Northern Amazon Region Research Articles

Neotropical non‐primate canopy mammals: historical trends, omissions, and geographic gaps in the knowledge

ABSTRACT Canopy mammals constitute a diverse and widely distributed group. However, these species have not been widely studied, and there are currently many gaps in our knowledge of their ecology, behaviour, distribution, and conservation status. We identified crucial trends and omissions in terms of research effort on research themes, taxonomic groups, countries, and protected areas (PAs) and geographic information biases. A systematic review was conducted by consulting two electronic databases (Web of Science and Scopus), including research conducted within neotropical countries (from central Mexico to northern Argentina) until the end of the first half of 2021. All the references obtained were reviewed and categorised, and the geographical location of each study was extracted to evaluate geographical gaps. We found that two orders (Carnivora and Didelphimorphia) and three families (Didelphidae, Felidae, and Cricetidae) were the most studied taxa, and were featured in more than 50% of cases. Brazil had the highest number of studies. Topics concerning diseases (19% of cases), distribution (14%), and ecology (14%) were the most frequently addressed; only 4.6% of the studies focused on anthropogenic disturbances, and less than 30% of the studies were conducted within PAs. We found that one of the largest and most important geographical biases in knowledge was in the northern Amazon region, where the number of studies was low or null. This study lays the groundwork for future research on these understudied mammals, to develop better research that can allow us to design more appropriate conservation strategies.

Long-Term Environmental Methylmercury Exposure Is Associated with Peripheral Neuropathy and Cognitive Impairment among an Amazon Indigenous Population.

Widespread contamination of the Amazon basin with mercury has been reported to occur since at least the mid-80s due to heavy gold mining activity. Although initial studies have indicated that this may lead to deleterious neurological consequences to the indigenous populations living in the region, further research is needed to better characterize the neurological burden of such long-term exposure. With this aim, a cross-sectional exploratory study has been conducted with the Yanomami indigenous population residing in a northern Amazon region. All participants underwent a structured interview; detailed neurological examination, including assessment for cognitive, motor, coordination, and sensory functions; and laboratorial testing for serum hemoglobin, blood glucose, and methylmercury levels in hair samples. This study enrolled 154 individuals of 30.9 ± 16.8 years of age, of which 56.1% were female. Mean methylmercury levels in hair were 3.9 ± 1.7 µg/g. Methylmercury levels in hair > 6.0 µg/g were found in 10.3%. Among participants with hair methylmercury levels ≥ 6.0 μg/g, the prevalences of peripheral neuropathy and reduced cognitive performance were, respectively, 78.8% (95%CI 15-177%, p = 0.010) and 95.9% (95%CI 16-230.8%, p = 0.012) higher than those of individuals with lower levels. These results suggest that chronic mercury exposure may lead to significant and potentially irreversible neurotoxicity to Yanomami population living in the northern Amazon basin.

Geothermal resource exploration in South America using an innovative GIS-based approach: A case study in Ecuador

Integrating geothermal energy contributes to a sustainable energy transition in South American countries. Geothermal energy is a non-variable and renewable resource that can be used for baseload power generation to reduce the overdependence on fossil fuel and hydropower plants. There is a vast and untapped geothermal potential in South America. Nevertheless, multiple barriers, including lack of geological, hydrogeochemical and geophysical background and outdated regional studies have blocked the development as it should be. Thus, this study aims to update and identify promising areas for further geothermal exploration through a favourability map implemented in a GIS-based model for Ecuador as a case study. The results show that approximately half (49.2%) of the national territory of Ecuador has promising areas to explore and develop geothermal systems along the Andean and South-west coast. New zones were identified, which contribute to increasing the national inventories of geothermal energy. Also, the Northern Amazon region presents mature oil fields and reservoirs close to their productive life. Thus, geothermal energy systems may help transition the petroleum industry into a clean energy provider. This research contributes to the needed improvement of existing geothermal resource inventories. The robustness of the proposed GIS-based model has been tested. Thus, it allows the analysis and combination of available open geodata in an effective, low-cost method, and even under a scenario of scarce data availability, to support decision-makers, researchers, or stakeholders, and guide geothermal exploration programs at a national level.

Pedoenvironments driving the monodominance of Peltogyne gracilipes (Leguminosae) in the Northern Amazon, Brazil

Monodominance is unusual in the tropics when compared to the high diversity of tropical forests. Peltogyne gracilipes (Leguminosae) is a deciduous tree species that forms monodominant forests in the Brazilian Northern Amazon region. Initial research confirmed that P. gracilipes monodominance was associated with higher soil magnesium content, while recent studies have indicated a larger number of variables, suggesting a more complex hydro-edaphic habitat. As such, the present study aimed to describe the hydro-edaphic habitat (pedoenvironment) where P. gracilipes is monodominant. Edaphic and topographic variables (drainage proxy) were used in a forest inventory conducted in 129 sampling plots. Trees with a stem diameter greater than 10 cm were analyzed. Aboveground biomass was used as a descriptive variable of the different habitats in the study area. A total of 3041 individuals were sampled (298 P. gracilipes). Multivariate analysis demonstrated that the highest P. gracilipes abundance occurred in poorly drained (seasonal flooding) low-altitude habitats (

The Spread of NDM-1 and NDM-7-Producing Klebsiella pneumoniae Is Driven by Multiclonal Expansion of High-Risk Clones in Healthcare Institutions in the State of Pará, Brazilian Amazon Region.

Carbapenem resistance among Klebsiella pneumoniae isolates is often related to carbapenemase genes, located in genetic transmissible elements, particularly the blaKPC gene, which variants are spread in several countries. Recently, reports of K. pneumoniae isolates harboring the blaNDM gene have increased dramatically along with the dissemination of epidemic high-risk clones (HRCs). In the present study, we report the multiclonal spread of New Delhi metallo-beta-lactamase (NDM)-producing K. pneumoniae in different healthcare institutions in the state of Pará, Northern Brazil. A total of 23 NDM-producing isolates were tested regarding antimicrobial susceptibility testing features, screening of carbapenemase genes, and genotyping by multilocus sequencing typing (MLST). All K. pneumoniae isolates were determined as multidrug-resistant (MDR), being mainly resistant to carbapenems, cephalosporins, and fluoroquinolones. The blaNDM-7 (60.9%—14/23) and blaNDM-1 (34.8%—8/23) variants were detected. MLST genotyping revealed the predomination of HRCs, including ST11/CC258, ST340/CC258, ST15/CC15, ST392/CC147, among others. To conclude, the present study reveals the contribution of HRCs and non-HRCs in the spread of NDM-1 and NDM-7-producing K. pneumoniae isolates in Northern (Amazon region) Brazil, along with the first detection of NDM-7 variant in Latin America and Brazil, highlighting the need for surveillance and control of strains that may negatively impact healthcare and antimicrobial resistance.

Spatial distribution and level of contamination of potentially toxic elements in sediments and soils of a biological reserve wetland, northern Amazon region of Ecuador

This study quantifies the degree of pollution and assess the ecological risk of As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, V and Zn in sediments and soils of the Limoncocha Biological Reserve (Ecuador), identified as a Ramsar site with high ecological and socioeconomic value. The hydrologic system of the Reserve is mainly formed by two rivers that drain into the Limoncocha lagoon, which occupies only five percent of the protected area but support a high anthropic influence. Local statistical baseline of studied potentially toxic elements is established using cumulative frequency method, and Al is selected as reference element due to the good correlation with the studied elements. The grade of pollution and the potential ecological risk are evaluated applying three individual (Contamination Factor, Geo-accumulation Index and Enrichment Factor) and six integrated (Degree and modified degree of contamination, Pollution Load Index, Nemerow and modified Nemerow pollution indexes and potential ecological risk index) indices. Results analysis are based on the combined application of traditional statistics, multivariate data analysis and self organizing maps. Outcomes suggest to classify sediments and soils as “moderate contamination and enrichment” due mainly to the concentrations of Cu (66.4–110 mg/kg) and Cd (0.0262–0.808 mg/kg), derived from domestic wastewaters and agricultural activities, and in a lesser extent due to Mo (0.822–4.37 mg/kg), Ni (10.3–25.8 mg/kg), Co (7.27–24.8 mg/kg) and V (60.3–178 mg/kg), derived from oil field drilling activities. The distributions of As (0.328–8.83 mg/kg), Ba (143–1100 mg/kg), Pb (7.20–26.5 mg/kg), Zn (60.1–276 mg/kg) and Cr (10.1–48.6 mg/kg) are heterogeneous in the studied sampling sites. Sediments located next to the pier and at the central area of the Limoncocha lagoon, show moderate potential risk and according to sediment quality guidelines, the calculated mean Effect Range Median quotient (mERMq) classify the sites as medium-low priority risk level. A three-level classification of a mean quotient based on soil quality and soil potential uses is proposed. Soil sites with high anthropogenic activities show low to moderate potential ecological risk being classified as poor soil quality sites but with all potential soil uses allowed according to the legal limits for land uses in Ecuador.

The expansion of the agricultural frontier in the northern Amazon region of Ecuador, 2000–2011: Process, causes, and impact

The Amazon forest has been characterized as one of the areas with the most extraordinary biodiversity in the world. However, the implementation of public policies throughout history has been one cause of an increasing presence of farmers who exert pressure on resources. The need to determine agricultural frontier growth and document the problem has been addressed by many authors who have focused their research on methodologies based on the use of geographic information systems. However, an approach based on quantitative and qualitative data could be constructive in validating and/or complementing such studies. In our case, from a historical contextualization, we identify the main causes of agricultural frontier expansion and, by analyzing information compiled from surveys and interviews, attempt to establish its main impacts. We found that the rate of deforestation for the period under review is at odds with rates determined by other methodologies. We also conclude that rapid population growth and the implementation of government projects in the area have led, first, to a division of land (farms) and a change in land use and, second, to a significant reduction in the forest cover.

English

The fruit seeds of the Northern Amazon Region were evaluated bromatologically and nutritionally in terms of the level of macro- and micro-elements and fatty acids present in them. Bromatologically, the seeds of camu-camu (369.08 kcal 100 g-1) and biribá (364.78 kcal 100 g-1) have the highest energy value. In terms of the macroelements, the highest concentration was potassium (554.23 mg 100 g-1) seen in graviola, followed by magnesium (123.11 mg 100 g-1) in biribá. In terms of micronutrients, the highest concentrations are zinc (4.14 mg 100 g-1) and manganese (4.12 mg 100 g-1) in abiu seeds. The fatty acids composition of the seeds studied had a higher percentage of unsaturated fatty acids. Among the most saturated is palmitic acid with a concentration of 40.4% for taperebá seeds while among the unsaturated is oleic acid with a concentration of 47.4% for bacuparí seeds. Key words: Oleic acid, bromatological, minerals, saturated fatty acids (SFA), unsaturated fatty acids (UFA). &nbsp

Characterization of Bioactive Compounds in Northern Amazon Fruits

Fruits and vegetables are highly appreciated because they are constituted by active phytochemicals with functional properties for the organism acting with modulating pharmacological effect. Given the pharmacological properties of this type of food, in this work were studied the concentrations of vitamin C, total carotenoids and reducing and non-reducing sugars of nine fruits developed in the northern Amazon region: Abiu, Acerola, Araçá, Bacuparí, Biribá, Camu-camu, Fruta-do-conde, Graviola and Tapereba. The concentration of vitamin C, the highest concentration in the shell of Camu-camu 2521.51 mg 100 g-1 and for acerola with 1731.4 mg 100 g-1 stand out. The highest concentrations of total carotenoids were also found for the Camu-camu, with concentrations of 0.67 mg 100 g-1 the shell of Camu-camu and 0.57 mg 100 g-1 for the pulp. The concentrations of sugars are higher for the pulps, with the highest concentrations for the pulp of the Fruta-do-conde with 16.31 g 100 g-1 followed by the pulp of the Graviola, both of the Annonaceae family with a concentration of 15.61 g 100 g-1. The different bioactive molecules were correlated for the different parts of the fruit, by means of multivariate analysis techniques (PCA and HCA), where 90.1% of the cases were explained for the pulps, 65.4% for the shell of the fruits and finally the 88.5% of the cases for the seeds. Given the results obtained in this work, these fruits can be used for the preparation of foods with functional interest.

Roadkilled mammals in the northern Amazon region and comparisons with roadways in other regions of Brazil

ABSTRACT Roadways and road traffic modify landscapes, posing a threat to the conservation of species in different biomes. The aim of the present study was to analyze roadkill records of wild mammals and to compare the results to findings from 37 other studies conducted in Brazil, to evaluate the richness and diversity of threatened species in different eco-regions of the country. This study was conducted between June 2007 and June 2008, along 60 km of the inter-state highway BR-364, which connects the municipalities of Ouro Preto d’Oeste and Presidente Médici in the state of Rondônia (northern Brazil). Two hundred twenty roadkills were recorded involving 13 species of mammals. Cingualata, Pilosa and Carnivora were the most represented orders. The most represented were the generalist species Dasypus novemcinctus (56.7%), Tamandua tetradactyla (10.5%), and Cerdocyon thous (8.2%), reflecting the adaptability of these species to habitat changes and presence of humans. The number of roadkilled individuals and species indicated no significant differences between the dry and rainy seasons. The findings indicate a high index of roadkills (3.38 individuals/km/year) and moderate number of run over species (0.20 species/km/year) in the region in comparison to records from other roadways in Brazil, with 46% species having an endangered status. Roadways in the eco-regions of the Cerrado (Brazilian savanna) accounted a significantly larger proportion of endangered species (mean: 52%) in comparison to the Pampa (lowlands of southern Brazil; 24%), but the differences in comparison to roadways in Amazonia (37%) and the Atlantic Forest (31%) were non-significant. The present findings underscore the need for emergency measures to minimize the impact of roadkills on mammals. Moreover, priority should be given to more impacted roadways and more threaten eco-regions.

Forest management in Bolivia under Evo Morales: The challenges of post-neoliberalism

Based on a study of the forest sector in the northern Amazon region of Bolivia, this paper addresses the reasons why the Bolivian so-called “postneoliberal” project is an adjustment of neoliberalism rather than a departure from it. First, Bolivia has aimed not so much at breaking away radically from neoliberal frameworks as at reasserting the importance of the state and of the national scale in regulatory actions. Second, the neoliberal period has left behind the insuperable legacy of a neoliberal approach to nature: by allowing local stakeholders to access forest resources, it has reinforced a commercial relationship with the non-human world. Third, it is not easy to reverse the internationalization of forest governance. All in all, the Bolivian state's reterritorialization of the country's margins through the control of forest resources has perpetuated processes that were initiated during the hybrid neoliberal period (1993–2005), though the focus has shifted from commoditizing the forest for the benefit of local stakeholders to facilitating the redistribution of this resource on a national scale. Since 2006 Evo Morales's forest governance has tried to integrate this multiscale dimension to create a pragmatic management model that combines agrarian colonization, conservation and extractivism. This explains both the apparent contradictions of the new Bolivian forest policy and the difficulties in creating a radically new form of governance. The case of Bolivian forests shows the extent to which neoliberalism has shaped spaces and scales in a way that guarantees its own resilience.

Rotavirus analyses by SYBR Green real-time PCR and microbiological contamination in bivalves cultivated in coastal water of Amazonian Brazil.

The contamination of mussels and oysters by viruses and bacteria is often associated with water contamination and gastroenteritis in humans. The present study evaluated viral and bacterial contamination in 380 samples, from nine mollusk-producing regions in coastal water north of the Brazilian Amazon. Rotavirus contamination was studied for groups A to H, using a two-step SYBR Green RT-qPCR (quantitative reverse transcription polymerase chain reaction), and bacterial families Enterobacteriaceae, Vibrionaceae, and Aeromonadaceae by classical and molecular methods. From the 19 pools analyzed, 26.3% (5/19) were positive for group A Rotavirus, I2 genotype for VP6 region, without amplifications for groups B-H. Bacteriological analysis identified Escherichia coli isolates in 89.5% (17/19) with identification of atypical enteropathogenic E. coli aEPEC in 10.5% (2/19), Salmonella (Groups C1 and G) (10.5%, 2/19), Vibrio alginolyticus (57.9%, 11/19) V. parahaemolyticus (63.2%, 12/19), V. fluvialis (42.1%, 8/19), V. vulnificus (10.5%, 2/19), V. cholerae non-O1, non O139(10.5%, 2/19) and Aeromonas salmonicida (52.6%, 10/19). All the samples investigated presented some level of contamination by enterobacteria, rotavirus, or both, and these results may reflect the level of contamination in the Northern Amazon Region, due to the natural maintenance of some of these agents or by the proximity with human populations and their sewer.

Phylogenetic structure is determined by patch size in rock outcrop vegetation on an inselberg in the northern Amazon region

ABSTRACT Although inselbergs from around the world are iconic ecosystems, little is known on the underlying mechanisms of community assembly, especially in their characteristic patchy outcrop vegetation. Environmental constraints are expected to cause phylogenetic clustering when ecological niches are conserved within evolutionary lineages. We tested whether vegetation patches from rock outcrops of the Piedra La Tortuga Natural Monument, in the northern Amazon region, are phylogenetically clustered, indicating that environmental filtering is the dominant driver of community assemblage therein. We classified all patches according to their size as very small (< 1 m2), small (1-4 m2), medium-sized (4-8 m2), and large patches (8-15 m2). From each class, we randomly selected 10 patches, totalizing 40 patches covering 226 m2. All individuals found in the 40 isolated patches were identified to the species level. We also correlated measurements of phylogenetic community structure with patch size. We found that species from patches are restricted to the clades monocots, fabids, malvids, and lamiids. We conclude that vegetation in this rock outcrop is phylogenetically clustered. Furthermore, we found that phylogenetic turnover between pairs of patches increases with patch size, which is consistent with a scenario of higher environmental stress in smaller patches. Further research is necessary to identify nurse species in inselberg vegetation, which is pivotal for conservation and restoration of this particular ecosystem.

Livelihood sustainability assessment of coffee and cocoa producers in the Amazon region of Ecuador using household types

Supporting small farmer livelihoods in fragile, biodiverse regions, such as tropical forests, is a priority for many development agencies and national governments. These regions tend to be characterized by recent human settlements, increasing populations and infrastructure development, as well as competitive land use activities, which exert pressure on fragile ecosystems. Improvement in livelihood strategies often focuses on increasing yields by improving productivity, but without taking into account alternative methods, such as better agricultural practices and their dependence on agrochemical inputs, changing land use through crop substitution, or improving product commercialization. In this research, we use household types, defined according to different land use patterns, in the Northern Amazon region of Ecuador to explore the limitations of, and identify future options for, improving livelihood strategies based on small-scale coffee and cocoa production. The results of the different types are discussed in order to highlight the methods' utility and identify benefits in terms of environmental and social objectives versus economic profitability. Lessons are drawn that could be useful in applications of public policy aimed at the betterment of small coffee grower and cocoa farmer livelihood strategies, which involve thousands of families in the Amazon region of Ecuador, without compromising the environment.

Annotated list of freshwater fishes of the Limoncocha Lagoon, Napo river basin, northern Amazon region of Ecuador

An annotated list of the freshwater fishes of the Limoncocha Lagoon, in the Limoncocha Biological Reserve in the northern Amazon region of Ecuador is presented. Fishes were captured between March and July of 2012, and we combined these results with previous studies to provide a comprehensive list of fishes in the Limoncocha Biological Reserve. Thirty-three species belonging to 14 families distributed in 7 orders were collected. The most representative orders in number of species and specimens were Characiformes, Siluriformes, and Perciformes, respectively, being Characiformes as the most important in terms of richness and abundance of species. Characidae (Characiformes) exhibited the greatest abundance and broadest distribution in our samples. A short morphological description and morphometric measurements of each species are also presented.

Complete Genome Sequence of a Vampire Bat Rabies Virus from French Guiana.

A rabies virus was detected in a common vampire bat (Desmodus rotundus) in French Guiana. Its genomic sequence was obtained and found to be closely related to other hematophagous bat-related viruses that widely circulate in the northern Amazon region. This virus is named AT6.

Intraspecific variability of camu-camu fruit in native populations of northern Amazonia

Abstract Similarly to most breeding programs of native species, camu-camu (Myrciaria dubia (Kunt) McVaugh) improvement is also restricted, due to the scarcity of research results. In this situation, the prospection, collection and conservation of germplasm in genebanks ensure successful selection and breeding studies of the species. In this sense, the purpose of this study was the intraspecific characterization of the biometric variability in fruits of native camu-camu populations of the State of Roraima, in the northern Amazon region. Of 16 populations, 247 sub-samples were evaluated. Analyses were performed with the multivariate technique of principal components and hierarchical clustering, to determine the variables with highest intraspecific variability for the studied traits. The populations found in the lower Rio Branco region performed best for the studied traits, indicating the great potential of the region as a reservoir of promising subsamples for future breeding programs of the species in the northern Amazon.

An update on the rainfall characteristics of Brazil: seasonal variations and trends in 1979-2011

We studied rainfall characteristics of Brazil for the period 1979–2011. This is an update for an earlier study with data from 1958 to 1978. We compared the three consecutive wet and dry months in the two data sets. In the northern most part rainy season earlier was in April to July and now it is occurring later. In a large part of the south central region the rainy season in austral summer and dry season in austral winter did not change. However, to the east of this region rainy season in the latter data occurs earlier. Calculation of linear tendencies showed, that over the northern Amazon region there is a significant increase of rainfall. This agreed with previous results. Over this region dry season is becoming drier and wet season wetter. In the west of Northeast Brazil (NEB) there is an increase of rainfall. In southeast Brazil there is a region of highly significant decrease of rainfall in both wet and dry seasons. This is confirmed in our analysis on river discharges in Sao Paulo and Minas Gerais states. The negative tendencies in rainfall have great impact on the hydroelectric generation not only in this region but also at the national level because the hydroelectric dams furnish energy on a national level. The increase in rainfall in Northern Amazon is probably associated with Atlantic warming that resulted in higher moisture transport from east. The decrease of rainfall in southeast Brazil seems to be associated with the plummet of rain producing systems from south due to increase of mean sea level pressure in the south.

Climate and land use drivers of the spatial and temporal distribution of malaria risk in the Peruvian Amazon

Background: Malaria remains one of the world's most devastating public health threats. In Peru, 75% of malaria occurs in the northern Amazon region of Loreto where 80% of cases are concentrated in ...

Holocene palaeoenvironmental history of the Amazonian mangrove belt

Wetland dynamic in the northern Brazilian Amazon region during the Holocene was reviewed using palynological, carbon and nitrogen isotopes records, and C/N ratio previously published. The integration of 72 radiocarbon dates recorded in 34 sediment cores sampled along the marine and fluvial littoral, and mainly influenced by the Amazon River, reveals that marine influence and mangrove vegetation were wider than today on the mouth of Amazon River between >8990–8690 and 2300–2230 cal yr BP, forming a continuous mangrove belt along the northern Brazilian Amazon littoral. The establishment of this mangrove strip is a direct consequence of the marine incursion caused by post-glacial sea-level rise possibly associated with tectonic subsidence during the Early and Middle Holocene. In the Late Holocene, in areas influenced by the Amazon River discharge, the mangroves were replaced by freshwater vegetation, and the coast morphology evolved from an estuarine dominated into a rectilinear coast due to coastal progradation. Nevertheless, the marine-influenced littoral, which is currently dominated by mangroves and salt-marsh vegetation, has persistently had brackish water vegetation over tidal mud flats throughout the entire Holocene. Likely, the fragmentation of this continuous mangrove line during the Late Holocene was caused by the increase of river freshwater discharge associated to the change from dry into wet climates in the Late Holocene. This caused a significant decrease of tidal water salinity in areas near the mouth of Amazon River. These changes in the Amazon discharge are probably associated with dry and wet periods in the northern Amazon region during the Holocene.