Tail Area Research Articles

Effects of Heavy Metal Contents on Phyllosphere and Rhizosphere Fungal Communities for Bothriochloa ischaemum in Copper Tailings Area

There are complex interrelationships between plant microorganisms (phyllosphere and rhizosphere) and host plants, which can promote plant growth and enhance the tolerance of host plants to stress. In this study, we selected the dominant species Bothriochloa ischaemum as the research subject in a copper tailings dam. Using high-throughput sequencing, we investigated the structures of the fungal communities and diversities in the phyllosphere and rhizosphere of B. ischaemum. This study also explored the effects of heavy metal content on fungal community characteristics. The results showed that Ascomycota and Basidiomycota were the dominant phyla in the phyllosphere and rhizosphere of B. ischaemum. The diversities and richness of the rhizosphere fungal community were higher than that of the phyllosphere fungal community. The diversities of rhizosphere and phyllosphere fungal communities was affected by different heavy metals. Phyllosphere fungal diversity was mainly affected by the content of Zn and Cu in leaves, and the content of Pb in roots was the key factor affecting the diversity of the rhizophere fungal community. Furthermore, Pleosporaceae had a very significant positive correlation with Cd in the phyllosphere, and Nectriaceae had a significant positive correlation with Zn in the rhizosphere. These fungal communities could be used as indicators of ecological recovery in areas with heavy metal pollution. The results could provide an ecological basis for the exploration and utilization of phyllosphere or rhizosphere fungi resources during ecological restoration processes. This study also provides guidance for selecting the plant-microbial symbionts during ecological restoration in areas with heavy metal pollution.

Analysis of Groundwater Environment Evaluation and Prediction

In accordance with the requirements of Technical guidelines for environmental impact assessment―groundwater environment (HJ 610-2016), the process of groundwater environmental impact assessment and prediction was analyzed. Groundwater Model System (GMS) was used to simulate Groundwater flow field and solute transport, the following main conclusions were draw. As long as the project conforms to the specifications and design and the management is in place during operation, the production area and tailings area in normal working conditions will not cause obvious adverse effects on the quality of groundwater. Under different assumptions, groundwater pollution of the production area and tailings area in abnormal conditions will not directly affect the drinking water, farmland irrigation water and surface water of surrounding residents.

In vivo hippocampal subfield volumes in bipolar disorder—A mega‐analysis from The Enhancing Neuro Imaging Genetics through Meta‐Analysis Bipolar Disorder Working Group

The hippocampus consists of anatomically and functionally distinct subfields that may be differentially involved in the pathophysiology of bipolar disorder (BD). Here we, the Enhancing NeuroImaging Genetics through Meta‐Analysis Bipolar Disorder workinggroup, study hippocampal subfield volumetry in BD. T1‐weighted magnetic resonance imaging scans from 4,698 individuals (BD = 1,472, healthy controls [HC] = 3,226) from 23 sites worldwide were processed with FreeSurfer. We used linear mixed‐effects models and mega‐analysis to investigate differences in hippocampal subfield volumes between BD and HC, followed by analyses of clinical characteristics and medication use. BD showed significantly smaller volumes of the whole hippocampus (Cohen's d = −0.20), cornu ammonis (CA)1 (d = −0.18), CA2/3 (d = −0.11), CA4 (d = −0.19), molecular layer (d = −0.21), granule cell layer of dentate gyrus (d = −0.21), hippocampal tail (d = −0.10), subiculum (d = −0.15), presubiculum (d = −0.18), and hippocampal amygdala transition area (d = −0.17) compared to HC. Lithium users did not show volume differences compared to HC, while non‐users did. Antipsychotics or antiepileptic use was associated with smaller volumes. In this largest study of hippocampal subfields in BD to date, we show widespread reductions in nine of 12 subfields studied. The associations were modulated by medication use and specifically the lack of differences between lithium users and HC supports a possible protective role of lithium in BD.

The influence of environmental condition on the creation of organic compounds in Pinus sylvestris L. rhizosphere, roots and needles

Key messageStudied organic molecules in Pinus sylvestris L. seem to have acted as a safety net for metal transport, chelation and sequestration, allowing adaptation and growth under highly polluted conditions.Pinus sylvestris L. is known for its ability to survive in areas of highly elevated metal pollution, such as flotation tailings. The aim of the study was to estimate the content of selected organic molecules (including aliphatic low molecular weight organic acids (ALMWOAs), phenolic compounds and terpenes) and the physiological mechanisms underlying differences in metal/metalloid tolerance of P. sylvestris growing in unpolluted (soil) and polluted (flotation tailings) areas. The dominant ALMWOAs in rhizosphere soil extracts were citric acid followed by malic and oxalic acids, whereas in flotation tailings malic and oxalic acids. In roots and needles, the content of ALMOWAs was significantly higher in P. sylvestris L. tissue from flotation tailings in comparison to soil. Phenolic compounds were detected only in roots and needles, with a generally higher content of nearly all detected compounds from flotation tailings. The composition of roots did not contain all the compounds detected in needles. The profile of needles additionally contained four hydroxybenzoic, protocatechuic and salicylic acids. In pine needles, 24 volatile terpenes were identified in total. The content of these compounds in pine needles from the polluted area was markedly different from the unpolluted area. The dominant volatile monoterpenes in P. sylvestris L. needles from the unpolluted area was three carene, while in pine needles from the polluted area monoterpenes α-pinene was dominant.

Ballasted track aerodynamic optimization by wind tunnel test and CFD simulation

Ballast flight problem sets back high-speed railway development, which causing damages to train and rail. The present paper puts forward wind tunnel tests and CFD simulation to study ballast flight mechanisms and ballasted track aerodynamics. A 1:1 scale ballasted track model was set up to analyze ballast flight phenomena, where aerodynamics influencing factors and impacts on ballast bed were investigated. A numerical model of CRH3 train-ballast bed was built by combining the Realizable k- ϵ viscous model and sliding mesh technique. CFD model with the above method was used to investigate aerodynamic effects as well as the mechanism of ballast flight, thus providing the theoretical basis for optimizing ballast bed profile and preventing ballast flight. Results show that pressure distribution exhibits large value at the center of the ballasted track and decreases at track edge. The head, tail and bogie area of the train result in large fluctuation of wind pressure, which has a great probability of ballast flight. Appropriate countermeasures should be taken, such as reduce shoulder ballast height and crib ballast could be effective methods to decrease the probability of ballast flight.

Approximation to multivariate normal integral and its application in time-dependent reliability analysis

It is common to evaluate high-dimensional normal probabilities in many uncertainty-related applications such as system and time-dependent reliability analysis. An accurate method is proposed to evaluate high-dimensional normal probabilities, especially when they reside in tail areas. The normal probability is at first converted into the cumulative distribution function of the extreme value of the involved normal variables. Then the series expansion method is employed to approximate the extreme value with respect to a smaller number of mutually independent standard normal variables. The moment generating function of the extreme value is obtained using the Gauss-Hermite quadrature method. The saddlepoint approximation method is finally used to estimate the cumulative distribution function of the extreme value, thereby the desired normal probability. The proposed method is then applied to time-dependent reliability analysis where a large number of dependent normal variables are involved with the use of the First Order Reliability Method. Examples show that the proposed method is generally more accurate and robust than the widely used randomized quasi Monte Carlo method and equivalent component method.

PANCREAS TRANSPLANTATION WITH ISOLATED SPLENIC ARTERY SUPPLY

Introduction: The critical deficiency of donor organs as a result of both strict criteria for potential donor selection and anatomic features of pancreas transplant blood supply limits the widespread application of pancreas transplantation. During the multiorgan grafts removal we have quite often to sacrifice the superior mesenteric artery (SMA) in favor of additional hepatic artery. In such cases the implied critical pancreas graft ischemia significantly limits its implementation. The evaluation of isolated splenic artery supply (ISAS) sufficiency of the pancreas graft had defined the purpose of this study. Materials and Methods: From January 2008 to February 2020, 61 patients had undergone pancreas transplantation: 34 women and 27 men. The median age was 34[30;39] years. In 53 (87%) cases we have performed standard Y-graft arterial reconstruction. In 9 (13%) cases we have performed pancreas transplantation with ISAS as a result of the SMA cutting off during organs’ explantation. We have used 640-slice dynamic volume perfused computed tomography (PCT) with measurement of the time of maximum PG’s tissue peak (TTP (sec.)), arterial blood flow (ABF) and arterial blood volume (ABV) in the PG’s head, body and tail areas to assess the PG’s condition. Results: 1 patient with ISAS PTx have died in early postoperative period due to infectious complications. In other 8 patients with pancreas graft’s ISAS we didn’t observe any pancreatic head necrosis and/or ischemic graft’s duodenum necrosis. Furthermore, there were no significant differences in the studied and controlled groups pancreas graft’s function: glycose – 4,4 vs 4,5 mmol/l (p=0,62), alpha amylase – 67 vs 84 U/l (p=0,7), pancreatic amylase – 39 vs 44 U/l (p=0,8), lipase – 42 vs 26 U/l (p=0,7), HbA1c 5,5 vs 5,4 % (p=0,9), intact insulin – 17 vs 10 mcIU/ml (p=0,4). We have found significant difference only in C-peptide level (2,5 vs 1,7 ng/ml (p=0,01)). The CT-perfusion results were: TTP–19[17;23] sec ABF –125[116;160], 125[117;139], 122[105;136] ml/min/100ml., ABV–40[32;58], 40[30;58], 42[36;62] ml/min. and statistically didn’t differ from perfusion parameters of PG with both functioning arteries. Conclusion: Pancreas transplantation with ISAS is reasonable due to well-developed arterial collaterals between splenic and superior mesenteric arteries systems. Preservation solution stream appearance through the SMA stump while flushing through the splenic artery during back-table procedure, in spite of risk of graft over flushing, can show the possibility of ISAS transplantation. The viability of the surgical technique with ISAS will allow to expand the criteria for pancreas harvesting and increase the number of transplantations.

THE EFFECT 0F COW MANURE ADDITION AND DRIP IRRIGATION SYSTEM WITH DIFFERENT WATER VOLUMES TO MELON PLANTS (Cucumis melo L.) GROWTH ON TIN-MINING LAND

Post tin mining tailings land in Bangka Belitung Islands Province has an area of around 400 000 ha. In terms of area, the land has the potential to be used as cultivated land, one of which is melon. The aims of the study is to see the effect of cow manure fertilizer and drip irrigation water volume on melon plants growth in post tin mining tailings area. This research was conducted from June to August 2018 in the tailings area of Dewi Makmur Village, Merawang District, Bangka Regency. This experimental used a completely randomized design (CRD) factorial method. The first factor was cow manure with three levels (K1 = 2.5 kg/planting hole; K2 = 5 kg / planting hole; K3 = 7.5 kg / planting hole) and the second factor was drip irrigation volume (A1 = 800 ml; A2 = 1 500 ml). The results showed that giving cow manure and water irrigatian has no significant effect on melon plant height, stem diameter and number of leaves, but the treatment 7.5 kg of cow manure and 1 500 ml water gave results that tended to be better.

Geoelectric interpretation of petrophysical and hydrogeological parameters in reclaimed mine tailings areas

The research applies non-invasive electrical resistivity imaging (ERI) for the quantitative interpretation of electric and hydrogeological parameters in a reclaimed tailings area. Composition, porous structure and clay content do not change significantly in the tailings matrix but have influence in bulk electrical resistivity. Therefore, the tailings matrix was included in a multiphase approach known as generalized Archie's equation and modelled for interpretation of bulk electrical resistivity, water content and saturation in the vadose zone of the waste deposit. The results are consistent to explain the sensitivity of electrical resistivity to tailings hydrogeological parameters.The model provides a reliable approximation of the distribution of water content and saturation in the vadose zone and describes quantitatively for the first time the role of the tailings matrix as contributor of the electrical response. It also confirms that pore-water of ionic composition and saturation are the controlling factors for the variability of the bulk electrical resistivity.The method described in the paper is beneficial for predicting electrical and hydraulic parameters in tailings facilities, which is important for monitoring the integrity of these structures into the future.

Metal brain bioaccumulation and neurobehavioral effects on the wild rodent Liomys irroratus inhabiting mine tailing areas.

Ecotoxicological studies are necessary in order to evaluate the effects of environmental exposure of chemicals on wild animals and their ecological consequences. Particularly, neurobehavioral effects of heavy metal elements on wild rodents have been scarcely investigated. In the present study, we analyzed the effect of metal bioaccumulation (Pb, As, Mg, Ni, and Zn) in the brain and in the liver on exploratory activity, learning, memory, and on some dopaminergic markers in the wild rodent Liomys irroratus living inside mine tailings, at Huautla, Morelos, Mexico. We found higher Pb concentration but lower Zn in striatum, nucleus accumbens, midbrain, and hippocampus in exposed animals in comparison to rodents from the reference site. Exposed rodents exhibited anxious behavior evaluated in the open field, while no alterations in learning were found. However, they displayed slight changes in the memory test in comparison to reference group. The neurochemical evaluation showed higher levels of dopamine and 5-hydroxyindolacetic acid in midbrain, while lower levels of metabolites dihydroxyphenyl acetic acid and homovanillic acid in striatum of exposed rodents. In addition, mRNA expression levels of dopaminergic D2 receptors in nucleus accumbens were lower in animals from the mining zone than in animals from the reference zone. This is the first study that shows that chronic environmental exposure to metals results in behavioral and neurochemical alterations in the wild rodent L. irroratus, a fact that may comprise the survival of the individuals resulting in long-term effects at the population level. Finally, we suggest the use of L. irroratus as a sentinel species for environmental biomonitoring of mining sites.

Fast Free-Text Authentication via Instance-Based Keystroke Dynamics

Keystroke dynamics study the way in which users input text via their keyboards. Having the ability to differentiate users, typing behaviors can unobtrusively form a component of a behavioral biometric recognition system to improve existing account security. Keystroke dynamics systems on free-text data have previously required 500 or more characters to achieve reasonable performance. In this paper, we propose a novel instance-based graph comparison algorithm called the instance-based tail area density (ITAD) metric to reduce the number of keystrokes required to authenticate users. Additionally, commonly used features in the keystroke dynamics literature, such as monographs and digraphs, are all found to be useful in informing who is typing. The usefulness of these features for authentication is determined using a random forest classifier and validated across two publicly available datasets. Scores from the individual features are fused to form a single matching score. With the fused matching score and our ITAD metric, we achieve equal error rates (EERs) for 100 and 200 testing digraphs of 9.7% and 7.8% for the Clarkson II dataset, improving upon state-of-the-art of 35.3% and 15.3%.

Nutrient status and pollution levels in five areas around a manganese mine in southern China

Nutrient status and pollution levels are the main factors affecting soil restoration. The nutrient status and pollution levels in five areas, an unexplored mine area (UA), an explored mine area (EA), a tailings area (TA), a reclamation area (RA) and an agricultural area (AA), around the Pingle manganese mine in Guangxi, China, were assessed in this study. The results showed that the average total phosphorus in these five areas ranged from 1.05 to 1.57 mg/kg, corresponding to grades of extremely high and high. The average total nitrogen values were 0.19, 0.69, 0.93, 1.24 and 1.67 mg/kg in EA, TA, RA, UA and AA, corresponding to grades of very low, low, medium-low, medium-high and medium-high, respectively. The average organic matter values were 12.78, 8.92, 22.77, 21.29 and 29.11 mg/kg in EA, TA, RA, UA and AA, which corresponded to grades of medium-low, low, medium-high, medium-high and medium-high, respectively. All these results indicated that the total phosphorus was sufficient in these areas, while the total nitrogen and organic matter were insufficient in EA, TA and RA. The available concentrations of Mn and Zn corresponded to the intermediate grade, while the values for Cu corresponded to the very low grade; these might be another factor restricting ecological reclamation. Contamination and ecological risk assessments based on the single contamination index, Nemerow multi-factor index and potential ecological risk index showed that the five tested areas around the Mn mine were considered heavily polluted and presented high ecological risk. Mn and Cd were the dominant pollutants.

RADIATION SITUATION IN THE TERRITORIES AFFECTED BY MINING ACTIVITIES IN STEPNOGORSK AREAS, REPUBLIC OF KAZAKHSTAN: PILOT STUDY.

The Republic of Kazakhstan has a long history of mining activities, viz., gold and uranium. Mining activities represent sources of potential naturally occurring radionuclides contamination of the environment and human health of population. The aim of this study was to investigate the radiation situation of industrially modified environment in Stepnogorsk areas of Kazakhstan to understand the sources of contamination. Quite high values of ambient equivalent dose rates in air ~2.87μSvh-1 were found in the Aqsu gold-mining site. The radon equivalent equilibrium volume activity (indoor) were in the range of 313-858Bqm-3 in the study area buildings. The high values of activity concentration of natural radionuclides found in Aqsu soil samples were 226Ra-4060, 232Th-1170 and 40K-4080Bqkg-1, respectively. However, our comprehensive surveys implied that the increased natural radiation background caused by the radionuclide transport from the tailing area did not have an impact, while evaluation of its potential radiation risks and remediation of the territories of the former gold mining should be needed.

Assessment of reactive oxygen species production and genotoxicity of rare earth mining dust: Implications for public health and mining management

Mining rare earth elements (REEs) can release large amounts of metal(loid)-rich dust, which can pose significant health risks to local residents. However, compared to other types of particulates, toxicity of mining dust has been largely overlooked. To provide experimental evidence on toxicity of REE mine dust, the study assessed the oxidative stress potential and genotoxicity of inhalable particles collected in a REE mining area, and associated toxicological response with source compositions. Both source types (i.e., mine and tailing area) and distances from source (i.e., industrial and residential areas) were considered when selecting the 44 sampling sites. The particle samples contained 2.3–3.5 folds higher concentrations of tested metal(loid)s than background concentrations in soil. Specially, elevated Fe, REEs, Cd, Pb were found. In spite of low cytotoxicity in lung epithelial A549 cells, there was increased cellular ROS production by of particle exposure. Samples with higher mining-originated source contributions (Provenance Index <0.3) had higher cellular ROS production (1.72 fold, 95%CI: 1.66–1.79 fold) than samples with lower mining contributions (1.58 fold, 95%CI: 1.52–1.65 fold). The factors soil (~46%), mine (~22%), and heavy metal (~20%) sources were recognized by source apportionment analysis as the main contributors to cellular ROS production; importantly, mine and heavy metal sources counted more in industrial samples. While samples generated genotoxicity, there were no differences in DNA damage between the location groups of sampling. Collectively, the results indicate that particles in mining areas may cause ROS production and DNA damage in lung cells depending on mine dust. Coupled with the long-range transportation potential of mine dust, safety measures on open pit and dust disposal sites should be adopted.

Dewatering of Nannochloropsis Sp Via Forward Osmosis: A Molecular Dynamics Study

Microalgal biomass is an essential source of renewable energy and the production of high-valued bio-products. Nannochloropsis sp. is a marine microalgae which contains high valued bio-compounds. However, it contains elevated moisture which hinders extraction of important significant bio-compounds. A dewatering process of Nannochloropsis sp via forward osmosis is proposed. The objective of the study is to evaluate the effect of salinity on the lipid membrane of microalgae Nannochloropsis sp by inducing osmotic pressure difference. A microalgae lipid membrane model was developed using molecular dynamics and evaluated through relative structural changes and water dynamics by varying the salinity. The results revealed at elevated salinity, compression occurs to the lipid membrane based on the tail order and area per head groups. The dynamics of water molecules showed that water migration happens as early as 20 ns. Despite membrane compression, a total of 5 water molecules migrated within the 150 ns. This suggests that forward osmosis is a promising alternative for microalgal dewatering.

Guidelines for Reporting of Figures and Tables for Clinical Research in Urology.

In an effort to improve the presentation of and information within tables and figures in clinical urology research, we propose a set of appropriate guidelines. We introduce six principles: (1) include graphs only if they improve the reader's ability to understand the study findings; (2) think through how a graph might best convey information, do not just select a graph from preselected options on statistical software; (3) do not use graphs to replace reporting key numbers in the text of a paper; (4) graphs should give an immediate visual impression of the data; (5) make it beautiful; and (6) make the labels and legend clear and complete. We present a list of quick "dos and don'ts" for both tables and figures. Investigators should feel free to break any of the guidelines if it would result in a beautiful figure or a clear table that communicates data effectively. That said, we believe that the quality of tables and figures in the medical literature would improve if these guidelines were to be followed. Patient summary: A set of guidelines were developed for presenting figures and tables in urology research. The guidelines were developed by a broad group of statistical experts with special interest in urology.

Investigation of protective effects of lithium borate on spermatogenesis and testes histopathology against cadmium-induced acute toxicity in rats

In this study, protective effects of lithium borate LTB on spermatogenesis as well as histopathological and immunohistochemical findings of testes in experimentally induced acute Cadmium Cd toxicity in rats were determined. Twenty-eight male Wistar albino rats, were used, weighing 200-220 g. Rats were randomly divided into 4 groups: Control, Cd, LTB, and LTB + Cd. Rats were anesthetized with ketamine at the end of the sixth day, blood was taken from their hearts, and the rats were decapitated. Typically, the control and LTB groups exhibited similar values. Compared with those observed for the control group, the sperm morphology i.e. abnormal sperm count increased for the Cd group, while the FSH, LH, total testosterone levels, sperm motility, and density decreased in a statistically significant manner. Clearly, no adverse effects of LTB on the sperm motility, density, and sperm morphology i.e. abnormal sperm count were observed, but LTB decreased the negative effects of Cd toxicity. Abnormal disturbances in the head and tail areas of the sperms increased; thus, the total abnormal sperm rate increases, leading to the decreased fertilization capacity. The histopathological examination of testicular tissues revealed severe haemorrhage and hyperaemia in intertubular intervals, tubule atrophy, severe degenerative and necrotic changes in spermatocytes, tubule wall thinning, and necrosis in basal germ cells. In immunohistochemically Caspase-3, 8-OHdG, and COX-2 staining, changes in the control and LTB groups were not detected, while the Cd toxicity group exhibited severe expression in the testis tissue. Histopathological and immunohistochemical changes were significantly decreased in the LTB + Cd group compared to the Cd group. In conclusion, in this study it was determined that LTB has protective effects on Cd-induced testicular toxicity in rats.

Edaphic factors influencing vegetation colonization and encroachment on arsenical gold mine tailings near Sudbury, Ontario

Mine tailings are found worldwide and can have significant impacts on ecosystem and human health. In this study, natural vegetation patterns on arsenical (As) gold (Au) mine tailings located in Sudbury, Ontario were assessed using transects located at the edge of the tailings and on the tailings. Vegetation communities were significantly different between the edge and open tailings areas of the site. Arsenic concentrations in both areas were extremely variable (from 285-17,567 mg/kg) but were not significantly correlated with vegetation diversity at the site. Nutrients (carbon (C), phosphorus (P)) and organic matter concentrations were associated with higher diversity and with the presence of climax vegetation on the tailings, but there were no significant relationships between tailings chemistry and vegetation indices on the edge. Encroachment onto the tailings from the edge occurred in conventional succession patterns, with a clear gradient from grasses (Agrostis gigantea) to trees such as Picea glauca. On the tailings, a nucleation pattern was visible, distinct from conventional succession. Trees and shrubs such as Betula papyrifera and Diervilla lonicera were associated with higher diversity and higher nutrient concentrations in the underlying tailings, whereas grasses such as A. gigantea were not. We concluded that at all areas of the site, vegetation - particularly trees - was facilitating amelioration of the underlying tailings. Despite high concentrations of As, nutrients appeared to have a greater influence than metals on vegetation diversity.

The importance of edaphic niches functionality for the sustainability of phytomanagement in semiarid mining impacted ecosystems

Mining activities on metal sulphide ores are considered one of the most environmentally damaging anthropogenic activities worldwide, mainly due to the production of metal(loid)- enriched tailings. The objective of the work was to elucidate which factors, including edaphic, vegetation and microbiological aspects, determine soil functionality in the phytomagement of mine tailings piles in semiarid areas. For this purpose, a field study was conducted using a transect experimental design in a former mining area located in southern Spain. Soil characteristics, including edaphic parameters, bacterial and fungal compositions, were determined. The variation in edaphic parameters (pH, electrical conductivity, organic carbon, particle size distribution, etc) through the deterioration transect caused a decrease in plant and microbial diversities, as well as in microbial productivity measured by enzymatic activities. Variation in bacterial relative abundances through the transect was better explained by soil fertility related factors, such as organic matter, pH, salinity, enzymatic activities or microbial biomass (which in turn were related to the presence of plants), than by metals concentrations. The presence of vegetation at the tailings allowed the transition from lithotrophic bacterial orders which dominated in bare tailings areas (e.g. Acidimicrobiales, Chromatiales) to organotrophic oriented orders (e.g. Cytophagales, Actinomycetales). Vegetated patches at the tailings pile and its borders shared some organotrophic bacteria with control forest samples (e.g. Rhizobiales), indicating that natural plant mediated successional processes might stimulate biogeochemical cycles similar to those occurring at non-polluted systems. This functionality of the impacted sites, which include unfavourable edaphic conditions, should be taken into account in the phytomanagement of mine tailings, since it may support its long-term sustainability. Unlike bacteria, variations in fungal relative abundances through the transect were not clearly explained by soil parameters or the presence of plants. Other factors related to spatial distribution or the type of organic substrates may be more determinant in the case of fungi.

Effects of soil heavy metal pollution on microbial activities and community diversity in different land use types in mining areas.

Microbial activities and community structures play crucial roles in the soil environment and can be served as effective indicators to assess the ecological influence of heavy metal pollution in soil. This article selected soil samples from five land use types (mining area, mineral processing area, heap mining area, tailing area, and vegetable area) in the Shizishan mining area in Tongling, Anhui Province, China. The physicochemical properties, pollution characteristics, enzyme activities (catalase, urease, alkaline phosphatase, neutral phosphatase, cellulase, and sucrase), microbial biomass carbon (MBC), basal respiration (SBR), and metabolic entropy (qCO2) in soil were determined and compared, and the relationship between environmental factors and the microbial activities and community diversity was analyzed. The results showed that, according to the Nemerow's Pollution Index (PN), the values were the heap mining area (24.47) > mineral processing area (12.55) > mining area (9.81) > tailings area (6.02) > vegetable area (4.51). With the increase of heavy metal contamination in the sampling area, the six enzyme activities, MBC and SBR decreased, but the qCO2 increased. Principal coordinate analysis (PCoA) and canonical correlation analysis (CCA) showed that the land use types, soil moisture content (MC), heavy metal content, pH, MBC, SBR, and qCO2 were significantly affected by the microbial community. The most dominant phyla were Proteobacteria (34.73%), Bacteroidetes (9.25%), Acidobacteria (8.99%), and Chloroflexi (8.68%) at the phylum (0.01) level by a total of 18 phyla. It was also found that Firmicutes and Phormidium were more tolerant to heavy metals. These results contributed to an insight into key environmental variables shaping the microbial activities, community structure, and diversity under various land use types in mining area.