This study provides data on the problem of potential complexation of phenolic compounds synthesized by the plants Solidago canadensis L. and Solidago gigantea Ait. with ammonium forms of nitrogen, partly immobilized in the soil. A comparative analysis of secondary metabolites of the studied plants was performed by HPLC. The leaves of invasively active Solidago canadensis contain nine times more rutin than the plants of Solidago gigantea. Adding to the leaf extracts (v/v1/20) aqueous ammonia solution to pH 8.0 on the chromatograms decreases the intensity or completely causes peaks of flavonoids to disappear; instead, there are peaks of new polar substances (tR 1.5 and 2.0 min). The selective effect of the phenol-ammonium complex on various plant species was revealed. At a concentration of 20 μg/mL, these substances stimulated the formation of lateral roots in soybean seedlings and chrysanthemum cuttings. The suppression of root growth in radish seedlings occurred at a concentration of flavonoids in the extract of 25 μg/mL. In addition, a positive chemotaxis of the Pseudomonas putida (PGPR) was detected in the nitrogen-containing complex based on rutin (5 μg/mL). The identified feature allows PGPR colonization of the root system of Solidago canadensis with corresponding changes in the structure of the microbial community. The ability of the obtained nitrogen-containing polar complexes to regulate the growth processes of plants at extremely low concentration points to promising research in this direction.

—In 2015–2017, attendance of 15 invasive and 22 native species of herbaceous plants by ants was studied in 6 habitats in the environs of Kyiv (Ukraine). Altogether, 14 ant species were found, of...

When assessing the condition of Lasius niger (Linnaeus, 1858) nest complexes, plant communities should be considered. The aim of this work is to analyse ecological characteristics and structure of L. niger nest complexes using vegetation data. The study was conducted in Ukraine, in June 2017 (a nest complex on a territory near Vyshneve, Kyiv Oblast, 502 nest mounds) and in June 2022 (Chaika, Kyiv Oblast, 72 nest mounds, Stara Ushytsia, Khmelnytskyi Oblast, 134 nest mounds). Morphometric parametres of the mounds (diameter, height), their relative position and size classes in squares of 100 m2 were studied. At the same time, vegetation plots were carried out. Differences in the structure of L. niger nest mounds discussed previously are at least partly result from differences in the ecological conditions of the localities. Of the six ecological indicators (Hd — Tm), three — soil acidity and nitrogen, and the hemeroby indicator, which assesses the degree of anthropogenic pollution — have a significant influence on the abundance of L. niger nest mounds. These factors were shown to have a significant influence on the ant colony volume indicator. For most indicators, except moisture and light, the optimum for L. niger was close to 50 points (middle of the scale). For the anthropogenic factor, the range of values was the widest, which indirectly confirms the relative tolerance of this species to the anthropogenic influence of moderate intensity and allows its existence in urban conditions where competitive pressure from other species is lower. The sign of regression coefficient, especially the positive sign for the acidity and nitrogen indicators, demonstrates positive effect of these factors on the ant colony structure indicators.

The aim of this work is to evaluate changes in the structure of nest complexes of two species of red wood ants: Formica rufa Linnaeus, 1761 and F. polyctena Foerster, 1850, in the city of Kyiv (Ukraine) using morpho[1]metric indicators, as well as to evaluate their dynamics. In 2014–2022, nest complexes of two species of red wood ants (Formica rufa, F. polyctena) were observed in urbanised forests within the city of Kyiv. A total of 472 F. rufa and 411 F. polyctena nests were studied in 7 nest complexes (4 — F. polyctena, 3 — F. rufa). The total volume of F. polyctena nests were found to decrease by 2020–2021, while the volume of F. rufa nests remained at the same level or even increased. This suggests that F. rufa is more resistant to changes in forestry conditions.