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On a global scale, the effects of human activities, in particular changes in the way land is used and exploited and the resulting contamination, have had profound negative effects on biodiversity and ecosystem functioning. Consequently, restoring the marginal lands through the use of solutions inspired and supported by nature appears to be one of the European Union's main objectives. In this respect, eco-innovative phytotechnologies, such as phytoremediation, have become an important ecological engineering approach for the recovery of contaminated land. A relatively new area of phytoremediation is phytomanagement in which non-food crops with high biomass yields are used to reduce and control the risks associated with soil pollution, while enabling profitable and sustainable use of resources by extracting contaminants and recovering marketable biomass. Consequently, the best choice of plant species is crucial to the successful phytomanagement of contaminated sites. This meta-analysis highlights the importance of using fast-growing plants for phytomanagement purposes, focusing on woody species. Those from the Salicaceae family, which includes poplars (Populus), have attracted the most attention in recent decades. On the basis of this meta-analysis, poplars appear to be the best candidates for the remediation of metal-contaminated soils, particularly when combined with the most appropriate microbial consortia. Finally, we describe the molecular determinants of poplar involved in the management of trace elements (TE), as well as the valorization processes that have been applied to poplar biomass from phytoremediation trials. [ABSTRACT FROM AUTHOR]

• 38 tree species were tested for the phytomanagement of different marginal lands. • O. carpinifolia performed well on the three sites compared to the nursery standard. • The PTE contents in the trees strongly differed depending on the species. • S. aquatica grandis exhibited the highest accumulation capacity at the three sites. The use of fast-growing trees producing a high quantity of biomass can bring significant practical and economic benefits to the reclamation of marginal lands. The present study aims to identify new shrub/tree species to offer a wider range of shrubs/trees useful for phytomanagement practices. We implemented three experimental sites in France of 1 ha each (Thann, Carrières-sous-Poissy and Leforest) contaminated by different potentially toxic elements (PTE) with a total of 38 different tree species. After two years of growth, the element concentrations in stem and leaf biomasses, tree survival rate and growth of plants were assessed. Although the three sites had elevated concentrations of total PTE and nutrients in their soil, the element contents in the trees strongly differed depending on the species. Alnus subcordata , Platanus orientalis , Ulmus pumila , Ostrya carpinifolia and the Acer species appeared to be well adapted to the drastic conditions of the sites and presented the lowest PTE concentrations in their aboveground biomass. Conversely, the Salix , Populus , Betula and Quercus species, especially Salix aquatica grandis , exhibited the highest accumulations of Cd, Zn and/or Mn at the three sites. Inoculation with the endomycorrhizal fungus Rhizophagus irregularis did not have a significant impact on the growth of the tree species at the three sites after two growing seasons. Overall, the present study offers two options for the phytomanagement of marginal lands. The first option is based on the production of clean biomass, which is useful for plant-based industrial processes (e.g., biomaterials, bioenergy) that could valorize this biomass. The second option is based on the production of TE-enriched biomass that could be better exploited in the eco-catalysis process. [ABSTRACT FROM AUTHOR]

Afforestation of trace element (TE)-contaminated soil, notably with fast growing trees producing large biomass has been demonstrated to be an attractive option for their bioremediation. Mycorrhizal fungi can form symbiotic associations with plants, contributing to TE tolerance and participating actively in bioremediation processes. We studied the effects of mycorrhizal inoculation on the growth of two poplar clones (Skado and I214), to large-scale. Two TE-contaminated sites of ca . 1 ha (Pierrelaye and Fresnes-sur-Escaut, France) were planted with 2200 trees, and were either inoculated with a mixed commercial inoculum or not-inoculated and allometric parameters were determined after 2 and 4 years of growth. The height diameter relationships remained linear overtime, although the second period of the experiment has been more favorable to growth of the Skado clone and its survival rates were higher compared than those of the I214 clone, at both sites. The inoculation with mycorrhizal significantly impacted the biomass production of the Skado clone at both sites, despite striking differences in soil structure and contamination. In overall, this bioaugmentation option with mycorrhizal fungi influenced more poplar growth than soil contamination and highly improved its biomass production. [ABSTRACT FROM AUTHOR]

The effects of the Populus alba tree on different biochemical soil properties, growing in a contaminated area, were studied for two years under field conditions. Two types of trace element contaminated soils were studied: a neutral contaminated soil (NC) and an acid contaminated soil (AC). One neutral non-contaminated area was studied as control. Soil samples were collected at depths of 0–20 cm and 20–40 cm. Leaves and litter samples were analysed. The addition of organic matter, through root exudates and litter, contributed to an increase in soil pH, especially in acid soil. Microbial Biomass Carbon (MBC) was significantly increased by the presence of the trees in all studied areas, especially in the upper soil layer. Similar results were also observed for protease activity. Both MBC and Protease activity were more sensitive to contamination than β-glucosidase activity. These changes resulted in a decrease of available trace element concentrations in soil and in an improvement of soil quality after a 2-year study. The total concentration of Cd and Zn in soil did not increase over time due to litter deposition. Analysis of P. alba leaves did not show a significant nutritional imbalance and trace element concentrations were normal for plants, except for Cd and Zn. These results indicate that P. alba is suitable for the improvement of soil quality in riparian contaminated areas. However, due to the high Cd and Zn concentrations in leaves, further monitoring of this area is required. [Copyright &y& Elsevier]

Repeated application of Cd-rich phosphate fertilizers can lead to the accumulation of this nonessential element in soil. This can result in increased plant uptake, with possible breaches of food or feed safety standards. We aimed to determine whether lignite (brown coal) can reduce Cd solubility and plant uptake in New Zealand pasture soils. In batch sorption experiments, we tested the capacity of lignite and lignite-soil mixtures to sorb Cd at various soil pH and Cd loadings. Over a pH range of 4-7, Cd sorption by lignite was 1-2 orders of magnitude greater than by a typic immature pallic soil containing 2% carbon. The addition of S wt % lignite to a range of soils revealed that lignite addition was most effective in reducing soluble Cd in soils with low pH. In a greenhouse experiment, we tested the effect of lignite on the accumulation of Cd and other elements by perennial ryegrass, Lolium perenne (L.). The addition of just 1 wt % lignite to the aforementioned soil reduced plant Cd uptake by 30%, without adversely affecting biomass or the uptake of essential nutrient elements including copper and zinc. This may be due to preferential binding of Cd to organic sulfur in lignite. [ABSTRACT FROM AUTHOR]

In the Saint-Marcel cave (France), wood barrels and thousands of bottles containing red wine were stored for vinification. After storage began, a fungal and bacterial outbreak occurred, and the area was invaded by numerous types of mold colonizing the cave ceilings and all objects related to human activities (the stairwell and oenological materials). In this study, using the metabarcoding approach, we have studied the microbial outbreak and have linked the identified microorganisms to oenological activity. Both 16S and ITS primers were used to sequence the samples collected from the cave. The results showed that the dominant microorganisms proliferating in the cave were related to wine vinification. For instance, Zasmidium cellare, a strain known for living in dark and ethanol-rich environments, was the dominant fungus on the cave stairwell. Furthermore, Guehomyces pullulans , a cold-adapted yeast used for juice clarification, was recorded as the major species on the blackened limestone ceilings. These findings reveal a complex community structure in the studied cave based on the assembly of bacteria and fungi. Finally, our results demonstrate that oenological activities could seriously affect cave preservation, changing the natural microbial communities populating cave environments. Unlabelled Image • Saint-Marcel cave has suffered of a fungal outbreak. • Oenological activities were suspected to lead to uncontrolled fungal proliferation. • High throughput sequencing has been used to assess microorganism communities. • Dominant microorganisms proliferating in the cave were related to wine vinification. [ABSTRACT FROM AUTHOR]

Growing industrial crops on marginal lands has been proposed as a strategy to minimize competition for arable land and food production. In the present study, eight experimental sites in three different climatic zones in Europe (Mediterranean, Atlantic and Continental), seven advanced industrial crop species [giant reed (two clones), miscanthus (M. × giganteus and two new seed‐based hybrids), saccharum (one clones), switchgrass (one variety), tall wheatgrass (one variety), industrial hemp (three varieties) and willow (eleven clones)], and six marginality factors alone or in combination (dryness, unfavorable texture, stoniness, shallow soil, topsoil acidity, heavy metal and metalloid contamination) were investigated. At each site, biophysical constraints and low‐input management practices were combined with prevailing climatic conditions. The relative yield of a site‐specific low‐input system compared with the site‐specific control was from small to large (i.e. from −99% in industrial hemp in the Mediterranean to +210% in willow in the Continental zone), due to the genotype‐by‐management interaction along with climatic variation between growing seasons. Genotype selection and improved knowledge on crop response to changing environmental, site‐specific biophysical constraint and input application has been detected as key to profitably grow industrial crops on marginal areas. This study may act to provide hints on how to scale up investigated cropping systems, through low‐input practices, under similar environmental and soil conditions tested at each site. However, further attention to detail on the agronomy of early plant development and management in larger multi‐year and multi‐location field studies with commercially scalable agronomies are needed to validate yield performances, and thereby to inform on the best industrial crop options. Growing industrial crops on marginal lands has been proposed as a strategy to minimize competition for arable land and food production. This study can bring an advancement to knowledge on the suitability of certain industrial crops to marginal and contaminated soils to mitigate indirect land‐use change (i‐LUC) in accordance with the RED II and to meet the European Green Deal towards an EU climate neutral in 2050. It ultimately can assist to make general recommendations of the most appropriate crop and management options at the different regions, climates, soils and marginal land types. [ABSTRACT FROM AUTHOR]

Growing lignocellulosic crops on marginal lands could compose a substantial proportion of future energy resources. The potential of poplar was explored, by devising a field trial of two hectares in 2007 in a metal-contaminated site to quantify the genotypic variation in the growth traits of 14 poplar genotypes grown in short-rotation coppice and to assess element transfer and export by individual genotypes. Our data led us to conclusions about the genotypic variations in poplar growth on a moderately contaminated site, with the Vesten genotype being the most productive. This genotype also accumulated the least amounts of trace elements, whereas the Trichobel genotype accumulated up to 170 mg Zn kg−1 DW in the branches, with large variation being exhibited among the genotypes for trace element (TE) accumulation. Soil element depletion occurred for a range of TEs, whereas the soil content of major nutrients and the pH remained unchanged or slightly increased after 10 years of poplar growth. The higher TE content of bark tissues compared with the wood and the higher proportion of bark in branches compared with the wood led us to recommend that only stem wood be harvested, instead of the whole tree, which will enable a reduction in the risks encountered with TE-enriched biomass in the valorization process. Unlabelled Image • We observed genotypic variations in growth of poplar at a moderately contaminated site. • There were large variations between genotypes for trace element accumulation. • Soil depletion occurred for a range of trace element after 10 years of growth. • Branches had accumulated a lot more elements than wood. • We recommend choosing stemwood-only harvesting instead of whole-tree harvesting. [ABSTRACT FROM AUTHOR]

In recent decades, show caves have begun to suffer from microorganism proliferation due to artificial lighting installations for touristic activity. In addition to the aesthetic problem, light encourages microorganisms that are responsible for physical and chemical degradation of limestone walls, speleothems and prehistoric paintings of cultural value. Microorganisms have previously been described by microscopy or culture-dependent methods, but data provided by new generation sequencing are rare. The authors identified, for the first time, microorganisms proliferating in one Swiss and in four French show caves using three different primers. The results showed that both photosynthetic and non-photosynthetic bacteria were the dominant taxa present in biofilms. Microalgae were heavily represented by the Trebouxiophyceae, Eustigmatophyceae and Chlorophyceae groups. Twelve diatoms were also recorded, with dominance of Syntrichia sp. (96.1%). Fungi were predominantly represented by Ascomycota, Zygomycota and Basidiomycota, fully half of the sampled biofilms where Fungi were detected. Comparing microbial communities from bleach-treated caves to those in untreated caves showed no significant difference except for a low-level change in the abundance of certain taxa. These findings provided by Illumina sequencing reveal a complex community structure in the 5 caves based on the assembly of bacteria, cyanobacteria, algae, diatoms, fungi and mosses. [ABSTRACT FROM AUTHOR]

Revegetation of industrial landfills and mine tailing may restore key soil functions and reduce the environmental impacts of contaminants. These marginal sites are often characterized by phytotoxic levels of trace elements (TE) (Cu, Fe, Mn, and Zn) and low nutrient status (N, P, and K). The aim of this study was to test the effect of digestate and bacterial inoculation on soil physicochemical properties (pH, CaCl 2 extractable Mn, and microbial enzyme activities) and birch (Betula pendula) growth and physiology on a red gypsum substrate in a lab-to-field experimental approach. The biomass of birches amended with digestate (D0.05% N) was on average 2- and 6-fold greater than that of control birch in the laboratory and field experiments, respectively. A higher concentration of digestate (0.1% N) had an inhibitory effect on plant growth, and reduced the survival rates of amended plants by 40% as compared with controls. The digestate (D0.05% N) treatment significantly increased leaf P and K contents while decreasing leaf Ca, Fe and Mn contents. Digestate also increased some key soil enzyme activities of C, N, P and S metabolism by >10-fold compared with the control soil. In a phytomanagement scenario, digestate would be a preferred amendment resource for the production of clean birch leaf biomass on contaminated red gypsum landfill, as birch trees amended with digestate had lower leaf TE and higher leaf nutrient contents than control birches. [Display omitted] • Digestate and bacterial inoculum were used to improve birch growth on red gypsum. • The digestate significantly increased birch biomass as well as leaf P and K content. • The two amendments decreased the leaf Fe, Mn and Zn contents. • Soil functionalities were enhanced upon digestate amendments. [ABSTRACT FROM AUTHOR]

This study deals with approaches for a social-ecological friendly European bioeconomy based on biomass from industrial crops cultivated on marginal agricultural land. The selected crops to be investigated are: Biomass sorghum, camelina, cardoon, castor, crambe, Ethiopian mustard, giant reed, hemp, lupin, miscanthus, pennycress, poplar, reed canary grass, safflower, Siberian elm, switchgrass, tall wheatgrass, wild sugarcane, and willow. The research question focused on the overall crop growth suitability under low-input management. The study assessed: (i) How the growth suitability of industrial crops can be defined under the given natural constraints of European marginal agricultural lands; and (ii) which agricultural practices are required for marginal agricultural land low-input systems (MALLIS). For the growth-suitability analysis, available thresholds and growth requirements of the selected industrial crops were defined. The marginal agricultural land was categorized according to the agro-ecological zone (AEZ) concept in combination with the marginality constraints, so-called 'marginal agro-ecological zones' (M-AEZ). It was found that both large marginal agricultural areas and numerous agricultural practices are available for industrial crop cultivation on European marginal agricultural lands. These results help to further describe the suitability of industrial crops for the development of social-ecologically friendly MALLIS in Europe. [ABSTRACT FROM AUTHOR]