Features of biocenotic interactions of harmful organisms in the ecosystems of the Main Botanical Garden of RAS

This article studies the biocenotic relationships of harmful organisms in the artificial ecosystems of the Main Botanical Garden of RAS. The research was conducted in 2021–2024. The study emphasizes the importance of monitoring research in the context of phytosanitary destabilization of ecosystems under the influence of anthropogenic factors. Monitoring of harmful organism biodiversity revealed an uneven distribution of pathogen-entomological complexes. Their species spectrum, the prevalence of specific components, and the multiplicity of their manifestations varied depending on the ecosystem type, its balance, and stability. The determination of the structure of these entomo-pathogenic complexes showed that they include background, dominant, and crop-specific atypical harmful species. Their composition and dominance structure differed across ecosystem types, comprising from two to five or more components. Variations in the dominance spectrum of individual harmful species were recorded on plants of the same taxonomic rank but located in different biocenoses. The pathogen complexes of most plant species form an associated system of pathogens from the divisions Deuteromycota, Ascomycota, and Basidiomycota, together with phytophagous insects from the orders Coleoptera, Hemiptera, Thysanoptera, and Lepidoptera. The taxonomic composition of both pathogens and phytophages remained unchanged, with no evidence of an expanding dominant species spectrum. Variation was noted in accordance with the parameters of phenology and migration (for phytophagous insects). The maximum infectious load was characterized for the phylloplane, whose microbiota was represented by obligate and facultative parasites, as well as facultative saprotrophs. An analysis of the composition of dominant parasitic complexes was conducted on plants from more than 75 genera. Transformations in the structure of pathogen-entomological complexes were recorded in representatives of 5 families of flowering plants. Depending on the ecosystem type, the proportion of parasitic complexes in a state of population equilibrium during the specified period ranged from 45 % to 75 %. Critical zones of destabilization in biocenotic interactions were identified in the consortia of 6 plant species: Acanthus L., Aesculus L., Amorpha L., Clematis L., Humulus L., and Sida L.