One of the most important problems of environmental sciences is to determine limits for the sustainable functioning of affected ecosystems. The effects of volatile hydrocarbons (such as gasoline and ...kerosene) on plants in natural ecosystems have been poorly studied to date. The present work outlines the data of a field experiment on the effects of kerosene on the plants of forest and bog communities in Central Russia. In this paper, we model the influence of kerosene spillage on plants growing in a coniferous broad-leaved (aspen–spruce) forest and a raised bog with a subshrub–sphagnum pine forest. We used TS-1 kerosene, which is the most commonly used fuel for commercial aviation in Russia. The applied pollutant (loads of 1 to 100 g/kg) had a significant impact on herbaceous plants, leading to the death of individuals even at minimal doses. The shrubs of the bog community as well as the mosses of both communities were more resistant to kerosene. The recovery processes of plant communities were clearly pronounced as early as 2 years after the application of the pollutant. The level of kerosene threshold exposure, which significantly affects the dominant plants of the herb–shrub layer, can be defined as 1–5 g/kg for the forest community and 5–10 g/kg for the bog community.
Increasing concentration of heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) in the soil may impose a serious threat to living organisms due to their toxicity and the ability to ...accumulate in plant tissues. The present review focuses on the phylogenetic relationships, sources, biotransformation and accumulation potential of hyperaccumulators for the priority HMs and PAHs. This review provides an opportunity to reveal the role of hyperaccumulators in removal of HMs and PAHs from soils, to understand the relationships between pollutants and their influence on the environment and to find potential plant species for soil remediation. The phylogenetic analysis results showed that the hyperaccumulators of some chemicals (Co, Cu, Mn, Ni, Zn, Cd) are clustered on the evolutionary tree and that the ability to hyperaccumulate different pollutants can be correlated either positively (Cd–Zn, Pb–Zn, Co–Cu, Cd–Pb) or negatively (Cu–PAHs, Co–Cd, Co–PAHs, Ni–PAHs, Cu–Ni, Mn–PAHs). Further research needs to be extended on the focus of commercializing the techniques including the native hyperaccumulators to remediate the highly contaminated soils.
The gradual drying up of saltwater bodies creates habitats that are characterised by changing environmental conditions and might be available only for a subset of plants from the local flora. Using ...two terrestrial areas with different ages on the Caspian Coast as a chronosequence, we investigated factors including microtopography, ground water level and soil salinity that drive plant community succession after the retreat of the sea. Vegetation of the two key sites appearing after the retreat of the Caspian Sea about 365 and 1412 years ago were compared in terms of both evolutionary and ecological traits of plants. Both edaphic conditions and vegetation differed between the two sites with harsher edaphic conditions and more xerophytes on the elder site. Species that grew only in the 'early' site were dispersed across the phylogenetic tree, but their loss on the 'late' site was not random. Species that grew only on the 'late' site were phylogenetically clustered. On the level of microtopography, elevated spots were more densely populated in the 'early' site than lowered spots, but on the 'late' site the situation was opposite. The main edaphic factors that drive the difference in vegetation composition between the two sites are likely salinity and moisture. During environmental changes, different plant traits are important to survive and to appear in the community de novo. Microtopography is important for forming plant communities, and its role changes with time.
The composition of soil organic carbon (SOC) is an important soil quality indicator. We investigated the effect of site-specific soil-forming factors on plant debris and SOC properties along a soil ...catena with Retisols and Stagnosols in a mixed coniferous–deciduous forest. We examined sites at the summit and middle slope positions with relatively well-aerated soils and sites at footslope positions with waterlogged soils. The concentrations of labile and stable pools of SOC were determined using the method of three-stage chemodestruction. The degree of litter decomposition was calculated, and ash content was determined in the folic and histic soil horizons. The results of our study showed that SOC mostly accumulated in the forest litter and histic horizons of Stagnosols at the footslope positions. The forest litter, folic, and histic horizons were dominated by labile carbon. Equal concentrations of labile and stable carbon were typical of the mineral horizons. The location of the soil in the catena affects the partition and characteristics of SOC in umbric and albic soil horizons. SOC was found to be more stable in the soils at the footslope positions compared to the soils in other locations, because of the lower decomposition of plant remains. Larger stocks of organic carbon, including labile carbon, were restricted to the footslope catena positions.
The criteria used include heavy metal (HM) levels in background soils of different countries and territories (Australia, China, Finland, North America, Northern Europe, and Western Siberia) and their ...threshold concentration values for soils of residential and/or agricultural areas in soil quality standards of Canada (soil quality guidelines), Germany (Trigger Values), the Netherlands (Serious Risk Concentrations), Russia (Maximum Permissible Concentrations), and the USA (Regional Screening Levels). The Retisols, Phaeozems and Chernozems of Western Siberia are characterized by the following range of mean concentrations of heavy metals in topsoil (in mg kg−1): Pb 5–35, Cu 5–100, V 5–180, Cr 5–212, Ni 7–100, Zn 10–135, Mn 50–1800, and Ba 373–1360.
The present study is the field experiment on kerosene pollution impact on southern taiga plant communities. Experimental sites were located in a mixed forest, a deciduous forest, a sedge fen and a ...wet meadow within the Amur Region of the Russian Far East. Kerosene loads from 1 to 500 g/kg of soil were applied to 50 × 50 cm plots in three replications and their effects on number of species and projective cover of ground vegetation were analysed in 1.5 months and 1 year after exposure. Statistical analyses of data included Student's t-test, Friedman ANOVA and correlation coefficient (r). Phylogenetic analysis was carried out for herbaceous plants on experimental plots. The highest susceptibility to kerosene pollution was found in the mixed forest, where the edificator species (Pteridium aquilinum subsp. pinetorum) was significantly suppressed by the kerosene load of only 1 g/kg of soil. Wetland communities regenerated faster than ground vegetation of forests, especially, in tests with high (>25 g/kg) kerosene loads. The wet meadow community was the most resistant to kerosene pollution, i.e., despite significant decreases in projective cover and number of species after exposure to kerosene loads of 5 and 25 g/kg in the first season, it had the highest regeneration success in the next season. In our study, the kerosene load of 25 g/kg of soil was the threshold level of pollution, above which there were significant structural changes in the studied plant communities. Depending on their abilities to resist kerosene pollution and to regenerate in the next year, dominant species of the studied plant communities were arranged in the following ascending order: Pteridium aquilinum ssp. pinetorum, Convallaria keiskei < Carex cespitosa, Calamagrostis purpurea < Lespedeza bicolor < Vaccinium uliginosum.
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•We discovered the impact of kerosene pollution on southern taiga phytocenoses.•Kerosene load of 25 g/kg of soil causes significant changes in vegetation structure.•The most vulnerable species to kerosene is Pteridium aquilinum subsp. pinetorum.•The most resistant species to kerosene is Vaccinium uliginosum.•Wetland communities demonstrate lower damage and higher recovery rate than forests.
Fires in the ecosystems of Central Kazakhstan trigger a pyrogenic succession for 1-2 decades as usual. In recent years, changes of climate and land use in region have led to the intensification of ...fires and the gradual steppification of the territory, where desert vegetation was previously successfully restored. We analyzed the change in aboveground phytomass stocks during 40 years of pyrogenic succession. In the zonal communities, the phytomass reaches the background values in eight years after the fire and does not change later. For intrazonal communities in river valleys and gullies, aboveground phytomass stocks at the 4
th
and 16
th
years of succession do not differ significantly, and the structure of phytomass fractions by the 16
th
year resembles background zonal communities. This can be associated with a more intense grazing on the intrazonal communities in river valleys and gullies in the studied region.
The contamination with organic and inorganic pollutants changes significantly soil microbial community structure. These shifts indicate anthropogenic pressure and help to discover new possibilities ...for soil remediation. In this study, the microbial community structure of Spolic Technosols formed at the territory of a former industrial sludge reservoir near the Kamensk-Shakhtinsky (Southern Russia) was studied using a metagenomics approach. The studied soils contain high concentrations of heavy metals (HM) (up to 72,900 mg kg
−1
) and 16 priority polycyclic aromatic hydrocarbons (PAHs) (up to 6670 mg kg
−1
). Its microbial communities demonstrate an excellent adaptability level reflected in their complexity and diversity. As shown by the high values of alpha diversity indices (Shannon values up to 10.1, Chao1 values from 1430 to 4273), instead of decreasing quantitatively and qualitatively on the systemic level, microbial communities tend to undergo complex redistribution. Regardless of contamination level, the share of Actinobacteria and Proteobacteria was consistently high and varied from 20 to 50%. Following the results of the Mann–Whitney U test, there were significant changes of less abundant phyla. The abundance of oligotrophic bacteria from Gemmatimonadetes and Verrucomicrobia phyla and autotrophic bacteria (e.g., Nitrospira) decreased due to the high PAH’s level. And abundance of Firmicutes and amoebae-associated bacteria such as TM6 and soil Chlamydia increased in highly contaminated plots. In the Spolic Technosols studied, the influence of factors on the microbial community composition decreased from PAHs concentration to soil characteristics (organic carbon content) and phylum–phylum interactions. The high concentrations of HMs influenced weakly on the microbial community composition.
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•Some people are more individualistic in soil colour perception than others.•The fraction of participants that supported a mode colour varies from 0.15 to 0.63.•Females have greater ...agreement in colour estimates than males; p < 0.03.•Soil horizons differ in how people agree on their colour.•For quick soil judging, we propose merging Munsell chips that are hard to distinguish.
Munsell Soil Colour Charts are widely used by soil scientists as the most unbiased way for determining the colour of soil samples. However, there are only a few studies on the variance in people's assessment of the colour of soil samples on this scale and the factors that determine this variance. In this work, we analyze the colour estimates of > 100 undisturbed soil samples by 20 people. For diverse soil samples collected from Anthrosols, Arenosols, Histosols, Podzols and Retisols at the Smolenskoye Poozerye national park, the fraction of votes that support the mode differs from 0.15 to 0.63 with mean of 0.29. The agreement of people’s estimates is significantly less pronounced for hue than for value (p = 0.0001) and chroma (p = 0.002) in dark and muted, but not in light and saturated samples. On average, females vote for mode in more fraction of samples than males (p = 0.026). Moreover, there are people who vote for and against mode more frequently that it is expected by chance. Within-sample variances of estimates calculated after conversion into RGB and CIELAB systems correlate weekly with uncertainty of estimates calculated as fraction of votes that do not support the mode. Soil horizons have different variances in colour estimates. The uncertainty in colour estimation with a Munsell Soil Colour Chart is highly dependent on both sample characteristics and people. The agreement between participants in colour assessment increases substantially when neighboring Munsell chips are treated as equal.
The state of meadow vegetation in areas with different ages of experimental spring burnout (from 1 to 12 years ago) was studied in the Tomsk region for 3 years. On experimental plots of 1 m2 and 100 ...m2 (small- and middle-scale levels, respectively), the dynamics of species richness, total projective cover of vegetation, and aboveground phytomass reserves were characterized, and the structure of communities was analyzed. It was revealed that a single fire in the spring significantly reduces species richness for small-scale plots and increases the total projective cover for middle-scale plots. Structural differences from control plots can be traced from 1 to 4 years for different characteristics. The effects of fire are more prominent for small-scale plots. To suppress tree growth and maintain the existence of meadows, grass fires seem to be a less effective practice than mowing. At the same time, the results obtained potentially allow us to consider prescribed burning as a tool for maintaining the stability of meadow plant communities in the south of Western Siberia, preventing them from becoming overgrown with tree undergrowth, in cases with a controlled frequency of burning and the use of appropriate fire safety measures.
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