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Wildfires as a major challenge for natural regeneration in Atlantic Forest
No full textThe natural regeneration management is a good strategy of ecological restoration of the Atlantic Forest, one of the most devastated biomes on the planet. However, the frequent occurrence of wildfires is one of the challenges to the success of this method. The objective of this study was to evaluate the effects of wildfires on forest dynamics in Atlantic Forest. The studied area was explored during the coffee cycle when plantations replaced primary forests. We used remote sensing data to analyze the forest dynamics over a period of 50 years (1966–2016). We used the INPE burn database to find the occurrence of hot spots from 1998 to 2016. During this period, we selected the years most affected by the fires for the identification of fire scars using the Normalized Burn Ratio spectral index. From this set of information, we used the methodology of weights of evidence to relate forest dynamics and wildfire events with biophysical and anthropic variables. The results showed that in 1966 the forest area accounted for 8.01% of the land cover, and in 2016 this number rose to 18.55% due to the spontaneous natural regeneration process. The regenerating areas were mainly related to the proximity of the remaining fragments and the portions of the landscape receiving the least amount of global solar radiation. The proximity to urban areas, roads and highways, damaged regeneration and favored both deforestation and wildfire events. Fire scars preferentially occur where there is greater sun exposure. It is possible to observe a negative correlation between the natural regeneration process and the fire scars. We concluded that fire severity is one of the factors that shape the landscape of the region while slowing the regeneration process in preferential areas. © 2018 Elsevier B.V
New subgenus and four species of Lepidocyrtus Bourlet (Collembola, Entomobryidae, Lepidocyrtinae) from Amazon
No full textHere a new subgenus of Lepidocyrtus Bourlet from South America is proposed. Fractocyrtus subgen.n. differs from other subgenera by tergal polychaetosis, dental tubercle truncate and dentes with numerous spine-like chaetae. Four new species of Lepidocyrtus are described, two of Setogaster Salmon and two of Fractocyrtus subgen.n. Lepidocyrtus (S.) amazonicus sp.n. and L. (S.) multisensillatus sp.n. are similar to L. nigrosetosus Folsom by basomedian field with chaetae smooth and dental tubercle rounded, but differ in dorsal chaetotaxy. Lepidocyrtus (F.) americanus sp.n. and L. (F.) mateosi sp.n. are similar by presence of numerous dental spines, but differ in chaetotaxy. Due to inconsistencies concerning scales on appendages of Lepidocyrtus subgenera, four synonyms are proposed, and the characteristics diagnostic to subgenera are shape and presence of dental tubercle, dental spines, mucronal spinelet and apical bulb of fourth antennal segment. An identification key to subgenera is also provided. © Koninklijke Brill NV, Leiden, 201
Do zombie ant fungi turn their hosts into light seekers?
No full textSpecialized parasites can modify host behavior to benefit transmission and reproduction. Such behavior is considered an extended phenotype of the parasite. The interactions between certain ant species and fungi of the genus Ophiocordyceps form an evident example. Once infected by Ophiocordyceps camponoti-atricipis, Camponotus atriceps ants die, biting at specific sites where abiotic conditions are optimal for fungal development. For many species of free-living fungi, light is needed to induce growth of the reproductive stage. However, the role of light in Ophiocordyceps behavioral manipulation and fruiting body development is largely unknown. Here, we investigated the association between illuminance and the incidence of dead manipulated C. atriceps ants. We identified ant graveyards in the field and experimentally changed the incident illumination for half of each graveyard using shading screens. Such screens resulted in a clear reduction of incident light, as well as slightly higher, more stable humidity levels. We measured the appearance of recently died, infected ants, the height at which they were found, and their fruiting body production. The presence of dead infected C. atriceps was strongly influenced by experimental light reduction. Shaded areas harbored fewer recently infected ants compared to naturally illuminated areas. In addition, in shaded areas, a smaller number of ants produced fruiting bodies and these ants also appeared to have climbed to higher elevations in comparison to control areas. Our findings indicate that light influences the place of the C. atriceps death, and fungal development by seemingly affecting fruiting body formation in O. camponoti-atricipis. © The Author(s) 2019. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved
Prey abundance drives habitat occupancy by jaguars in Amazonian floodplain river islands
No full textThe jaguar (Panthera onca) is widely distributed across a broad range of habitat types, where its feeding habits and habitat use patterns vary significantly. The jaguar and its main arboreal prey – the brown-throated sloth (Bradypus variegatus) and the red howler monkey (Alouatta juara) – are widespread in the Amazonian floodplain forests of the Mamirauá Reserve. These forest-dwelling species are the most common mammal species both in the continuous forest and the forest patches surrounded by a river matrix – the fluvial islands – of the Solimões and Japurá rivers. We used sign surveys along line-transects to assess the pattern of habitat occupancy by jaguars in Amazonian floodplain forests. Specifically, we (i) tested whether habitat occupancy by jaguars differs between river islands and continuous forest; and (ii) evaluated whether and how the local abundance of sloths and howler monkeys influence the probability of site occupancy by jaguars. We built an occupancy model and used Bayesian inference to reach these goals. The proportion of sites estimated to be used by jaguars was ψ = 0.75 (HPD95: 0.36–1.00), and it did not differ between islands and continuous forest. The abundance of both prey species had a direct influence on jaguar's habitat use, whereas the aquatic matrix seems to have a negligible effect on the use of islands by jaguars. We conclude that the isolation of the river islands within the aquatic matrix does not hamper jaguars to use them. We also conclude that prey search modulates jaguars’ habitat occupancy patterns with both prey species having a similar effect. This finding is compatible with the previously reported importance of sloths to the diet of jaguars in the study region despite its lower abundance than howlers. Finally, we suggest that sign surveys are an alternative method to assess the pattern of jaguar habitat occupancy in floodplain forests. © 2019 Elsevier Masson SA
Screening for fmr1 expanded alleles in patients with autism spectrum disorders in Manaus, Northern Brazil
Get PDFFragile X Syndrome (FXS) is a neurodevelopmental disorder caused by dynamic mutations of a CGG repetition segment in an X chromosome’s single gene. It is considered the leading hereditary cause of both Autism Spectrum Disorders and Intellectual Disability. Some authors suggest that all individuals diagnosed with some of these latter conditions to be clinically and molecularly trialled for FXS due to the high levels of comorbidity between both conditions and also due to the variable expressiveness of this syndrome. This study has focused on verifying the presence of FMR1 expanded alleles since there is a lack of information about this kind of mutation in autism patients from the northern region of Brazil. The presence of large alleles for this gene could offer new therapeutic or pharmacological methods for the treatment of these patients. Both the presence and the frequency of CGG expansions were verified in 90 autism males by molecular analysis. Four of them had intermediate alleles and four others presented premutated alleles. Premutation carriers are on the propensity of developing the late onset Fragile X-associated tremor/ataxia syndrome. No full mutation alleles were found. Further studies are necessary to obtain more accurate statistical data about this kind of dynamic mutation. © 2019, Academia Brasileira de Ciencias. All rights reserved
Retrocessos sob o Presidente Bolsonaro: Um desafio à sustentabilidade na Amazônia / Setbacks under President Bolsonaro: A Challenge to Sustainability in the Amazon / Retrocesos bajo el Presidente Bolsonaro: Un Desafío a la Sostenibilidad en la Amazonía
No full textA new species and two new records of besleria (gesneriaceae) from Brazil
No full textWe describe and illustrate Besleria discreta, a new species from the Brazilian state of Espírito Santo. The new species has been found in a mountainous area in the southern part of the state and can be recognized by leaf blades that are slightly bullate on the adaxial surface and a short corolla. We also report the occurrence of two species that have not previously been recorded in the Amazon rainforest in Brazil: Besleria concinna and Besleria neblinae. Data on morphology, ecology, distribution, and preliminary conservation status of the three taxa are also provided. © Copyright 2019 by the American Society of Plant Taxonomists
Comparação quimiométrica de diferentes tratamentos de elicitação no perfil químico de calos de Duroia macrophylla Huber
No full textAuthor Correction: Climatic controls of decomposition drive the global biogeography of forest-tree symbioses (Nature, (2019), 569, 7756, (404-408), 10.1038/s41586-019-1128-0)
No full textIn this Letter, the middle initial of author G. J. Nabuurs was omitted, and he should have been associated with an additional affiliation: ‘Forest Ecology and Forest Management Group, Wageningen University and Research, Wageningen, The Netherlands’ (now added as affiliation 182). In addition, the following two statements have been added to the Supplementary Acknowledgements. (1): ‘We would particularly like to thank The French NFI for the work of the many field teams and engineers, who have made extraordinary efforts to make forest inventory data publicly available.’ (1): ‘Sergio de Miguel benefited from a Serra- Húnter Fellowship provided by the Generalitat of Catalonia.’ Finally, the second sentence of the Methods section should have cited the French NFI, which provided a national forestry database used in our analysis, to read as follows: ‘The GFBi database consists of individual-based data that we compiled from all the regional and national GFBi forest-inventory datasets, including the French NFI (IGN—French National Forest Inventory, raw data, annual campaigns 2005 and following, https://inventaire-forestier.ign.fr/spip.php?rubrique159, site accessed on 01 January 2015)’. All of these errors have been corrected online. © 2019, The Author(s), under exclusive licence to Springer Nature Limited