Influence Of Soil Microorganisms Research Articles

Forest structural diversity is linked to soil microbial diversity

AbstractEfforts to catalog global biodiversity have often focused on aboveground taxonomic diversity, with limited consideration of belowground communities. However, diversity aboveground may influence the diversity of belowground communities and vice versa. In addition to taxonomic diversity, the structural diversity of plant communities may be related to the diversity of soil bacterial and fungal communities, which drive important ecosystem processes but are difficult to characterize across broad spatial scales. In forests, canopy structural diversity may influence soil microorganisms through its effects on ecosystem productivity and root architecture, and via associations between canopy structure, stand age, and species richness. Given that structural diversity is one of the few types of diversity that can be readily measured remotely (e.g., using light detection and ranging—LiDAR), establishing links between structural and microbial diversity could facilitate the detection of belowground biodiversity hotspots. We investigated the potential for using remotely sensed information about forest structural diversity as a predictor of soil microbial community richness and composition. We calculated LiDAR‐derived metrics of structural diversity as well as a suite of stand and soil properties from 38 forested plots across the central hardwoods region of Indiana, USA, to test whether forest canopy structure is linked with the community richness and diversity of four key soil microbial groups: bacteria, fungi, arbuscular mycorrhizal (AM) fungi, and ectomycorrhizal (EM) fungi. We found that the density of canopy vegetation is positively associated with the taxonomic richness (alpha diversity) of EM fungi, independent of changes in plant taxonomic richness. Further, structural diversity metrics were significantly correlated with the overall community composition of bacteria, EM, and total fungal communities. However, soil properties were the strongest predictors of variation in the taxonomic richness and community composition of microbial communities in comparison with structural diversity and tree species diversity. As remote sensing tools and algorithms are rapidly advancing, these results may have important implications for the use of remote sensing of vegetation structural diversity for management and restoration practices aimed at preserving belowground biodiversity.

Determination of quizalofop-p-ethyl in onion: residual dissipation pattern, weed control efficiency, and food safety assessment under field conditions.

Monitoring pesticide residue levels becomes crucial to maintain quality and guarantee food safety as the consumption of onion green leaves and immature and mature bulbs (either raw or processed) rises. A field experiment was conducted for two consecutive seasons with quizalofop-p-ethyl (5% EC) at 50 and 100 g a.i. ha-1 to evaluate weed control efficiency and to determine terminal residues. Post-emergence application of fop herbicide at 100 g a.i. ha-1 kept the weed density and dry weight reasonably at a lower level and enhanced the productivity of onion with higher economic returns. A rapid, sensitive, and analytical method was developed using high-performance liquid chromatography (HPLC) with excellent linearity (r2 > 0.99). The limit of quantification for quizalofop-p-ethyl was established at 0.04 mg kg-1 with signal to noise (S/N) ratio ≥ 10. The method was successfully applied and initial quantified residues were in the range of 2.5-4.4 mg kg-1 irrespective of seasons and doses. Finally, the presence of targeted herbicide residues in harvested samples was confirmed by liquid chromatography tandem mass spectrometry (LC-MS/MS) under optimized operating conditions. Dietary risk assessment assured harvested onions were safe for consumption at the recommended dose. It also can be concluded that quizalofop ethyl did not adversely influence soil micro-organisms at standard rates of application.

Biochar for Soil Carbon Sequestration: Current Knowledge, Mechanisms, and Future Perspectives

Biochar, a sustainable solid material derived from biomass pyrolysis enriched in carbon, has emerged as a promising solution for soil carbon sequestration. This comprehensive review analyzes the current knowledge on biochar’s application in this context. It begins by examining biochar properties and production methods, highlighting its recalcitrant nature as a potential stable carbon sink. The influence of various feedstocks and pyrolysis conditions on various physicochemical properties of biochar and its soil carbon sequestration potential is explored. Mechanisms through which biochar enhances soil carbon sequestration are discussed, including its role as a physical barrier against carbon loss and its ability to promote stable soil aggregates and influence soil microorganisms. Challenges and limitations, such as variations in biochar properties and optimal application rates, are addressed, along with strategies for maximizing biochar effectiveness through amendments. The review concludes by emphasizing the importance of long-term field studies, standardized protocols, and economic assessments to support the widespread adoption of biochar for soil carbon sequestration and its potential in climate change mitigation.

Microbial gene activity in straw residue amendments reveals carbon sequestration mechanisms in agricultural soils

Land-use practices and their intensity along with climatic conditions alter amounts of soil organic carbon content and consequently influence soil microorganisms. However, land-use management, such as crop residue incorporation to soils has a potential to mitigate losses of soil organic carbon and thereafter promote the diversity of soil microorganisms. To gain insight of microbial functional diversity and activity under organic soil amendments, a glasshouse experiment with arable and grassland soils was performed. Straw was added as a crop residue and microbial activity in the soils was monitored using a captured metatranscriptomics technique. The overall expression of genes related to soil organic matter degradation differed between the two land-use systems. Straw addition enhanced the expression of genes involved in the degradation of organic material, particularly in arable soils. After a month of the amendment, the overall gene expression in arable soils had a similar pattern to that of the grasslands. The straw addition triggered the upregulation of a set of enzyme families catalysing the organic matter degradation in both land-uses but downregulated a higher number of enzyme families in grasslands. However, in the grasslands, the gene families involved in the biosynthesis of carbohydrates were upregulated at straw addition. These findings indicate that arable soils with a low organic carbon content have a potential to get a higher and more active microbial diversity with amendments. In soils such as grasslands the amendments trigger a carbon sequestration process from the added organic material to the soil and can significantly contribute to enhanced soil carbon sequestration.

Effects of Drying and Rewetting Cycles on Carbon Dioxide Emissions and Soil Microbial Communities

Extreme rainfall and drought events attributed to climate change are anticipated to occur in the current century, resulting in frequent drying and rewetting cycles (DWCs) in soils, which will, in turn, influence soil properties and microorganisms. Sample plots of Sophora japonica, Pinus tabulaeformis, and Ginkgo biloba were selected, and undisturbed soil columns were collected. CK was the constant drying treatment; the precipitation intensities of R80, R40, and R20 were 80 mm, 40 mm, and 20 mm, respectively, and the total precipitation for the four treatments was 160 mm. Significant differences were observed in the cumulative CO2 emissions among the various DWC frequencies for the same woodland soils. A significant correlation was observed between the Birch effect and the DWC frequencies of the three woodland soils. A Pearson’s correlation analysis revealed that background nutrient contents were the key factors influencing alpha diversity. In conclusion, DWCs generally increased CO2 fluxes, cumulative CO2 emissions, and the Birch effect in addition to decreasing the alpha diversity of soil microorganisms when compared to those in the constant drying treatment.

Shifts of lipid metabolites help decode immobilization of soil cadmium under reductive soil disinfestation

Cadmium (Cd) contamination in soil can cause serious environmental problems and threaten human health. Previous studies have shown that the reductive soil disinfestation (RSD) is regarded as an effective soil disinfection technology, which will affect the bioavailability of Cd. However, the influence of soil microorganisms and their metabolites on the morphologies of Cd during RSD treatment are still poorly understood. Here, a laboratory incubation experiment that composed of untreated soil (CK), two RSD treatments with flooded soil (FL) and added 2% bean dregs soil (BD) was conducted. After the treatment, the content of different morphologies of Cd in the soil and the molecular characteristics (the composition of the microbial community, functional enzymes and metabolites) of the soil were measured. The study found that, compared to CK treatment, the dominant phyla, such as Acidobacteria, Bacteroidetes, Firmicutes, etc., were significantly increased in BD treatment, and enzymes related to metabolism also showed noticeable enhancement. The differential accumulated metabolite (DAM) analysis revealed that the abound of lipids and lipid-like molecules involved with fatty acyls, steroids and steroid derivatives, glycerophospholipids, fatty acids and conjugates, glycerolipids, and sphingolipids were significant different among treatments. The correlation analysis showed the exchangeable fraction cadmium contents (EX-Cd) were negatively correlated with the content of glycerophospholipids and sphingolipids, and positively correlated with glycerolipids content. However, the relationship between the residual cadmium (RS-Cd) and these three metabolites was just the opposite. Compared with another two treatments, the BD treatment significantly reduced EX-Cd contents. Biological interaction network analysis indicated that the phyla Gemmatimonadetes and Proteobacteria assumed the primary responsibility for the morphological transformation of Cd through their corresponding functional enzymes. Overall, this study provided a new perspective on RSD-mediated soil Cd immobilization, and the findings should be beneficial to further applications of RSD technology on the remediation of Cd-polluted soils.

Preface

Recent developments in the field of materials engineering revolutionized the engineering applications in different strategic sectors including automobile, aerospace, marine, biomedical, agriculture, energy engineering and structural and construction engineering. Developing new material systems and novel manufacturing processes enhanced the ability of engineers to address several technological challenges in various industrial applications. Understating the behavior of the materials helps to develop potential engineering applications to improve the quality of the human life. Utilizing computational tools to analyze the materials and processes brings additional advantage to understand the complex issues and accelerates the development of science and technology. Interdisciplinary research couples the expertise of several professionals belong to diversified fields and promotes rapid growth in achieve a common goal in addressing the research challenges. In this context, we believe that the International Conference on Materials, Mechanical and Energy Engineering (ICMMEE 202) organized on 07th & 08Th May 2021 has become a viable platform for knowledge shearing among the experts from various research fields in materials and mechanical engineering. Dr. M. Ananda Rao, Principal Scientist, CSIR – NML Madras Complex, Chennai, India delivered inaugural address on “Metallurgical failure investigations of industrial components”. Dr. Martin Sebesta, Institute of Laboratory Research on Geomaterials, Comenius University in Bratislava, Slovakia, delivered a key-note address on “Transformation of ZnO and TiO2 nanoparticles in the soil environment (influence of soil microorganisms and plants)”. Several post graduate and doctoral students have presented their research work at ICMMEE 2021 in the areas of materials engineering, thermal engineering, mechanical processing, physics, materials in civil engineering, design and analysis of structures etc. We believe that the knowledge exchanged at ICMMEE 2021 immensely helps to the researchers working on relevant fields and contributes to the growth of science and technology. Due to the COVID-19 pandemic and imposed lock down, the conference was virtually conducted through Google meet. All the keynote addresses and the contributory talks were presented through online. We thank the Bapatla Education Society, Bapatla for supporting the event. We also sincerely thank the Head of the Institute, Bapatla Engineering College, Head of the Mechanical Engineering Department, Bapatla Engineering College for their encouragement in successfully organizing the conference. Our sincere thanks to the keynote speakers, reviewers, technical and advisory committee members, organizing committee, and all authors for making ICMMEE 2021 a grand success.List of ICMMEE 2021 committees, Session chairs, Editorial board, Reviewers are available in this pdf.

Soil microbes drive the effect of plant species and genotypic diversity interaction on productivity.

PurposeThe effect of plant species and genotypic diversity on productivity has been well documented but little is known about the contribution of the interaction between species and genotypic diversity. Since the influence of soil microorganisms on the plant diversity-productivity relationship is increasingly recognized, we investigated potential interactions between plant species diversity, plant genotypic diversity and soil microbes. We hypothesized that the non-additive effects of plant species and genotypic diversity on productivity could be microbe-driven.MethodsWe set up pea and wheat monocultures and mixtures in a growth chamber, varying for their levels of genotypic diversity under three different soil microbial contexts. We assessed plant shoot and root biomass production, soil mineral nitrogen content and described the soil bacterial communities.ResultsWe found that shoot biomass in mixtures involving both species and genotypic diversity was higher than expected considering the additive effects of plant species diversity and genotypic diversity. Rather than a synergy between two positive effects of species and genotypic diversity, we observed that species mixture compensated the negative effect of genotypic diversity. Regarding microbial influence, we found that the effect of plant species diversity, plant genotypic diversity and their interaction on productivity were all driven by the soil microbial community as no effect was observed in a pre-sterilised soil.ConclusionOur study suggests that the plant diversity-productivity relationship could be shaped by a three-way interaction between plant species diversity, plant genotypic diversity and soil microbes. Thus, plant-microbe and plant-plant interactions could be a determinant of the plant diversity-productivity relationship.

Influence of soil microorganisms and physicochemical properties on plant diversity in an arid desert of Western China

Soil microorganisms and physicochemical properties are considered the two most influencing factors for maintaining plant diversity. However, the operational mechanisms and which factor is the most influential manipulator remain poorly understood. In this study, we examine the collaborative influences of soil physicochemical properties (i.e., soil water, soil organic matter (SOM), salinity, total phosphorus and nitrogen, pH, soil bulk density and fine root biomass) and soil microorganisms (fungi and bacteria) on plant diversity across two types of tree patches dominated by big and small trees (big trees: height ≥ 7 m and DBH ≥ 60 cm; small trees: height ≤ 4.5 m and DBH ≤ 20 cm) in an arid desert region. Tree patch is consists of a single tree or group of trees and their accompanying shrubs and herbs. It was hypothesized that soil physicochemical properties and microorganisms affect plant diversity but their influence differ. The results show that plant and soil microbial diversity increased with increasing distances from big trees. SOM, salinity, fine root biomass, soil water, total phosphorus and total nitrogen contents decreased with increasing distance from big trees, while pH and soil bulk density did not change. Plant and soil microbial diversity were higher in areas close to big trees compared with small trees, whereas soil physicochemical properties were opposite. The average contribution of soil physicochemical properties (12.2%–13.5%) to plant diversity was higher than microbial diversity (4.8%– 6.7%). Salinity had the largest negative affect on plant diversity (24.7%–27.4%). This study suggests that soil fungi constrain plant diversity while bacteria improve it in tree patches. Soil physicochemical properties are the most important factor modulating plant diversity in arid desert tree patches.

The influence of soil microorganisms on heavy metal content in the substrate of waste rock dumps

The environmental effects of mining and its impact on natural resources are of a holistic nature. One of the modern methods employed for the remediation of technogenically disturbed soils is the application of microorganisms. This paper studies the impact made by soil microorganisms on the accumulation rate of heavy metals in the substrate of waste rock dumps in the process of soil reclamation. Suspensions of soil microorganisms (microorganisms utilising mineral nitrogen forms / MUMN; microorganisms decomposing silicates / MDS; microscopic fungi / MF) were applied to the rock dump surface. Separate groups as well as their combinations were applied. The heavy metal content analysis did not indicate a significant exceedance of the maximum allowable concentration limits (MACL) in the soil of the waste rock. The only metal whose content exceeded the maximum admissible concentration limits was nickel. It has found that the application of microorganisms influences the concentration of several heavy metals due to pH level changes of the rock dump soil.

Effects of simulated drought on biological soil quality, microbial diversity and yields under long-term conventional and organic agriculture.

ABSTRACTDrought and agricultural management influence soil microorganisms with unknown consequences for the functioning of agroecosystems. We simulated drought periods in organic (biodynamic) and conventional wheat fields and monitored effects on soil water content, microorganisms and crops. Above the wilting point, water content and microbial respiration were higher under biodynamic than conventional farming. Highest bacterial and fungal abundances were found in biodynamically managed soils, and distinct microbial communities characterised the farming systems. Most biological soil quality parameters and crop yields were only marginally affected by the experimental drought, except for arbuscular mycorrhizal fungi (AMF), which increased in abundance under the experimental drought in both farming systems. AMF were further strongly promoted by biodynamic farming resulting in almost three times higher AMF abundance under experimental drought in the biodynamic compared with the conventional farming system. Our data suggest an improved water storage capacity under biodynamic farming and confirms positive effects of biodynamic farming on biological soil quality. The interactive effects of the farming system and drought may further be investigated under more substantial droughts. Given the importance of AMF for the plant's water supply, more in-depth studies on AMF may help to clarify their role for yields under conditions predicted by future climate scenarios.

Water availability regulates negative effects of species mixture on soil microbial biomass in boreal forests

Soil microorganisms are critical for the maintenance of terrestrial biodiversity and ecosystem functions. Both plant diversity and water availability are individually known to influence soil microorganisms; however, their interactive effects remain largely unknown. Here, we investigated whether the effects of tree species mixtures on microbial biomass and composition were altered by water availability. This was accomplished by sampling soils in the growing season from stands that were dominated by Populus tremuloides and Pinus banksiana, respectively, and their relatively even mixtures under reduced (−25% throughfall), ambient, and added (+25% throughfall) water. Microbial community biomass and composition were determined by phospholipid fatty acid analysis. We found that water addition increased soil total microbial biomass and by individual groups, whereas water reduction had no effect. Under ambient water conditions, soil total microbial biomass, arbuscular mycorrhizal fungal, bacterial, gram-positive (GP) bacterial, and gram-negative (GN) bacterial biomass were significantly lower in mixtures than from those of constituent monocultures, but saprotrophic fungal biomass and the ratios of fungal/bacterial and GP/GN bacteria were not significantly affected by tree species mixtures. Water reduction increased species mixture effects on total and individual group microbial biomass from negative to neutral, while water addition only increased mixture effects on arbuscular mycorrhizal fungal and GP bacterial biomass. Across all water treatments, soil total and individual group microbial biomass significantly increased with the abundance of broadleaved trees, but only weakly with species richness. Further, microbial community compositions differed significantly with both overstory type and water treatment. Microbial community compositions exhibited strong associations with tree species richness, soil moisture, soil pH, and litterfall production, whereas microbial biomass did not. Our results suggest that higher species diversity is not always of benefit for soil microorganisms; however, mixed tree species have the potential to regulate ecosystem responses to climate change.

Responses of Soil Microbial Community Structure and Activity to Incorporation of Straws and Straw Biochars and Their Effects on Soil Respiration and Soil Organic Carbon Turnover

Like straw, biochar incorporation can influence soil microorganisms and enzyme activities and soil carbon (C) responses; however, few studies have compared the various effects of straw and biochar and the underlying mechanisms. An experiment was performed to study the changes in soil respiration (SR) and soil organic C (SOC) fluxes in response to the incorporation of three kinds of straw (reed, smooth cordgrass, and rice) and their pyrolyzed products (biochars) at Chongming Island, China. In addition, the microbial activity and community structure of some amended soils were also analyzed to clarify the mechanisms of these responses. The results showed that all biochar incorporation (BC) induced lower SR than the corresponding unpyrolyzed straw incorporation (ST), and the average SR in the soils following BC and ST during the experimental periods was 21.69 and 65.32 μmol CO2 m−2 s−1, respectively. Furthermore, the average SOC content was 16.97 g kg−1 following BC, which was higher than that (13.71 g kg−1) following ST, indicating that compared to ST, BC was a low-C strategy, even after accounting for the C loss during biochar production. Among the BC treatments, reed-BC induced the lowest SR (17.04 μmol CO2 m−2 s−1), whereas smooth cordgrass-BC induced the highest SR (27.02 μmol CO2 m−2 s−1). Furthermore, in contrast with ST, BC significantly increased the abundance of some bacteria with poorer mineralization or better humification ability, which led to lower SR. The lower easily oxidizable C (EOC) and higher total C contents of biochars induced lower SR and higher SOC in the soil following BC compared to that following ST. Among the BC treatments, the higher total nitrogen content of rice biochar led to significantly higher soil microbial biomass, and the lower EOC content of reed biochar led to lower soil microbial activity and SR.

Protective effects of farnesol on a Rhizobium strain exposed to cadmium

Soil acts as a repository for many metals that human activity releases into the environment. Cadmium enters agricultural soils primarily from application of phosphate fertilizers and sewage sludge. Among soil bacteria, rhizobia have a great agronomic and environmental significance and are major contributors to a sustainable maintenance of soil fertility. However, the services that this group of microorganisms provides are affected by environmental constraints, such as Cd contamination. Bioactive compounds also influence soil microorganisms. Farnesol is a phytocompound with recognized bioactivity, inducing both beneficial and harmful effects. In this study, Rhizobium sp. strain E20-8 was exposed to sole or combined exposure to Cd and farnesol. Results showed that farnesol (25 and 200 µM) did not affect rhizobia; exposure to Cd (µM) inhibited rhizobia growth and induced several biomarkers of oxidative stress; exposure to the combination of farnesol and Cd reduced oxidative damage, and the highest concentration of farnesol tested reduced Cd accumulation and allowed a significant growth recovery. Farnesol protective effects on rhizobia exposed to Cd is novel information which can be used in the development of microbe-based environmental engineering strategies for restoration of metal contaminated areas.

Influence of soil microorganisms on metal corrosion of underground pipelines

Abstract There have been revealed and summarized the regularities in biocorrosion of steel 17G1S-U, which is traditionally used for manufacturing oil and gas mains. The basic regularities of biocorrosion processes in the 17G1S-U pipe steel under the influence of SRB Desulfovibrio Sp. strains Kyiv-10 was obtained by weight-loss testing and surface analysis techniques. Effective inhibitors are proposed, which allow protecting steel 17G1S-U against the development of anaerobic corrosion under the influence of sulfate-reducing bacteria (SRB). The effectiveness of inhibitors is estimated by the degree of their protective effect. The porous structure of the surface film contributes to the initiation of localized corrosion. Damage analysis of the specimen surface corroded under different test conditions was performed.

Phosphorus fractions in subtropical soils depending on land use

Land-use change from forest to agriculture, which is driven by the demands of sustaining the growing global population, affects nutrient dynamics and availability in soil. Although phosphorus (P) is one of the main limiting nutrients in agricultural production, little is known about the influence of soil microorganisms on the dynamics of P cycling in subtropical land use systems. The objective was to assess the impacts of land use (organic farming, conventional farming and forest) on forms and distribution of P in soil.After conversion of forest, the P stock significantly increased by 373% and 170% in soil under organic farming at 0–10 and 10–20 cm depth, respectively. In conventional farming, the P stock increased by 64% and 36% at 0–10 cm and 10–20 cm depth, respectively compared to forest. The larger (up to 4 times) fraction of organic P (Po) than inorganic P (Pi) implies that total P is regulated by organic P. Easily-available P fractions (microbial biomass P, NaHCO3-Pi and Po), moderately available P (NaOH-Po) and non-available P (HCl-Pi and Po) were much higher in organic farming than conventional farming and forest, especially at the 0–10 cm depth. Compared to organic farming, the higher (>100) Corg: Po ratio that soils under conventional farming and forest are P limited which correspond with higher (2–8 times) activity of acid phosphatase in conventional farming and forest. Concluding, land use and management practices i.e. crop rotation, residue input and farmyard manure application significantly increase different fractions of P in organic farming.

Influence of soil bacteria and carbonic anhydrase on karstification intensity and regulatory factors in a typical karst area

Sequestration of atmospheric CO2 is attracting considerable attention due to global warming. Karstification significantly affects the sequestration of atmospheric CO2. Microorganisms and carbonic anhydrase (CA) can promote karstification, but the actual contribution of microorganisms and CA to karstification intensity (KaI) under natural conditions remains unclear. In this study, the influence of soil microorganisms and CA on KaI and main regulatory factors was investigated through field soil column dissolution experiments. Guilin Yaji Karst Experimental Site was used as the typical karst area, and Silai clastic rock area was the control area. Results showed that surface soil in various geomorphological positions in the karst area presented KaI in the following order: saddle>slope>depression. Addition of composite CA-producing microbial inoculants or composite inhibitors regulated CA activity in surface soil, thereby influencing KaI. Illumina high-throughput sequencing results indicated that the soil dominant bacterial phyla were generally the same in various experimental groups and plots, and the bacterial abundance in surface soil was regulated by additives. Addition of composite microbial inoculants increased the total bacterial abundance of surface soil, whereas addition of composite inhibitors reduced the total bacterial abundance. The ratio of CA-producing bacterial abundance to total bacterial abundance was the largest at saddle in the karst area, in corresponding to the highest KaI. This finding suggested the significant role of CA-producing bacteria in promoting KaI. Correlation analysis revealed that the main soil regulatory factors of KaI were soil pH, total hydrogen, total organic carbon, and exchangeable calcium.

Links between soil microbial communities and plant traits in a species-rich grassland under long-term climate change.

Climate change can influence soil microorganisms directly by altering their growth and activity but also indirectly via effects on the vegetation, which modifies the availability of resources. Direct impacts of climate change on soil microorganisms can occur rapidly, whereas indirect effects mediated by shifts in plant community composition are not immediately apparent and likely to increase over time. We used molecular fingerprinting of bacterial and fungal communities in the soil to investigate the effects of 17 years of temperature and rainfall manipulations in a species‐rich grassland near Buxton, UK. We compared shifts in microbial community structure to changes in plant species composition and key plant traits across 78 microsites within plots subjected to winter heating, rainfall supplementation, or summer drought. We observed marked shifts in soil fungal and bacterial community structure in response to chronic summer drought. Importantly, although dominant microbial taxa were largely unaffected by drought, there were substantial changes in the abundances of subordinate fungal and bacterial taxa. In contrast to short‐term studies that report high resistance of soil fungi to drought, we observed substantial losses of fungal taxa in the summer drought treatments. There was moderate concordance between soil microbial communities and plant species composition within microsites. Vector fitting of community‐weighted mean plant traits to ordinations of soil bacterial and fungal communities showed that shifts in soil microbial community structure were related to plant traits representing the quality of resources available to soil microorganisms: the construction cost of leaf material, foliar carbon‐to‐nitrogen ratios, and leaf dry matter content. Thus, our study provides evidence that climate change could affect soil microbial communities indirectly via changes in plant inputs and highlights the importance of considering long‐term climate change effects, especially in nutrient‐poor systems with slow‐growing vegetation.

Response of soil microbial community to the simultaneous influence of metals and an organic substance

Organic substances and metals multidirectionaly influence soil microorganisms. The results of an evaluation of the response of the soil microbial community to the simultaneous application of organic substance and metals which are a part of compost from the sewage sludge are presented. For two seasons after soil treatment, the increase in Corg to 2.1 ± 0.4% and that in Cd, Cr, Cu, Ni, Pb, and Zn mobile forms to 1.1 ± 0.03, 3.8 ± 0.8, 6.0 ± 1.2, 2.1 ± 0.5, 3.2 ± 0.7, and 12.3 ± 2.7 mg/kg correspondingly resulted in the growth of microbial biomass in comparison with a control soil. The respiratory activity of the treated soils increased during the first season and decreased to the level of control plots by the end of the second season. The value of a metabolic quotient did not exceed the control level. An analysis of the principal components of the obtained data revealed that the major factor determining the variability of the microbial community is the alteration of the content of organic substance in the soil.

Modification of 137Cs transfer to rape (Brassica napus L.) phytomass under the influence of soil microorganisms

After nuclear accidents, such as those experienced in Chernobyl and Fukushima, microorganisms may help purify contaminated soils by changing the mobility of radionuclides and their availability for plants by altering the physical and chemical properties of the substrate. Here, using model experiments with quartz sand as a substrate we investigate the influence of microorganisms on 137Cs transfer from substrate to plants. The highest transition of 137Cs from substrate to plants (50% increase compared to the control) was observed after Brassica napus L. seeds were inoculated by Azotobacter chroococcum. The best results for reducing the accumulation of 137Cs radionuclides (30% less) were noted after the inoculation by Burkholderia sp.. Furthermore, Bacillus megaterium demonstrated an increased ability to accumulate 137Cs. This research improves our prediction of the behavior of radionuclides in soil and may contribute towards new, microbiological countermeasures for soil remediation following nuclear accidents.