111,359 research outputs found

    Future of oil and gas development in the western Amazon

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    The western Amazon is one of the world's last high-biodiversity wilderness areas, characterized by extraordinary species richness and large tracts of roadless humid tropical forest. It is also home to an active hydrocarbon (oil and gas) sector, characterized by operations in extremely remote areas that require new access routes. Here, we present the first integrated analysis of the hydrocarbon sector and its associated road-building in the western Amazon. Specifically, we document the (a) current panorama, including location and development status of all oil and gas discoveries, of the sector, and (b) current and future scenario of access (i.e. access road versus roadless access) to discoveries. We present an updated 2014 western Amazon hydrocarbon map illustrating that oil and gas blocks now cover 733 414 km(2), an area much larger than the US state of Texas, and have been expanding since the last assessment in 2008. In terms of access, we documented 11 examples of the access road model and six examples of roadless access across the region. Finally, we documented 35 confirmed and/or suspected untapped hydrocarbon discoveries across the western Amazon. In the Discussion, we argue that if these reserves must be developed, use of the offshore inland model-a method that strategically avoids the construction of access roads-is crucial to minimizing ecological impacts in one of the most globally important conservation regions

    Storm intensity and old-growth forest disturbances in the Amazon region

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    We analyzed the pattern of large forest disturbances or blow-downs apparently caused by severe storms in a mostly unmanaged portion of the Brazilian Amazon using 27 Landsat images and daily precipitation estimates from NOAA satellite data. For each Landsat a spectral mixture analysis (SMA) was applied. Based on SMA, we detected and mapped 279 patches (from 5 ha to 2,223 ha) characteristic of blow-downs. A total of 21,931 ha of forest were disturbed. We found a strong correlation between occurrence of blow-downs and frequency of heavy rainfall (Spearman\u27s rank, r2 = 0.84, p \u3c 0.0003). The recurrence intervals of large disturbances were estimated to be 90,000 yr for the eastern Amazon and 27,000 yr for the western Amazon. This suggests that weather patterns affect the frequency of large forest disturbances that may produce different rates of forest turnover in the eastern and western Amazon basin

    Determination of Region of Influence Obtained by Aircraft Vertical Profiles Using the Density of Trajectories from the HYSPLIT Model

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    Aircraft atmospheric profiling is a valuable technique for determining greenhouse gas fluxes at regional scales (104–106 km2). Here, we describe a new, simple method for estimating the surface influence of air samples that uses backward trajectories based on the Lagrangian model Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT). We determined “regions of influence” on a quarterly basis between 2010 and 2018 for four aircraft vertical profile sites: SAN and ALF in the eastern Amazon, and RBA and TAB or TEF in the western Amazon. We evaluated regions of influence in terms of their relative sensitivity to areas inside and outside the Amazon and their total area inside the Amazon. Regions of influence varied by quarter and less so by year. In the first and fourth quarters, the contribution of the region of influence inside the Amazon was 83–93% for all sites, while in the second and third quarters, it was 57–75%. The interquarter differences are more evident in the eastern than in the western Amazon. Our analysis indicates that atmospheric profiles from the western sites are sensitive to 42–52.2% of the Amazon. In contrast, eastern Amazon sites are sensitive to only 10.9–25.3%. These results may help to spatially resolve the response of greenhouse gas emissions to climate variability over Amazon

    Mineralogy of soils with unusually high exchangeable Al from the western Amazon region.

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    Some soils from the western Amazon region contain KCl-extractable Al contents 5 to 10 times greater than is typical for highly weathered soils containing predominantly kaolinite and gibbsite. We studied a soil sequence from the Brazilian western Amazon consisting of two Typic Udifluvents on the levee of the Javari River, onde Aeric Endoaquent in the backswamp, and two Typic Hapludults on an adjacent terrace

    The Amazon Myth in Western Literature.

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    This dissertation identifies and evaluates the ways in which the Amazon myth has functioned. The Amazon myth functions within broader discourses about the Orient, Africa, and women. It has implications for the ways we define self and other. Because they are often represented as a threat to the border from long ago and/or far away, Amazons can serve both as an excuse for fortifying the center against the margin, and as a way of projecting fantasies into the void. The Amazon myth has incited men to action as they have searched for adventure and Amazons abroad. Intended in part as a warning to women of what they could become and of what could happen to them if they rebelled against traditional roles, it has also provided an alluring model to women searching for more power and autonomy. The Amazon myth projects onto foreign soil tensions felt in the home society and provides a safe sphere for the expression and resolution of those tensions. As a breach of the Great Chain of Being, usurping Amazons can serve either as a critique of that idea or as a call to arms for heroic men to defend it. The first chapter develops the theoretical framework for the dissertation. This framework is derived primarily from Michel Foucault, Edward Said, and Christopher Miller. Foucault devised what he termed the three axes of genealogy: the axes of truth, power, and ethics. The uses of the Amazon myth reflect the interplay of these during different eras. Said and Miller have shown how Foucault\u27s theory applies to discourses about the Orient and Africa, respectively. Interpretations of the Amazon myth have tended to reflect each era\u27s thought about the other , whether other-as-foreigner or other-as-woman or both. The subsequent chapters follow a chronological order. The second chapter is an investigation of Amazon myths in Greek and Roman societies; the third, an analysis of medieval treatments of Amazon myths. The fourth is an examination of uses of Amazon myths during the Renaissance, and the fifth is an analysis of Amazons during the Romantic and Victorian eras

    World News

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    A group of environmental experts warned that four infrastructure projects in the Amazon have caused a rush of deforestation even before building has begun. The report on the world’s largest tropical forest, by international environmental experts charged with advising Brazil and rich countries donating to a program which has channeled $350 million to conserving the Amazon, came after data in June showed the Amazon deforestation rate jumped 40 percent last year. Profitable soy farming is seen as a special threat. Roughly 15 percent of the Amazon - an area larger than western Europe of continuous tropical forest that is home to up to 30 percent of the world’s animal and plant species - has so far been cut down

    Devising new ways to make local retail contribute to urban vibrancy

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    In most of the Western world, local independent stores are becoming ever more rare. Retail is increasingly dominated by large players - big retailers, global franchises and digital giants like Amazon

    The onset of grasses in the Amazon drainage basin, evidence from the fossil record

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    Poaceae (the grass family) originated in the Cretaceous, but first dominate the palynological records of the Amazon drainage basin (ADB) in the Neogene (23 to 2.5 million years ago (Ma)). However, the ecological role of grasses in the landscape during this time remains to be resolved. In this paper, we summarise the global significance of grasses and the relevance of the fossil record, and evaluate the history of the grasses in the ADB. We present a 3-stage model of the changing role of grasses, which we based on a revision of Neogene depositional environments, the palynological record, and modern grass distribution in the Neotropics. Our model comprises the following hypotheses: (H1) assumes that from c. 23 to 9 Ma western Amazonia was dominated by a megawetland (the ‘Pebas system’) that harboured large amounts of (aquatic?) grasses. In (H2) we propose that from c. 9 Ma Andean uplift prompted megafans (extremely large alluvial fans) that extended from the Andes into the lowlands. Meanwhile, the ‘Pebas’ megawetland gradually transformed into a fluvial system. In this scenario, grasses would have had a competitive advantage and were able to colonise the newly formed megafan and fluvial landscapes. Finally, in (H3) we suggest that landscape dynamics and climatic change intensified from c. 3.5 Ma, allowing for a renewed expansion of the grasses. In addition, both the fossil and molecular records suggest that from c. 5 Ma grasses were firmly established in the tropical alpine vegetation (páramo), the tropical lowland floodplains (várzeas), and savannas (cerrado). Although further study will have to confirm the precise nature of the ADB grass history, we anticipate that abiotic processes during the Neogene and Quaternary left a strong imprint in the grass phytogeography of northern South America

    Avifauna of the upper Purus River: relevant records for an area lacking ornithological surveys

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    Birds are the best-known vertebrate group, although many localities in the world are considered to be knowledge gaps. This is the case of many little-known environments in the Amazon biome, the world’s largest tropical forest. Here, we present a survey of birds in the upper Purus basin, comprising the municipalities of Manoel Urbano and Feijó in the Brazilian state of Acre, and Boca do Acre and Pauini in the state of Amazonas. In this region, poorly-studied habitats, such as open rainforest dominated by palms or bamboo, still predominate. We recorded 452 bird species during 45 field trips between May and July in 2016, and June to August in 2017. Twenty-four of these species are associated with bamboo habitat, 28 are endemic to the southwestern Amazon basin, and seven are threatened with extinction. This high diversity is typical of the western Amazon basin, one of the richest regions in the world in the number of species, due to the heterogeneity of the local environments. The data presented here highlight the importance of the region for the conservation of birds, including species typical of the western Amazon, some of which are still poorly-known

    Increasing biomass in Amazonian forest plots

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    A previous study by Phillips et al. of changes in the biomass of permanent sample plots in Amazonian forests was used to infer the presence of a regional carbon sink. However, these results generated a vigorous debate about sampling and methodological issues. Therefore we present a new analysis of biomass change in old-growth Amazonian forest plots using updated inventory data. We find that across 59 sites, the above-ground dry biomass in trees that are more than 10 cm in diameter (AGB) has increased since plot establishment by 1.22 ± 0.43 Mg per hectare per year (ha-1 yr-1), where 1 ha = 104 m2), or 0.98 ± 0.38 Mg ha-1 yr-1 if individual plot values are weighted by the number of hectare years of monitoring. This significant increase is neither confounded by spatial or temporal variation in wood specific gravity, nor dependent on the allometric equation used to estimate AGB. The conclusion is also robust to uncertainty about diameter measurements for problematic trees: for 34 plots in western Amazon forests a significant increase in AGB is found even with a conservative assumption of zero growth for all trees where diameter measurements were made using optical methods and/or growth rates needed to be estimated following fieldwork. Overall, our results suggest a slightly greater rate of net stand-level change than was reported by Phillips et al. Considering the spatial and temporal scale of sampling and associated studies showing increases in forest growth and stem turnover, the results presented here suggest that the total biomass of these plots has on average increased and that there has been a regional-scale carbon sink in old-growth Amazonian forests during the previous two decades
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