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Trees in urban areas face harsh environmental conditions. Ectomycorrhizal fungi (EcM) form a symbiosis with many tree species and provide a range of benefits to their host through their extraradical hyphal network. Although our understanding of the environmental drivers and large scale geographical variation of EcM communities in natural ecosystems is growing, our knowledge of EcM communities within and across urban areas is still limited. Here, we characterized EcM communities using Illumina miseq sequencing on 175 root samples of the urban tree Tilia tomentosa from three European cities, namely Leuven (Belgium), Strasbourg (France) and Porto (Portugal). We found strong differences in EcM richness and community composition between cities. Soil acidity, organic matter and moisture content were significantly associated with EcM community composition. In agreement, the explained variability in EcM communities was mostly attributed to general soil characteristics, whereas very little variation was explained by city and heavy metal pollution. Overall, our results suggest that EcM communities in urban areas are significantly associated with soil characteristics, while heavy metal pollution and biogeography had little or no impact. These findings deliver new insights into EcM distribution patterns in urban areas and contribute to specific inoculation strategies to improve urban tree vitality.

Introduction: Imported malaria is a frequent diagnosis in Portugal, and in the most severe clinical forms it may present a high mortality rate., Material and Methods: We present seven cases of severe imported malaria, admitted to an intensive care unit between 2000 and 2010, with particular focus on risk factors, clinical presentation, treatment and results., Results: All patients had a history of recent travel to African endemic areas for malaria. Plasmodium falciparum was the agent isolated in all cases. Most patients had an inadequate prophylaxis. High parasitaemia in non-immune patients and treatment delay were associated with more severe clinical presentation. All the cases were complicated by organ failure, and three patients needed organ support and in two exchange blood transfusions were performed. There was one single death that was associated with marked delay in the initiation of therapy., Conclusion: In these patients, early and aggressive treatment, with a organ support in a critical care setting, allowed a good outcome with low mortality and no significant sequelae, despite the severity of presentation.