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Establishing which factors determine species distributions is of major relevance for practical applications such as conservation planning. The Amazonian lowlands exhibit considerable internal heterogeneity that is not apparent in existing vegetation maps. We used ferns as a model group to study patterns in plant species distributions and community composition at regional and landscape scales. Fern species composition and environmental data were collected in 109 plots of 250 × 2 m distributed among four sites in Brazilian Amazonia. Interplot distances varied from 1 to ca 670 km. When floristically heterogeneous datasets were analyzed, the use of an extended Sørensen dissimilarity index rather than the traditional Sørensen index improved model fit and made interpretation of the results easier. Major factors associated with species composition varied among sites, difference in cation concentration was a strong predictor of floristic dissimilarity in those sites with pronounced heterogeneity in cation concentration. Difference in clay content was the most relevant variable in sites with uniform cation concentrations. In every case, environmental differences were invariably better than geographic distances in predicting species compositional differences. Our results are consistent with the ideas that: (1) the relative predictive capacity of the explanatory variables depend on the relative lengths of the observed gradients; and (2) environmental gradients can be hierarchically structured such that gradients occur inside gradients. Therefore, site‐specific relationships among variables can mask the bigger picture and make it more difficult to unravel the factors structuring plant communities in Amazonia.

International audienceWhite-sand forests are thought to host many ectomycorrhizal fungi, as demonstrated by the numerous fruiting body collections made by Rolf Singer in the lower Rio Negro in the late 1970s. Despite recognition of the importance of ectomycorrhizal fungi in white-sand forests, there has not yet been a systematic examination of diversity and taxonomic composition across white-sand forests, or more widely across lowland Amazonian forests. In an effort to broaden our view of ectomycorrhizal fungal diversity and distribution on white-sand forests, we collected ectomycorrhizal fruiting bodies in 10 plots of white-sand forests in Brazil and French Guiana between 2012 and 2014. We collected 221 specimens and 62 morphospecies, from the 10 plots, confirming that all studied white-sand forests host ectomycorrhizal fungi. Additionally, we searched for taxa associated with white sands among specimens deposited in Brazilian herbaria. We report 1006 unique ectomycorrhizal specimen records in 18 Brazilian herbaria, of which 137 specimens and 64 species are reported from white-sand forests, mainly in the state of Amazonas, Brazil. Russulaceae and Amanitaceae were frequent in all habitats, and Cortinarius were more frequent on white sands. Our results highlight the high diversity and heterogeneity of ectomycorrhizal communities on white-sand forests, and the wide distribution of ectomycorrhizal fungi throughout Brazil, irrespective of soil type.Florestas em solos arenosos são consideradas como hospedeiras de muitos fungos ectomicorrízicos (EM), como demonstrado pelas numerosas coletas feitas por Rolf Singer na região do Rio Negro, Amazonas, no final dos anos 70. Apesar do reconhecimento da importância dos fungos ectomicorrízicos em florestas em solos arenosos, não houve nenhum estudo sistemático da diversidade e da composição taxonômica nas florestas em solos arenosos ou mesmo mais amplamente nas terras baixas da Floresta Amazônica. Para ter uma visão global da diversidade e da distribuição de fungos EM em florestas em solos arenosos, foram coletados basidiomas desses fungos em 10 parcelas de florestas em solos arenosos no Brasil e na Guiana Francesa entre 2012 e 2014. Além disso, uma busca foi feita por espécimes depositados em herbários brasileiros que tinham a informação de serem coletas feitas em solo arenoso. Nas 10 parcelas amostradas foram coletados 221 espécimes e 62 morfoespécies, o que confirma que todas as florestas em solos arenosos hospedam fungos EM. Recuperamos 1006 espécimes registrados em 18 herbários brasileiros, dos quais 137 espécimes e 52 espécies são registros de florestas em solos arenosos principalmente no estado do Amazonas, Brasil. Russulaceae e Amanitaceae foram frequentes em todos os habitats e Cortinarius foi o táxon mais frequente em solo arenoso. Os resultados apresentados enfatizam a alta diversidade e heterogeneidade das comunidades de EM em florestas em solos arenosos, assim como a ampla distribuição de fungos em todo o Brasil, não exclusivamente em florestas em solos arenosos

Fungi are important components of tropical ecosystems, especially in the recycling of nutrients. However, there is little information on how fungal diversity is structured at scales suitable to plan their conservation. We tested if the distribution of fruiting bodies of litter fungi was random in the landscape (over 25 km 2 ) in a tropical evergreen forest in Central Amazonia. We used linear regressions to evaluate the inXuence of rainfall, soil characteristics and topography on morphospecies richness and composition. Fungi were collected twice in thirty 0.25 £ 250 m plots. Short-term rainfall was represented by the cumulative rainfall in the three days before each plot was surveyed. Plots were classiWed in two groups based on cumulative rainfall. Clay content in soil and rainfall inXuenced morphospecies richness, but responses to edaphic factors depended on rainfall. Wetter periods apparently decreased limiting moisture conditions in higher areas, allowing fungal activity and fruiting body production. Morphospecies composition was inXuenced by clay content, but inXuence on fungi was probably indirect as clay content was correlated with altitude, plant community and nitrogen availability. Our results suggest that the species of litter fungi are not randomly distributed in the landscape. Furthermore, they indicate that it is viable to conduct mesoscale evaluations of fungal diversity, if the temporal and spatial variation and their interaction are taken into account. Resumo (in Portuguese) Fungos são importantes componentes dos ecossistemas tropicais, atuando especialmente na reciclagem de nutrientes. Entretanto, existe pouca informação sobre como a diversidade de fungos está estruturada em escalas adequadas para planejar sua conservação. Nós testamos se a distribuição de corpos de frutiWcação de fungos de liteira ocorre de forma aleatória na paisagem (em 25 km 2 ) em uma Xoresta na Amazônia Central. Utilizamos regressões lineares para avaliar a inXuência da precipitação, do solo e topograWa sobre a riqueza e composição 1 C amostrados em trinta parcelas de 0,25 £ 250 m em duas ocasiões. A precipitação em curto prazo foi representada pela chuva acumulada em três dias antes da parcela ser amostrada. As parcelas foram classiWcadas em dois grupos baseados na precipitação acumulada. O conteúdo de argila no solo e a precipitação inXuenciaram a riqueza de morfoespécies, mas as respostas aos fatores edáWcos dependeram da precipitação. Períodos mais chuvosos aparentemente diminuíram condições limitantes de umidade nas áreas mais elevadas, permitindo a atividade e produção de corpos de frutiWcação pelos fungos. A composição de morfoespécies foi inXuenciada pelo conteúdo de argila, mas provavelmente a inXuência sobre os fungos foi indireta, dado que o conteúdo de argila esteve correlacionado com altitude, comunidade de plantas e disponibilidade de nitrogênio. Nossos resultados sugerem que as espécies de fungos de liteira não estão distribuídas aleatoriamente na paisagem. Além disso, indicam que conduzir avaliações da diversi...

Extrapolation of local abundance-environment relationships to broader scales provides species distribution models used for conservation planning. We investigated the importance of environmental heterogeneity and geographic distance on pteridophyte species spatial distribution on 38 plots of 250 x 2.5 m distributed over 90 km 2 in Central Amazon. Inclusion of canopy openness in our models increased the capacity of predicting community composition even under the narrow range of canopy openness found in our plots. Nevertheless, there was still a large amount of unexplained variance (55-65%). The response of the community to the light gradient was hierarchical and we did not find evidences of light partitioning. Most species were concentrated in low light plots but a few common and abundant occurred along the entire gradient. Soil properties were the major determinants of community composition. Contrary to similar studies, slope was not a good predictor of pteridophyte community composition, indicating that this relationship may be site-specific. There was no correlation between Boristic distances and geographic distances. We concluded that mesoscale turnover is low, although locally environmental variation determines high turnover of species. Studies among different Amazonian physiognomies tend to find high levels of beta-diversity. However, coarse comparisons can not reveal subtle patterns that are relevant for biodiversity conservation planning. This study found

Ferraz et al. (2008) indicated the need for planning in biological monitoring in the Amazon, and reviewed what they considered recent progress. The problems and solutions they discuss are well known, and it is unlikely that many biologists would disagree with most of them. However, the authors do not indicate that most of these issues are already being addressed in practice in the Amazon, especially by the Programa de Pesquisas em Biodiversidade (PPBio) of the Brazilian Ministry of Science and Technology. The only major issue about which we do not agree with Ferraz et al. (2008) relates to the design of monitoring programs. The authors recommended tailoring experimental designs to specific threats, which will result in a multitude of idiosyncratic designs and incompatible data sets. We suggest that generic broad‐scale designs will allow us to answer more questions with greater confidence, because the investment in each location provides information about regional and global questions. Although specific designs may be more effective in some cases, there are insufficient resources available to install different research infrastructure for every possible threat.

A new species, Geastrum inpaense, is described morphologically and molecularly. Geastrum lloydianum, G. schweinitzii, Phallus merulinus and Staheliomyces cinctus are reported here as new records for Central Amazonia. In addition, Mutinus fleischeri is reported as a new record for the Americas and Phallus atrovolvatus, as a new record for Brazil.

Abstract-EUBrazilOpenBio is a collaborative initiative addressing strategic barriers in biodiversity research by integrating open access data and user-friendly tools widely available in Brazil and Europe. The project deploys the EU-Brazil Hybrid Data Infrastructure that allows the sharing of hardware, software and data on-demand. This infrastructure provides access to several integrated services and resources to seamlessly aggregate taxonomic, biodiversity and climate data, used by processing services implementing checklist cross-mapping and ecological niche modelling. A Virtual Research Environment was created to provide users with a single entry point to processing and data resources. This article describes the architecture, demonstration use cases and experimental results.