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The intensive exploitation of agricultural land has caused a depletion of soil organic carbon (SOC) and a decline in soil fertility, with a consequent decrease in the productivity of agroecosystems, also contributing to atmospheric GHG emissions. The ability of soil to storage organic carbon (OC) depends on its persistence and susceptibility to decomposition. SOC is generally partitioned into fractions differing in protection mechanisms and in turn decomposability. This study aimed to compare the OC pool repartition in soils managed with three different fertilization practices (mineral – CONV, manure – ORGM and green manure – ORG-GM) during a medium-term trial in vineyard, in order to understand the best solution in increasing C sequestration. The OC fractionation by acid hydrolysis allowed separating three fractions of OC: a labile, quickly mineralizable pool, a recalcitrant pool with a slower turnover and a stable pool protected by microbial attack. The results showed that the periodic application of organic matrices (manure and green manure), although did not increase total OC, enriched the soil along time with readily available OC, thus promoting the release of nutrients. Green manure has also been shown to promote the accumulation of stabilized OC, able to improve the structure of the soil and, therefore, its fertility.

DOI of original article:https://doi.org/10.1016/j.catena.2019.104178 .- Rosangela Addesso, Alessandro Bellino, Ilenia Maria D'Angeli, Jo De Waele, Ana Zélia Miller, Cristina Carbone, Daniela Baldantoni: Vermiculations from karst caves: The case of Pertosa-Auletta system (Italy) CATENA, Volume 182, November 2019, Pages 104178, The authors regret the presence of incomplete information in the author affiliations (reported correctly above) and in the acknowledgments of the original article (provided in the amended version below). The authors are obliged to Mr. Vincenzo Manisera, speleologist of the MIdA Foundation, for sharing his experiences and for his invaluable help in all the field activities, to Dr. Sacha A. Berardo (University of Salerno, Italy) for the language editing, and to the two anonymous reviewers, who provided helpful comments and suggestions. Funding was provided by the Spanish project MINECO CGL2016-75590-P with ERDF funds, by the MIdA Foundation, which generously supported the whole project, and by the University of Salerno, which provided facilities for carrying out the research. The authors would like to apologise for any inconvenience caused.

Póster presentado en 20th Eruropean Astrobiology Network Association Conference (EANA-2021) Online.- September 7-10, (2021)

Virtual congress because of the Covid-19 pandemic.Originally scheduled to take place in Dublin, Ireland.; International audience

Polycyclic aromatic hydrocarbons (PAHs) are worldwide contaminants and, due to their long-range transport, they can accumulate far from the emission sources, in carbon-rich forest soils; thus new exploration in the indigenous microbial response to PAH exposure is important to deeper understanding of PAH natural degradation process. Since most of the studies are limited to aged PAH contaminated soils, we aimed to fill the gap in our knowledge on recent contamination. In order to investigate indigenous microbial community involvement in soil PAH degradation, a mesocosm trial was established. Soils from two forest systems (holm oak and black pine) were spiked with 3 PAHs (phenanthrene, pyrene and benzo[a]pyrene) and incubated under controlled conditions (T: 22 °C, R.H.: 88%). Along 360 days, structural and functional changes in soil microbial community were monitored analyzing bacterial and fungal biomass (by phospholipid fatty acid and ergosterol content) and enzyme activities (hydrolase, laccase and peroxidase).Both soil types indicated a capability of indigenous native microbial community to degrade almost completely PAHs yet after one year, with phenanthrene and pyrene faster degrading than benzo[a]pyrene, according to their molecular weight. In pine soil, the PAH degradation proceeds with a minor extent likely in relation to the sequestration of PAHs in soil richer in organic matter. In both forest soils fungi are mainly involved in the degradation of PAHs, as highlighted by the increase of both content of the fungal marker and enzyme activity mainly carried out by fungi, e.g. laccase in holm oak soil. Regarding the community structure, PAH contamination influences the relative abundance of several soil microbial groups yet after 4 days from contamination, when the microbial community composition shifts towards Gram+ bacteria in holm oak soil, whereas in pine soil pyrene and phenanthrene stimulate fungi and actinomycetes. In the long-term, after one year from contamination, a variation in microbial community was more evident in the holm oak soil, with an increase of fungi in the treatment with benzo[a]pyrene, and an increase of Gram+ in the treatment with phenanthrene. All the enzymes activities, after some fluctuations in the early stages of incubation, decreased after one year. During the quick and strong PAH degradation, hydrolytic activity showed high and constant values, exhibiting a stability in the long-term after the contamination. The obtained findings show the role of several microbial groups in PAH natural attenuation in different forest soils. Different PAH degradation rates between systems can be attributable to soil microbiome dominated by different populations in the two investigated forest soils. The use of indigenous microorganisms in bioremediation processes can reduce the risks associated with PAH contaminated soils, and a better understanding of the effects of PAH contaminants on soil microbial community is very critical for understanding microbial activity during bioremediation. The findings highlight the importance of fungi in the potential recovery of a soil polluted by organic contaminants.

In urban environments, high levels of pollutants, as polycyclic aromatic hydrocarbons (PAHs) and trace elements, coming mainly from anthropogenic sources as vehicular exhausts, industrial emissions and waste incineration, impose serious environmental and biological problems. These pollutants cause concern, especially for their potential toxicity and the adverse health effects. In this work the results of a passive biomonitoring study, concerning the accumulation of trace elements and PAHs in Quercus ilex leaves and in the epiphytic moss Leptodon smithii, are presented. Both biomonitors were sampled in two Italian Regions (Campania and Toscana) along a gradient of environmental disturbance in i) urban, ii) periurban and iii) extraurban areas. Fresh leaves and mosses were extracted by sonication in a mix of methane dichloride and acetone (1:1=v:v) and analysed for 16 EPA PAHs by GC-MS. Oven-dried (75 °C) plant samples were mineralized with acids (HF:HNO3=1:2=v:v) and analysed for elements (Al, B, Ba, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, V and Zn) by AAS and ICP-OES. In both Regions, trace element and PAH concentrations were generally higher in leaves and mosses sampled in urban areas than in periurban and extraurban ones, confirming the suitability of the selected native species to monitor air pollutants in the Mediterranean areas. The high concentrations of some elements in leaves (Mn, Na and Zn) and in mosses (B, Ba, Cd, Mn, Ni and V) from the extraurban site of Toscana, likely due to the influence of marine aerosols and of an industrial settlement located about 40 Km from the sampled area, put in evidence the importance of selecting suitable “reference” sites in order to find out situations at risk and properly evaluate the degree of pollution in urban areas.