Oleh O. Didur

This research focuses on the rare flora of valley-terrace landscapes within Ukraine’s steppe zone, highlighting their role as vital ecological corridors and refugia for sustaining biodiversity. The aim of the work was to conduct a comprehensive sozological analysis of the VTL flora, determine its taxonomic structure, and assess the spatial distribution of rare species of various conservation ranks (international, national, and regional) across administrative regions. The study is based on the principles of ecofloristics and sozological audit. The analysis was performed considering biomorphological characteristics and coenomorphic structure (according to Belgard’s system). The sozological assessment was carried out in accordance with the categories of the IUCN Red List of Threatened Species, the European Red List, and the Red Data Book of Ukraine. It was established that the rare fraction of the VTL flora in the steppe zone includes 371 species of vascular plants (28.08% of the total composition), belonging to 222 genera and 82 families. A multi-level conservation status of the phytobiota was revealed: 8 species are included in the IUCN Red List, 14 in the European Red List, 41 species are protected at the national level (Red Data Book of Ukraine), and all 372 species hold the status of regionally rare. The analysis of territorial distribution showed the highest concentration of rare species in the Dnipropetrovsk (289 species) and Donetsk (111) regions. A statistical phenomenon was identified in the Kherson region, where 100% of the regional rare flora (42 species) is concentrated specifically within valley-terrace landscapes. The study highlights that the high phytodiversity of VTL is determined by significant ecotopic heterogeneity and the ecotone effect, which allows for the coexistence of representatives from various ecological groups: from hygrophytes and paludants of floodplains to psammophytes of arenas and halophytes of loess terraces. A strong correlation (rs = 0.95; 95% CI: 0.803–0.989) between the total regional rare flora and its presence in river valleys confirms the role of valley-terrace landscapes as representative cores of sozological potential and key refugia for rare species within the steppe zone. Special emphasis is placed on threats to biodiversity associated with military aggression, which leads to habitat degradation, ruderalization, and the expansion of invasive species. The study results provide a scientific framework for optimizing the nature reserve fund network, updating regional red lists, and implementing biodiversity conservation strategies to protect Ukraine's unique gene pool.

Winter wheat competitive ability against weeds in agrophytocenoses is determined, in part, by varietal characteristics, with implications for the grain yield of this globally important crop. Field experiments conducted in 2021–2023 were aimed at evaluating the competitive ability of the newest winter wheat cultivar of Ukrainian selection (Tsarychanka, Koshova, Oleksiyvka, Hratsiya Myronivska, Vezha Myronivska, Estafeta Myronivska) in the Steppe arid conditions. Weed abundance and pressure were determined by the dominant species Sinapis arvensis, Fumaria officinalis, Raphanus raphanistrum, and Thlaspi arvense, and varied depending on the crop development phase, maturity group of cultivars, and weather conditions. Early- maturing wheat cultivar displayed the highest biometric and structural parameters, such as plant height, leaf surface area, spike length, grain number per spike, and 1000 kernel weight, and were also characterized by the lowest weed air-dry mass in crops. Grain yield varied depending on the growing season conditions, reaching the highest average for all maturity groups in 2022 (7.12 t/ha), which was the highest for early-maturing cultivar in all years of research (6.31 t/ha). Thus, early-maturing cultivar excelled in terms of resistance to weed competition, adaptation to adverse climate conditions, and productivity, and were determined to be the most competitive among the newest cultivar of winter wheat created by Ukrainian breeders.

Висвітлено, що військові дії чинять значний вплив на біосферу на різних екологічних рівнях, істотно змінюючи екосистеми та їхні компоненти, а міра їх впливу залежить від характеру порушень, стійкості біологічних систем і часових рамок конфлікту. Через військову агресію прискореними темпами відбувається деградація земель, що становить серйозну загрозу продовольчій безпеці, знищуються ландшафтні ресурси, дерева, тваринний світ, порушується структура ґрунту, погіршуються умови існування наземної та підземної біоти. Показано, що військова агресія призводить до накопичення потенційно токсичних елементів, таких як кадмій, у ґрунті, рослинах. Пошкодження рослин проявляється у вигляді змін їхнього росту та фізіологічних характеристик, особливо за підвищеної концентрації кадмію, який легко поглинається корінням рослин. Оцінено вплив хімічного забруднення ґрунтів (на прикладі потенційно токсичного кадмію) на індикаторний вид лісової рослини. В умовах вегетаційного досліду вивчено вплив кадмію на низку основних морфометричних характеристик паростків рослини гравілату міського (Geum urbanum L.), який є широко розповсюдженим по всій території України багаторічним трав’янистим лісовим видом. Досліди показали, що після 10 діб впливу кадмію в дозі (відносно гранично допустимої концентрації) 1ГДК, 2ГДК, 4ГДК (3, 6 та 12 мг/кг субстрату) у рослин спостерігається статистичне достовірне гальмування росту їх надземної і підземної частини. З’ясовано, що маса паростків, їх висота та довжина коренів зі збільшенням концентрації токсиканту зменшуються, що підтверджено дисперсійним аналізом та множинним порівнянням середніх значень показників. Моделювання дїї кадмію у дозі 5ГДК (15 мг/кг субстрату) також виявило негативний вплив на вказані морфометричні характеристики дослідної рослини. За результатами моделювання побудовано працездатні моделі лінійної регресії з високим ступенем апроксимації, які прогнозують зниження значень досліджених морфометричних характеристик паростків індикаторної рослини порівняно з дозою кадмію 4ГДК (12 мг/кг субстрату). Припускається, що буферна здатність ґрунтів по відношенню до потенційно токсичного кадмію виявляє більший рівень буферної ємності на відміну від піщаного субстрату, а отже, і більшу стійкість до деградації. Результати експериментів свідчать, що досліджений суглинковий гумусований ґрунт проявляє більш високий рівень буферної здатності до впливу кадмію порівняно з піском, на якому спостерігаються менші середні значення маси паростків модельної рослини, її висоти та довжини підземної частини.

As a component of urban parks, soil is an essential part of urban green infrastructure; soil influences the green plantings in megacities, being affected by environmentally unfavorable factors. To reveal relationships between soil buffering capacity and ecological microbial groups of park soils, soil acid-base buffering capacity (pHBC) was determined with the Arrhenius method. We counted the soil microorganisms using differential diagnostic nutrient media with serial dilutions. Soil microbial biomass was determined by thermal rehydration. In statistical data processing, we used the methods of descriptive statistics, univariate analysis of variance, etc. We established strong positive correlations between pH values and pHBC in the acid and acid-base range, and a negative correlation between pH values and buffering capacity in the alkaline range; a strong correlation between the abundancies of amylolytic and pedotrophic soil microorganisms. We determined the effect of the three following soil sustainability-associated latent factors: Factor 1 – effect correlated with total pHBC, pHBC in the acid range and soil acidity, Factor 2 and Factor 3 – effects characterized by the direction of microbial processes and which formed a balanced system between the soil humus decomposition and the entry of plant litter. We revealed a beneficial impact of subcrown space on the abundancies of soil microorganisms. We recommend using acid and acid-base buffering capacity and microbiological characteristics as soil quality indicators. The abundance of soil microorganisms increased in the forested sites.

Herein, we report for the first time the biosynthesis of silver nanoparticles (AgNPs) using leaf extracts of Chaenomeles Lindl. (Rosaceae) plants and its spectral characteristics, as well as antifungal and antibacterial activity. Phytosynthesis of silver nanoparticles on the base of aqueous plant extracts and silver nitrate solution was carried out by an ecofriendly and cost-effective approach. UV-Vis spectroscopy was applied to validate the plant-mediated biosynthesis of AgNPs colloidal solutions by the Surface Plasmon Resonance (SPR) bands in the region of 450–500 nm, characteristic of polycrystalline silver nanoparticles. Scanning microscopy (SEM) revealed a wide variation in range 5–58 nm and a close to spherical shape of plant-derived AgNPs. Raman scattering spectroscopy revealed the suitability of biosynthesized silver nanoparticles as the substrates for surface-enhanced Raman scattering (SERS) spectroscopy with the highest efficiency of AgNPs, biosynthesized from leaf extract of Ch. × superba, which enhanced the Rhodamine 6G dye applied at a concentration of 10–7 M. Assay of antifungal activity performed by well diffusion method revealed the dose-dependent effect of all AgNPs against the phytopathogenic fungus Fusarium culmorum. The most effective AgNPs (Ch. speciosa-AgNPs, Ch. cathayensis-AgNPs, and Ch. japonica-AgNPs) achieved a 1.42–1.63 times greater zone of inhibition of the F. culmorum colonies’ growth compared to the corresponding doses of the known chemical fungicide "Quadris". Micro preparations of the zones of incomplete growth inhibition presented changes in the mycelium morphology of F. culmorum due to the action of nanoparticles, such as deformation (curvature, expansion), and a decrease in the hyphae length and density compared to the control sample. Disc-diffusion assay showed notable species-specific antibacterial activity of AgNPs both against Gram-negative (Klebsiella pneumoniae) and Gram-positive (Staphylococcus aureus) strains. Summarizing, the results indicate the undeniable suitability of aqueous leaf extracts of the genus Chaenomeles species for the successful biosynthesis of silver nanoparticles with many useful properties, whose diverse applications require further research.

Wheat is one of humanity’s leading food crops, and ensuring high, sustainable yields is the key to food security. The yield of the crop depends on the agrophytocenosis conditions, including meteorological factors, the number of weeds, pathogens and pests, which change from year to year. Crop yield forecasts are becoming necessary to make informed crop management decisions. The paper presents the results of the multiple regression analysis of actual field data in the system of integrated protection of winter wheat crops in the conditions of the Northern Steppe zone of Ukraine. The predictive value of the models that linked yield and gluten content in grain with the number of pathogens and pests was reduced due to the statistical insignificance of correlations between indicators. In order to overcome the shortcomings of modeling, it is probably necessary to use a more reliable algorithm and a larger sample of data. Regression models reflecting the correlation of yield and gluten content in grain with relative air humidity during the phase of milky ripeness of winter wheat grain showed predictive value (R2 = 91.9–99.7%) and made it possible to determine the necessary limits of the meteorological parameter to achieve high quantitative and qualitative yield indicators.

Intensive land degradation occurs under conditions of accelerated urbanization; it is strongly associated with the loss of soil natural capital, primarily animals, plant cover, and biological diversity in general. The creation and functioning of parks, in particular green spaces, in the urbanized areas is an effective mechanism for optimizing the ecological situation within the cities and preventing desertification. The soils of parks are an integral component of green infrastructure; they determine the conditions for the growth and development of both individual plants and green spaces as a whole. The soil buffering capacity actively participates in the mechanisms of implementation of the development and stabilization of soil fertility potentials. The buffering capacity determines the proportion of the soil potential that controls the processes of immobilization (deposition) and mobilization (release, loss) of a particular element of fertility: first of all, mineral nutrients for plant growth, productive moisture, thermal energy in soil, gas composition of soil air, and acidity. We collected soil samples beneath the crowns of trees growing in the territory of the Taras Shevchenko Central Culture and Leisure Park, as one of the largest parks in the city of Dnipro (Ukraine). The soil samples were collected in order to assess the soil acid-base (pH) buffering capacity (pHBC) and determine the direction of microbiological processes in urban soils of the park area afforested with stands from such introduced tree species as green ash (Fraxinus pennsylvanica), black locust (Robinia pseudoacacia), northern red oak (Quercus rubra), tree of heaven (Ailanthus altissima), Kentucky coffee tree (Gymnocladus dioica), and box elder (Acer negundo). The acid-base buffering capacity of the urban soil was determined using the Arrhenius method and estimated according to the buffering area within the acid-base range, calculated using the Simpson formula. Direction of microbial processes in the soil was determined according to the indexes of mineralization-immobilization, pedotrophicity, and oligotrophicity. The output was processed using statistical methods (arithmetic mean and standard deviation were calculated; the difference in the means was found according to the Tukey’s comparison test; interdependencies were determined by linear correlation). We have found significant, strong positive correlations between the pH level of urban soils in the rhizosphere area of the introduced species of park dendroflora and the buffering area within the acid and acid-base (total) range of external influence, as well as a strong negative correlation between pH and buffering area in the alkaline range of external influence. We identified weak mineralization signs according to the ratio of functional groups of microbiota in the studied sites forested with Fraxinus pennsylvanica and Acer negundo.

The network of natural forests and shelterbelts is a crucial element of agroforestry systems for the efficient and environmentally sustainable land use in Ukraine. From 2016 to 2021, we studied the quality of black soils structure under steppe wildland herbaceous vegetation, man‐made tree plantations of Robinia pseudoacacia L. and Quercus robur L., and native forest vegetation of ravines and floodplains in the steppe zone of Ukraine. According to the visual evaluation of soil structure (VESS) scores, the content of the agronomically valuable fraction (AVF), soil organic carbon (SOC) and earthworm casts, native forest soils (Chernozems and Phaeozems) had a significantly ( p < .05) higher soil structural quality in 0–25 cm layer as compared with the Chernozems under the steppe vegetation and shelterbelt plantations. In the conditions of steppe landscapes, VESS methods were shown to provide efficient diagnostics to differentiate the black soil structural quality of low‐intensity land use systems, that is steppe wildlands, shelterbelts, native forests: VESS indicators significantly ( p < .05) correlated with quantitative characteristics of soil structure. The most significant dependence was found between VESS parameters and earthworm casts content. The need to improve VESS method was demonstrated, that is to assign higher weight to the earthworm bioturbation process as one of the key indicators of soil structural quality.

Peach is one of the most important fruit crops, and its cultivation occupies the third largest area among all fruit crops grown in the temperate climate zo