vulnerable to fires, allowing the programing of an action plan for an effective forest fire management. The fire danger map produced by calculating the Fire Danger Index can be a decision-support tool for forest managers to locate areas at high risk in order to take preventive measures to limit the loss of natural resources, properties, and even human lives.

Abstract This study presents the development and application of forest fuel models to predict fire behaviour in different forest habitats, focusing on biomass distribution, moisture variability and the calorific value of soil cover components. On analysing forest fire data from 2007 to 2013, we identified high-risk habitats, especially in younger stands and in stands dominated by Scots pine. The variability of moisture in the different soil cover components, including litter and deadwood, was statistically analysed; it revealed significant dependencies on litter moisture and rain-free intervals. These dependencies allowed the creation of equations to accurately predict fuel load and moisture content based on stand age, habitat type and environmental conditions. Using the calorific value measurements with an average calorific value of 18,920 kJ/kg for dry soil cover materials, fuel models were developed to estimate the potential intensity of fires. The models categorise the biomass into decayed, dead and live components and take into account key variables such as bulk density and moisture content that influence fire spread. Data-driven categorisation enables fire risk assessments at the compartment level, which increases accuracy compared to more comprehensive district-level assessments. Applications of fuel models include mapping the spatial distribution of biomass by fuel type, creating fire hazard maps and optimising firefighting infrastructure. These models support planning and operations by enabling forest managers to visualise high-risk areas and predict fire behaviour based on real-time meteorological data. The models are a critical step towards a more effective firefighting system that provides fine-grained, actionable insights into fire risk at the local level.