Tupchii O. Transformation of windbreaks in the eastern part of the Right-Bank Forest-Steppe under climate change

Analysis of the dynamics of climatic indicators of the research region for ten-year periods from 1961 to 2024 showed climate changes, the main cause of which was the increase in high air temperatures. The year of field research was the first calendar year that exceeded the warming by 1.5 °C compared to the pre-industrial level. Analytical analysis of prognostic models indicates a probable increase in air temperature in Ukraine by another 1–1.5 °C in the next 30 years. The identified trends in climate change are necessary for the development of recommendations for the implementation of innovative agroforestry with the introduction of drought-resistant tree species to adapt agricultural landscapes to climate change. The study of the optimization of the parameters of windbreaks within the framework of their transformation into agroforestry systems, the current state and amelioration properties of windbreaks was carried out in the period 2023–2025. The studied windbreaks of age classes VI–VIII fully exert amelioration on the inter-strip space. The protective heights of transformed windbreaks are 2–4 m lower than traditional plantations, which is reflected in a decrease in their productivity to the class of productivity I–II. It was found that the transformation of traditional windbreaks into linear plantations of the silvo-arable agroforestry system leads to a change in both the parametric structure of the windbreaks and their structural features. In general, all transformed plantations have acquired an sieve-looked and blown disigns which has an effective effect on wind regulation and meliorative protection of adjacent territories. Transformed windbreaks are characterized by a better health condition than traditional ones. This is evidenced by the health condition index, which varies within 2.0–2.9 and 1.5–2.4 in traditional and transformed windbreaks, respectively. The absence of dead trees or their small proportion (up to 2.6 %) in transformed windbreaks improves the condition of these plantations. This fact is confirmed by the lower values of the average weighted Kraft classes, which indicate a higher proportion of pre-dominant and dominant trees in transformed stands. Agrochemical analysis of soils of windbreaks showed that humus reserves in windbreaks exceed the similar indicator of arable lands by 10.7 and 3.4 % at distances of 3Н and 10Н, respectively. Lower humus content was recorded in transformed windbreaks, which is explained by a decrease in the thickness of the forest litter, and elsewhere by its complete loss. A significant predominance of easily hydrolyzable nitrogen was found in the upper 0–10 cm soil layer in all windbreaks compared to its content in deeper horizons. A significantly lower nitrogen content was noted in the upper soil layer of transformed windbreaks compared to traditional belts. This phenomenon is explained by the greater presence and activity of soil microorganisms in traditional windbreaks, associated with a greater capacity of forest litter and precipitation. The greatest accumulation of phosphorus was found in traditional windbreaks in the upper 0–10 cm soil layer, where its stock was 156.80 mg/kg. Such a phosphorus stock is due to the slightly acidic soil reaction (pH – 6.47) and the presence of a high concentration of organic matter and mycorrhizal fungi, which create an environment for the absorption of phosphorus ions by plant roots. In transformed windbreaks, the phosphorus content in the upper soil layer is in all cases 11.4–14.5 % lower compared to the similar indicator in traditional windbreaks. Significant accumulation of phosphorus was recorded in the arable soil layer at distances of 3 and 10 heights from the windbreaks, where its content ranged from 117.60 to 170.40 mg/kg. Such stocks are explained by the neutral acidity of the soil and its intensive cultivation. Soils under windbreaks are characterized by an acidic reaction of the soil solution, where the pH takes on values from 4.64 to 5.50. The soil of the lower horizons of windbreaks is characterized by lower acidity than the upper soil layers. This is explained by the accelerated mineralization of organic matter. The acidity of the soil of transformed windbreaks is significantly different from the acidity of the soils of traditional windbreaks with a trend of its decrease. In general, the research data confirm the positive impact of both traditional and transformed windbreaks on adjacent arable lands. Analysis of the coenotic structure of the living aboveground cover revealed a predominance of the share of sylvans and ruderants in both traditional and transformed windbreaks. However, in traditional windbreaks, the share of sylvans (39.0–49.4 %) was greater than the share of ruderants (20.3–42.0 %), and in transformed windbreaks, the predominance of ruderal vegetation (22.1–41.3 %) over forest (17.3–31.7 %) is already clearly visible.