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The importance of seed and vegetative propagation for the spontaneous expansion of black locust on abandoned agricultural land was evaluated in the present study. The dynamics of expansion was reconstructed on the basis of spatial distribution data on the age of individuals of this species. A non-homogeneous Poisson process with a linear trend and a Widom-Rowlinson model were the most appropriate in explaining the spatial distribution of R. pseudoacacia individuals. The negative linear trend was statistically significant for the vast majority of polygons in the area of spontaneous expansion of R. pseudoacacia, but insignificant in the artificial plantation. The model parameter η indicates the aggregated spatial distribution of R. pseudoacacia in the zone of spontaneous spread due to the vegetative mechanism of spread. The distribution of R. pseudoacacia in the artificial tree plantation was close to regular, or either random or aggregated. In the early stages, the seed reproduction is the most likely process of R. pseudoacacia spreading. The seed mechanism of spreading follows a spatial pattern, which is explained by a linear trend. The next stage is a combination of both seed and vegetative mechanisms of spread, which also lasts about 4–5 years. At the last stage, the spread occurs mainly through the vegetative mechanism, and the rate of spread of the community slows down significantly. The trigger for the spread is anthropogenic impact.

This study aimed to evaluate the effect of biostimulants derived from Streptomyces avermitilis metabolites on entomopathogenic nematodes: Steinernema carpocapsae, Steinernema feltiae, and Heterorhabditis bacteriophora, obtained from the soil of several Miscanthus × giganteus plantations in 2020–2023. The nematodes were isolated, identified, and cultured using live insects (the greater wax moth Galleria mellonella). Three preparations containing biostimulants – Charkor, Stimpo, and Regoplant, were tested for compatibility with entomopathogenic and plant parasitic nematodes. Their effect on nematode survival was evaluated using the Petri dish test. The study showed that the effect of biostimulants on the survival of nematodes depended on the concentration of aversectin contained in the evaluated preparations. Stimpo and Regoplant had an adverse effect on plant parasitic nematodes. The highest G. mellonella mortality was observed at the higher dose of Charkor (0.4%), and the lowest at the lower dose of Regoplant (1.22%). The study showed that the virulence of the nematodes decreased after 48 hours of incubation in Regoplant and Stimpo solutions containing aversectin. The degree of interaction between nematodes depended on the nematode species, trophic preferences, and the concentration of active ingredients in the preparations. This conclusion is crucial for the selection of appropriate types of entomopathogenic nematodes and the application rate of plant parasitic nematodes in the assessment of their short- and long-term spread, persistence, and recycling in field conditions.

Reliable indicators of success are needed to monitor the process of reclaiming disturbed land in order to understand the achievement of reclamation objectives. The formation of coherent dynamics of vegetation and soil development is ultimately a crucial condition for the success of reclaiming territory disturbed by surface mining and the possibility of using reclaimed land in agricultural production. The study revealed a relationship between the phytoindicator of vegetation hemeroby and the physical properties of technosols to prove its application as a measure of the restoration of the disturbed ecosystem in the reclamation process. The plant communities were classified into beta-, alpha-euhemerobic, polyhemerobic and metahemerobic levels of anthropogenic transformation. The technosols varied in the proportion of hemeroby levels of plant communities. The hemeroby level was consistent with the physical properties of technosols. A decrease in hemeroby level resulted in increased soil electrical conductivity, decreased soil penetration resistance and altered soil aggregate structure. The hemeroby of plant communities is a dependable phytoindicator of ecosystem restoration during reclamation.

The study established the classification position of the soils of the Dnipro River valley (within the Dnipro-Orilsky Nature Reserve) according to the international WRB classification. The pits were laid along three transects that passed through the most significant relief gradients within the study area. The study of the morphological structure of 20 soil profiles showed that the soil cover is closely related to the geo-morphological structure of the river valley. The morphological characteristics of typical profiles of these soils reflect their structure, properties and genesis and determine the classification position of the soils according to the WRB. Multidimensional scaling allowed us to perform soil ordination in the space of two dimensions. Dimension 1 differentiates soils by the gradient of relief height and/or moisture level. Dimension 2 differentiated hydromorphic soils. The properties of Quaternary sediments were found to determine the position of soils at both levels of classification (reference groups, main and additional classifiers). The distribution of each of the reference groups is clearly related to the geomorphology of the valley. Arenosols and Cambisols form the soil cover of the floodplain terrace, while Fluvisols and Gleysols are found mainly in the floodplain.

Floodplain ecosystems are hotspots of biological diversity and perform important ecosystem functions in the landscape. The key to understanding the sustainability of ecosystem function is knowledge of the relationships between ecosystem components. The article reveals the role of morphological and physical properties of soil, as well as phytoindication of environmental factors as drivers of biological diversity of soil macrofauna of protected ecosystems of the Dnipro River floodplain. The studies were conducted in the forest floodplain ecosystems of the “Dnipro-Orilskiy” Nature Reserve. The studies of morphological properties of soils allowed us to identify the representatives of two reference groups: Fluvisol and Gleysol. The soil physical property data were subjected to principal component analysis, which extracted four principal components whose eigenvalues exceeded unity and described 79.9% of the variation in traits. The principal components of variation in soil physical properties and phytoindication assessments of environmental factors were used as predictors of the community structure of soil macrofauna. These predictors were able to explain 29.6% of the community variation. Physical soil properties are most important as a driver of soil macrofauna. The morphological properties of the soil and phytoindicator assessments are able to explain a much smaller part of the community variation. The pure influence of the predictors is small, indicating that they interact significantly in influencing soil animals. The results obtained have implications for the development of optimal strategies for floodplain ecosystem management and biodiversity conservation.

Antioxidant enzymatic activity and soluble protein content in Robinia pseudoacacia L. (black locust), invasive tree in Europe, plants were determined under feeding conditions of the caterpillars of Parectopa robiniella Clemens, 1863, invasive miner in Europe, in trees of three (I, II, III) age groups (5–10, 15–25, and 40 years). Biochemical analysis data showed significant differences between reference and experimental leaf samples in different urban ecosystems. There was no association between changes in catalase and peroxidase activity and protein content under the influence of leaf blotch miners depending on the tree age. Significant variability of proteins under P. robiniella influence was noted; the highest of its values were recorded in the leaves of ІІІ-aged trees. In most plantings (and especially in trees of age group III), an increase (1.2 to 2.7 times) in GPx activity or the absence of its changes was registered both in the ecologically favorable zone and in the locations affected by emissions from road transport and industrial enterprises. Plants of age groups I and II in the emission areas of metallurgical, pipe-rolling, and chemical industries experienced a significant decrease in GPx activity (by 20.2–44.6%) in the leaves damaged by the phytophage. In most of the plantings studied, catalase showed an increase/stability of its activity in all age groups of trees under condition of pest attack. The highest increase in САТ activity (2.1 times) was recorded in young R. pseudoacacia plants in an ecologically favorable area of the city.

The aims of this research are to assess the relationship between the concepts of hemeroby and naturalness of plant communities and to test the hypothesis about the ordinal nature of the response of social behavior types of plants under anthropogenic influence. Study area is the recreational zone of the Botanical Garden of Dnipro National University, named after Oles Gonchar, Dnipro City, Ukraine (48.43°N 35.05°E). Four polygons (105 relevés in each) were examined. Two polygons were in the zone after park reconstruction, and two were in the zone without reconstruction. The vegetation community ordination was performed using RLQ analysis. The Q-table was represented by eight dummy variables, which indicated social behavior types. The most important predictors of naturalness were aggressive alien species and invaders and weeds (positive dependence) and disturbance tolerants (negative dependence). The most important predictors of hemeroby were aggressive alien species (negative dependence) and ruderal competitors, invaders, and disturbance tolerants (positive dependence). Naturalness and hemeroby reflect different strategies for transforming a plant community and are not completely symmetrically opposed concepts. The response of a plant community is multivariate, so the naturalness metric based on the social behavior types is only able to distinguish well between the extreme states of a plant community, but is a poor measure for a more detailed assessment of naturalness.

The study evaluated the influence of aquatic environmental features, morphological and functional traits of water bodies and directional spatial processes on the macrophyte community of floodplain ecosystems formed as a result of water flow regulation by the construction of dams. The fluvial processes were found to be still the main factor in the formation of geomorphological and ecological characteristics of floodplain ecosystems, and also determine the spatial patterns of variability of aquatic macrophyte communities. The influence of water properties on macrophytes is significantly spatially structured, as it is modified by the morphological and functional characteristics of the water bodies. The exchange of water in the floodplain system is influenced by the functional types of water bodies, which explains their significant correlation with spatial variables. The development of macrophyte communities on a broad scale is driven by the characteristics of the aquatic environment, the morphology of the water bodies and the functional types of the water bodies. On a fine scale, the patterns are described by a pure spatial component. The impact of fine scale patterns on the variability of macrophyte communities increases with increasing community disturbance, both natural and anthropogenic. [ABSTRACT FROM AUTHOR]

Taxonomic ratio in an ecological context is considered as an indicator of the level of competitive exclusion. In spite of more than a century of discussions on taxonomic ratio, the problem of finding an unbiased estimator for flora characterisation remains unsolved. The traditional form of taxonomic ratio (species/genus or species/families ratio) is biased, which depends on the area of territory for which the floral composition was established. This circumstance makes the taxonomic ratio an inadequate characteristic of the flora. To solve the problem of finding an unbiased estimator for the taxonomic ratio, we have combined two fundamental ecological generalisations. The first is that species that belong to the same genus usually live in similar habitats and have similar morphological features. The struggle for life between species from the same genus is, therefore, more intense than between species from different genera. The second is species–area relationship. We have considered the problem of finding an unbiased taxonomic relationship using the Arrhenius curves to fit species–area relationships. This combination allowed us to find a form of unbiased taxonomic relationship. The example of Cyanophyceae flora shows that this indicator is closely related to a wide range of ecological and biogeographical characteristics of vegetation. The residual of the linear equation of dependence of the logarithm of the number of species on the logarithm of the number of genera is an unbiased indicator of the taxonomic relation, which is independent of the number of genera (or number of families) and the sampling size (or area). An unbiased taxonomic relationship is a characteristic of regional flora, which depends on a wide range of its ecological and biogeographical features.

The study was conducted in the landscapes of south-eastern Ukraine during the nesting seasons 1988–2018. Within the landscape system associated with the Molochny Estuary, the ten most important ecosystem types were investigated, including the following: agricultural land, vegetated strips, meadows, islands and spits, reedbeds, urban areas, salt marshes, steppe, cliffs, artificial forests. Bird species responded to temperature and precipitation gradients. The patterns of responses were presented using Huisman, Olff and Fresco expanded by the Jansen-Oksanen hierarchical models. The nature of species response in the gradient of temperature or precipitation conditions depends on the type of particular ecosystem and is not uniform for all populations inhabiting the different landscape types. The bird communities were revealed to demonstrate an abrupt dynamic over time. The continuous changes in community structure initiated by the external environmental factors are combined with modifications of internal biotic interactions, which may lead to abrupt reorganization of the community.

The habitat suitability for the Common Pochard, a duck species in decline, was studied in the middle reaches of the Orel’ River, Central Ukraine, in 2015–2017. The ducks were counted on their breeding grounds with the use of the ground survey technique. The positions of individual birds were estimated by GPS and plotted on the Google Earth map. The Ecological Niche Factor Analysis (ENFA) was applied to assess the habitat suitability. Sentinel-2 image was used to extract 13 ecogeographical variables and to get two measures of the ecological niche (marginality and specialization). The ENFA procedure was applied twice at landscape and sub-landscape levels to describe the habitat selection across sequential spatial scales. Both the axes of marginality and specialization of the ecological niche of the species proved to be significantly different from the random alternatives. At landscape level, the distribution may be predicted with the use of Aerosol/Coastal, Vegetation and Hydrothermal Composite indices (marginality) and Modified Normalized Difference Water (MNDW) Index along with several vegetation indices (specialization). At sub-landscape level, MNDW played a crucial role. The importance of MNDW is mediated by the preference for the wetlands with the stretches of open water which are used by the ducks to initiate flight safely and to optimize diving possibilities. The ENFA is a reliable tool for the assessment of the habitat suitability and for setting the conservation priorities for the Common Pochard.

Different approaches were applied to assess soil moisture optima and tolerance of the ecological niche temporal projection of terrestrial invertebrates within an experimental polygon created to investigate the reclamation processes after deep underground hard-rock mining in the Ukrainian steppe drylands. Sampling was carried out in 2013–2015 on a variant of artificial soil (technosols). To investigate the spatiotemporal variation in the abundance, species richness and species composition of invertebrate assemblages the animals were sampled using pitfall traps. The readily available water for plants, precipitation, wind speed, atmospheric temperature, atmospheric humidity, and atmospheric pressure were used as environmental predictors. The two-dimension geographic coordinates of the sampling locations were used to generate a set of orthogonal eigenvector-based spatial variables. Time series of sampling dates were used to generate a set of orthogonal eigenvector-based temporal variables. Weighted averaging, generalized linear mixed models, Huisman-Olff-Fresco models expanded by Jansen-Oksanen, correspondence analysis, and constrained correspondence analysis were used to estimate soil moisture species optima and tolerance. The moisture content in the technosols was revealed to be the most important factor determining the temporal dynamics of terrestrial invertebrate community in conditions of semi-arid climate and the ecosystem which formed as a result of the reclamation process. The species response to the soil water content is affected not only by the soil water content but also by the complex of the other environmental, temporal, and spatial factors. The effect of other factors on the species response must be extracted previously to find real estimations of the species optima and tolerance.

Miscanthus × giganteus biomass plays a crucial role in producing renewable energy and bio-based products, supporting global sustainability objectives. However, its introduction into the European Union has made it susceptible to the ectoparasitic needle nematode Longidorus spp., which are known vectors of severe viral diseases. The aim of the presented research was to assess the effectiveness of the following soil amendments: vermicompost from Eisenia fetida and silver nanoparticles (Ag-NPs) applied to the soil with Miscanthus plants following artificial inoculation of Longidorus elongatus. A two-year experiment was conducted at the National Institute of Horticulture Research in Skierniewice using concrete rings filled with medium sandy soil amended with 10% peat. Treatments included: control (no amendments), vermicompost (4 L of E. fetida vermicompost), and Ag-NPs (60 mg/L soil). Each treatment was replicated four times. Application of both vermicompost and Ag-NPs positively influenced soil parameters and crop yield while suppressing nematode populations. Significant reductions in L. elongatus density were observed: vermicompost reduced nematode population by 80% and Ag-NPs by 90% compared to the control (15%). [ABSTRACT FROM AUTHOR]

The tree species composition can influence the dynamics of herbaceous species and enhance the spatial heterogeneity of the soil. But there is very little evidence on how both overstorey structure and soil properties affect the spatial variation of the herb layer. The aim of this study is to evaluate the factors of the soil and overstorey structure by which it is possible to explain the fine-scale variation of herbaceous layer communities in an Eastern European poplar-willow forest. The research was conducted in the “Dnipro-Orils’kiy” Nature Reserve (Ukraine). The research polygon (48°30′51″N, 34°49″02″E) was laid in an Eastern European poplar-willow forest in the floodplain of the River Protich, which is a left inflow of the River Dnipro. The site consists of 7 transects. Each transect was made up of 15 test points. The distance between rows in the site was 3 m. At the site, we established a plot of 45×21 m, with 105 subplots of 3×3 m organized in a regular grid. The adjacent subplots were in close proximity. Vascular plant species lists were recorded at each 3×3 m subplot along with visual estimates of species cover using the nine-degree Braun-Blanquet scale. Within the plot, all woody stems ≥ 1 cm in diameter at breast height were measured and mapped. Dixon’s segregation index was calculated for tree species to quantify their relative spatial mixing. Based on geobotanical descriptions, a phytoindicative assessment of environmental factors according to the Didukh scale was made. The redundancy analysis was used for the analysis of variance in the herbaceous layer species composition. The geographic coordinates of sampling locations were used to generate a set of orthogonal eigenvector-based spatial variables. Two measurements of the overstorey spatial structure were applied: the distances from the nearest tree of each species and the distance based on the evaluation of spatial density of point objects, which are separate trees. In both cases, the distance matrix of sampling locations was calculated, which provided the opportunity to generate eigenvector-based spatial variables. A kernel smoothed intensity function was used to compute the density of the trees’ spatial distribution from the point patterns’ data. Gaussian kernel functions with various bandwidths were used. The coordinates of sampling locations in the space obtained after the conversion of the trees’ spatial distribution densities were used to generate a set of orthogonal eigenvector-based spatial variables, each of them representing a pattern of particular scale within the extent of the bandwidth area structured according to distance and reciprocal placement of the trees. An overall test of random labelling reveals the total nonrandom distribution of the tree stems within the site. The unexplained variation consists of 43.8%. The variation explained solely by soil variables is equal to 15.5%, while the variation explained both by spatial and soil variables is 18.0%. The measure of the overstorey spatial structure, which is based on the evaluation of its density enables us to obtain different estimations depending on the bandwidth. The bandwidth affects the explanatory capacity of the tree stand. A considerable part of the plant community variation explained by soil factors was spatially structured. The orthogonal eigenvector-based spatial variables (dbMEMs) approach can be extended to quantifying the effect of forest structures on the herbaceous layer community. The measure of the overstorey spatial structure, which is based on the evaluation of its density, was very useful in explaining herbaceous layer community variation.

The study of potential possibilities of mesofauna as bioindicator of soil contamination by heavy metals is one of the most important areas of urban ecology and soil biology. The work presents the results of ecotoxicological and bioindicative assessment of the environment and the biota of the Melitopol urbosystem of Ukraine. The dynamics of chemical properties of soils in different functional zones of the city is analysed. The complex indices of pollution of environmental components are determined. A bioindicative assessment of the ecological condition of the territory of the urbosystem on the indicators of vitality of the soil mesofauna is carried out. For the first time, regional species-bioindicators for the territory of the city of Melitopol were determined. The ecomorphic structure of soil mesofauna of various functional zones of the city was revealed.

The article presents the results of evaluation of the role of edaphic and vegetation factors on beta diversity of soil macrofauna by means of the MDM-approach. The multinomial diversity model (MDM) is a method for relating the Shannon diversity to ecological factors. The research was conducted in the ‘Dnipro-Orils’kiy’ Nature Reserve (Ukraine). The research polygon was laid in the forest within the Orlova ravine (48º31’13 “N, 34º48”15 “E). The study site comprises 1.0 ha of deciduous woodland bordered by an area of herbaceous cover within the ravine. In the soil of the studied polygon, 38 species of soil invertebrates were identified, which characterizes the gamma diversity. Alpha diversity, or the number of species on average at each sample point is 4.3. Beta diversity is 8.8. The principal component analysis of the edaphic parameters revealed four statistically significant principal components. For vegetation characteristics, six statistically significant principal components were identified. The sequential analysis of the effects shows that edaphic factors accounted for 20.9% (0.81 bit) of the available entropy (1.71–0.91). The largest decrease in the community entropy takes place under the action of the principal components 2 and 3 (0.06 bit and 0.05, respectively). A permutation test showed that these effects are statistically significant. In turn, 28.4% of the community β-diversity is attributable to vegetation factors. The greatest decrease in community entropy is related to the principal vegetation components 1, 3 and 4 (0.07, 0.05 and 0.04 bits, respectively). A permutation test indicated that this effect is statistically reliable. Geostatistical models substantially describe the varying effects on the beta-diversity of edaphic principal components 1 and 2, and the vegetation principal components 1 and 3. It was found that edaphic and plant factors play an important role in structuring the communities of soil macrofauna on the level of beta diversity. Community sensitivity to environmental factors varies in space and is spatially structured. For different environmental factors, specific spatial patterns of community sensitivity are allocated. Beta diversity may be due to the fact that the species of soil macrofauna communities also vary in the degree of sensitivity to various environmental factors. The species of soil microfauna are also divided according to their extent of sensitivity to different ecological factors.

The study subject was the soil heterogeneity at a recultivation site Nikopol manganese-ore basin (Pokrov, Ukraine). The soils at the locality are sod lithogenic soils developed on gray-green clays. The study ran by applying soil penetration resistance indices. The penetration resistance was measured across a regular grid of 7 × 15 points (21 × 45 m). The distance between the measurement points was 3 m. The parameters were recorded at every 5 cm to a depth of 50 cm. The environmental parameters were determined by phytoindication. Geostatistical analysis showed the average level of spatial dependence of soil penetration resistance. According to the features of the profile variation in penetration resistance with the depth, the measurement points have been divided into three clusters. The clusters formed morphologically homogeneous soil areas. These areas significantly differed in their soil acidity and in nitrogen content in soil.

Sewage sludge is a promising fertiliser for sweet sorghum growing on marginal land. We investigate the effects of different doses of sludge on the characteristics of chlorophyll fluorescence. Two types of sewage sludge were used: without flocculant and treated with flocculant. Sludge application helps to reduce the amount of inactive chlorophyll in the reaction centres, increases photosynthetic activity, and reduces the sensitivity of the photosynthetic apparatus to adverse environmental factors. Flocculated sludge had the more beneficial effect, particularly at the early stages of development; the optimal dose was 40-60t/ha. [ABSTRACT FROM AUTHOR]

This article presents the features of the phylogenetic organization of the plant communities of the Dnieper River terrace within the ‘Dnieper-Orilskiy’ Nature Reserve and the patterns of its spatial variation involving remote sensing data of the Earth’s surface. The research materials were collected in the period 2012−2016 from within the nature reserve. The research polygon is within the first terrace (arena) of the Dnieper valley. Sandy steppe, meadow, forest and marsh communities within the Protoch river floodplain and the Orlova ravine, as well as artificial pine plantations were the habitats present within the research polygon. The vegetation description was carried out on 10×10 m (100 m2) plots. A total of 94 geobotanical descriptions were made. Data on plant phylogeny was obtained by the Phylomatic service. Phylogenetic diversity of the communities was assessed by the Faith, Simpson and Shannon indices. Phylogenetic analysis was performed by means of a double principal coordinate analysis (DPCoA). The vegetation cover within the investigated polygon was represented by 189 species. Abundance Phylogenetic Deviation (APD) for the investigated metacommunity was evaluated to −0.53, which is statistically significantly different from random alternatives (p = 0.001). The APD negative value indicates that phylogenetic organization of the investigated metacommunity is overdispersed. The permutation procedure allowed us to establish that the eigenvalues of the DPCoA-axes obtained as a result of the real phylogenetic tree were significantly higher than their own number for the random phylogenetic trees for the first seven axes. This indicates that the first seven axes are useful for additional information on the ordination structure of the metacommunity.

The recreation loading causes soil compaction which induces negative tendencies for the urban environment. The objectives of this study were to investigate the role of relief and tree stand density in the soil penetration resistance variation within an urban park, to assess the most suitable variogram models to evaluate the autocorrelation of regression models, and to map the spatial variability of soil penetration resistance. The combination of regression and spatial models allowed the research team to evaluate the spatial variation of the soil penetration resistance on different soil layers. [ABSTRACT FROM AUTHOR]

The article discusses the role of the soil aggregate structure in quantifying the marginality and specialisation axes of the ecological niche of the micromollusc Vallonia pulchella (Muller 1774) that inhabits technosols. The experimental polygon consisted of 105 samples located within 7 transects (15 samples each). The distance between rows of sampling points was 3 m. The average density of V. pulchella was 1393 ind.·m-2. The soil aggregate fraction of 1-5 mm was found to be predominant within the technosol. The spatial variation of aggregate fractions was characterised by a moderate level of the spatial dependence. It was impossible to choose an adequate covariance model from among the traditional ones to interpolate the spatial variation of aggregate fractions, and only the Matérn model was best suited. The axis of marginality and specialisation of the V. pulchella ecological niche projected in soil aggregate fractions was significantly different from a random alternative. The ecological niche of the V. pulchella was presented by integral variables, such as the axis of marginality and specialisation, which were the basis to build a map of the spatial variation of the habitat suitability index. The marginality of the V. pulchella ecological niche correlates with soil penetration resistance indicators at depths ranging from 0-5 to 20-25 cm, soil humidity, acidity, and aeration. The specialisation correlates with the soil mechanical impedance at 25-35 cm, nitrogen content, and the soil acidity regime. [ABSTRACT FROM AUTHOR]

The article investigated the influence of factors on the dependence of tree height on tree diameter in a park stand. The role of tree damage, density, and stand diversity as predictors in the dependence of tree height on its diameter was revealed. The hypothesis of the scale dependence of the influence of stand density on plant growth was tested. The number of plants that are within a radius of 3, 5, 7, 10 meters was determined for each of the recorded plant specimens. The diversity according Shannon of the plant community was estimated based on the information on the species composition of plants within a radius of 10 meters from the focal plant. The age of plants in the community was positively correlated with the diversity of vegetation in the surroundings of a particular plant. About 74.1% of the trees were found to have the signs of pathological damage. The best model to explain tree damage was a model that included as predictors plant species, its age, the diversity of the surrounding stand, and its density estimated from a 7-m radius sampling site. The GLM approach allowed to reveal that 83% of tree height variation can be explained by the information on tree and shrub species, plant condition (healthy plant or damaged one), its diameter and stand density. The stand density and the square of this index were found to be statistically significant predictors if the density was calculated for a sample area with a radius of 7 meters. [ABSTRACT FROM AUTHOR]