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In assessing the ecological conditions and classification of urban soils, data about soil biota should be taken into account. The environment of urban territories is characterized by significant changes compared to their surrounding environments. It is established that the algal flora of urban soils lose their zonal features and features associated with the edification influence of higher plants. Specific biotopes with a definite species structure are formed in urboecosystems. Fifty 50 algae species have been recorded in the soils of the Henichesk urboecosystems (Kherson region, Ukraine): Cyanoprocaryota – 21, Chlorophyta – 13, Charophyta – 2, Eustigmatophyta – 1, Xanthophyta – 11, Bacillariophyta – 2. Among dominant and subdominant species were Cyanoprocaryota and Chlorophyta. The other phyla were represented by Klebsormidium dissectum, K. flaccidum, Hantzschia amphioxys, Eustigmatos magnus, Botrydiopsis eriensis. Compared with the surrounding environment, the urbanized flora of Henichesk has a low species richness, and is characterized by prevalence of Cyanoprocaryota and Chlorophyta species. The coefficient that takes into account the percentage of preservation of species richness in a particular urban area compared to the background indicators of species richness can be used to evaluate the urban transformation of soil biota. The degree of degradatory changes in the composition of living organisms and the direction of these changes depends on the specificity and intensity of exploitation of the territory of the urban ecosystem. The most diverse composition of algae species within the the city of Henichesk was noted in the recreational, residential, and transport zones, in comparison with the industrial zone and the zone of special use. Different functional areas of the city are distinguished not only by the algae species richness, but also by the composition of dominants. Among the dominants and subdominants of the recreational and transport zones were species of different phyla. The dominants and subdominants of the residential and industrial zones were Cyanoprocaryota species, in the zone of special use – representatives of Chlorophyta. The distribution of species richness of algae along the soil profile in the city acquires an atypical character. The species richness increases not in the most superficial layers of soil, but in the lower, aphotic parts of the soil profile. The soil biota, on the one hand, depends on the ecological conditions of soil, and on the other as a result of its life activity, changes the ecological functions of the soil, strengthening or weakening them. The reduction in the species richness of the soil algae of the urboecosystem Henichesk shows the limitations of ecological functions of urban soils. It is established that changes in the composition of algae in soils of urban ecosystems are one of the indicators of the presence and severity of transformation processes. These processes occur with the soil biota and soil as a whole under the conditions of urban ecosystems and can be used as indicators in the environmental assessment of urban soils, in the development and subsequent examination of ways to reduce negative expression of urbanization.

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The study of the processes of restoration of species richness and productivity of steppe ecosystems after fires is an urgent problem that affects not only the conservation of biodiversity but also the maintenance of pasture resources. This article presents the results of a study of post-pyrogenic effects in steppe ecosystems, taking into account changes in the species composition of cyanoprokaryotes and algae that are art of the biological soil crust, which performs ecologically important functions in xerophytic ecosystems. The investigations were carried out in virgin and postpyrogenic steppe ecosystems of the "Troitsk Clough" reserve (Zaporizhia region, Ukraine). For three years, the dynamics of the projective cover and the height of the vegetation cover in virgin areas of herbs-fescue-feather-grass and fescue-feather-grass steppes was studied as well as within two ecosystems of post-pyrogenic development after fires that occurred in the spring and winter periods. We discovered that restoration of the herbs-fescue-feather-grass and fescue-feather-grass steppes after fires occurs at different rates. The cause of the slow restoration of vegetation cover can be its severe damage by fire at the beginning of the vegetation season and the development of erosion processes. The number of species of cyanoprokaryotes and algae in the biological soil crust of virgin and post-pyrogenic ecosystems is not significantly different. It varies from 35 to 49 species. The greatest diversity is noted for Cyanoprokaryota. Chlorophyta is in the second place. Among the dominants, the filamentous forms of Cyanoprokaryota prevail. Nostoc edaphicum was noted as a nitrogen fixing representative. The similarity of the species lists of cyanoprokaryotes and algae of post-pyrogenic and virgin ecosystems, according to the calculated Jaccard coefficient, varies from 49.1% to 55.3%. This indicates a strong specificity of the composition of cyanoprokaryotes and algae in post-pyrogenic biological soil crusts. Changes in their composition reflect different stages of post-pyrogenic succession. In the first year after a fire, there is a slight increase in species richness, which is a consequence of the favorable effect of increasing the amount of mineral substances in the soil after the organic matter has burned out. The "pioneer" group includes: Phormidium autumnale, Ph. dimorphum, Ph. retzii, Ph. (Leptolyngbya) henningsii, Luticola mutica, Hantzschia amphioxys. Gradually this effect is leveled and the species richness of cyanoprokaryotes and algae is stabilized at a level peculiar for this type of ecosystem.

The role of Cyanoprokaryota ecological groups in the ecosystems of the North Azov region was revealed in this work. On the territory of Pryazovskyi National Nature Park, 9 experimental polygons were studied, which covered steppe areas or slopes, salt marshes, coastal sandy soils and water bodies (rivers, lakes, estuaries, sea bays, lagoons). As a result of research on the territory of Pryazovskyi National Nature Park, 124 species of cyanoprokaryotes were identified, which include 127 intraspecific taxa. It was proved that the procedure of canonical correspondence analysis is the most suitable for the analysis of the species matrix. The axes identified as a result of the ordination procedure, which indicate the coordinated dynamics of the species, correlated with both synecological characteristics, such as diversity indicators, and with autoecological characteristics, such as ecotypes of cyanoprokaryotes in relation to habitat types or types of adaptation to salinity conditions. The first four canonical axes together explain 47.5% of species matrix variability. Canonical axis 1 explains 18.0% of the variability of the species matrix and is mostly marked by aqual subaerophytes and eurybionts. This axis indicates the presence of a gradient of salinity conditions where the most saline conditions correspond to the positive values of the axis, and the negative values correspond to less saline. Canonical axis 2 describes 12.1% of species matrix variability. This axis differentiates aquatic ecosystems from others. Canonical axis 3 explains 10.0% of the communities’ variability. This axis distinguishes freshwater ecosystems from saline ecosystems. Markers of freshwater communities are stenotopic halotolerants, which are narrow-range, common mainly in the temperate zone of Europe. The canonical axis 4 explains 7.3% of variability of the matrix of species and is able to differentiate sand ecosystems. The ecotopic structure and geographic range width of community species have the greatest independent value among the considered sources of variation. The independent role of adaptation to the salinity conditions of the ecotope and the role of the type of ecosystems is somewhat smaller. The interaction between the sources of variation is important in the variation of the structure of communities. The interaction between the ecotopic structure and the geographic range width of species and the triple interaction between the ecotopic structure of a community, the width of the geographic range of species and the ecosystem type plays the greatest role in the variation of community structure. Ecotopic groups, which indicate the preference of a particular habitat, correlate with the species composition of the communities. It is shown that the ratio of ecototopic groups in a community is a characteristic that reveals the features of the community as a whole.