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Oak (Quercus robur L.) forest stands are among the most common forest formations in the forest-steppe zone of Ukraine. Investigations of the patterns of distribution of trees by diameter and the dynamics of the commodity structure of mature oak stands of coppice origin were carried out based on the forest survey data from 28 temporary sample plots, on the sites designated for the final felling in the Left-Bank Forest Steppe of Ukraine (Sumy, Kharkiv, and Poltava Regions). We distributed trees by diameter classes and technical suitability categories. To establish the commodity structure of the stand, we selected model trees that corresponded to the average size of trees in terms of diameter classes and their qualitative characteristics. Then, we constructed a model tree stem profile using Institute of Forest Ecosystems Research (IFER)’s method of “6 points”. Based on stands’ structure and quality condition as well as on the growth tables, the commodity structure dynamics table for the changes in the commodity structure for the coppice oak stands in the Left-Bank Forest Steppe of Ukraine has been developed. The results of the analysis of wood stock dynamics showed that the maximum average increment of class A and B wood is 90–100 years. Therefore, the age of technical maturity and the associated age for the final felling in commercial oak forests of second site class and above should be assigned to 91–100 years.

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]

Deadwood is an important component of forest ecosystems, and difference in the deadwood carbon stock depends on many variables including forest management. The aim of our study was to determine the patterns of formation of deadwood stocks in oak (Quercus robur L.) forests in the Left Bank Forest-steppe of Ukraine. As an outcome of the research, the data on deadwood parameters were obtained. The growth characteristics and coarse woody debris (CWD) characteristics were measured on intensive monitoring and inventory plots. Assessment of morphometric parameters of the CWD in oak stands was carried out by measuring diameters at top and bottom cut and length; to determine the carbon content, deadwood density was used. The distribution of deadwood by tree species, sizes and stages of decomposition was defined. The stock of dead trees (snags) in oak forest is 15.2 m3/ha and that of logs is 21.5 m3/ha. The carbon accumulation in oak forest stands in the Left Bank Forest-steppe of Ukraine was 3.4 and 4.5 t C/ha in dead trees and logs, respectively. The dynamics of deadwood stocks according to the results of repeated observations was given. [ABSTRACT FROM AUTHOR]

This paper focuses on the impacts of expected climate change according to scenarios of the IPCC Fifth Assessment Report (2014) on forests distribution in the north-eastern part of Ukraine in the 21st century. De Martonne aridity index was used for determination of vulnerability level. Ranges of temperature, precipitation and de Martonne index for main tree species were determined. Main tree species' distribution and forest health condition (defoliation and trees mortality) were assessed by vulnerability zones. In the 21st century, significant climate warming (by 3-6° C) in the north-eastern part of Ukraine will cause increasing of drought risk, that will be unfavourable for forest vegetation. At present, 61.2% of forests grow on the southern limit of their natural range at moderately and slightly humid climate. Significant deterioration of forest health condition is expected. Forest and forest-steppe zones shifting to the north and replacement by steppe are highly probable, as well as shifting of natural ranges of main tree species. Some tree species probably will disappear and will be replaced by more xeric ones, including introduced. According to our models, the flatland part of Ukraine probably will gradually become forestless, while forests will be preserved only at sites with available soil moisture. We propose to implement adaptation measures based on the best practices for sustainable forest management, as well as improvement of technologies for forest cultivation and control of forest fires. The study was carried out in the frame of the Integrated drought management program in Central and Eastern Europe supported by the Global Water Partnership. [ABSTRACT FROM AUTHOR]

In the context of global climate change, the sustainable use of forest resources becomes of particular relevance and is only possible after a comprehensive assessment of all components of forest ecosystems is made. At present, complex research on phytomass and mortmass of Scots pine forests of the Left-bank Forest steppe of Ukraine has been carried out to a limited extent. Therefore, it is important to assess the quantitative and qualitative indices of phytomass and mortmass of forest stands. For the study, observations on 40 monitoring and inventory plots were used. On the plots, indicators of the main components of forest ecosystems were determined. The plots represented the main types of forest vegetation conditions, productivity of Ia-II classes, age 40 to 120 years. The data were analysed by productivity classes and types of forest vegetation conditions. The phytomass stock varied from 60 to 360 t/ha. The maximum of the mortmass of dead trees was 13, while the coarse woody debris was 17 t/ha. The diversity of dead wood by species composition was very low. It was represented predominantly by Scots pine (Pinus sylvestris L.). The diversity of the coarse woody debris by the decomposition stages was rather high, both by the representation of different stages of decomposition and amount by stages. The average share of the stock of dead trees and coarse woody debris from the growing stock in bark was 8.8% and 9.4%, respectively. The average stage of decomposition of coarse woody debris was 2.6. About 1.2 and 1.5 tons of carbon per hectare are stored in dead trees and coarse woody debris of pine forests, which amounts about 2.4% of the carbon stock in the pine forest biomass' reservoir. [ABSTRACT FROM AUTHOR]