Anthropogenic Soil Research Articles

Effects of cadmium toxicity on the physiology and growth of a halophytic plant, Tamarix usneoides (E. Mey. ex Bunge)

Heavy metal polluted soils can be remediated using plants, a process called phytoremediation. However, high concentrations of heavy metals can negatively affect plant physiology and growth. We experimentally evaluated the effects of cadmium (Cd) on the growth, (i.e. height, shoot and biomass) and physiology (i.e. leaf chlorophyll and relative water contents) of Tamarix usneoides. In a greenhouse experiment, T. usneoides clones were subjected to a once off treatment of 100 mmol/l NaCl with three different Cd concentrations (6, 12, and 18 mg/kg) applied 3 times/week for eight weeks. We predicted that plant health would decrease with an increase in Cd concentration. Results revealed a 35.9% reduction in chlorophyll content between the 18 mg/kg Cd treated plants and the control, suggesting that T. usneoides experienced a reduction in photosynthetic rate, which in turn influenced the growth and relative water content (RWC) of the plant. Although T. usneoides’ growth and physiology were significantly decreased at 12 and 18 mg/kg Cd concentrations, the plants tolerated up to 6 mg/kg Cd concentration, a level found in most anthropogenic Cd-contaminated soils. Tamarix usneoides should thus be confirmed as a good phytoremediation candidate once its ability to extract, translocate and concentrate Cd has been determined.

Pseudo-total antimony content in topsoils of the Berlin Metropolitan Area

PurposeSb is a metalloid that naturally occurs in traces in the Northern German Lowland Area, only. Its frequent and still growing demand for industrial purposes and its release during coal combustion and by vehicular emissions lead to an enrichment of Sb in topsoils. Numerous analyses on heavy metals have been conducted in the urban environment so far, but although Sb can be ecologically harmful and potentially carcinogenic, only few studies on Sb in soils were carried out.Materials and methodsDue to the formation of anthropogenic soils by men, especially in the course of industrialization and after World War II, more than 50% of the Berlin soils consist of anthropogenic material like redeposited natural material, debris, waste, or ashes. This composition of soils of the Berlin Metropolitan Area can function as a model for other metropolitan regions of Central Europe. In the urban and peri-urban area of Berlin, analysis of more than 900 topsoil samples has been performed measuring the content of 12 heavy metals and metalloids (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, and Zn). As a reference for the natural environment, soil profiles of typical parent rock material have been investigated taking also the regional (0.3 mg/kg), the local background value (0.61 mg/kg), and the baseline value (0.07 mg/kg) for Sb into account.ResultsBy doing so, we could show the spatial distributional pattern of Sb in the Berlin Metropolitan Area and statistically evaluate our results in dependency of land-use, parent material, and soil parameters such as organic carbon content and pH. Thereby, we could prove an average enrichment two to six times over the regional background value. Median Sb content is very low in forest topsoils (0.54 mg/kg) and reaches its maximum in roadside soils (1.75 mg/kg). Technogenic materials, vehicular emissions, industrial processes, and (former) land-use are the predominant factors for Sb enrichment and distribution in the study area. Some single samples show an enrichment of up to 600% of the regional background value for topsoils.ConclusionOur study revealed that the Sb content in the Berlin Metropolitan Area is elevated compared to natural environments. Furthermore, we could demonstrate that Sb is a previously neglected key pollutant, specific to metropolitan areas. Due to the high environmental relevance, further Sb data from selected investigated spaces in other metropolises and specific land-use types are needed to assess the potential environmental risk of Sb in metropolitan areas.

Map of Anthropogenic Soil Erosion of Russia

The last map of anthropogenic soil erosion in Russia was compiled more than 20 years ago on a scale of 1 : 5 000 000. In recent years, additional data on soil erosion have been accumulated. New mapping approaches have appeared that enable us to present more detailed digital data at the country level. The geometric part of the Unified State Register of Soil Resources of Russia (on the initial scale of 1 : 2 500 000) (USRSRR) was used as the basis for map updating. Information on soil erosion was read from the old erosion map for each delineated soil area of the USRSRR. Then it was expertly analyzed and corrected, using the data on soil properties in each soil mapping unit. After that, the information on anthropogenic soil erosion was corrected based on the soil plowing map of Russia and the map of pastures. At the last stage, additional data obtained over the past twenty-year period were entered into the database. The updated map is presented in a GIS format (shapefile). The map contains information on the distribution of soils disturbed as a result of water and anthropogenic erosion.

Soil solution in Swiss forest stands: A 20 year's time series.

Soil solution chemistry is influenced by atmospheric deposition of air pollutants, exchange processes with the soil matrix and soil-rhizosphere-plant interactions. In this study we present the results of the long-term Intercantonal Forest Observation Program in Switzerland with soil solution measurements since 1998 on a current total of 47 plots. The forest sites comprise two major forest types of Switzerland including a wide range of ecological gradients such as different nitrogen (N) deposition and soil conditions. The long-term data set of 20 years of soil solution measurements revealed an ongoing, but site-specific soil acidification. In strongly acidified soils (soil pH below 4.2), acidification indicators changed only slowly over the measured period, possibly due to high buffering capacity of the aluminum buffer (pH 4.2-3.8). In contrast, in less acidified sites we observed an increasing acidification rate over time, reflected, for example, by the continuous decrease in the ratio of base cations to aluminum (BC/Al ratio). Nowadays, the main driver of soil acidification is the high rate of N deposition, causing cation losses and hampering sustainable nutrient balances for tree nutrition. Mean nitrate leaching rates for the years 2005-2017 were 9.4 kg N ha-1 yr-1, ranging from 0.04 to 53 kg N ha-1 yr-1. Three plots with high N input had a remarkable low nitrate leaching. Both N deposition and nitrate leaching have decreased since 2000. However, the latter trend may be partly explained due to increased drought in recent years. Nonetheless, those high N depositions are still affecting the majority of the forest sites. Taken together, this study gives evidence of anthropogenic soil acidification in Swiss forest stands. The underlying long-term measurements of soil solution provides important information on nutrient leaching losses and the impact climate change effects such as droughts. Furthermore, this study improves the understanding of forest management and tree mortality regarding varying nitrate leaching rates.

Actualization of the contents of the soil map of Russian Federation (1 : 2.5 M scale) in the format of the classification system of Russian soils for the development of the new digital map of Russia

The Soil Map of the Russian Federation, 1 : 2.5 M scale (1988) requires updating to include soil data that have been accumulated in the past decades, reflect real changes in the soil cover, including anthropogenic transformation, and ensure precise localization of soil objects and correspondence of the map to satellite data with the use of digital soil mapping technologies. The substantive-genetic classification system of Russian soils (2004, 2008) provides the conceptual basis for this updating. The conversion of soil information from the initial map of 1988 into the new classification system is being performed for each polygon of the digitized map. It is based on the analysis of a vast body of diverse information and includes both the search for analogues of the names of mapping units in the new classification system (renaming of the soils) and the correction of the composition of soils in the polygons: new natural soils, cultivated soils (agrosoils), and urban soils are added to the attribute database. The largest number of new natural soils has appeared in legend sections “Soils of tundra” and “Soils of taiga and broadleaved forests”. Anthropogenic soils (119 legend units) that are shown on the map for the first time, have their maximum representation (36 units) in the section “Soils of steppes”; it is close to the number of natural soils (37 units) in this zone. A considerable percent of anthropogenic soils (> 50% of the natural soils) is also typical of legend sections “Soils of broadleaved forests and forest-steppes,” “Soils of dry steppes and semideserts,” “Salt-affected and solonetzic soils”. The total number of natural and anthropogenic soil units (425) in the new legend is more than twice as large as the initial number of natural soil units in the base map (205). The results of the renaming and updating of soils for each soil polygon are fixed in a separate section of the attribute database to the map and will be used for generating the new map by the methods of digital soil mapping.

Trait-based aerial dispersal of arbuscular mycorrhizal fungi.

Dispersal is a key process driving local-scale community assembly and global-scale biogeography of plant symbiotic arbuscular mycorrhizal (AM) fungal communities. A trait-based approach could improve predictions regarding how AM fungal aerial dispersal varies by species. We conducted month-long collections of aerial AM fungi for 12 consecutive months in an urban mesic environment at heights of 20 m. We measured morphological functional traits of collected spores and assessed aerial AM fungal community structure both morphologically and with high-throughput sequencing. Large numbers of AM fungal spores were present in the air over the course of one year and these spores exhibited traits that facilitate aerial dispersal. Measured aerial spores were smaller than average for Glomeromycotinan fungi. Trait-based predictions indicate that nearly 1/3 of described species from diverse genera demonstrate the potential for aerial dispersal. Diversity of aerial AM fungi was relatively high (20 spore species and 17 virtual taxa) and both spore abundance and community structure shifted temporally. The prevalence of aerial dispersal in AM fungi is perhaps greater than previously indicated and a hypothesized model of AM fungal aerial dispersal mechanisms is presented. Anthropogenic soil impacts may liberate AM fungal propagules initiating the dispersal of ruderal species.

Anthropogenic Invasion of Micromycetes to Undisturbed Ecosystems of the Larsemann Hills Oasis (East Antarctica)

The Progress Station is the largest Russian Antarctic station. The anthropogenic impact on primary soils in the area of this station is reflected in the chemical structure of soils and structure of microbial communities. The article shows a multiple increase in the number of microorganisms (especially microscopic fungi) in contaminated soils around the Progress Station. The anthropogenic impact changes the structure of complexes of soil microorganisms. The proportion of mesophilic microorganisms significantly increases under these conditions. Fifty-three micromycete species of 28 genera have been identified in samples of primary soils and anthropogenic substrates. Their diversity decreases from the anthropogenic soils and anthropogenic substrates to the control (“clean”) soils. It is shown that an increase in the number of micromycete species in the area of the polar station results from the invasion of new micromycete species due to human activities. Some native species of micromycetes can adapt to anthropogenic substrates and can be destructors of different introduced materials. Over 56 and 70% among micromycetes from the contaminated soils and anthropogenic substrates, respectively, can be considered potentially pathogenic species. Therefore, invasive processes change the structure of complexes of soil micromycetes, which can serve as an indicator of anthropogenic impact on ecosystems in the Larsemann Hills oasis in East Antarctica.

Soil fauna of cut and burnt forest areas in the Khibiny Mountains

In the framework of monitoring the restoration of anthropogenic disturbed soil cover and its invertebrates fauna in the polar mountains, a study of pine forest cut and burnt forest areas have been conducted in the inter-mountain valley of the Khibiny Mts. Changes of edaphic factors that determine the diversity and abundance of soil fauna were revealed five years after exposure the fire: decrease of soil pH (from 3.8 to 4.2), and content of total carbon and nitrogen, and a steady increase of humidity in the upper soil horizon in the felling and in the burned pine forest. In soil samples at four sites, representatives of 20 taxonomic groups of invertebrates have been taken into account, with greater diversity and minimal numbers in the burnt pine forest. A significant reduction of soil fauna number has been detected as a result of all types of anthropogenic impact, with insignificant differences in this parameter between disturbed sites (burnt pine forest, forest cutting, and burnt forest cutting). In a pair of control pine forest and a burnt pine forest an increasing differences in the structure of the soil fauna has been revealed in comparison with the study of these territories in 2015 or two years after a ground fire. The importance of a vegetation layer confirmed for preserving the soil fauna and maintaining the hydrothermal regime favorable for its recovery. The attraction of light- and thermophilic species of ground beetles and staphylinids, which are not typical for Khibiny Mts has been revealed on the burning felling and burning pine forest. Thus, burnt territories enrich the local fauna of this Polar Mountain Massif and the fauna of the Murmansk region as a whole.

Buried soils as archives of paleo-pollution in the North China Plain

Abstract Ancient soils contain geochemical signatures of human land use, making them usable as a “golden spike,” or globally synchronous marker, to identify traces of the early “Anthropocene.” This article examines the sedimentary record in northern China to determine when, and under what cultural circumstances, did ancient pollution appear in buried soils and sediments. Using methods of Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Local Enrichment Factor (LEF), we analyzed the elemental geochemistry of soil and sediment samples (n = 333) that span the Holocene from three rural sedimentary sequences in Henan Province. We compared results to geochemical data from a 2000-year sequence of urban occupation from the nearby city of Kaifeng. We expected to find higher concentrations of heavy metals in anthropogenic soils at both rural and urban locations, as pollution from human activities intensified as a result of pre-modern industrialization around 1000 BP. Instead, ancient soils in rural contexts are moderately enriched (LEF ≈ 6) in several metals (arsenic, barium, zinc, and lead) starting around the Bronze Age (ca. 4000−3000 BP). Additionally, after 1000 BP, most soils show no significant enrichment. At the urban site of Kaifeng, ancient soils have heavy metal concentrations (zinc and lead) an order of magnitude greater than the rural sites. This study showed that, while anthropogenic soils are sinks for ancient pollution, they contain a signature that must be understood within a localized geochemical context. Anthropogenic soils are therefore a useful proxy for defining the geographic extent, and thus the patchiness, of ancient human land use activities, rather than a “golden spike” of the early “Anthropocene.”

Mapping of urban environmentally sensitive areas in Bratislava city

Environmentally sensitive areas within urban environment (U-ESA) play an essential role in maintaining urban ecological balance and ecological safety. The aims of our study were to analyse and evaluate the U-ESA spatial distribution in Bratislava city, in terms of the impact of sealed area, soil quality and urban green areas infrastructure as well as the occurrence of urban heat island in the summer months. These phenomena significantly reduce the ecological functions and ecosystem services of urban soils and can result in negative affect of the living standard and health condition of urban population. The methodology for assessing U-ESA is based on a multi-criteria process in which the following parameters have been identified and synthesized: pedo-urban complexes and their quality, urban heat island (UHI) areas and spatial distribution of urban vegetation types. Pedo-urban complexes (soil units including sealing areas, land use and soil degradation forms) were classified according to WRB. Georeferenced databases and maps became the basis for the identification of parameters involved within identification of U-ESA. Several partial products were compiled: vectorized land cover/land use categorized according to the Extended Nomenclature Urban Atlas 2012, database of pedo-urban complexes, modelled urban heat island map and map of urban vegetation types. Overlaying and synthesis of these partial results confirm thesis that sealed surfaces are one of the main causes of the increased incidence urban heat islands, but not entirely. The resulting U-ESA, designed areas in Bratislava, which are under increased risk in terms of quality of living standards. The key point of the research in the future is to find assessment of the soil quality in urbanized areas. We assume that the assessment should be based on ecosystem functions of pedo-urban complexes, i.e. anthropogenic soils. The identification of the U-ESA can be used for solving of housing comfort and quality of living standards in the frame of urban development and balanced spatial urban planning.

A comparative assessment of the estimates of the saturated hydraulic conductivity of two anthropogenic soils and their impact on hydrological model simulations

In this study, different methods were compared in order to determine the soil hydraulic conductivity at the saturation (K<sub>s</sub>) of two heavily anthropized soils in northern Italy: an irrigated field and a landfill cover. In situ, laboratory measurements (falling head and evaporation method) and pedotransfer functions (ROSETTA and HYPRES) were used for the K<sub>s</sub> estimation. In accordance with scientific literature, the results have shown that K<sub>s</sub> is largely dependent on the type of technique used in taking the measurements. The ROSETTA and HYPRES pedotransfer functions show quite similar performances, while their easiness and convenient use make them potential alternative techniques for the K<sub>s</sub> estimation in comparison with the in situ and laboratory measurements. The K<sub>s</sub> estimate is sensitive to the selected method and this sensitivity affects the hydrological model simulations. Therefore, none of the tested methods can be considered as a benchmark, but the results found in this study confirm that the applied method for the determination of K<sub>s</sub>, may provide a first estimate of K<sub>s</sub> to be subsequently optimised after the simulations.

Geotechnical Properties of Anthropogenic Soils in Road Engineering

The construction of a roads network consumes high amounts of materials. The road materials are required to fulfill high standards like bearing capacity and low settlement susceptibility due to cyclic loading. Therefore, crushed aggregates are the primary subbase construction material. The material-intensity of road engineering leads to depletion of natural resources, and to avoid it, the alternative recycled materials are required to be applied to achieve sustainable development. The anthropogenic soils (AS), which are defined as man-made unbound aggregates, are the response to these requirements. For the successful application of the AS, a series of geotechnical laboratory and field tests were conducted. In this article, we present the set of 58 test results, including California Bearing Ratio (CBR) bearing capacity tests, oedometric tests, and cyclic CBR tests, to characterize the behavior of three AS types and to compare its reaction with natural aggregate (NA). The AS tested in this study are recycled concrete aggregate (RCA), fly ash and bottom ash mix (BS), and blast furnace slag (BFS). The results of the tests show that the AS has similar characteristics to NA, and in some cases, like compression characteristic, RCA and BFS behave a stiffer response to cyclic loading. The test results and analysis presented here extend the knowledge about AS compressibility and AS response to cyclic loading.

Attribution analysis for water yield service based on the geographical detector method: A case study of the Hengduan Mountain region

Ecosystem services, which include water yield services, have been incorporated into decision processes of regional land use planning and sustainable development. Spatial pattern characteristics and identification of factors that influence water yield are the basis for decision making. However, there are limited studies on the driving mechanisms that affect the spatial heterogeneity of ecosystem services. In this study, we used the Hengduan Mountain region in southwest China, with obvious spatial heterogeneity, as the research site. The water yield module in the InVEST software was used to simulate the spatial distribution of water yield. Also, quantitative attribution analysis was conducted for various geomorphological and climatic zones in the Hengduan Mountain region by using the geographical detector method. Influencing factors, such as climate, topography, soil, vegetation type, and land use type and pattern, were taken into consideration for this analysis. Four key findings were obtained. First, water yield spatial heterogeneity is influenced most by climate-related factors, where precipitation and evapotranspiration are the dominant factors. Second, the relative importance of each impact factor to the water yield heterogeneity differs significantly by geomorphological and climatic zones. In flat areas, the influence of evapotranspiration is higher than that of precipitation. As relief increases, the importance of precipitation increases and eventually, it becomes the most influential factor. Evapotranspiration is the most influential factor in a plateau climate zone, while in the mid-subtropical zone, precipitation is the main controlling factor. Third, land use type is also an important driving force in flat areas. Thus, more attention should be paid to urbanization and land use planning, which involves land use changes, to mitigate the impact on water yield spatial pattern. The fourth finding was that a risk detector showed that Primarosol and Anthropogenic soil areas, shrub areas, and areas with slope <5° and 25°–35° should be recognized as water yield important zones, while the corresponding elevation values are different among different geomorphological and climatic zones. Therefore, the spatial heterogeneity and influencing factors in different zones should be fully considered while planning the maintenance and protection of water yield services in the Hengduan Mountain region.

Robust DNA protocols for tropical soils

Studies in the Amazon are being intensified to evaluate the alterations in the microbial communities of soils and sediments in the face of increasing deforestation and land-use changes in the region. However, since these environments present highly heterogeneous physicochemical properties, including contaminants that hinder nucleic acids isolation and downstream techniques, the development of best molecular practices is crucial. This work aimed to optimize standard protocols for DNA extraction and gene quantification by quantitative real-time PCR (qPCR) based on natural and anthropogenic soils and sediments (primary forest, pasture, Amazonian Dark Earth, and várzea, a seasonally flooded area) of the Eastern Amazon. Our modified extraction protocol increased the fluorometric DNA concentration by 48%, reaching twice the original amount for most of the pasture and várzea samples, and the 260/280 purity ratio by 15% to values between 1.8 to 2.0, considered ideal for DNA. The addition of bovine serum albumin in the qPCR reaction improved the quantification of the 16S rRNA genes of Archaea and Bacteria and its precision among technical replicates, as well as allowed their detection in previously non-amplifiable samples. It is concluded that the changes made in the protocols improved the parameters of the DNA samples and their amplification, thus increasing the reliability of microbial communities’ analysis and its ecological interpretations.

Biosolids amendments improve an anthropogenically disturbed urban turfgrass system

AbstractRehabilitating anthropogenically disturbed soils is vital to restore soil functionality and improve plant growth. Biosolids can be used to improve such soils and increase soil organic C (OC) stocks, but repeated applications of such organic byproducts may result in excess soil P. Here, we present further data that complete the observations for a 5‐yr study (September 2013–October 2018) conducted on an anthropogenic soil tall fescue (Festuca arundinacea Schreb.) system. This study compared the effects of irrigation strategies (with or without irrigation during summer heat stress) and soil amendments (annual applications of biosolids products and a conventional synthetic fertilizer) for improving soil properties and tall fescue health. Biosolids amendments applied at the agronomic N rate (ANR) reduced soil bulk density at the 0‐ to 5‐cm depth by 33–53% and at the 5‐ to 10‐cm depth by 4–9% relative to synthetic fertilizer. Soil OC in the top 10 cm increased from 1.74 to 13.6 g OC kg−1 (i.e., +682%) over the 5‐yr period for the conventionally fertilized tall fescue, and larger gains were observed in the biosolids treatments. Repeated applications of biosolids amendments at the ANR increased total P concentrations; however, biosolids containing high Fe concentrations did not increase water‐soluble P compared with biosolids applied at the agronomic P rate (APR) and synthetic fertilizer after 5 yr. Biosolids amendments applied at the ANR improved tall fescue visual quality (maintained acceptable quality 86–92% of the time), clipping biomass, and leaf tissue N accumulation (P &lt; .05).

Anthropogenic Signatures in the Context of Landscape Evolution: Evidence from Citanduy Watershed, Java, Indonesia

The impact of humans on landscapes may differ across regions because anthropogenic intervention on the respective landscapes occurs in different human-induced contexts. This study was designed to assess the human-induced landscape evolution of the Citanduy Watershed, Java, Indonesia, and determine its anthropogenic signatures. Several approaches were used, namely anthropogenic landscape identification, anthropogenic soil development, sediment analysis, and monitoring of changes to Segara Anakan lagoon at the mouth of the Citanduy Rier. Five types of anthropogenic landscapes were observed in the research area, from a slightly modified landscape to a fully anthropogenic landscape. The anthropogenic signature was also found in the sediment of the lagoon. Present and recent environmental evolution of the lagoon was reconstructed based on series changes in the lagoon area. This reconstruction was then linked to the governmental program and anthropogenic intervention to reveal the complexity of the human-induced landscape evolution. Anthropogenic phenomena were found to strongly influence the evolution of Segara Anakan lagoon, as recorded approximately through three phases of its evolution: 1) natural processes occurring continuously until 1960, 2) human-induced landscape evolution, the boundary of which occurred in 1960–1980, and 3) the recent anthropogenic evolution that has existed since 1980.

Прошлое и будущее обработки почвы под зерновые культуры

Abstract. The purpose of the research is to show and explain why it is impossible to eliminate anthropogenic soil compaction and reduce the dependence of crop productivity on the weather conditions of the growing season with the help of first-generation soil cultivation technologies. Methods. To achieve this goal, the analysis of the impact of the results of the application of first-generation technologies on the yield of cultivated crops. On the basis of which, with the help Of the theory of solving inventive problems, the laws of creating second-level technologies are developed and the directions of their implementation are determined. The scientific novelty lies in the development of a new direction of improving the technology of soil cultivation for crops. Results. It is established that the creation of the first generation of technologies took place on the “layer-plane” principle, implemented according to the scheme “deep-less deep-very shallow”. Given that plants for maximum productivity does not need any specific soil density, and requires an optimal combination of density and moisture regime, this led to a chronic predisposition of the first generation technologies to anthropogenic soil compaction and complete dependence of crops on current weather conditions. It is possible to eliminate the specified lacks at transition to technologies of the second level. By abandoning today's “horizontal” principle of minimizing processing, and moving to minimize the “vertical”, when not all the area of the field will be processed to the same depth and with the same intensity. In practice, this is realized by dividing the entire area of the field into many micro plots, each of which creates a soil density that provides maximum yield under a particular regime of moisture. Mutual influence and addition of sites to each other reduces the overall dependence of crop yield on weather conditions of the growing season. The increase in barley yield is up to 11 % compared to the technology based on plowing and up to 20 % compared to the minimum processing. Spring wheat, respectively: 15 % and 23 %.

Natural and Anthropogenic Soils of the Polar–Alpine Botanical Garden (Kirovsk)

Natural and Anthropogenic Soils of the Polar–Alpine Botanical Garden (Kirovsk)

Pollution Indices as a Tool for the Assessment of Heavy Metals in Soil of Automobile Workshops in Benin City

Soil contamination by heavy metals is increasing day by day. In this study, pollution indices which include geo-accumulation index (I-geo), enrichment factor (EF), environmental risk factor (ERF), contamination factor (CF), degree of contamination (CD), contamination/pollution index (C/PI) and pollution load index (PLI) among others were used. The City was divided into four zones; Northwest (NW), Northeast (NE), Southwest (SW) and Southeast (SE). The average total levels of heavy metals in soil samples analyzed in SE, SW, NE, NW and control were 143.1, 118.6, 129.1, 143.3 and 0.85 mg/kg respectively. The levels of Cd in soils from all the zones were greater than the target values. The results of the I-geo ranged between highly polluted to very highly polluted. The CF showed very high level of contamination for all the heavy metals in all the zones. The C/PI values were less than 1 (contamination range) for all the heavy metals in all zones except for Cd which was greater than 1 (pollution range) in all zones. The negative values of ERF recorded for all the metals in all zones implied that the heavy metals analyzed may present potential environmental threat. The PLI values were 331.08, 313.12, 287.54 and 313.86 for NW, NE, SW and SE respectively. This study revealed that automobile workshop is one of the major sources of anthropogenic soil pollution in Benin City and its environs. Keywords : Automobile Workshop, Heavy Metals, Pollution Indices and Soil. DOI: 10.7176/CMR/12-4-04 Publication date: April 30 th 2020

Anthropogenic Soils of Botanical Gardens: A Review

A review of publications on soils of botanical gardens forming in different landscape conditions and approaches to their classification is presented. Transformation of the soil profiles—the appearance of new horizons and features, acceleration or deceleration of pedogenetic processes, and, under conditions of intensive soil formation, relatively rapid disappearance of anthropogenic features—are noted for the soils of botanical gardens. Differentiation of the soil properties (pH, humus content, composition of the soil adsorption complex, nutrient content, etc.) within a given garden is due to differences in the duration of the anthropogenic impact on soils, land use history, introduced plants, soil and soil management. However, some general patterns of changes in the chemical properties of soils of botanical gardens relative to their natural background analogues can be identified. Soils of botanical garden are characterized by an increase in the humus content; the relative intensity of humus accumulation gains maximum in the botanical gardens of northern territories (the Bol’shoi Solovetskii Island, St. Petersburg); minimum differences with natural soils are observed in soils of the Mediterranean region and humid subtropics. The share of humic acids in the composition of humus also increases. The soil pH shifts towards higher values, especially in forest soils of the temperate and subtropical zones. The content of available nutrients (phosphorus and, sometimes, potassium) becomes higher. The diversity of the factors of anthropogenic influence on the soils of botanical gardens predetermines the diversity of their profiles. These soils combine the features of agrogenic soils (owing to their loosening and application of fertilizers), urban soils (owing to the application of various materials containing anthropogenic inclusions), and natural soils. According to the classification system of Russian soils, soils of botanical gardens can be classified the within the groups of agro-natural soils (agrosoils), agrozems, and agrostratozems; often, they belong to urbi-stratified subtypes of these and other soils.