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The phenolic compounds in the leaves of 12 species of birch trees of the subgenera Neurobetula, Betulenta, and Betula were biochemically profiled using HPTLC. The duration of the vegetation period was found to be significantly related to the content of total phenols (r = 0.74) and flavonoids in leaves (r = 0.65). The correlations for Neurobetula plants were 0.86 and 0.91, respectively. The relationship between the duration of the growing season and the concentration of phenolic compounds in Betula plants was inverse (r = −0.84). A cluster analysis of phytochemical profiles revealed that the studied birch species form groups that coincide with the subgenera proposed by De Jong due to an affinity with the qualitative composition of phenolic compounds. A multiple correlation analysis confirmed the relationship between the qualitative composition of phenolic compounds and the morphological characteristics of the leaves. The results of phytochemical profiling revealed that the qualitative composition of polyphenols in the leaves of 12 birch species is quite specific, allowing the use of individual compounds as additional differential biochemical characters in identifying species and hybrids and studying their potential role in plant adaptation to habitat conditions. [ABSTRACT FROM AUTHOR]

The russian military aggression and the related socio-economic and environmental consequences have significantly affected the climate and production of ecosystem services through damage to forests, ecosystems, landscape fires and emissions of gases into the atmosphere. The study aims to estimate carbon dioxide emissions due to landscape fires in Ukraine during the year 2022. The OroraTech wildfire monitoring technology was used to detect fires, while perimeters of burned areas were delineated with Sentinel 2 time series. The Copernicus Dynamic Land Cover map was used to extract burned land covers. Emissions were calculated based on the intensity of fires (dNBR) with the share of burned biomass in different types of land cover. Biomass models were selected considering the dominant tree species within a specific region and the species structure of the sown areas of croplands. The volume of biomass losses was estimated as a result of fires of different severities. It was estimated that during in 2022, landscape fires burned 749.5 thousand hectares thereof: croplands - 419.1 thousand hectares; other natural vegetation - 273.8 thousand hectares; conifer forests - 31.1 thousand hectares; other forests - 25.5 thousand hectares. The impact of the war on landscape fires is confirmed by the large proportion of fires in the 60-kilometre buffer zone along the frontline - 68.9% of the total area of fire. Among all fires, 42.5% of fires occurred in the occupied territory. Total CO2 emissions from all types of landscape fires reached 5.20 million tons and other greenhouse gases - 0.28 million tons. It is the first detailed mapping of landscape fires with an analysis of each polygon for the whole territory of Ukraine. The results provide important information for assessing the loss of ecosystem services and estimating carbon dioxide emissions as well as for confirming the impact of hostilities on landscape fires. [ABSTRACT FROM AUTHOR]

Energy independence of the country can be solved in several ways. One of them is the creation of energy plantations of woody plants. The area increase of such plantations is limited by the insufficient amount of high-quality planting material. Hybrid plants of the genus Populus are of considerable interest when creating plantations. Given that not all hybrids are successfully propagated by conventional vegetative methods, the use of biotechnological methods, namely microclonal propagation, solves the mentioned problem. This method allows obtaining a large amount of highquality, uniform planting material. The purpose of this study was to develop the technology of microclonal propagation of black poplar hybrids ‘San Giorgio’ and ‘Ghoy’. The study used generally accepted biotechnological methods in the author’s modification at all stages of obtaining planting material of regenerating plants of poplar hybrids. Studies have established a positive effect when obtaining an aseptic culture of sterilising substances 0.1% AgNO3, 2.5 and 1.25% NaClO, 0.05% sodium merthiolate and 0.1% HgCl2. The largest number of aseptic viable explants was obtained by cultures using a 0.05% solution of sodium merthiolate after exposure for 5 and 10 minutes. When rooting microshoots on a hormone-free nutrient medium ½ MS and with the addition of 0.1-1.0 mg/l IBA, it was established that the best parameters for rooting microshoots are on a hormone-free nutrient medium ½ MS. Adaptation was carried out for 4 weeks in a greenhouse on a substrate that included components of peat:sand:perlite in a ratio of 1:1:1. The viability of regenerating plants of black poplar hybrids ‘San Giorgio’ and ‘Ghoy’ was more than 91%. The conducted research and the obtained results will be useful for producers of planting material and the scientific environment, which develop renewable energy sources through the creation of energy plantations of fast-growing woody plants. [ABSTRACT FROM AUTHOR]