Abstract The volcanic Trindade Island is a remote Brazilian offshore territory in the South Atlantic, located ca. 1.140 kilometers east of the southeast coast of Brazil. The island’s permanent exposure to geological hazards requires assessment. However, the lack of erosion and landslides temporal data impedes predictive geohazard analyses. Therefore, we compiled pre-existing data from nautical charts and surveyed the surface terrain on Trindade Island to generate Digital Terrain Models (DTMs) and comparative accuracy analyses. The DTM based on pre-existing data shows the lowest accuracy (root mean square error - RMSE: 12.3 m) yet is adequate for regional studies. In contrast, the DTM developed from real-time kinematic global navigation satellite systems (RTK-GNSS) has the highest vertical accuracy (RMSE: 0.48 m), but spatial variability of ground elements was underestimated and limited to meter-sized (and larger) elements. The DTM obtained using the unmanned aerial vehicle (UAV) with ground control points (GCP), on the other hand, presented lower accuracy (RMSE: 2.37 m) than the RTK-GNSS model but still allowed observation of centimetric (and larger) ground features. For geohazard assessment on Trindade Island, models that allow fine-scale studies are needed. A UAV with GCP provides such standards and proved to be the most viable option in remote and complex sites as well. Hence, this study, the first to allow multi-temporal analysis of geohazard assessment on Trindade Island, offers a viable solution for similar analyses in other remote locations.

RESUMO As espécies de Arecaceae, conhecidas popularmente por palmeiras, além de se destacarem na paisagem amazônica, agregam valores econômico e social. O presente trabalho teve como objetivo analisar as características físico-químicas dos óleos extraídos de cinco variedades de frutos de pupunha (Bactris gasipaes Kunth). Para tanto, amostras de frutos de cinco matrizes provenientes de plantios foram coletadas no município de Cruzeiro do Sul, região do alto Juruá (74º0’ W a 72ºW e 7º05’ S a 9º40’ S) e foram determinados o teor de óleo, densidade, índice de refração, espectrofotometria e cromatografia em camada delgada. Os dados foram submetidos às análises de variância (ANOVA) e de regressão, cuja diferença entre as médias dos tratamentos foi testada por meio do teste de Tukey a 5% de significância, realizados com o auxílio do software RStudio Core Team, versão 3.6.3 e com pacote ExpDes.pt, car, stats e fBasics. Os resultados apontaram teores de óleo essencial de 24,29%, 24,28% para as matrizes 2 e 4 e abaixo de 8,1% para as matrizes 1,3 e 5. O índice de acidez variou de 1,26 a 5,22 mg NaOH/g de óleo, enquanto o índice de refração variou de 1,4510 a 1,4690. A análise de cromatografia em camada resultou em sete Rfs, sendo eles nas faixas 0,325; 0,45; 0,5; 0,6; 0,7; 0,8 e 1 para todos os óleos analisados, com curvas espectroscópicas apresentando diferenças significativas nas faixas de 320 a 540 nm, indicando diferentes grupos funcionais e/ou substâncias nos extrativos vegetais. De acordo com os resultados, o óleo essencial das amostras de frutos de pupunha (Bactris gasipaes) apresentou valores distintos e significativos para os cinco parâmetros físico-químicos avaliados, o que desperta a atenção para uma possível ocorrência de variabilidade genética no material estudado, mas sugerindo, ao mesmo tempo, que se amplie a investigação, com um maior tamanho amostral e se confirme uma alternativa de investimento em melhoramento genético.

ABSTRACT In addition to standing out in the Amazonian landscape, Arecaceae species, popularly known as palm trees, add economic and social values. The purpose of this paper was to analyze the physical and chemical characteristics of the oils extracted from five varieties of peach palm fruits (Bactris gasipaes). In order to achieve such purpose, fruit samples from five plantation matrices were collected in the municipality of Cruzeiro do Sul, in the upper Juruá region (74º0 ‘W at 72ºW and 7º05’ S at 9º40 ‘S). We determined the oil content, the density, the refractive index, the spectrophotometry, and the thin layer chromatography. The data were subjected to analyses of variance (ANOVA) and regression. The difference between the means of the treatment was tested with the Tukey test at 5% significance, performed with the aid of RStudio Core Team software, version 3.6.3 and with ExpDes.pt package, car, stats and fBasics. Our findings showed essential oil contents of 24.29%, 24.28% for matrices 2 and 4, and below 8.1% for matrices 1.3 and 5. The acidity index ranged from 1.26 to 5.22 mg NaOH / g oil, whereas the refractive index ranged from 1.4510 to 1.4690. The analysis of layer chromatography resulted in seven RFs, with the ranges 0.325; 0.45; 0.5; 0.6; 0.7; 0.8 and 1 for all oils analyzed. Spectroscopic curves showed significant differences in the ranges 320 to 540 nm, indicating different functional groups and/or substances in the extractives. According to the results, the essential oil from the samples of peach palm fruits (Bactris gasipaes) showed distinct and significant values for the five physical and chemical parameters evaluated, which calls attention to a possible occurrence of genetic variability in the material studied. The findings suggest that the investigation should be expanded with a larger sample size, and that an alternative investment in genetic improvement should be confirmed.

ABSTRACT Beachrocks are a common feature along the Brazilian coast and although their occurrence in intertidal zones is concentrated in tropical regions, similar formations have been described submerged on the continental shelf in subtropical regions. In the state of Paraná, submerged sandstones are present on the continental shelf and their formation could be associated with the cementation of beach sediments. This would provide an excellent indicator of the stabilization of the coastline during lower sea-level periods. In this study, samples were identified and collected in Paraná State, Southern Brazil, at depths between 18 and 33 meters in the continental shelf and at 6 meters depth in the Paranaguá Bay inlet. As in situ observations proved problematic, analysis relied mainly on their petrography, mineralogy, ages and isotopic values (δ13C and δ18O). Whole rock dating demonstrated that the oldest acquired sample was formed 28109-26406 cal. years BP, being exposed to atmospheric conditions during the Last Glacial Maximum. This exposure is reflected in its cements, composed uniquely of microcrystalline and spar calcite, and on its δ18O/δ13C values, which indicates formation on a fresh water environment. Contrarily to most carbonate cemented products described along Brazilian coastline, δ13C values ranged between -26.36 and -51.07‰ on all other samples, interpreted as a result of cement precipitation prompted by methane, either: in a paleo-estuarine/ paleo-lagunar to transgressive environment buried under a pile of coarser material or; after transgression and drowning of organic-rich sediments by coarser sediments, and due to upward migration of methane on the sedimentary column. Both processes would result in cements identified on these samples, apart from the one collected closer to shore which indicates some freshwater influence. Two of the samples separated by 15km distance perpendicularly to the actual coastline and 11m depth difference yielded max and minimum ages of 7913 and 7452 cal. years BP. Such a short time span between these samples could be either the result of their formation on a linked environment or older carbon signature from drowned environments being present on younger cements.

ABSTRACT This study aimed to map habitats and species distribution in a benthoscape section of the Paranaguá Bay inlet, Paraná State, Southern Brazil. The degree of correspondence between maps independently generated through sidescan imagery and macrofauna and sediment samples was also evaluated. The study area had approximately 9km2 and was chosen considering both diverse landscape features and proximity to future port developments. Sampling was performed in 67 evenly distributed and unreplicated sites. Patterns related to backscatter intensity (high and low) and the presence or absence of bedforms were observed, as well as other large-scale features like sand waves and beach rock outcrops. Local sedimentary environments were represented in a mosaic used for comparisons with sedimentary and faunistic data. Cluster analysis using grain size data formed four groups with similar particle size distribution. A strong correspondence between habitats and grain size distribution was found in only one habitat class. Macrofauna around the deeper Poço Point region and the Mel Island shallower banks presented high species richness and number of individuals. These were considered habitats of high biological relevance. Regions with bedforms indicate higher rates of sand transport in which a few species can thrive. The navigation channel had the lowest number of species and individuals when compared to vicinal regions, indicating persistent impacts. The study evidenced local estuarine bottom heterogeneity and contributed to the understanding of local processes of both bottom sediments dynamics and their associate faunal components.

ABSTRACT Discussions are useful to the advance of science, and we appreciate the opportunity to discuss the paper by Castro et al. (2014) for the second time. Here we maintain the interpretations presented in our discussion paper (Angulo et al. 2016). In the discussion paper we emphasized that the vertical position of a paleo-sea level indicator is not the position of the paleo-sea level. We pointed out that: (1) to reconstruct paleo-sea levels it is crucial to determine the vertical distance between the indicators to their present homologous one; (2) margin of errors can only be established if considering the indicator’s intrinsic characteristics and (3) the interpretation of a sea level 3.0 to 4.5 m below the present one at 11.9 to-11.1 ka BP is in strong contradiction with worldwide established data and would require a detailed discussion. We consider that Castro et al. (2018) do not properly address or answer the comments we made in the discussion paper. More work and discussions are necessary to elucidate several questions that still remain about the sea level behavior in the Holocene.

ABSTRACT The present work discusses and reinterprets paleo-sea level indicators used to build Holocene sea-level curve for the coast of Rio de Janeiro at former works. We conclude that: (a) the paleo-sea levels inferred by vermetid remains show that sea-level has fallen over the past 4400 years, at least; (b) the paleo-sea level inferred by the beachrock facies and dated shells of Jaconé shows that sea-level was near the present elevation between 8198 and 5786 years before present; and (c) several shells from other beachrocks were deposited probably thousands of years after the specimens died and consequently do not allow precise reconstructions of paleo-sea levels. These conclusions differ from the conclusions of the original paper.

Na Reserva Florestal Walter Egler, localizada a 64 km de Manaus, no município de Rio Preto da Eva, foi investigada a ocorrência de Pteridófitas ao longo de uma toposseqüência. O grupo ocorre nos três ambientes observados na área (baixio, vertente e platô) com diferença tanto qualitativa quanto quantitativa. Foram registrados 375 indivíduos, distribuídos em oito famílias, 10 gêneros e 17 espécies; entre epífitas, hemiepífitas, herbáceas e arbóreas. Das 8 famílias, 4 ocorrem em todos os ambientes: Dennstaedtiaceae, Hymenophyllaceae, Dryopteridaceae e Lomariopsidaceae, enquanto, Cyatheaceae e Vittariaceae ocorrem apenas no baixio. Das 17 espécies encontradas, sete ocorrem apenas no baixio, três na vertente e cinco são comuns em todos os ambientes.

The occurrence of Pteridophytes was investigated along a transect at the Walter Egler Forest reserve, located 64 km from Manaus in the municipality of Rio Preto da Eva. The group occurs on the three landscapes observed in the area (lowland, slope and plateau) with a both qualitative and quantitative difference. Three hundred and seventy five (375) individuals were established, distributed in 8 families, 10 genera and 17 species; among epiphytes, hemepiphytes, herbaceous and arboreal. Of the 8 families, 4 occur on all landscapes: Dennstaedtiaceae, Hymenophyllaceae, Dryopteridaceae and Lomariopsidaceae, whereas, Cyatheaceae and Vittariaceae occur only on lowland. Of the 17 identified species, 7 occur only lowland, 3 on slope, and 5 are common on all landscapes.