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Human activities cause modifications of the soil characteristics, leading to a significant reduction of the soil fertil- ity and quality. The aim of this study was to evaluate the relationships between microbial activity or biomass and chemical char- acteristics (i.e. heavy metal and organic matter contents) of a degraded urban soil. The study area is located in an urban park (about 10 ha, called Quarantena) near to the Fusaro Lake of Campi Fle- grei (Southern Italy); the Park was established in 1953 to shelter animals coming from any place of the Planet and execute veterinary checks before their delivery to different European zoos. In 1997, the park was abandoned and nowadays in it a large amount of urban wastes accumulates. Surface soils (0-10 cm) were sampled at three points: two of them covered by Holm Oak specimens (P1 and P2) and one covered by herbaceous species, particularly legumes (P3). P1 was localized at the border of the park and next to a busy road; P2 at the centre of the Quarantena Park; P3 at a gap area near the Fusaro Lake. The results showed that the soil sampled at P1 showed the highest Cr and Ni concentrations; the soil sampled at P3 had high levels of Cu and Pb, exceeding the threshold values of 100 μg g-1 d.w. fixed by the Italian law for urban soils, probably due to boat traffic, fishing practice and agricultural activities; the soil sampled at P2 had interme- diate values of metal concentrations but the highest amount of organic matter (more than 20% d.w.). Despite of metal contamination, P1 and P3 showed higher soil microbial biomass and activity as compared to P2. Therefore, at this site, the organic matter accumulation could be due to the scarce litter degradation. In conclusion, although the studied area was not too large, a wide heterogeneity of soil quality (in terms of the investigated chemical and biological characteristics) was detected, depending on the local human impact.

Soil is a prime component of terrestrial areas that provides many services that guarantee the functionality of the ecosystems, support organism life, sustain plant or crop productivity, regulate gas exchanges between atmosphere and biosphere, allow organism wellness and maintain the environmental quality. In the last century, human density rapidly increased, causing strong environmental variations to satisfy their needs and leading to an excessive land transformation. Land use changes determine deep alterations of ecosystem functionality that governs physical, chemical and microbiological processes. As soil formation is slower than its consumption,it is necessary to preserve soil quality in order to sustain environment health. Because soil functions are difficult to measure, soil properties that are sensitive to specific changes can be used as indicators of soil quality. The present research provides a contribution to the actual knowledge on the characteristics of soils affected by environmental degradation due to intensive or extensive use of lands by humans (quarries, agriculture,urbanization) and by management of a natural reserve. The overall aim of the research was to evaluate the quality of soils undergone to different kinds of anthropic impacts. Particularly, the research aimed: i) to exam the feasibility to recover quarries through the single addition of organic amendments; ii) to evaluate the chemical, biological characteristics of agricultural soils inside an urban fabric and of forest soils inside a National Park. Besides, the studies were also focused on the relationships between the chemical characteristics of the soils and the biota and a minimum data set of indicators was proposed in order to provide a useful tool to decision-makers to monitor, conserve or improve soil quality. The main results of the research focused on quarry recover through a single application of the investigated organic amendments (compost and a mixture of compost and poultry manure) highlighted an improvement of the substrate properties, as, over the time, the metal availabilities decrease and microbial community increase. The agricultural soils inside the urban fabric and the soils of the Vesuvius National Park appeared slightly contaminated by Cu e Pb, nevertheless, soil microbial biomass were scarcely affected by their concentrations. In addition, only four indicators, selected from twenty-five parameters, appeared enough to monitor the quality of soils inside the Vesuvius National Park.

Plastic sheets are widely used in farming soil to improve the productivity of cultures. Due to their absorption capacity, plastic sheets can alter element and metal content in soils, and in turn affect soil properties. The use of biodegradable films is an attractive eco-sustainable alternative approach to overcome the environmental pollution problems due to the use of plastic films but their impacts on soil are scarcely studied. The aim of the research was to evaluate the impact of conventional plastic and bioplastic sheets on total and available concentrations of elements (Al, Ca, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn) in soils. The research was performed in mesocosm trials, filled with soil covered by conventional plastic and bioplastic sheets. After six months of exposure, soils were characterized for pH, water content, concentrations of organic and total carbon and total nitrogen, and total and available Al, Ca, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn element concentrations. The results highlighted that soils covered by bioplastic sheets showed higher total and available concentrations of elements and higher contamination factors, suggesting that bioplastic sheets represented a source of metals or a less-effective sink to these background metals in soils, compared to conventional plastic ones.

The knowledge of the effects of fire on soil properties is of particular concern in Mediterranean areas, where the effects of vegetation type are still scarce also. This research aimed: to assess the properties of burnt soils under different vegetation types; to highlight the soil abiotic properties driving the soil microbial biomass and activity under each vegetation type; to compare the biological response in unburnt and burnt soils under the same vegetation type, and between unburnt and burnt soils under different vegetation types. The soils were collected at a Mediterranean area where a large wildfire caused a 50% loss of the previous vegetation types (holm oak: HO, pine: P, black locust: BL, and herbs: H), and were characterized by abiotic (pH, water, and organic matter contents; N concentrations; and C/N ratios) and biotic (microbial and fungal biomasses, microbial respiration, soil metabolic quotient, and hydrolase and dehydrogenase activities) properties. The biological response was evaluated by the Integrative Biological Responses (IBR) index. Before the fire, organic matter and N contents were significantly higher in P than H soils. After the fire, significant increases of pH, organic matter, C/N ratio, microbial biomass and respiration, and hydrolase and dehydrogenase activities were observed in all the soils, especially under HO. In conclusion, the post-fire soil conditions were less favorable for microorganisms, as the IBR index decreased when compared to the pre-fire conditions.

Recently, surface soils of remote or protected areas, that receive pollutants from the surroundings or in situ activities through dry and wet deposition, exceed the baseline content of heavy metals. In the last decades, the use of single and integrated indices is a powerful tool to process, analyze and convey information about metal accumulation degree for decision makers to better manage protected areas. Single indices provide information about only one metal, whereas the integrated ones give a holistic evaluation. The aim of the research was to assess the temporal trends of three single (Contamination Factor, Enrichment Factor and Geo-accumulation Index) and two integrated (Pollution Load Index, Nemerow index) indices in order to evaluate if the touristic impact caused soil metal (Cr, Cu, Ni and Pb) accumulation. In autumn 2016 and in spring 2016 and 2017, the surface soils (0–10 cm) were collected at eight sites inside the Vesuvius National Park (Southern Italy), characterized by intense tourism from spring to autumn. The metal concentrations were measured in the soils and used to calculate the indices. In addition, the Ecological Risk Factor was calculated and the phytotoxicological assays were performed. The findings showed that the surface soils of the Vesuvius National Park were polluted by Cr, Cu, Ni and Pb, according to both single and integrated indices. The touristic impact would seem to be the main cause of soil metal accumulation, as the highest values of the calculated indices were detected for samples collected at the end of the touristic season and the lowest at the beginning of the touristic season. Anyway, Cu and Pb would seem also to derive by ex situ anthropogenic sources, whereas Cr and Ni also by natural sources, such as spontaneous fires and substrate weathering. Finally, the soils showed phytotoxic effects and low ecological risks.

The study of particulate matter pollution in urban areas is of great concern due its adverse effects on human health. Roadside vegetation, intercepting and filtering it, contributes to improve air quality. The aim of the research was to investigate the capability of Q, ilex leaves, already known good biomonitors of air quality, in filtering air metals. Besides, the main derivation (i.e. air or root uptake) of the investigated metals in leaf tissue was evaluated. The concentrations of Cd, Cr, Cu, Ni and Pb were measured in three groups of Q, ilex leaves (unwashed, water washed and chloroform washed). Besides, several leaf traits (i.e. length, width, petiole length, leaf area, leaf mass area and thickness) were evaluated. The findings highlighted that Cd, Cr, Cu, Ni and Pb in Q, ilex leaves exceeded the chemical fingerprint. In particular, Cd and Pb appeared the main contaminants of the investigated area as also after water washing of the leaves, their concentrations exceeded the chemical fingerprint. Ni, Cr and Pb appeared to be accumulated on leaf deposit; whereas, Cd appeared mainly adsorbed to leaf cuticle. Higher leaf width, lower leaf area and shorter petiole favoured leaf metal accumulation. Root uptake and translocation to leaves cannot be excluded for Cr and Ni; whereas, leaf Cu content would seem to depend on both leaf deposit and soil content. In conclusion, Q, ilex can be useful in filtering air metal pollution, especially for Ni, Cd, Cr and Pb, and improving air quality. (C) 2018 Elsevier Ltd. All rights reserved.

Altitude, exposure, and plant cover may have a significant impact on the soil system, affecting its abiotic characteristics and, in turn, soil microbial composition and activity. In the Mediterranean area, the relationships among environmental features and soil characteristics are still scarcely investigated. The present study aimed to evaluate the effects of altitude, slope exposure, and plant cover on soil abiotic characteristics and the responses of the soil microbial community. Surface soil was sampled at 32 field points of the Vesuvius Mountain (Southern Italy) at two slope exposures (North and South), two altitudes (600 and 900 m a.s.l), and under two different plant covers (pines and shrubs), and it was analyzed for soil abiotic and biotic characteristics. The results showed that soil characteristics mainly differed according to site altitude, but some characteristics also changed according to site exposure and plant cover. The soil organic carbon (Corg) showed significant high values at low altitude, south exposure, and under pines and played a role in influencing the soil microbial community. In soil covered by pines, the greatest soil Corg amount matched with the highest values of C/N ratio and fungal biomass. Finally, high Corg and water availability significantly enhanced the microbial activities.

40 páginas, 4 gráficos, 3 tablas .-- The definitive version is available at http://www.elsevier.com, Soil quality is strongly affected by microbial biomass that is involved in organic matter mineralization and the supply of nutrients to plants. The effects of trace elements on soil microbial biomass and activity are still controversial, and the contents of the elements in different forms, more than the total amounts, may affect soil microbial community. Volcanic soils are peculiar environments because of their chemical characteristics. Therefore, the aims of this research were to evaluate in volcanic soils: i) the elemental composition; ii) the elemental availability; and iii) the effects of elemental fractions on soil microbial biomass and activity. In order to reach the aims, the BCR sequential extraction method was applied in order to separate 22 elements in different soil fractions: acid soluble, reducible, oxidisable and residual. The studied biological parameters were: microbial and fungal biomasses, soil respiration, metabolic quotient, coefficient of endogenous mineralization, dehydrogenase and hydrolase activities, and phytotoxicity. Among the investigated elements, Al, B, Ba, Ca, Cr, Fe, K, Mg, Mn, Na, Ni, Ti, V and Zn were scarcely available; Cd appeared to be the most ready available element; Zn was mainly present in the acid soluble and in the residual fractions. Microbial biomass and activity appeared to be mainly affected by the reducible and oxidasable fractions of the investigated elements more than the acid soluble or residual ones. With the exception of La and V, the elemental content in the various fractions would seem to stimulate the microbial biomass and activity. Finally, the investigated volcanic soils showed phytotoxic properties., This research activity has been realised in collaboration of the Biology Department of University Federico II of Napleas and the Vesuvius National Park within the “Azione di Sistema - Impatto antropico da pressione turistica nelle aree protette: interferenze su territorio e biodiversità” funded by “Ministero dell'Ambiente e della Tutela del Territorio e del Mare” (CUP: E65J13000030001), Direttiva Conservazione della Biodiversità. Chemical analysis has been economically supported by Ministry of Economy and Competitiveness of Spain (CTM2013-47874-C2-2-R)

36 páginas, 5 figuras, 4 tablas. -- The definitive version is available at http://www.elsevier.com, Soil element composition derives from parent material disaggregation during pedogenesis and weathering processes but also by anthropogenic inputs. Elements are present in soils in different chemical forms that affect their availability and mobility. The aim of the study was to evaluate the main derivation, natural or anthropogenic, of elements in the soils of the Vesuvius National Park (a natural environment strongly affected by human impacts). Besides, the effects of age of the lava from which soils derive, different vegetation covers, traffic fluxes along the two roads connecting the Vesuvius crater and altitudes of the sites on the pseudo-total element concentrations and on their contents in different fraction of soil were investigated. To reach the aims, BCR (Bureau Commun de Référence) sequential extraction was performed in order to determine the distribution of elements into: acid-soluble, reducible, oxidizable and residual fractions. The relationship between the main environmental media and distribution of elements was discussed using non-metric multidimensional scaling (NMDS). The findings showed that, with the exception of Cd, Cu, Pb and Zn that would seem to derive also from human activities, the other investigated elements (Al, As, B, Ba, Ca, Cd, Cr, Cu, Fe, K, La, Mg, Mn, Na, Ni, P, Pb, Si, Ti, V, W and Zn) mainly had a natural derivation. Among the investigated elements, only Cd could represent a potential high risk for the studied andosols. The highest element accumulations in the soils at low altitude could be attributable to an integrated effect of plant cover, vicinity of downtowns and traffic flux. The acid-soluble fraction of elements appeared more linked to lava age; the reducible and oxidizable ones to plant cover; the residual one to the chemical composition of the parent material that gave origin to the soils., This research activity has been realised in collaboration of the Biology Department of University Federico II of Napleas and the Vesuvius National Park within the “Azione di Sistema - Impatto antropico da pressione turistica nelle aree protette: interferenze su territorio e biodiversità” funded by “Ministero dell'Ambiente e della Tutela del Territorio e del Mare”, Direttiva Conservazione della Biodiversità. Dr. García-Delgado thanks the Spanish Ministry of Economy and Competitiveness for his post-doctoral contract (JCFI-2015-23543). Chemical analysis has been economically supported by Ministry of Economy and Competitiveness of Spain (CTM2013-47874-C2-2-R).