Forest fires can threaten amphibians because ash-associated contaminants transported by post-fire runoff impact both terrestrial and aquatic ecosystems. Still, the effects of these contaminants on the skin microbiome of amphibians have been overlooked. Thus, the main objective of this study was to assess the effects of ash from different severity wildfires (moderate and high) on the skin microbiome of the Iberian frog (Rana iberica). Bacterial isolates sampled from R. iberica skin microbiome were tested for their antimicrobial activity against the pathogen Aeromonas salmonicida. The isolates with antimicrobial activity were identified and further exposed to several concentrations (0, 6.25, 12.5, 25, 50, 75, and 100%) of Eucalypt (Eucalyptus globulus) aqueous extracts (AAEs) of ash from both a moderate and a high severity wildfire. The results showed that 53% of the bacterial isolates presented antimicrobial activity, with Pseudomonas being the most common genus. Exposure to AAEs had diverse effects on bacterial growth since a decrease, an increase or no effects on growth were observed. For both ash types, increasing AAEs concentrations led to an increase in the number of bacteria whose growth was negatively affected. Ash from the high severity fire showed more adverse effects on bacterial growth than those from moderate severity, likely due to the higher metal concentrations of the former. This study revealed that bacteria living in Iberian frogs' skin could be impaired by ash-related contaminants, potentially weakening the individual's immune system. Given the foreseen increase in wildfires' frequency and severity under climate change, this work raises awareness of the risks faced by amphibian communities in fire-prone regions, emphasising the importance of a rapid implementation of post-fire emergency measures for the preservation and conservation of this group of animals.

Polycyclic aromatic hydrocarbon (PAH) extracts of fine particles (PM₂.₅) collected from combustion of seven wood species and briquettes were tested for mutagenic activities using Ames test with Salmonella typhimurium TA98 and TA100. The woods were Pinus pinaster (maritime pine), Eucalyptus globulus (eucalypt), Quercus suber (cork oak), Acacia longifolia (golden wattle), Quercus faginea (Portuguese oak), Olea europea (olive), and Quercus ilex rotundifolia (Holm oak). Burning experiments were done using woodstove and fireplace, hot start and cold start conditions. A mutagenic response was recorded for all species except golden wattle, maritime pine, and briquettes. The mutagenic extracts were not correlated with high emission factors of carcinogenic PAHs. These extracts were obtained both from two burning appliances and start-up conditions. However, fireplace seemed to favour the occurrence of mutagenic emissions. The negative result recorded for golden wattle was interesting, in an ecological point of view, since after confirmation, this invasive species, can be recommended for domestic use.

The contamination left by abandoned mines demands sustainable mitigation measures. Hence, the aim of this study was to examine the phytoremediator ability of Eucalyptus globulus Labill. to be used for cleaning up metal-contaminated soils from an African abandoned iron (Fe) mine (Ait Ammar, Oued Zem, Morocco). Plantlets of this species were exposed to a control (CTL), a reference (REF), and a mine-contaminated soil (CS). Morphological (growth, leaf area) and physiological stress biomarkers (photosynthetic efficiency, pigments content, leaf relative water, and malondialdehyde (MDA) levels) and metal bioaccumulation were assessed. The growth and leaf area of E. globulus increased overtime in all soils, although at a lower rate in the CS. Its photosynthetic efficiency was not markedly impaired, as well as MDA levels decreased throughout the experiment in CS. In this soil, higher metal contents were detected in E. globulus roots than in leaves, especially Fe (roots: 15.98–213.99 μg g⁻¹; leaves: 5.97–15.98 μg g⁻¹) and Zn (roots: 1.64–1.99 μg g⁻¹; leaves: 0.67–1.19 μg g⁻¹), indicating their reduced translocation. Additionally, though at low extent, the plants bioaccumulated some metals (Pb > Zn > Cu) from CS. Overall, E. globulus may be potentially used for the phytoremediation of metals in metal-contaminated soils.

The purpose of the present study was to evaluate the effect of planting trees (Pinus pinaster or Eucalyptus globulus) and amending with wastes (sewage sludges and paper mill residues) on the nutrient content of mine soils and under field conditions. The studied soils were located in a settling pond and a mine tailing within a former copper mine. The soil samples were analyzed for several physico-chemical characteristics and the concentration of nutrients. The untreated settling pond soil had levels of N and K adequate only for the growth of eucalyptuses and pines, and moreover, the concentration of Ca and P were undetectable. The untreated mine tailing soil presented the same condition, also with adequate levels of Ca and Mg for eucalyptuses and pines. Planting these trees increased the concentration of Mg in the settling pond up to adequate levels only for such trees. Amending with wastes increased the phytoavailable concentration of all nutrients up to adequate levels for most plant species. In conclusion, it is recommended to amend mine soils with wastes rich in nutrients and re-amend after some time because they raise them up to adequate levels for most plants but are depleted over time. It is possible to increase the concentration of all nutrients in mine soils by adding organic wastes, even to values adequate for most plant species.

Background, aim and scope Pulp and paper mills generate a plethora of pollutants depending upon the type of pulping process. Efforts to mitigate the environmental impact of such effluents have been made by developing more effective biological treatment systems in terms of biochemical oxygen demand, chemical oxygen demand, colour and lignin content. This study is the first that reports an evaluation of the effects of a tertiary treatment by fungi (Pleurotus sajor caju, Trametes versicolor and Phanerochaete chrysosporium and Rhizopus oryzae) on individual organic compounds of a Eucalyptus globulus bleached kraft pulp and paper mill final effluent after secondary treatment (final effluent). Material and methods The tertiary treatment with P. sajor caju, T. versicolor and P. chrysosporium and R. oryzae was performed in batch reactors, which were inoculated with separate fungi species and monitored throughout the incubation period. Samples from effluent after secondary and after tertiary treatment with fungi were analysed for both absorbance and organic compounds. The samples were extracted for organic compounds using solid-phase extraction (SPE) and analysed by gas chromatography-mass spectrometry (GC/MS). The efficiencies of the SPE procedure was evaluated by recovery tests. Results A total of 38 compounds (carboxylic acids, fatty alcohols, phenolic compounds and sterols) were identified and quantified in the E. globulus bleached kraft pulp mill final effluent after secondary treatment. Recoveries from the extraction procedure were between 98.2% and 99.9%. The four fungi species showed an adequate capacity to remove organic compounds and colour. Tertiary treatment with R. oryzae was able to remove 99% of organic compounds and to reduce absorbance on 47% (270 nm) and 74% (465 nm). P. sajor caju, T. versicolor and P. chrysosporium were able to remove 97%, 92% and 99% of organic compounds, respectively, and reduce 18% (270 nm) to 77% (465 nm), 39% (270 nm) to 58% (465 nm) and 31% (270 nm) to 10% (465 nm) of absorbance, respectively. Discussion The wide variety of organic compounds found in the final effluent must be due to the degradation of E. globulus wood in pulp and paper mill. The concentrations of organic compounds in the final effluent of E. globulus bleached kraft pulp mill were in residual levels maybe due to the secondary treatment. The recovery tests showed the effectiveness of the extraction procedure, and no losses of analyte were suspected in the analytical determinations. Lignin derivatives such as vanilic acid, syringic acid, guaiacol, syringol and phloroglucinol were totally removed by R. oryzae, but the 47% absorbance reduction obtained at 270 nm suggests that these species were not able to complete degradation of lignin macromolecular compounds. Conclusions The organic compounds (carboxylic acids, fatty alcohols, phenolic compounds and sterols) were removed more efficiently by tertiary treatment with R. oryzae or P. chrysosporium, followed by P. sajor caju and T. versicolor. Regarding the removal of both colour and organic compounds, the tertiary treatment with R. oryzae was the most efficient. Recommendations and perspectives In order to reduce the deleterious impacts of paper mill effluents, efforts have been made to develop more effective advanced tertiary treatments. This study may serve as a basis of characterisation, in terms of organic compounds of E. globulus bleached kraft pulp mill final effluent after secondary treatment and as an effort to understand the effects of tertiary treatments with fungi on low concentrations of organic compounds from biological secondary treatment.

Aluminum in acidic conditions is toxic to plants. Aluminum tolerance in some plant species has been ascribed to arbuscular mycorrhizal fungal symbiosis. In this study, the application of aluminum was found to inhibit mycelia development of saprobe fungi Fusarium concolor and Trichoderma koningii and the hyphal length of the arbuscular mycorrhizal fungi Glomus mosseae and Glomus deserticola in vitro. Several levels of aluminum were applied to Eucalyptus globulus plants and inoculated with arbuscular mycorrhizal fungi alone or together with both saprobe fungi. The application of 1,500 mg kg⁻¹ decreased the shoot and root dry weight, chlorophyll content and total P, Mg, and Ca concentrations in the shoot of E. globulus. However, both mycorrhizal fungi G. mosseae and G. deserticola inoculated alone increased the shoot dry weight of Eucalyptus, compared with a non- arbuscular mycorrhizal inoculated control treated with 1,500 mg kg⁻¹ of aluminum. When 1,500 mg kg⁻¹ of aluminum was applied, T. koningii increased the effect of G. deserticola on the shoot weight of eucalyptus, whereas with 3,000 mg kg⁻¹, shoot weight and arbuscular mycorrhizal colonization decreased in all treatments. With 1,500 mg kg⁻¹, the highest accumulation of aluminum in the shoot was obtained when G. deserticola was inoculated together with T. koningii. The possibility of manipulating an arbuscular mycorrhizal inoculation together with a saprobe fungus confers a high aluminum resistance in E. globulus. The effect of such combined inoculation is particularly important in some Chilean volcanic acid soils, mainly those which have been intensively cropped and are without lime addition, which facilitates the increase of phytotoxic aluminum species and limits their agricultural use. Therefore, such dual inoculation in field conditions deserves further investigation. Overall, the arbuscular mycorrhizal and saprobe fungi contribute to the increase in resistance of E. globulus to aluminium.

The knockdown and adulticidal activities of individual Cymbopogon citratus and Eucalyptus globulus essential oils (EOs) and their combinations were evaluated against three medical insect pests (Aedes aegypti, Aedes albopictus, and Musca domestica) using a WHO susceptibility test. The knockdown and adulticidal activities against the three medical insect pests of combinations of C. citratus and E. globulus EOs were higher than those of individual EOs alone. Combinations of 7.5% C. citratus + 7.5% E. globulus EOs and 10% C. citratus + 10% E. globulus EOs exhibited the highest efficacy against females of the three species with 100% knockdown and mortality rates at 1 and 24 h after exposure, respectively. Their adulticidal activities were equivalent to that of 10% w/v cypermethrin. In contrast, 70% v/v ethyl alcohol negative control was not effective at all. The combinations of EOs showed a synergistic effect, i.e., their adulticidal activity was improved by 0.2 to 100%, with increased knockdown and mortality rates, compared to individual EOs. The highest synergistic effect on effective knockdown and adulticidal activities against females of the three species was achieved by a combination of 2.5% C. citratus + 2.5% E. globulus EOs, with 36.6 to 100% knockdown rate increase and 33.5 to 98.9% mortality rate increase. This study demonstrates that all tested combinations of C. citratus and E. globulus EOs were effective adulticidal agents against females of Ae. aegypti, Ae. albopictus, and M. domestica and have a high potential for development into a botanical insecticide for controlling populations of Aedes mosquitoes and houseflies.

The phytoremediation efficiency of multi-metal-polluted sites in an electronic waste recycling town by Eucalyptus globulus was evaluated through a series of 2-year field experiments. Different initial planting densities (2500, 5000, and 10,000 plants per ha), coppice rotations, and harvesting position (5 or 30 cm above the ground) protocols were designed to improve the remediation potential of the species. There were unnoticeable variations in metal concentrations and distribution characteristics in plant tissues in a low and medium planting-density field during the experimental period. At the end of the experiment, total biomass production per hectare in different protocols displayed a wide range with maximum yield produced in high density, moderate harvesting, and coppice rotation protocol being 2.9 times higher than the minimum yield. The moderate harvest protocol performed with medium planting density was the optimal Cd and Cu decontamination technique. Although the high planting-density field without coppice rotation had the strongest potential for Pb decontamination, it would take more time to remove other metals for the multi-metal-polluted soil decontamination. Considering the remediation efficiency and maintainability of the cultivation system, the moderate harvest protocol performed with the medium planting density was commended for phytoremediation of e-waste recycling impacted area.