Urban Park Soils Research Articles

A comparative study of soil metal concentrations in Chilean urban parks using four pollution indexes

Toxic metal enrichment in urban soils from natural and anthropogenic sources is a public health concern that challenges sustainable urban development. Active and legacy mining is likely a major contributor of localized metal pollution in resource-based economies, although other sources associated with industrial and transportation activities may also contribute in urban settings. In mining countries, such as Chile, with no soil quality regulation, public policies that seek to protect human health should assess metal distribution and pollution indexes to guide interventions, especially in urban green spaces. To assess the role of active and legacy mining waste sites within the urban and peri-urban areas, metal concentrations in the soils of urban parks were measured in this study, and four pollution indexes were calculated for four cities of Chile. Copiapó and Andacollo in northern Chile represented the cities with several active and legacy mining waste sites located within the urban and peri-urban areas, while conurbation La Serena-Coquimbo and Gran Santiago represented the cities in mining districts that lacked major mining waste sites within their urban perimeters. A total of 82 (Copiapó), 30 (Andacollo), 26 (La Serena-Coquimbo), and 59 (Gran Santiago) composite surface soil samples were collected from the urban parks. Considering Canadian guidelines for residential/parkland soils, the value for Cu (63 mg/kg) was found to be exceeded in 99%, 50%, 100%, and 97% of samples collected from Copiapó, La Serena-Coquimbo, Andacollo, and Gran Santiago, respectively. The guidelines for lead (140 mg/kg) and zinc (250 mg/kg) were exceeded in less than 12% of samples collected from Copiapó and Gran Santiago. Arsenic was not mainly quantified (<10% quantification frequency, quantification limit = 36 mg/kg). The calculated modified pollution load, Nemerow, and soil quality indexes indicated that soils in the urban parks were more polluted in cities with urban mine wastes, however, the pollution load index ranked higher metal pollution in Gran Santiago. This study presented the first comparative study of metals in urban parks of Chile, highlighting a large proportion of parks with soil copper concentrations above the international guidelines, while showing higher median values in cities containing urban mine waste disposal sites.

Anthropogenic Soils of Urban Parks: A Review

Anthropogenic Soils of Urban Parks: A Review

Spatial and temporal patterns of methane uptake in the urban environment

The environmental changes associated with urbanization have a considerable impact on soil-atmosphere gas exchange, which directly affects the level of greenhouse gases in the atmosphere. At the same time, the CH4 storage in urban ecosystems can be underestimated as a result of human disturbances through land management practices, as well as climatic conditions. The primary aim of this study, therefore, was to investigate anthropogenically induced and environmental factors controlling seasonal and spatial heterogeneity of CH4 uptake under different land uses (grasslands, city park, arable lands) across the city. An attempt has also been made in estimating methane oxidation on the urban scale (Wroclaw, Poland) and quantifying its role in urban C balance in a one-year period. The soil CH4 fluxes were collected biweekly from July 2017 to August 2018, using the static chamber method and analyzed by the CRDS laser spectroscopy Picarro G2201-i system.The observations of CH4 magnitude proved that urban soil ecosystems act as the sinks for atmospheric CH4, despite large part of the city grounds are excluded from the active oxidation surface. The efficiency variability of this sink is pronounced both spatially and temporally. The significantly higher (p > 0.05) net CH4 uptake occurred in the urban park soils and grasslands (locally exceed 0.66 ± 0.17 nmol·m−2·s−1), while the consumption of methane in arable lands was about one and half times lower than on all of the sites explored. The estimated seasonal differences in CH4 uptake between study sites indicate that atmospheric exchange of CH4 in urban soils mainly depends on temperature dynamics, which reduce methane consumption by 50–80% for the summer and winter periods. Using land-cover data, the current estimates of CH4 sink in the land uses across the city of Wroclaw accounted for −45 ± 18 tones CH4 on an annual basis.

Antimony, beryllium, cobalt, and vanadium in urban park soils in Beijing: Machine learning-based source identification and health risk-based soil environmental criteria

The pollution situation of antimony (Sb), beryllium (Be), cobalt (Co), and vanadium (V) is poorly understood, although they are widely used in daily life and production processes. Moreover, threshold levels (“soil environmental criteria”, SEC) for these pollutants are lacking in China, which impedes effective soil quality management. This study explored pollution characteristics for park soils in urban area of Beijing, China at first. Then multivariate statistical analysis and machine learning model were used to identify the main sources of pollutants. Additionally, probabilistic health risk and SEC were studied to assess the risks of pollutants and manage soil pollutants. The results revealed that the overall pollution levels of Be, Co, Sb, and V were low, but Be and Sb were enriched to varying degrees. Source apportionment showed that Sb (85.5%) was mainly derived from fuel combustion and industrial legacy, Co (66.7%) and V (82.5%) from natural processes, and Be from the natural background (39.3%) and anthropogenic sources (53.8%). Risk assessment indicated that the pollutants' carcinogenic and noncarcinogenic risks were negligible. Exposure frequency and soil ingestion rate were the most important parameters affecting health risks. The SEC of Be, Co, Sb, and V were 31, 39.7, 41.3, and 348 mg/kg, respectively, all of which are higher than the corresponding soil quality standards in China, indicating that current soil quality standards may be too conservative for urban park land. This study provides a reference for the management of soil pollutants in Beijing's urban parks, and the formulation of soil environmental quality standards.

A novel method to analyze the spatial distribution and potential sources of pollutant combinations in the soil of Beijing urban parks

Organic and inorganic pollutants are often co-sedimentary in soils and have the same sources in the urban environment. The identification of the sources and distribution of combined pollutants is a basic step in risk management. In this study, the levels of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) were measured in urban park soils in Beijing. Bivariate local Moran’s I and positive matrix factorization (PMF) source apportionment were used to identify the spatial clustering patterns and potential sources of PAHs and HMs, as well as to ultimately define a pollution risk control area. The results revealed an obvious clustered distribution of PAHs and HMs in the park soils. High-high areas were defined as sites containing a complex mixture of pollutants, which were mainly located in the center and north of Beijing. High-low and low-high areas were located outside the city center but had the potential for combined pollution, and therefore require continuous attention. Bivariate local indicators of spatial association (LISA) enabled a more accurate analyses of the mechanism controlling the spatial distribution of PAH and HM combinations in urban parks. The source apportionment indicated that industrial and traffic emissions were the most important sources of the pollutant combinations in urban parks, with traffic emissions accounting for most of the pollution.

Diversity patterns and drivers of soil microbial communities in urban and suburban park soils of Shanghai, China.

BackgroundThe rapid expansion of urbanization leads to significant losses of soil ecological functions. Microbes directly participate in key soil processes and play crucial roles in maintaining soil functions. However, we still have a limited understanding of underlying mechanisms shaping microbial communities and the interactions among microbial taxa in park soils.MethodsIn this study, the community variations of bacteria and fungi in urban and suburban park soils were investigated in Shanghai, China. Real-time PCR and high-throughput Illumina sequencing were used to examine the microbial abundance and community composition, respectively.ResultsThe results showed that soil molecular biomass and fungal abundance in urban park soils were significantly higher than those in suburban park soils, while no significant difference was observed in the bacterial abundance between urban and suburban park soils. The alpha diversity of soil microbes in urban and suburban park soils was similar to each other, except for Chao1 index of fungal communities. The results of similarity analysis (ANOSIM) revealed remarkable differences in the composition of bacterial and fungal communities between urban and suburban park soils. Specifically, park soils in urban areas were enriched with the phyla Methylomirabilota and Verrucomicrobiota, while the relative abundance of Gemmatimonadota was higher in suburban park soils. Moreover, the fungal class Eurotiomycetes was also enriched in urban park soils. Compared with suburban park soils, nodes and average paths of the bacterial and fungal networks were higher in urban park soils, but the number of module hubs and connectors of the bacterial networks and negative interactions among bacterial taxa were lower. Compared with suburban park soils, Acidobacteriota bacterium and Mortierellomycota fungus played more important roles in the ecological networks of urban park soils. Soil available zinc (Zn), available nitrogen (N), pH, and total potassium (K) significantly affected fungal community composition in park soils in Shanghai. Soil available Zn was also the most important factor affecting the bacterial community composition in this study.ConclusionThere were significant differences in the soil molecular biomass, fungal abundance, and the community composition and co-occurrence relations of both soil bacterial and fungal communities between urban and suburban park soils. Soil available Zn played an important part in shaping the structures of both the bacterial and fungal communities in park soils in Shanghai.

Assessment of human health risk due to lead in urban park soils using in vitro methods

Beijing parks always have a large flow of local residents and tourists, and the soil Pb could threaten human health by incidental ingestion. Soil samples from eleven parks in Beijing were collected to assess the human health risk associated with Pb. Lead bioaccessibility in these parks ranged from 3.2 ± 0.4% to 12.1 ± 0.5% in the physiologically based extraction test (PBET) gastric phase and increased when approaching the city center. The chemical forms and soil properties (Fe, organic matter, and grain size) were important factors affecting the soil Pb bioaccessibility. The geo-accumulation index of Beihai Park (BH, near the city center) reached 1.3 ± 0.1 indicating moderate contamination. Lead health risk to children in BH should be of concern though its hazard quotient was below one. Results obtained from the Diffusive Gradients in Thin-films (DGT)-induced fluxes in the soils (DIFS) model showed that Pb-release in some parks farther from the city center was a “partially sustained case” (Rdiff < R < 0.95) indicating that soil particles could partially replenish effective Pb to the soil solution. A relatively higher desorption rate constant (k1) and shorter characteristic response time (Tc) were also found in these parks, indicating non-negligible release risk. Soil Pb based on the PBET method and DIFS model could provide a reliable reference to park managers for the health risk management of Pb pollution.

Physicochemical and microbial properties of urban park soils of the cities of Marrakech, Morocco and Toruń, Poland: Human health risk assessment of fecal coliforms and trace elements

The public green space (PGS) in urban areas presents an image of nature and its animal and plant biodiversity in the city. Due to intense urbanization in the world, pollutants such as trace elements (TE) or pathogenic microorganisms are continually emitted into the environment and pose a threat to ecosystems. The aim of this work was to assess the soil quality of PGS in the cities of Marrakech (Morocco) and Toruń (Poland) through physicochemical and microbiological approaches and to assess related health risks. Eighteen soils from the most visited historic parks in Marrakech and Toruń were sampled and analyzed. The results showed that content of Total Organic Carbon (TOC) in Toruń urban soils is about three times higher than that measured in Marrakech urban park soils. These differences are related to the naturally higher content of organic matter in the soils of temperate climate regions than in Mediterranean soils. The concentrations of trace element (TE) showed a similar trend in both cities, except for Pb in one Marrakech site, which exhibited a high concentration (400 mg Pb Kg−1 in Bab Rab Park). Soil enzymes present a high sensitivity to anthropogenic disturbances and can be used as tool to evaluate early disturbance of urban soils. The alkaline phosphatase (APHa) and urease (URa) activities are less affected by anthropogenic pressure than dehydrogenase (DHa). Slight sensitivity to TE was observed in the microbial community in the order fungi < actinomycetes < bacteria. Total and fecal coliforms (TC, FC) were present in all soil samples, with higher concentrations in Marrakech sites. Based on estimated FC risk, the highest percentage did not exceed 11% of the guideline limit set by International Commission on Microbiological Specifications for Foods. Hazard index showed no health risk for adults caused by studied TE concentrations in the park soils of Marrakech and Toruń, but potential adverse non-cancer health effects for children. Their safety depends on their own behavior and the ways by adults supervise them.

Heavy metal(loid)s in the topsoil of urban parks in Beijing, China: Concentrations, potential sources, and risk assessment

Urban parks play an important role in the urban ecosystem and are also used by residents for recreation. The environmental quality of urban park soils might influence human health following long-term exposure. To assess potential sources and pollution risks of heavy metal(loid)s in the topsoil of urban parks, we subjected metal concentrations in soil samples from 121 parks in the Beijing urban area to geostatistical analyses, conditional inference tree (CIT) analyses, ecological risk and human health risk assessment. CIT effectively explained the influence of human activity on the spatial variation and accumulation of soil metal(loid)s and identified the contributions of natural and anthropogenic inputs. The main factors influencing the accumulation of heavy metal(loid)s, including urbanization duration, park age, per capita GDP, industrial output, and coal consumption, were evaluated by CIT. Except for Cr and Ni, the average concentrations of the metal(loid)s tested (Cu, Pb, Zn, Hg, As, and Cd) were higher than the background values. In the urban parks, Ni and Cr derived mostly from soil parent materials. Concentrations of Cu, Zn, Pb, Cd, As, and Hg were strongly associated with human influences, including industrial, agricultural, and traffic activity. After assessing health and ecological risks, we conclude that heavy metal(loid)s in the soil of Beijing urban parks pose no obvious health risk to humans, and the ecological risk is also low.

Potential sources, influencing factors, and health risks of polycyclic aromatic hydrocarbons (PAHs) in the surface soil of urban parks in Beijing, China

Urban parks are an important part of the urban ecological environment. The environmental quality of parks is related to human health. To evaluate sources of polycyclic aromatic hydrocarbons (PAHs) in soils of urban parks and their possible health risks, soil samples from 122 parks in Beijing, China, were collected and analyzed. The total content of 16 PAHs between 0.066 and 6.867 mg/kg. Four-ring PAHs were predominant, followed by 5-ring PAHs, while the fraction of 2-ring PAHs was the lowest. The dominant PAHs sources were found to be coal combustion and oil fuels such as gasoline and diesel. A conditional inference tree (CIT) was used to identify the key influencing factors for PAHs. Traffic emissions was the most important factor, followed by coal consumption, as well as the history and location of the park. Incremental lifetime cancer risk (ILCR) for urban park soil in Beijing were low under normal conditions. The soil PAHs exposure pathway risk for both children and adults decreased in the following order: ingestion > dermal contact > inhalation. The risk from soil in parks to children’s health is slightly higher than that of adults, although the health risk due to exposure to PAHs was not extraordinary. Ecosystem risk was negligible.

Investigation and Analysis of Soil Radioactivity Level in Parks in a City

Using a portable microcomputer multi-channel gamma spectrometer to directly measure the radioactive content in the soil, the on-site gamma energy spectrum measurement was carried out on the soil of 7 parks in a certain city. The survey results show that the specific activity of 40k in the urban park soil ranges from 470.88 bq/kg to 640.2 bq/kg. The specific activity of 238u ranges from 26.77 bq/kg to 33.31 bq/kg. The specific activity of 232th ranges from 42.14 bq/kg to 54.72 bq/kg. The content of the three radionuclides in the soil in the park is lower than the national average, and far lower than the radioactivity of ordinary building materials.

Impact of urban green spaces, native tree species and seasons on soil pH in Kaunas, Lithuania

Tree growth is sensitive to soil pH in urban areas and is often higher than in rural forest. However, there are knowledge gaps on how soil pH and alkalization are affected by urban environments and seasonal climate as well as the cascading effects on tree species. In order to fulfill these gaps, we analyzed the soil pHCaCl of four common native deciduous tree species: Acer platanoides, Tilia cordata, Quercus robur and Betula pendula in five different types of urban green spaces in Kaunas city municipality (Lithuania). The results show that soil pH in urban environments with Betula pendula sites were most alkaline (pH 7.04), whereas the soil pH of urban environments with Acer platanoides (pH 6.7) and Tilia cordata (pH 6.8) were most acidic. The soil pH of street tree greeneries was alkaline, while soils of peri-urban forests and large urban parks were acidic. Differently to natural conditions in peri urban forests the soil pH level drop down by 0.5 is observed during spring-autumn period in broad street greeneries with largest urban pressure. The variation in soil pH of the different types of green space and tree species shows that city planner should consider the unique conditions of all green space to maximize their potential for human well-being.

Fungal community composition analysis of 24 different urban parks in Shanghai, China

Urban parks are an important constituent of cities; they harbour microbial diversity which plays a key role in soil ecosystem functioning. The bacterial diversity of many urban parks around the world has been reported; however, the role of fungi is often ignored. There are only one or two published reports of fungal community composition analysis from urban parks. In the present study, we investigated soil fungal diversity in 24 urban parks in Shanghai using Illumina MiSeq sequencing. At the taxonomic level, 540,657 effective fungal sequences were acquired from the soil from 24 urban parks. Other than some unclassified phyla, the operational taxonomic units (OTUs) collected from all 24 urban park soils were distributed into five fungal phyla; of these, Ascomycota was the most dominant phylum, followed by Zygomycota and Basidiomycota. Many fungi identified in the present study are known to play key roles in the environment, with particularly important roles in maintaining sustainability in the soil ecosystem. The identified mycorrhizal fungi may play a major role in the biogeochemical cycle, as these fungi obtain carbon from their host plants and allocate it to the soil ecosystem; they also participate in mineralisation of various inorganic substances, helping with the growth of plants.

Современное состояние урбаноземов в ядре агломерации Баку

This article presents the results of studies the soils of urban parks, gardens, roadside zones in the core of the agglomeration of Baku. The urban soils were studied as indicators of the ecological status of the city of Baku. The impact of soil condition on the green areas in seven districts of Baku has been evaluated.

Chemical characterization of urban park soils of the metropolitan region of São Paulo

In the last years, urban soils have been increasingly subject of investigations concerning their description and composition. In several important cities all over the world, urban soils show a significant increase in metal levels, due to the rise of pollution originated from continuous urbanization and industrial development. This metal contamination can disturb the natural geochemical cycles and their depending ecosystems. The expected population growth during the next decades will concentrate in urban areas, which are already the predominant human habitat. Metal contamination is a key issue in São Paulo City, the biggest urban agglomeration in Latin America. There has been little research on metal levels in São Paulo urban soils and almost nothing related to the city’s parks. The present study presents the concentration of major and trace elements in soil samples of nine parks of the metropolitan region of São Paulo. Top soil samples (0-20 cm) were collected in lines across the parks in order to have representative samples of the entire park. Instrumental Neutron Activation Analysis (INAA) and X-ray Fluorescence (XRF) were used for whole elemental analysis. The outcome of this study showed that the soils of the public parks studied presented, in general, concentration levels higher than the reference values for soils in São Paulo State. For As, V and Ni, which showed significant enrichment factors in relation to reference values, there is an indication of anthropogenic source. Cluster analysis grouped the elements Zn, Sb, Pb and Cu, well known as traffic-related elements, which may indicate a vehicular source.

Assessment of phytotoxicity, environmental and health risks of historical urban park soils

Urban soil areas can be contaminated with potentially dangerous heavy metals (HM), which might have got there by means of the human activity. The aim of the present study was to determine the contamination level of the city park soils and its impact on urban ecosystem. The indices assessing soil contamination such as Enrichment Factor (EF), Geoaccumulation Index (Igeo), Nemerow Pollution Index (IPIN), and indices assessing health risks, namely Hazard Index (HI) and Carcinogenic Risk (CR), have been calculated. Furthermore, the phytotoxic effect of the soil samples has been determined. The soil contains in average 58.6 mg/kg Zn, 0.3 mg/kg Cd, 27.2 mg/kg Pb and 16.6 mg/kg Cu. Based on EF index, it has been confirmed that the increased amounts of Zn, Cd and Pb in the soil are of the anthropogenic origin. The soil may be classified as moderately to strongly polluted in the case of Zn and Pb according to Igeo. Nevertheless, soil contamination in the park is at a safe level as per IPIN. Based on HI and CR indices, it is possible to state that the soil in the park does not pose any health risks. Subject to the outcomes of the toxicity test, the concentrations of HMs found out in the soils are not inhibitory for plants.

The orthographic effects (word spelling) on the perception, production, and learning of spoken words in a second language

The total concentrations, fractionation of metals and human health risk in surface-exposed lawn soils from 18 urban parks in Guangzhou were investigated. Cd was predominantly associated with the acid-soluble fraction and Pb mainly with the reducible fraction, whereas Cr, Ni, Cu, and Zn were strongly associated with the residual fraction. The hazard indices for the metals were <1, indicating that exposure to the urban park soil does not pose significant risks of non-carcinogenic effects from the metals analyzed. The probabilities of Cd, Cr, and Ni posing carcinogenic risks to children and adults were negligible (probability <1 × 10−6).

Increased copper levels inhibit denitrification in urban soils

ABSTRACTThe consequences of urbanisation for Earth's biogeochemical cycles are largely unexplored. Copper (Cu) in urban soils is being accumulated mainly due to anthropogenic activities under rapid urbanisation. The increasing Cu concentrations may contribute to altering soil nitrogen (N) cycling in urban ecosystems through modulating denitrification processes. This research aims to identify how Cu impacts urban soil denitrification functions and denitrifier abundance. An urban park soil with a background total Cu concentration of 7.9μgg–1 was incubated anaerobically with different Cu amendments (10, 20, 40, 80 and 160μg Cu g–1 soil), similar to prevalent Cu contents in urban soils. We evaluated the soil denitrification functions using the acetylene (C2H2) inhibition method and assessed the denitrifier abundance by quantitative polymerase chain reaction (qPCR) analyses of denitrifying marker genes (nirK, nirS and nosZ). At the function level, we observed that both the potential soil denitrification activity and the N2O emission rate due to denitrification were significantly (P&lt;0.05) inhibited by Cu; even the lowest Cu addition (10μg Cu g–1 soil) drastically affected the denitrification function. Moreover, Cu significantly (P&lt;0.05) decreased the abundance of nirK and nirS genes at the additions of 160μg Cu g–1 soil and 40μg Cu g–1 soil, respectively, whereas it had no clear impact on nosZ gene copies. Further correlation analyses revealed that the potential denitrification activity was positively correlated to the copy numbers of nirK and nirS genes, but it was not correlated to nosZ gene abundance. These findings indicate that Cu additions inhibited soil denitrification function and decreased denitrifier abundance in the investigated urban park soil. Our results suggest that Cu accumulation in urban soils, resulting from urbanisation, may generally influence denitrification in urban ecosystems.

Composition and functional genes analysis of bacterial communities from urban parks of Shanghai, China and their role in ecosystem functionality

Urban park soil plays a vital part in urban ecosystems, which harbor a considerable microbial diversity. Those microbes regulate soil fertility, plant health, and biogeochemical cycling. The existing studies have hardly focused on microbial diversity from urban parks, especially from China. As Shanghai, the largest city of China has experienced extensive urbanization, the present study focused on bacterial community compositions and their functional genes collected from 24 urban parks soils to ensure soil health and microbial sustainability of major parks of this city. To elucidate the bacterial communities from all 24 urban parks, soils were analyzed by sequencing V3-V4 region of the 16S rRNA gene using Illumina MiSeq. At the taxonomic level, 12,67,055 16S rRNA gene sequences were secured from all the soil samples. Out of 43 classified phyla, all the urban park soils had higher relative abundances of Proteobacteria and Acidobacteria accounting for 33.01–45.49 and 18.7–30.12%, respectively. A total of 6909 bacterial functional genes showing high functional gene diversity for essential biogeochemical processes (including carbon, nitrogen, phosphorus and sulfur cycles) exist in Shanghai urban parks that could be helpful in maintaining fertility of park soils and thus greenery of city. This is the first extensive report on soil microbial diversity from urban parks of China. Our results provide a foundation or a guideline to urban planners and to compare future research related to urban parks soil biodiversity and ecosystem function.

Molecular and Biological Differences Among Ochroconis Strains Collected from Indoor and Outdoor Environments.

The molecular, morphological, and physiological characters of 55 Ochroconis strains collected from indoor and outdoor environments were studied. In Japan, Ochroconis species are often found in indoor detergent-rich environments, such as bathrooms and washing machines, and the predominant species have been identified as O. humicola, similar to that in other Asian and European countries. Although Ochroconis species have rarely been found in outdoor environments such as mountains, forests, and agricultural fields, in the present study, Ochroconis strains were specifically isolated from the soils of urban city parks. Phylogenetic analysis conducted using the 28S ribosomal RNA (28S rDNA) gene sequence showed that almost all of the Ochroconis strains found in indoor environments (i.e., water supply) were O. humicola. Although city parks were often surrounded by residences, more than half of the Ochroconis strains collected from the soils of city parks examined in this study were different Ochroconis species. The ability to use detergents as nutrients was found in a new genetic group (probably a new species) isolated from the soils of city parks as well as in O. humicola and O. constricta. Ochroconis humicola is assumed to adapt mostly to indoor environments and to penetrate from the outdoors, e.g., soils of urban areas. To elucidate the factors promoting indoor fungal predominance, the ability of using surfactants as nutrients was compared among these three species. Additionally, growth under alkaline and drought conditions, and heat tolerance were examined. Indoor predominance of O. humicola compared to that of the other two species was attributed to the ability of using a non-ionic surfactant as nutrient and to growth under alkaline conditions.