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Fungi play a key role in the functioning of soil in terrestrial ecosystems, and in particular in the remediation of degraded soils. The contribution of fungi to carbon and nutrient cycles, along with their capability to mobilise soil trace elements, is well-known. However, the importance of life history strategy for these functions has not yet been thoroughly studied. This study explored the soil-fungi relationship of two wild edible fungi, the ectomycorrhizal Laccaria laccata and the saprotroph Volvopluteus gloiocephalus. Fruiting bodies and surrounding soils in a mine-spill contaminated area were analysed. Isotope analyses revealed Laccaria laccata fruiting bodies were 15N-enriched when compared to Volvopluteus gloiocephalus, likely due to the transfer of 15N-depleted compounds to their host plant. Moreover, Laccaria laccata fruiting bodies δ13C values were closer to host plant values than surrounding soil, while Volvopluteus gloiocephalus matched the δ13C composition to that of the soil. Fungal species presented high bioaccumulation and concentrations of Cd and Cu in their fruiting bodies. Human consumption of these fruiting bodies may represent a toxicological risk due to their elevated Cd concentrations. ; This work was supported by European Union Seventh Framework Programme (FP7/2007–2013) [grant number 603498 - RECARE], and Spanish Ministry of Science, Innovation and Universities [grants number CGL2014–52858-R – RESTECO and CGL2017–82254-R - INTARSU]. MGM was supported by Spanish Ministry of Economy and Competitiveness [grant number BES-2015–073882], and MTD by a postdoctoral grant by Universidad de Sevilla (V Plan Propio de Investigación) ; Peer reviewed

15 páginas.-- 3 figuras.-- 3 tablas.-- referencias.-- The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fpls.2018.01682/full#supplementary-material ; There is an increasing consensus that microbial communities have an important role in mediating ecosystem processes. Trait-based ecology predicts that the impact of the microbial communities on ecosystem functions will be mediated by the expression of their traits at community level. The link between the response of microbial community traits to environmental conditions and its effect on plant functioning is a gap in most current microbial ecology studies. In this study, we analyzed functional traits of ectomycorrhizal fungal species in order to understand the importance of their community assembly for the soil–plant relationships in holm oak trees (Quercus ilex subsp. ballota) growing in a gradient of exposure to anthropogenic trace element (TE) contamination after a metalliferous tailings spill. Particularly, we addressed how the ectomycorrhizal composition and morphological traits at community level mediate plant response to TE contamination and its capacity for phytoremediation. Ectomycorrhizal fungal taxonomy and functional diversity explained a high proportion of variance of tree functional traits, both in roots and leaves. Trees where ectomycorrhizal fungal communities were dominated by the abundant taxa Hebeloma cavipes and Thelephora terrestris showed a conservative root economics spectrum, while trees colonized by rare taxa presented a resource acquisition strategy. Conservative roots presented ectomycorrhizal functional traits characterized by high rhizomorphs formation and low melanization which may be driven by resource limitation. Soil-to-root transfer of TEs was explained substantially by the ectomycorrhizal fungal species composition, with the highest transfer found in trees whose roots were colonized by Hebeloma cavipes. Leaf phosphorus was related to ectomycorrhizal species composition, specifically higher leaf phosphorus was related to the root colonization by Thelephora terrestris. These findings support that ectomycorrhizal fungal community composition and their functional traits mediate plant performance in metal-contaminated soils, and have a high influence on plant capacity for phytoremediation of contaminants. The study also corroborates the overall effects of ectomycorrhizal fungi on ecosystem functioning through their mediation over the plant economics spectrum. ; This work was financially supported by European Union Seventh Framework Programme (FP7/2007–2013) (Grant No. 603498- RECARE); Spanish Ministry of Science, Innovation and Universities (Grant No. CGL2014-52858-R- RESTECO and Grant No. CGL2017-82254-R- INTARSU). MG-M was supported by Spanish Ministry of Economy and Competitiveness (Grant No. BES-2015-073882). During manuscript preparation, ÁL-G was supported by European Union's Horizon 2020 Marie Curie Individual Fellowship (Grant No. 708530 –DISPMIC). ; Peer reviewed

12 páginas.- 5 figuras.- 4 tablas.- referencias.- The Supplementary data to this article: in https://doi.org/10.1016/j.soilbio.2020.108102 ; Soil biodiversity loss due to pollution may affect ecosystem services negatively. This environmental problem may be solved by phytoremediation, which is an effective strategy to manage and remediate contaminated areas. During this remediation process, the establishment of plant communities may improve soil fungal community structure and, in particular, may favour mycorrhizal symbiotic associations. As a consequence, afforestation of degraded lands will have different outcomes on fungal diversity and functionality, which will depend on the selected tree and shrub species. We analysed soil fungal diversity and functional guilds by high-throughput sequencing of environmental DNA in a trace element contaminated area, part of a large scale phytoremediation project running for 20 years. We selected five habitats for comparison purposes: three under the canopy of selected tree species (wild olive, white poplar and stone pine), adjacent treeless areas (grassland) and non-remediated areas (bare soil). Soil fungal diversity and richness seemed to be enhanced by phytoremediation. White poplar soil had the highest diversity and richness compared to wild olive and stone pine. Fungal communities were especially different between stone pine, with soils rich in organic C and high C:N ratio, and grassland soils. We identified 9,428 fungal OTUs from which 1,283 were assigned to a unique functional guild; the most abundant belonging to saprotrophic, plant pathogenic and ectomycorrhizal functional guilds. Ectomycorrhizal fungi were more abundant in soils under ectomycorrhizal host trees. Saprotrophs were abundant in grassland and wild olive soils, while plant pathogens were abundant in non-remediated soils. The remediation of soils (clean-up and amendment addition) allowed the natural establishment of grassland habitats throughout the study area, increasing fungal diversity, richness, taxonomy and functionality, when compared to non-remediated soils. Tree afforestation allowed the establishment of a forest type community bringing a further recruitment of fungal taxa, mainly the ectomycorrhizal fungal guild. Afforestation with different tree species showed species-specific effects on soil N, organic C, Ca and C:N ratio which led to increased spatial heterogeneity in areas with potential to recruit a wider diversity of fungi. ; This work was supported by European Union Seventh Framework Programme (FP7/2007–2013) [grant number 603498 - RECARE], and Spanish Ministry of Science, Innovation and Universities [grants number CGL2014-52858-R – RESTECO and CGL2017-82254-R – INTARSU]. MG-M was supported by Spanish Ministry of Economy and Competitiveness [grant number BES-2015-073882]. AL-G was supported by European Union's Horizon 2020 Marie Curie Individual Fellowship [grant number 708530 – DISPMIC], Spanish Ministry of Science, Innovation and Universities [grant number CGL2015-69118-C2-2-P-COEXMED-II] and University of Jaén under the Plan 6-UJA postdoctoral fellowship. MTD was supported by a postdoctoral grant by Universidad de Sevilla (V Plan Propio de Investigación) and by Spanish Ministry of Science, Innovation and Universities [grant number CGL2017-85891-R- DEGRAMED]. ; Peer reviewed

Ecosystem services are the direct and indirect contributions of ecosystems to human well-being. Despite the importance of soil services, they are often underestimated and largely unrecognized. We introduce briefly the framework recently proposed by Schwilch et al. (2016), and present some results of the potential use of different tree species to remediate contaminated soils on Mediterranean conditions. Disruptions of biogeochemical cycles by human activities act as a direct driver of global change. The Guadiamar Green Corridor (Seville, Spain), is an example of extensive soil contamination by trace elements originated by mining activities. In the large-scale remediation and restoration plan, soil was cleaned-up, amendments were added, and trees of several native species were planted (Domínguez et al. 2008). We present some approaches to study tree-soil interactions, soil functioning and the provided ecosystem services. 1) Potential of trees for the phytostabilization of soil contaminants. The immobilization of contaminants by plant roots, litter decomposition and their associated microbes means an improvement of soil quality and therefore a regulation service. We measured the effects of different tree species (Marañón et al. 2015). 2) Carbon storage in soil. We assessed the effectiveness of different tree species in providing this regulation service. 3) Promoting soil biodiversity. We evaluated the colonization by mycorrhizal fungi of roots of Quercus ilex planted on different soil conditions of acidity and contamination level. References: Domínguez MT et al. (2008). Environmental Pollution, 152: 50-59. Marañón T et al. (2015). Web Ecology, 15: 45-48. Schwilch G et al. (2016). Ecological Indicators, 67: 586-597. ; European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n° 603498 (RECARE). Proyecto RESTECO- CGL2014-52858-R, Ministerio de Economía y Competitividad, Programa Retos. ; No

Comunicación oral en la Sesión 66- "Soil-Plant Interactions and Soil Ecosystem Services Delivery" del "5th International Ecosummit. Ecological Sustainability. Engineering Change", 29 August - 1 September, 2016, Montpellier, Francia. ; Introduction. Afforestation on contaminated soils contributes to stabilization of trace elements, and to carbon accumulation in biomass and soil. We have assessed two ecosystem services - phytoremediation and carbon sequestration – delivered by trees and shrubs planted on a contaminated land. Methods. The Guadiamar Green Corridor (SW Spain) is a large-scale case of phytoremediation. After the 1998 mine spill, which contaminated over 4000 ha, soil was cleaned up, remediated and afforested. For phytoremediation assessment, we selected seven tree species and measured concentration of 24 mineral elements, 13C and 15N, in five ecosystem compartments: leaves, roots, litterfall, topsoil and deep soil. For carbon sequestration assessment, we selected four woody species in three sites. We measured soil carbon fractions, microbial biomass and a suit of soil enzyme activities. Soil respiration was monitored over one year in one of the sites. Results. Tree leaves had the highest variation in chemical concentration (mean CV 79%), and the identity of tree species was a major source of variation. In contrast, topsoil had lower variation (mean CV 25%) and only three elements presented significant differences associated to tree species. Microbial biomass and activity was strongly influenced by soil pH, increasing under trees which neutralized soil acidity, like Populus. Soil underneath trees accumulated more organic matter and lost less C by respiration than in the open microsites. Discussion. Soil chemical footprint of seven planted tree species was still weak, 16 years after plantation, probably due to their young age. However, those trees planted in a contaminated and remediated soil were contributing effectively to the phytostabilization of trace elements by their immobilization in roots and organic matter. Soil underneath trees presented a higher net contribution to carbon sequestration than open. The role of tree plantations in contaminated soils and their potential delivering ecosystem services are discussed. ; European Union: Seventh Framework Programme grant 603498. RECARE project. ; Spanish Ministry of Economy and Competitivity: RESTECO project - CGL2014-52858-R ; No

Comunicación oral y póster presentados en la Reunión Plenaria del proyecto europeo RECARE, Hella, Islandia, 29 mayo-2 junio 2017. Se presentan resultados sobre las dos medidas de recuperación de suelos contaminados evaluadas en el Corredor Verde del Guadiamar: a) adición de enmiendas y b) plantación de árboles. ; Evaluation of two measures to remediate contaminated soils at the Guadiamar study site (Spain): a) amendment addition and b) tree plantation. Contribution to the RECARE Plenary Meeting, 2017 (Hella, Iceland). ; European Union 7th Framework Programme. ; No

15 páginas.- 10 figuras.- 3 tablas.- 74 referencias.- Supplementary data to this article can be found online at https://doi.org/10.1016/j.catena.2019.03.013 ; In the wider context of heathland restoration, we investigated how field scale experimental acidification with sulphur (sulfur)affected soil biodiversity, fertility and function over a period of 17 years. A field experiment was conducted in the Isle of Purbeck, England, using ferrous sulphate and elemental sulphur as acidifying agents. We tested the effects of acidification on soil fertility, plant communities, litter decomposition, microbiology (including fungi bacteria and actinomycetes), arbuscular and ericoid mycorrhizal colonisation, and soil fauna (including earthworms, nematodes, rotifers and tardigrades). We found that elemental sulphur had a considerable and persistent effect on soil pH, lowering it to levels found in the surrounding reference acid grassland and heathland sites. A newly adapted heathland restoration index based on soil chemistry, found that elemental sulphur was by far the most successful treatment leading to soil conditions similar to the heathlands. Overall, acidification caused a loss of base cations and an increase in toxic aluminium compounds. Consequently the more mesotrophic components of soil biology were reduced by acidification during the course of the experiment. This transformed the soil biological system into one typical of acid grasslands and heathlands. Concomitant litter decomposition was similarly inhibited by acidification, with the microbiota more strongly hindered in acidified soil than the macroscopic fauna. Acidification resulted in a reduction in nematode and rotifer abundance and earthworm biomass. The vegetation community was also strongly modified by the elemental sulphur treatments and, where grazing was restricted, soil acidification allowed a restored heathland community to endure. Arbuscular mycorrhizal colonisation of grasses was reduced where heather plants were established, while ericoid mycorrhizas had developed sufficient populations in the acidified pastures to match the colonisation rate in the native heathlands. © 2019 Elsevier B.V. ; This project was part of the RECARE project ( http://www.recare-project.eu/ ) which received funding from the European Union 's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 603498 ; Peer reviewed