The effect of technological oil spill in soil within electrical generation substations, analysed by ecological regime in the context of relief properties

Technological oil spills within electrical substations are the source of considerable environmental contamination. The aim of this study is to evaluate the relation between phytoindication assessments of ecological factors and geomorphological covariates and investigate the effect of the technological oil spill on ecological regimes within electrical substations. During the fieldwork 175 geobotanical releves were analysed in the years 2016–2017 within Dnipropetrovsk region (Ukraine). Within each electrical substation the geobotanical prospecting was conducted both in plots with undisturbed vegetation cover (control, the plot size 3 × 6 m) and in plots with technological oil spill (pollution, plot size 3 × 3 m). Phytoindication assessment of the following ecological factors was made: soil water regime, soil aeration, soil acidity, total salt regime, carbonate content in the soil, nitrogen content in the soil, radiation balance, aridity or humidity, continental climate, cryo-climate, light regime. HydroSHEDS data were taken for the basis for creating a digital elevation model with resolution of the data layer 15 arcseconds. The phytoindication assessments of the ecological regimes are characterized by correlation of geomorphological properties. The soil humidity is characterized by statistically significant negative correlation with the topographic position index and positive correlation with the vector ruggedness measure. The variability of damping correlates with four geomorphological predictors. This environmental regime has positive correlation with digital elevation model and diffuse insolation and negative correlation with topographic wetness index and direct insolation. The soil acidity of the edaphotope within Dnipropetrovsk region correlates with statistical signiicance with the vector ruggedness measure. The soil humidity of the edaphotope is associated with variation of the topographic wetness index, direct insolation, diffuse insolation and entropy of terrain diversity. The highest carbonate content in the soil correlates with higher risks of erosion, which is characterized by loss of soil and vertical distance to channel network. The nitrogen content in the soil is very sensitive to geomorphological features of the area. This results in the correlation of this indicator with six geomorphological predictors. Obviously, the most favourable supply of the nitrogen content in the soil is formed on upland areas. This allows positive correlation of the phytoindication assessment of the nitrogen content in the soil and the height relief. The use of relief variable as the covariate revealed the nature of the impact of soil contamination on ecological factors. Technological oil pollution leads to deterioration of water regime, reducing the availability of plant available forms of nitrogen and deterioration of soil aeration. There are also changes in microclimatic properties. There are more extreme thermal regimes and greater level of illumination. A key task for further research is to study the influence of relief features on the degree of negative transformation of soil due to technological oil pollution

Analysis of the spatial organization of Vallonia pulchella (Muller, 1774) ecological niche in Technosols (Nikopol manganese ore basin, Ukraine)

The ecological niche of Vallonia pulchella (Muller, 1774) was investigated by means of the general factor analysis of GNESFA. It was revealed that the ecological niche of a micromollusk is determined by both edaphic factors and ecological features of vegetation. Ecological niche optima may be presented by integral variables such as marginality and specialization axes and may be plotted in geographic space. The spatial distribution of the Vallonia pulchella habitat suitability index (HSI) within the Technosols (sod-lithogenic soils on red-brown clays) is shown, which allows predicting the optimal conditions for the existence of the species

Tree canopy affects soil macrofauna spatial patterns on broad- and meso- scale levels in an Eastern European poplar-willow forest in the floodplain of the River Dnipro

This paper tested the hypothesis that the placement of trees in the floodplain ecosystem leads to multiscale spatial structuring and plays an important role in formation of the spatial patterns of the soil macrofauna. The research polygon was laid in an Eastern European poplar-willow forest in the floodplain of the River Dnipro. The litter macrofauna was manually collected from the soil samples. The distances of the sampling locations from the nearest individual of each tree species were applied to obtain a measure of the overstorey spatial structure. The pure effect of tree structured space on the soil animal community was presented by the broad-scale and meso-scale components. The soil animal community demonstrated patterns varying in tree structured space. The tree induced spatial heterogeneity was revealed to effect on the vertical stratification of the soil animal community. The complex nature of the soil animal community variability depending on the distance from trees was depended on the interaction of tree species in their effects on soil animals. The importance of the spatial structures that interact with soil, plants and tree factors in shaping soil macrofauna communities was shown

Tree canopy affects soil macrofauna spatial patterns on broad- and meso- scale levels in an Eastern European poplar-willow forest in the floodplain of the River Dnipro

This paper tested the hypothesis that the placement of trees in the floodplain ecosystem leads to multiscale spatial structuring and plays an important role in formation of the spatial patterns of the soil macrofauna. The research polygon was laid in an Eastern European poplar-willow forest in the floodplain of the River Dnipro. The litter macrofauna was manually collected from the soil samples. The distances of the sampling locations from the nearest individual of each tree species were applied to obtain a measure of the overstorey spatial structure. The pure effect of tree structured space on the soil animal community was presented by the broad-scale and meso-scale components. The soil animal community demonstrated patterns varying in tree structured space. The tree induced spatial heterogeneity was revealed to effect on the vertical stratification of the soil animal community. The complex nature of the soil animal community variability depending on the distance from trees was depended on the interaction of tree species in their effects on soil animals. The importance of the spatial structures that interact with soil, plants and tree factors in shaping soil macrofauna communities was shown

Phylogenetic Diversity of Plant Metacommunity of the Dnieper River Arena Terrace Within the ‘Dnieper-Orilskiy ’ Nature Reserve

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 effect of soil on spatial variation of the herbaceous layer modulated by overstorey in an Eastern European poplar-willow forest

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 role of edaphic, vegetational and spatial factors in structuring soil animal communities in a floodplain forest of the Dnipro river

This paper examines the role of ecological factors, derived from principal component analysis performed on edaphic and vegetational dataset as well as spatial variables, in structuring the soil macrofauna community of the Dnipro floodplain within the ‘Dnipro-Orilsky’ Nature Reserve (Ukraine). The soil macrofauna was defined as invertebrates visible to the naked eye (macroscopic organisms). The test points formed a regular grid with a mesh size of 3 m with 7 × 15 dimensions. Thus, the total test point number was 105. At each point, soil-zoological samples of 0.25 × 0.25 m were taken for quantifying the soil macrofauna. The spatial structure was modeled by a set of independent spatial patterns obtained by means of principal coordinates of neighbor matrices analysis (PCNM-variables). Spatial PCNM-variables explain significantly more variations of the community (19.9%) than edaphic factors (4.1%) and vegetation factors (3.2%). Spatial and combined environmental and spatial effects were divided into three components: broad-scale component was characterized by periodicity of spatial variation with a wavelength of 24.0–44.5 m, medium-scale – 11.1–20 m, fine-scale – 6.6–11.0 m. For a broad-scale component, environmental factors of a vegetational nature are more important, for medium-scale, edaphic factors are more important, for fine-scale, both vegetation and edaphic are important. For litter-dwelling animals, the most characteristic spatial patterns are on the broad and medium-scale levels. For endogeic and anecic animals, the most significant variability is on the fine-scale level