Journal articles: 'Amazonian region'

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Almeida, Marlus Queiroz, João Rafael Alves-Oliveira, Diego Matheus De Mello Mendes, Rafael Sobral, Alberto Moreira da Silva-Neto, and José Wellington de Morais. "Alien spiders: First record of Loxosceles gaucho Gertsch, 1967 (Araneae: Sicariidae) in the Amazon region, Brazil." Papéis Avulsos de Zoologia 59 (October 31, 2019): e20195953. http://dx.doi.org/10.11606/1807-0205/2019.59.53.

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We present the first record for Loxosceles gaucho Gertsch, 1967 in the Amazonian region of Brazil. Four males, fifteen females and forty-nine immatures were collected in different places in Manaus, Amazonas, Brazil. This is the third species of Loxosceles reported in the Amazon region along with L. amazonica Gertsch, 1967, and L. similis Moenkhaus, 1898. This is the first record of an invasive species of a venomous animal in the state of Amazonas, Brazil, which is noteworthy due to its synanthropic habit, which increases the risk to the local population.

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Terborgh, John, and Ellen Andresen. "The composition of Amazonian forests: patterns at local and regional scales." Journal of Tropical Ecology 14, no. 5 (September 1998): 645–64. http://dx.doi.org/10.1017/s0266467498000455.

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An analysis was conducted of floristic patterns contained in 48 1-ha tree plots distributed at 29 sites in seven neotropical countries, with a primary emphasis on the Amazonian region. Analyses were made with family level data, using detrended correspondence analysis and multidimensional scaling to generate two-dimensional ordinations. Dissimilarity values for all pairs of plots were then used to compare forest composition at both local (flooded vs unflooded forests) and regional scales (e.g., western vs central vs eastern Amazonia). The predominate family of trees in a large majority of Amazonian and Guianan forests (by number of stems) is either Palmae or Leguminosae (sensu latu), followed by Moraceae and Euphorbiaceae. The forests of western Amazonia are particularly rich in palms, Moraceae, and Myristicaceae, whereas those of eastern Amazonia and the Guianas are rich in Lecythidaceae and Chrysobalanaceae. Dissimilarity between sites increases with distance for both flooded and unflooded forests. The tree communities of flooded and unflooded forests within a region tended to resemble one another more closely than forests of either type resembled the homologous forests of the adjoining regions. Within Amazonia the edaphic properties of each region and its geological history are tightly interrelated. It is therefore difficult to distinguish between evolutionary and ecological interpretations of the results.

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Vigna, María Susana, and Santiago Duque Escobar. "Silica-scaled chrysophytes from the Amazonian region in Colombia." Nova Hedwigia 69, no. 1-2 (August 1, 1999): 151–62. http://dx.doi.org/10.1127/nova.hedwigia/69/1999/151.

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da Silva, Maria Aparecida, Maria Aparecida de Jesus, Rafaela Saraiva Peres, and Ceci Sales-Campos. "Notes on Fomitiporia Murrill in Amazon region: a list of species and new records." Check List 17, no. 2 (March 1, 2021): 323–31. http://dx.doi.org/10.15560/17.2.323.

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Twenty-three specimens of the fungi genus Fomitiporia Murrill collected during the rainy season in the Amazonian region of Amazonas and Roraima states, Brazil. Eight species were listed, namely F. apiahyna s. l. (Speg.) Robledo, Decock & Rajchenb., F. calkinsii (Murrill) Vlasák & Kout, F. conyana Alves-Silva & Drechsler-Santos, F. impercepta Morera, Robledo & Urcelay, F. langloisii Murrill, F. maxonii Murrill, F. murrillii Alves-Silva, R.M. Silveira & Drechsler-Santos, and F. neotropica Camp.-Sant., Amalfi, R.M. Silveira, Robledo & Decock.  Our new data includes the first records of species from the Amazonian region, Brazil, and the Americas.

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Clement, Charles R., William M. Denevan, Michael J. Heckenberger, André Braga Junqueira, Eduardo G. Neves, Wenceslau G. Teixeira, and William I. Woods. "The domestication of Amazonia before European conquest." Proceedings of the Royal Society B: Biological Sciences 282, no. 1812 (August 7, 2015): 20150813. http://dx.doi.org/10.1098/rspb.2015.0813.

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During the twentieth century, Amazonia was widely regarded as relatively pristine nature, little impacted by human history. This view remains popular despite mounting evidence of substantial human influence over millennial scales across the region. Here, we review the evidence of an anthropogenic Amazonia in response to claims of sparse populations across broad portions of the region. Amazonia was a major centre of crop domestication, with at least 83 native species containing populations domesticated to some degree. Plant domestication occurs in domesticated landscapes, including highly modified Amazonian dark earths (ADEs) associated with large settled populations and that may cover greater than 0.1% of the region. Populations and food production expanded rapidly within land management systems in the mid-Holocene, and complex societies expanded in resource-rich areas creating domesticated landscapes with profound impacts on local and regional ecology. ADE food production projections support estimates of at least eight million people in 1492. By this time, highly diverse regional systems had developed across Amazonia where subsistence resources were created with plant and landscape domestication, including earthworks. This review argues that the Amazonian anthrome was no less socio-culturally diverse or populous than other tropical forested areas of the world prior to European conquest.

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Alves-Martins, Fernanda, Leandro Schlemmer Brasil, Leandro Juen, Paulo De Marco Jr, Juliana Stropp, and Joaquín Hortal. "Metacommunity patterns of Amazonian Odonata: the role of environmental gradients and major rivers." PeerJ 7 (May 6, 2019): e6472. http://dx.doi.org/10.7717/peerj.6472.

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BackgroundWe identified and classified damselfly (Zygoptera) and dragonfly (Anisoptera) metacommunities in Brazilian Amazonia, relating species distribution patterns to known biological gradients and biogeographical history. We expected a random distribution of both Zygoptera and Anisoptera within interfluves. At the Amazonian scale, we expected Anisoptera metacommunities to be randomly distributed due to their higher dispersal ability and large environmental tolerance. In contrast, we expected Zygoptera communities to exhibit a Clementsian pattern, limited by the large Amazonia rivers due to their low dispersal ability.MethodsWe used a dataset of 58 first-to-third order well-sampled streamlets in four Amazonian interfluves and applied an extension of the Elements of Metacommunity Structure (EMS) framework, in which we order Zygoptera and Anisoptera metacommunities by known spatial and biogeographic predictors.ResultsAt the Amazonian scale, both Zygoptera and Anisoptera presented a Clementsian pattern, driven by the same environmental and biogeographical predictors, namely biogeographic region (interfluve), annual mean temperature, habitat integrity and annual precipitation. At the interfluve scale, results were less consistent and only partially support our hypothesis. Zygoptera metacommunities at Guiana and Anisoptera metacommunities at Tapajós were classified as random, suggesting that neutral processes gain importance at smaller spatial scales.DiscussionOur findings were consistent with previous studies showing that environmental gradients and major rivers limit the distribution of Odonata communities, supporting that larger Amazonian rivers act as barriers for the dispersal of this group. In addition, the importance of habitat integrity indicates that intactness of riparian vegetation is an important filter shaping metacommunity structure of Amazonian stream Odonata.

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Lopes, Gerson P., Tamily C. M. Santos, and Paúl M. Velazco. "First record of Vampyrodes caraccioli (Thomas, 1889) (Chiroptera, Phyllostomidae) in the state of Amazonas and its updated distribution in Brazil." Check List 12, no. 3 (June 22, 2016): 1909. http://dx.doi.org/10.15560/12.3.1909.

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Abstract: The present note reports the first record of Vampyrodes caraccioli in the Brazilian state of Amazonas, and the central Amazon region, based on 44 specimens caught in the Auati-Paraná Extractive Reserve, north bank of the Solimões/Amazonas River. Our record fills a distribution gap of this species in the Brazilian Amazon and illustrates that the current knowledge on the distribution of Amazonian bats is far from complete.

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Chambouleyron, Rafael, and Karl Heinz Arenz. "Amazonian Atlantic: Cacao, Colonial Expansion and Indigenous Labour in the Portuguese Amazon Region (Seventeenth and Eighteenth Centuries)." Journal of Latin American Studies 53, no. 2 (May 2021): 221–44. http://dx.doi.org/10.1017/s0022216x21000213.

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AbstractA product native to the Amazon forest, cacao became the most important staple of the Portuguese Amazonian colonial economy from the late seventeenth until the mid-nineteenth century. Based on extensive research in Brazilian and European archives, this article analyses cacao exploitation in Portuguese Amazonia, examining its dual spatial dimension: the expansion of an agricultural frontier, and the expansion of an extractive frontier in the deep hinterland, with a particular focus on the role that Indian labour played in this development.

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Mota, Edvaldo Pereira, Igor Luis Kaefer, Mario da Silva Nunes, Albertina Pimentel Lima, and Izeni Pires Farias. "Hidden diversity within the broadly distributed Amazonian giant monkey frog (Phyllomedusa bicolor: Phyllomedusidae)." Amphibia-Reptilia 41, no. 3 (June 30, 2020): 349–59. http://dx.doi.org/10.1163/15685381-bja10003.

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Abstract Phyllomedusa bicolor is a large-sized nocturnal tree frog found in tropical rainforests throughout much of the Amazonian region of Brazil, Colombia, Bolivia, Peru, Venezuela, and the Guianas. Very little is known about P. bicolor genetic diversity and genealogical history of its natural populations. Here, using a sampling design that included populations covering most of its distributional range, we investigated the spatial distribution of genetic variability of this species, and we tested the hypothesis that P. bicolor is composed of deeply structured genetic groups, constituting more than one lineage across the Brazilian Amazonia. The results suggested two main lineages in two geographic mega-regions: Western and Eastern Amazonia, the latter consisting of three population groups distributed in the Guiana and Brazilian Shields. The present findings have implications to taxonomy, to understanding the processes that lead to diversification, and to defining strategies of conservation and medicinal use of the species.

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Davidson, Eric A., Mercedes M. C. Bustamante, and Alexandre de Siqueira Pinto. "Emissions of Nitrous Oxide and Nitric Oxide from Soils of Native and Exotic Ecosystems of the Amazon and Cerrado Regions of Brazil." Scientific World JOURNAL 1 (2001): 312–19. http://dx.doi.org/10.1100/tsw.2001.261.

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This paper reviews reports of nitrous oxide (N2O) and nitric oxide (NO) emissions from soils of the Amazon and Cerrado regions of Brazil. N2O is a stable greenhouse gas in the troposphere and participates in ozone-destroying reactions in the stratosphere, whereas NO participates in tropospheric photochemical reactions that produce ozone. Tropical forests and savannas are important sources of atmospheric N2O and NO, but rapid land use change could be affecting these soil emissions of N oxide gases. The five published estimates for annual emissions of N2O from soils of mature Amazonian forests are remarkably consistent, ranging from 1.4 to 2.4 kg N ha–1 year–1, with a mean of 2.0 kg N ha–1 year–1. Estimates of annual emissions of NO from Amazonian forests are also remarkably similar, ranging from 1.4 to 1.7 kg N ha–1 year–1, with a mean of 1.5 kg N ha–1 year–1. Although a doubling or tripling of N2O has been observed in some young (<2 years) cattle pastures relative to mature forests, most Amazonian pastures have lower emissions than the forests that they replace, indicating that forest-topasture conversion has, on balance, probably reduced regional emissions slightly (<10%). Secondary forests also have lower soil emissions than mature forests. The same patterns apply for NO emissions in Amazonia. At the only site in Cerrado where vegetation measurements have been made N2O emissions were below detection limits and NO emissions were modest (~0.4 kg N ha–1 year–1). Emissions of NO doubled after fire and increased by a factor of ten after wetting dry soil, but these pulses lasted only a few hours to days. As in Amazonian pastures, NO emissions appear to decline with pasture age. Detectable emissions of N2O have been measured in soybean and corn fields in the Cerrado region, but they are modest relative to fluxes measured in more humid tropical agricultural regions. No measurements of NO from agricultural soils in the Cerrado region have been made, but we speculate that they could be more important than N2O emissions in this relatively dry climate. While a consistent pattern is emerging from these studies in the Amazon region, far too few data exist for the Cerrado region to assess the impact of land use changes on N oxide emissions.

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IRMLER, ULRICH. "The genus Mimogonia (Coleoptera: Staphylinidae: Osoriinae) from the Neotropical region with descriptions of four new species." Zootaxa 1651, no. 1 (November 30, 2007): 57–64. http://dx.doi.org/10.11646/zootaxa.1651.1.3.

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Four new species of the rove beetle genus Mimogonia Coiffait, 1978 are described from South America, Mimogonia hermani, Mimogonia hanagarthi, Mimogonia adisi, and Mimogonia huggerti. The new species were collected in the Amazonian regions of Peru or Bolivia and the state Amazonas in Brazil. Additional records are published of M. similis from Iquitos (Peru) and M. subopaca from Puerto Maldonado (Peru). A key to the Neotropical species of the genus is given.

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Lemos, Vanda P., Antônio R. de Oliveira Meireles, Kelly das Graças Fernandes, Milena C. de Moraes, Marcondes L. da Costa, Any K. Terra Silva, and Dirse C. Kern. "Nutrients in Amazonian Black Earth from Caxiuanã Region." Journal of the Brazilian Chemical Society 22, no. 4 (2011): 772–79. http://dx.doi.org/10.1590/s0103-50532011000400022.

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Santos-Silva, Antonio, and Maria Helena Galileo. "New Brazilian Cerambycidae from the Amazonian region (Coleoptera)." ZooKeys 603 (July 6, 2016): 131–40. http://dx.doi.org/10.3897/zookeys.603.7335.

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Leão, Ilza Maria S., Carlos Humberto S. Andrade, Maria Lúcia B. Pinheiro, Arnaldo F. I. da Rocha, Maria Iracema L. Machado, Afrânio A. Craveiro, Jose Wilson Alencar, and Francisco José A. Matos. "Essential Oil ofCroton lanjouwensisJablonski from Brazilian Amazonian Region." Journal of Essential Oil Research 10, no. 6 (November 1998): 643–44. http://dx.doi.org/10.1080/10412905.1998.9700995.

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Sapucci, Luiz F., Luiz A. T. Machado, João F. G. Monico, and Artemio Plana-Fattori. "Intercomparison of Integrated Water Vapor Estimates from Multisensors in the Amazonian Region." Journal of Atmospheric and Oceanic Technology 24, no. 11 (November 1, 2007): 1880–94. http://dx.doi.org/10.1175/jtech2090.1.

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Abstract Water vapor is an atmospheric component of major interest in atmospheric science because it affects the energy budget and plays a key role in several atmospheric processes. The Amazonian region is one of the most humid on the planet, and land use change is able to affect the hydrologic cycle in several areas and consequently to generate severe modifications in the global climate. Within this context, accessing the error associated with atmospheric humidity measurement and the validation of the integrated water vapor (IWV) quantification from different techniques is very important in this region. Using data collected during the Radiation, Cloud, and Climate Interactions in Amazonia during the Dry-to-Wet Transition Season (RACCI/DRY-TO-WET), an experiment carried out in southwestern Amazonia in 2002, this paper presents quality analysis of IWV measurements from RS80 radiosondes, a suite of GPS receivers, an Aerosol Robotic Network (AERONET) solar radiometer, and humidity sounding from the Humidity Sounder for Brazil (HSB) aboard the Aqua satellite. When compared to RS80 IWV values, the root-mean-square (RMS) from the AERONET and GPS results are of the order of 2.7 and 3.8 kg m−2, respectively. The difference generated between IWV from the GPS receiver and RS80 during the daytime was larger than that of the nighttime period because of the combination of the influence of high ionospheric activity during the RACCI experiment and a daytime drier bias from the RS80.

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Cabrera-Barona, Pablo F., Manuel Bayón, Gustavo Durán, Alejandra Bonilla, and Verónica Mejía. "Generating and Mapping Amazonian Urban Regions Using a Geospatial Approach." ISPRS International Journal of Geo-Information 9, no. 7 (July 17, 2020): 453. http://dx.doi.org/10.3390/ijgi9070453.

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(1) background: Urban representations of the Amazon are urgently needed in order to better understand the complexity of urban processes in this area of the World. So far, limited work that represents Amazonian urban regions has been carried out. (2) methods: Our study area is the Ecuadorian Amazon. We performed a K-means algorithm using six urban indicators: Urban fractal dimension, number of paved streets, urban radiant intensity (luminosity), and distances to the closest new deforested areas, to oil pollution sources, and to mining pollution sources. We also carried out fieldwork to qualitatively validate our geospatial and statistical analyses. (3) results: We generated six Amazonian urban regions representing different urban configurations and processes of major cities, small cities, and emerging urban zones. The Amazonian urban regions generated represent the urban systems of the Ecuadorian Amazon at a general scale, and correspond to the urban realities at a local scale. (4) conclusions: An Amazonian urban region is understood as a set of urban zones that are dispersed and share common urban characteristics such a similar distance to oil pollution sources or similar urban radiant intensity. Our regionalization model represents the complexity of the Amazonian urban systems, and the applied methodology could be transferred to other Amazonian countries.

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Barham, Bradford, and Oliver Coomes. "Wild Rubber: Industrial Organisation and the Microeconomics of Extraction During the Amazon Rubber Boom(1860–1920)." Journal of Latin American Studies 26, no. 1 (February 1994): 37–72. http://dx.doi.org/10.1017/s0022216x00018848.

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Concern over the fate of the rain forest and peoples of Amazonia has inspired a renewed interest in the extraction of natural products from the region. Accounts of the Amazon Rubber Boom (1860–1910) are of particular interest in view of the dominance of the rubber industry during one of the most influential periods in the region's history as well as the continuing economic importance of wild rubber extraction to thousands of Amazonian households today. For many observers, the organisation and performance of the wild rubber industry – then and now – provides a good illustration of extractive industries in Amazonia.

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RIBEIRO-JÚNIOR, MARCO A., and SILVANA AMARAL. "Catalogue of distribution of lizards (Reptilia: Squamata) from the Brazilian Amazonia. IV. Alopoglossidae, Gymnophthalmidae." Zootaxa 4269, no. 2 (May 22, 2017): 151. http://dx.doi.org/10.11646/zootaxa.4269.2.1.

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We present distribution data of all Alopoglossidae and Gymnophthalmidae lizards known from the Brazilian Amazonia, totaling 54 species-level taxa, belonging to 17 genera and two families. This represents 22 more species-level taxa than previously reported. Data were based on 17,431 specimens deposited in three North American and eight Brazilian museums, including the main collections harboring Amazonian material. Most species (~80%) are endemic to Amazonia; non-endemic species are mainly associated with open vegetation (savanna) enclaves or open dry (semideciduous) forest in Amazonia, with a few exceptions. As a whole, seven taxa (including one species complex) are widespread in Amazonia, six are restricted to eastern Amazonia, seven to western Amazonia, two to southwestern Amazonia, 11 to southern Amazonia, 11 to northern Amazonia (either in part of it or widespread in the Guiana region), and six to the southern peripheral portion of Amazonia. Besides, four species present unique distributions. Considering this study and the other three catalogues of distribution of lizards already published, the total number of lizard species from Brazilian Amazonia increased from 97 to 142 species-level tava. It represents an increase of 45 species from the region since the last revision.

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Salas López, Rolando, Darwin Gómez Fernández, Jhonsy O. Silva López, Nilton B. Rojas Briceño, Manuel Oliva, Renzo E. Terrones Murga, Daniel Iliquín Trigoso, Elgar Barboza Castillo, and Miguel Ángel Barrena Gurbillón. "Land Suitability for Coffee (Coffea arabica) Growing in Amazonas, Peru: Integrated Use of AHP, GIS and RS." ISPRS International Journal of Geo-Information 9, no. 11 (November 13, 2020): 673. http://dx.doi.org/10.3390/ijgi9110673.

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Peru is one of the world’s main coffee exporters, whose production is driven mainly by five regions and, among these, the Amazonas region. However, a combined negative factor, including, among others, climate crisis, the incidence of diseases and pests, and poor land-use planning, have led to a decline in coffee yields, impacting on the family economy. Therefore, this research assesses land suitability for coffee production (Coffea arabica) in Amazonas region, in order to support the development of sustainable agriculture. For this purpose, a hierarchical structure was developed based on six climatological sub-criteria, five edaphological sub-criteria, three physiographical sub-criteria, four socio-economic sub-criteria, and three restrictions (coffee diseases and pests). These were integrated using the Analytical Hierarchy Process (AHP), Geographic Information Systems (GIS) and Remote Sensing (RS). Of the Amazonas region, 11.4% (4803.17 km2), 87.9% (36,952.27 km2) and 0.7% (295.47 km2) are “optimal”, “suboptimal” and “unsuitable” for the coffee growing, respectively. It is recommended to orient coffee growing in 912.48 km2 of territory in Amazonas, which presents “optimal” suitability for coffee and is “unsuitable” for diseases and pests. This research aims to support coffee farmers and local governments in the region of Amazonas to implement new strategies for land management in coffee growing. Furthermore, the methodology used can be applied to assess land suitability for other crops of economic interest in Andean Amazonian areas.

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Saunaluoma, Sanna, and Denise Schaan. "Monumentality in Western Amazonian formative societies: geometric ditched enclosures in the Brazilian state of Acre." Antiqua 2, no. 1 (February 28, 2012): 1. http://dx.doi.org/10.4081/antiqua.2012.e1.

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In Amazonia, monumentality has traditionally been considered characteristic of the late pre-colonial densely populated complex societies. Recent archaeological fieldwork concerning the geometric earthworks in the Brazilian state of Acre has shown that the southwestern Amazonian interfluvial zone was a significant setting for long-term large landscape modifications. We describe the geometric ditched enclosure sites of Acre as early monumental public spaces reserved for ceremonial purposes, analogous to the central Andean ceremonial-civic centers of the Formative period. The geometric earthwork sites contain contiguous ditches and embankment structures of varying forms enclosing areas typically 3-10 hectares in size. Documented cultural features are sparse within the enclosed areas. Making use of satellite imagery, aerial photographs, and pedestrian surveys, 360 earthwork enclosures have been recorded in southwestern Amazonia. Our radiocarbon dates suggest that construction and use of geometric earthworks began at the latest around 1000 BC, and prevailed in the region until 1400 AD. The relatively small number of ceramics recovered from the geometric ditched enclosure sites appear to be local substyles of the same tradition, sharing certain attributes with contemporary ceramic traditions of the upper Amazonian region. This, and consistency in ceremonial earthwork architecture, indicate close cultural interaction between communities that built and used the earthwork sites, and imply probable relationships also with the central Andean area.

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Ferreira, Leandro V., Denise A. Cunha, and Pia Parolin. "Effects of logging on Virola surinamensis in an Amazonian floodplain forest." Environment Conservation Journal 15, no. 3 (December 20, 2014): 1–8. http://dx.doi.org/10.36953/ecj.2014.15301.

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Virola surinamensis is a dioecious timber species of Amazonian floodplain forests. It is threatened by extinction and a priority species in the conservation program of genetic resources with high economic value for Brazil. The present study was aimed to assess the population structure of Virola surinamensis and the impact of logging in the estuary region of Brazilian Amazonia. Our data suggest that altering the dioecious population structure by logging likely creates the imbalance of male and female individuals in the population. New policies are needed to protect Virola trees with a special regard on reproductive matriarch trees.

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Zatti, Suellen A., Stephen D. Atkinson, Antônio A. M. Maia, Jerri L. Bartholomew, and Edson A. Adriano. "Ceratomyxa gracillima n. sp. (Cnidaria: Myxosporea) provides evidence of panmixia and ceratomyxid radiation in the Amazon basin." Parasitology 145, no. 9 (January 17, 2018): 1137–46. http://dx.doi.org/10.1017/s0031182017002323.

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AbstractWe describe a new freshwater myxosporean species Ceratomyxa gracillima n. sp. from the gall bladder of the Amazonian catfish Brachyplatystoma rousseauxii; the first myxozoan recorded in this host. The new Ceratomyxa was described on the basis of its host, myxospore morphometry, ssrDNA and internal transcribed spacer region (ITS-1) sequences. Infected fish were sampled from geographically distant localities: the Tapajós River, Pará State, the Amazon River, Amapá State and the Solimões River, Amazonas State. Immature and mature plasmodia were slender, tapered at both ends, and exhibited vermiform motility. The ribosomal sequences from parasite isolates from the three localities were identical, and distinct from all other Ceratomyxa sequences. No population-level genetic variation was observed, even in the typically more variable ITS-1 region. This absence of genetic variation in widely separated parasite samples suggests high gene flow as a result of panmixia in the parasite populations. Maximum likelihood and maximum parsimony analyses placed C. gracillima n. sp. sister to Ceratomyxa vermiformis in a subclade together with Ceratomyxa brasiliensis and Ceratomyxa amazonensis, all of which have Amazonian hosts. This subclade, together with other Ceratomyxa from freshwater hosts, formed an apparently early diverging lineage. The Amazonian freshwater Ceratomyxa species may represent a radiation that originated during marine incursions into the Amazon basin that introduced an ancestral lineage in the late Oligocene or early Miocene.

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Baioni, Davide, Alessio Murana, and Mario Tramontana. "Amazonian thermokarst in Danielson crater, Arabia Terra region, Mars." Planetary and Space Science 104 (December 2014): 310–17. http://dx.doi.org/10.1016/j.pss.2014.09.006.

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Schneider, Maria Paula Cruz, Maria Iracilda da Cunha Sampaio, and Horacio Schneider. "Esterase D in Cebus apella from the Amazonian region*." Animal Blood Groups and Biochemical Genetics 13, no. 2 (April 24, 2009): 109–13. http://dx.doi.org/10.1111/j.1365-2052.1982.tb01049.x.

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Vijayan, S., and Rishitosh K. Sinha. "Amazonian fluvial outflow channels in Jovis Tholus region, Mars." Journal of Geophysical Research: Planets 122, no. 5 (May 2017): 927–49. http://dx.doi.org/10.1002/2016je005237.

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Heckmann, M. I. O., C. T. Mendes-Junior, M. S. Tada, M. G. Santos, G. M. K. Cabello, Francisco M. Salzano, A. L. Simoes, and V. Engracia. "CFTR Haplotype Distribution in the Brazilian Western Amazonian Region." Human Biology 77, no. 4 (2005): 499–508. http://dx.doi.org/10.1353/hub.2005.0063.

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Leopoldo, P. R., W. Franken, E. Salati, and M. N. Ribeiro. "Towards a water balance in the Central Amazonian region." Experientia 43, no. 3 (March 1987): 222–33. http://dx.doi.org/10.1007/bf01945545.

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Morais, José Wellington de, and Ester Paixão da Silva. "Occurrence of Symphyla (Myriapoda) in the region of the Upper Solimões River, Amazonas, Brazil." Pesquisa Agropecuária Brasileira 44, no. 8 (August 2009): 981–83. http://dx.doi.org/10.1590/s0100-204x2009000800028.

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The present work aimed at identifying the Symphyla species diversity and abundance in various land-use systems under different degrees of intensification in western Amazonia. This is the first inventory of Symphyla in primary and secondary forest, crops, agroforestry systems and pastures which was carried out in Benjamin Constant municipality, in the region of the Upper Solimões River, Brazil. Samples (n = 101) were collected using a metal corer, and the symphylan extraction was carried out using Berlese-Tullgren funnels. Two genera and three species of symphylans were encountered. Considering the diversity encountered in Amazonian inventories, with only four genera and five known species overall, the three species found in the present study are considered a reasonable representation of the regional diversity. Two of the Hanseniella species found have been known to cause plant damage.

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Morales, Juan Enrique Tacoronte, and Maria Teresa Cabrera. "Diplodomica II. Repugnatorial Secretion of Ecuadorian Endemic Millipede Rhinocricus sp. (Diplopoda, Spirobolida, Rhinocricidae) from Orellana Province, Amazonia, Ecuador." Chemistry Proceedings 3, no. 1 (November 14, 2020): 90. http://dx.doi.org/10.3390/ecsoc-24-08435.

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Millipedes (Myriapoda: Diplopoda) represents one of the oldest and most evolutionary successful classes of invertebrates. The order Spirobolida is dominantly tropical, and the family Rhinocricidae is widely distributed in the Ecuadorian edaphic fauna inhabiting the Amazonia region. The millipedes collected were stimulated mechanically, and an ejected repugnatorial fluid was subjected to structural analysis. The analysis of the defensive–repugnatorial secretion of the endemic millipede Rhinocricus sp., inhabiting in the Amazonian region of Orellana, Republic of Ecuador, and chemical evidence (chromogenic reactions: KI starch paper and rodanine test in aqueous ammonia) as well, revealed the quinonoide composition of the secretion. We identified 2-methyl-3-methoxy-1,4-benzoquinone as an active major component.

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Pulido-Santacruz, Paola, Alexandre Aleixo, and Jason T. Weir. "Morphologically cryptic Amazonian bird species pairs exhibit strong postzygotic reproductive isolation." Proceedings of the Royal Society B: Biological Sciences 285, no. 1874 (March 7, 2018): 20172081. http://dx.doi.org/10.1098/rspb.2017.2081.

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We possess limited understanding of how speciation unfolds in the most species-rich region of the planet—the Amazon basin. Hybrid zones provide valuable information on the evolution of reproductive isolation, but few studies of Amazonian vertebrate hybrid zones have rigorously examined the genome-wide underpinnings of reproductive isolation. We used genome-wide genetic datasets to show that two deeply diverged, but morphologically cryptic sister species of forest understorey birds show little evidence for prezygotic reproductive isolation, but substantial postzygotic isolation. Patterns of heterozygosity and hybrid index revealed that hybrid classes with heavily recombined genomes are rare and closely match simulations with high levels of selection against hybrids. Genomic and geographical clines exhibit a remarkable similarity across loci in cline centres, and have exceptionally narrow cline widths, suggesting that postzygotic isolation is driven by genetic incompatibilities at many loci, rather than a few loci of strong effect. We propose Amazonian understorey forest birds speciate slowly via gradual accumulation of postzygotic genetic incompatibilities, with prezygotic barriers playing a less important role. Our results suggest old, cryptic Amazonian taxa classified as subspecies could have substantial postzygotic isolation deserving species recognition and that species richness is likely to be substantially underestimated in Amazonia.

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Macía, Manuel J., and Jens-Christian Svenning. "Oligarchic dominance in western Amazonian plant communities." Journal of Tropical Ecology 21, no. 6 (October 19, 2005): 613–26. http://dx.doi.org/10.1017/s0266467405002579.

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The oligarchy hypothesis proposes that large areas of Amazonian plant communities are dominated by limited sets of species. We tested this hypothesis by (1) quantifying dominance of the 10 most common species, genera and families in each region; and (2) assessing the consistency of relative abundance ranks between areas and across scales in dominance patterns for trees and lianas in two distant Amazonian regions (∼1900 km), the Yasuní and Madidi National Parks in Ecuador and Bolivia, respectively. The analyses were based on sixty-nine 0.1-ha plots in which all woody plants with a diameter at breast height (dbh) ≥2.5 cm were inventoried (19 775 individuals and 1729 species in total). The plots were located at two Yasuní and five Madidi sites, with an average of 10 plots per site. Overall, oligarchic dominance was pronounced at all the spatial scales investigated, although decreasing with increasing scale. Cross-scale relative abundance ranks were more consistent in Yasuní than in Madidi, while no such difference was apparent within single sites. Quantitative dominance and consistency of relative abundance ranks increased with taxonomic rank, being stronger at the family level than at genus and species levels. Species-level dominance was somewhat stronger within the 10 most common families in either region, than in other families. Dominance was similarly strong for canopy (dbh ≥10 cm) and understorey trees (dbh <10 cm), and less pronounced among lianas. In conclusion, our results provide strong evidence that western Amazonian forests can be dominated by limited oligarchies of species, genera and families over large expanses.

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Meira, Domingos Alves, Jordão Pellegrino Júnior, Jussara Marcondes-Machado, Kimiyoski Tsuji, Elinda Satie Matsuoka, Elizete Haida, and Albert Boutros El Khoury. "Frequency of human leukocyte antigen (hla) in patients with malaria and in the general population of Humaitá county, Amazonas state, Brazil." Revista da Sociedade Brasileira de Medicina Tropical 20, no. 3 (September 1987): 153–58. http://dx.doi.org/10.1590/s0037-86821987000300005.

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In August 1983,85 inhabitants of the municipality of Humaitá, Amazonas State, Brazil were studied to determine the prevalence of antigens to HLA-A, -B, -C and DR. Thirty-eight were sick with malaria due to Plasmodium falciparum. All subjects were examined for splenomegaly, blood parasitaemia and antibodies to malaria. They constituted three groups: 1) 25 subjects native to the Amazon region who had never had malaria; 2) 38 Amazonian subjects who had malaria in the past or currently had an infection; 3) 22 patients with malaria who had acquired the infection in the Amazon Region but came from other regions of Brazil. Blood was taken from each person, the lymphocytes were separated and typed by the test of microlymphocytotoxicity. There was a high frequency of antigens that could not be identified in the groups studied which suggests the existence of a homozygote or phenotype not identified in the population. There was a high frequency of the phenotype Ag(W24) (44.7%) in group 2 when compared with group 1 (32%) or group 3 (9%). Also the individuals in group 2 showed an elevated frequency of antigen DR(4)80%) when compared with group 1 (36.6%) or group 3 (16.6%). These observations suggest the possibility of a genetic susceptibility to malaria among Amazonian residents and indicate a necessity for more extensive studies of the frequency of HLA antigens among inhabitants of this endemic malarial zone.

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Elizanilda Ramalho do Rego, Mailson Monteiro do Rêgo, and Bruno de Campos Souza. "GENETIC VARIABILITY IN CATTLEYA VIOLACEA (ORCHIDACEAE) IN THE AMAZONIAN REGION." Acta Horticulturae, no. 813 (March 2009): 413–20. http://dx.doi.org/10.17660/actahortic.2009.813.53.

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Felippe-Bauer, Maria Luiza, Rosana de S. Veras, Eloy G. Castellon, and Nancy A. Moreira. "A new Culicoides from The Amazonian Region, Brazil (Diptera: Ceratopogonidae)." Memórias do Instituto Oswaldo Cruz 95, no. 1 (January 2000): 35–37. http://dx.doi.org/10.1590/s0074-02762000000100004.

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Pina-Costa, Anielle de, Patrícia Brasil, Sílvia Maria Di Santi, Mariana Pereira de Araujo, Martha Cecilia Suárez-Mutis, Ana Carolina Faria e. Silva Santelli, Joseli Oliveira-Ferreira, Ricardo Lourenço-de-Oliveira, and Cláudio Tadeu Daniel-Ribeiro. "Malaria in Brazil: what happens outside the Amazonian endemic region." Memórias do Instituto Oswaldo Cruz 109, no. 5 (August 2014): 618–33. http://dx.doi.org/10.1590/0074-0276140228.

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Arora, V. K., and G. J. Boer. "Terrestrial ecosystems response to future changes in climate and atmospheric CO<sub>2</sub> concentration." Biogeosciences 11, no. 15 (August 8, 2014): 4157–71. http://dx.doi.org/10.5194/bg-11-4157-2014.

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Abstract. The response of the terrestrial carbon cycle to future changes in climate and atmospheric CO2 is assessed by analysing simulation results for the 2006–2100 period made with the second generation Canadian Earth system model (CanESM2) for the RCP 2.6, RCP 4.5 and RCP 8.5 climate change scenarios. Our interest is in the extent to which global terrestrial carbon pools and sinks, in particular those of the Amazonian region, are vulnerable to the adverse effects of climate change. CanESM2 results indicate that land remains an overall sink of atmospheric carbon for the 2006–2100 period. The net carbon uptake by land in response to changes in climate and atmospheric CO2 is close to 20, 80 and 140 Pg C for the RCP 2.6, 4.5 and 8.5 scenarios, respectively. The latitudinal structure of future atmosphere–land CO2 flux remains similar to that observed for the historical period with northern mid- to high-latitude regions gaining carbon from the atmosphere while the tropics remain either carbon neutral or a modest source of atmospheric carbon depending on scenario. These changes occur in conjunction with simulated precipitation and soil moisture increases over northern mid- and high-latitude land regions and precipitation and soil moisture decreases over the South American continent in all scenarios. Compared to other regions of the globe, which are either carbon sinks or near neutral, the Amazonian region is simulated to be a net source of carbon during the 21st century. Moreover, and unexpectedly, the rate of carbon loss to the atmosphere from the Amazonian region is largely independent of the differences between the three scenarios considered.

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Arora, V. K., and G. J. Boer. "Terrestrial ecosystems response to future changes in climate and atmospheric CO<sub>2</sub> concentration." Biogeosciences Discussions 11, no. 3 (March 5, 2014): 3581–614. http://dx.doi.org/10.5194/bgd-11-3581-2014.

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Abstract. The response of the terrestrial carbon cycle to future changes in climate and atmospheric CO2 is assessed by analyzing simulations, for the 2006–2100 period, made with the second generation Canadian Earth system model (CanESM2) for the RCP 2.6, RCP 4.5 and RCP 8.5 climate change scenarios. Our interest is in the extent to which global terrestrial carbon pools and sinks, in particular those of the Amazonian region, are vulnerable to the adverse effects of climate change. CanESM2 results indicate that land remains an overall sink of atmospheric carbon for the 2006–2100 period. The net carbon uptake by land in response to changes in climate and atmospheric CO2 is close to 20, 80 and 140 Pg C for the RCP 2.6, 4.5 and 8.5 scenarios, respectively. The latitudinal structure of future atmosphere–land CO2 flux remains similar to that observed for the historical period with northern mid- to high-latitude regions gaining carbon from the atmosphere while the tropics remain either carbon neutral or a modest source of atmospheric carbon depending on scenario. These changes occur in conjunction with simulated precipitation and soil moisture increases over northern mid- and high-latitude land regions and precipitation and soil moisture decreases over the South American continent in all scenarios. Compared to other regions of the globe, which are either carbon sinks or near neutral, the Amazonian region is simulated to be a net source of carbon during the 21st century. Moreover, and unexpectedly, the rate of carbon loss to the atmosphere from the Amazonian region is largely independent of the differences between the three scenarios considered.

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Malhado, A. C. M., Y. Malhi, R. J. Whittaker, R. J. Ladle, H. ter Steege, O. L. Phillips, N. Butt, et al. "Spatial trends in leaf size of Amazonian rainforest trees." Biogeosciences 6, no. 8 (August 10, 2009): 1563–76. http://dx.doi.org/10.5194/bg-6-1563-2009.

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Abstract. Leaf size influences many aspects of tree function such as rates of transpiration and photosynthesis and, consequently, often varies in a predictable way in response to environmental gradients. The recent development of pan-Amazonian databases based on permanent botanical plots has now made it possible to assess trends in leaf size across environmental gradients in Amazonia. Previous plot-based studies have shown that the community structure of Amazonian trees breaks down into at least two major ecological gradients corresponding with variations in soil fertility (decreasing from southwest to northeast) and length of the dry season (increasing from northwest to south and east). Here we describe the geographic distribution of leaf size categories based on 121 plots distributed across eight South American countries. We find that the Amazon forest is predominantly populated by tree species and individuals in the mesophyll size class (20.25–182.25 cm2). The geographic distribution of species and individuals with large leaves (>20.25 cm2) is complex but is generally characterized by a higher proportion of such trees in the northwest of the region. Spatially corrected regressions reveal weak correlations between the proportion of large-leaved species and metrics of water availability. We also find a significant negative relationship between leaf size and wood density.

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Del Valle Coello, Juan José. "Forest Economies: A Remedy to Amazonian Deforestation?" IU Journal of Undergraduate Research 2, no. 1 (May 31, 2016): 63–71. http://dx.doi.org/10.14434/iujur.v2i1.20929.

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Commonly described as the “lungs of the planet,” the Amazon rainforest represents over half of the remaining rainforest in the world, constituting an important global carbon sink and one of the most culturally- and biologically-diverse regions of the world. The past half-century has seen a worrisome amount of deforestation in this rainforest, but different regions within the Amazon, however, compare differently in terms of deforestation trajectories. What has been the role of products obtained from managing forests, such as the now globally-consumed açaí palm fruit, in reverting deforestation trends? My hypothesis is that there is a statistically significant negative correlation between such forest products and extent of deforestation. This study examines, within the historical and social context of the Amazon Delta and Estuary, the relationship between açaí agroforestry and deforestation. The focus units are the municípios (roughly equivalent to counties) that constitute the Amazon Delta and Estuary, all located in the northern Brazilian states of Amapá and Pará. Statistical data for deforestation obtained from PRODES, a Brazilian governmental project, which monitors deforestation via satellite, is used to ascertain deforestation in the region. This dataset is then correlated with census-based production data for each município for the period from 2002 to 2012. Mapping these variables onto municípios does visually demonstrate a contrast between areas of high deforestation and high açaí production; however, the relationship is not statistically significant.

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Gouvea, Raul. "Sustainability and Entrepreneurship." International Journal of Social Ecology and Sustainable Development 5, no. 3 (July 2014): 48–64. http://dx.doi.org/10.4018/ijsesd.2014070105.

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This article elaborates on the diverse entrepreneurial activities of indigenous communities in the Brazilian Amazon region. This article argues that further sustainability of the Brazilian Amazonian region is intrinsically linked to the entrepreneurial activities by indigenous communities in the Amazon region. Amazonian indigenous communities are under increasing economic and social pressure. Fostering sustainable indigenous entrepreneurship in these disadvantaged indigenous communities has the potential to improve indigenous communities, economic and social welfare, preserve their culture, customs, and traditional knowledge, in addition to the rebuilding of these communities. Thus, engagement of indigenous communities in sustainable activities further protects the local natural capital. The article also proposes the creation of a center for indigenous entrepreneurship in the Amazon region aiming at supporting and fostering indigenous entrepreneurship.

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Capriles, José M., Umberto Lombardo, Blaine Maley, Carlos Zuna, Heinz Veit, and Douglas J. Kennett. "Persistent Early to Middle Holocene tropical foraging in southwestern Amazonia." Science Advances 5, no. 4 (April 2019): eaav5449. http://dx.doi.org/10.1126/sciadv.aav5449.

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The Amazon witnessed the emergence of complex societies after 2500 years ago that altered tropical landscapes through intensive agriculture and managed aquatic systems. However, very little is known about the context and conditions that preceded these social and environmental transformations. Here, we demonstrate that forest islands in the Llanos de Moxos of southwestern Amazonia contain human burials and represent the earliest settlements in the region between 10,600 and 4000 years ago. These archaeological sites and their contents represent the earliest evidence of communities that experienced conditions conducive to engaging with food production such as environmental stability, resource disturbance, and increased territoriality in the Amazonian tropical lowlands.

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Saturno, Jorge, Florian Ditas, Marloes Penning de Vries, Bruna A. Holanda, Mira L. Pöhlker, Samara Carbone, David Walter, et al. "African volcanic emissions influencing atmospheric aerosols over the Amazon rain forest." Atmospheric Chemistry and Physics 18, no. 14 (July 23, 2018): 10391–405. http://dx.doi.org/10.5194/acp-18-10391-2018.

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Abstract. The long-range transport (LRT) of trace gases and aerosol particles plays an important role for the composition of the Amazonian rain forest atmosphere. Sulfate aerosols originate to a substantial extent from LRT sources and play an important role in the Amazonian atmosphere as strongly light-scattering particles and effective cloud condensation nuclei. The transatlantic transport of volcanic sulfur emissions from Africa has been considered as a source of particulate sulfate in the Amazon; however, direct observations have been lacking so far. This study provides observational evidence for the influence of emissions from the Nyamuragira–Nyiragongo volcanoes in Africa on Amazonian aerosol properties and atmospheric composition during September 2014. Comprehensive ground-based and airborne aerosol measurements together with satellite observations are used to investigate the volcanic event. Under the volcanic influence, hourly mean sulfate mass concentrations in the submicron size range reached up to 3.6 µg m−3 at the Amazon Tall Tower Observatory, the highest value ever reported in the Amazon region. The substantial sulfate injection increased the aerosol hygroscopicity with κ values up to 0.36, thus altering aerosol–cloud interactions over the rain forest. Airborne measurements and satellite data indicate that the transatlantic transport of volcanogenic aerosols occurred in two major volcanic plumes with a sulfate-enhanced layer between 4 and 5 km of altitude. This study demonstrates how African aerosol sources, such as volcanic sulfur emissions, can substantially affect the aerosol cycling and atmospheric processes in Amazonia.

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Chao, K. J., O. L. Phillips, T. R. Baker, J. Peacock, G. Lopez-Gonzalez, R. Vásquez Martínez, A. Monteagudo, and A. Torres-Lezama. "After trees die: quantities and determinants of necromass across Amazonia." Biogeosciences 6, no. 8 (August 11, 2009): 1615–26. http://dx.doi.org/10.5194/bg-6-1615-2009.

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Abstract. The Amazon basin, one of the most substantial biomass carbon pools on earth, is characterised by strong macroecological gradients in biomass, mortality rates, and wood density from west to east. These gradients could affect necromass stocks, but this has not yet been tested. This study aims to assess the stocks and determinants of necromass across Amazonian forests. Field-based and literature data were used to find relationships between necromass and possible determinants. Furthermore, a simple model was applied to estimate and extrapolate necromass stocks across terra firma Amazonian forests. In eight northwestern and three northeastern Amazonian permanent plots, volumes of coarse woody debris (≥10 cm diameter) were measured in the field and the density of each decay class was estimated. Forest structure and historical mortality data were used to determine the factors controlling necromass. Necromass is greater in forests with low stem mortality rates (northeast) rather than in forests with high stem mortality rates (northwest) (58.5±10.6 and 27.3±3.2 Mg ha−1, respectively). Using all published necromass values, we find that necromass across terra firma forests in Amazonia is positively related to both forest dynamics (mortality mass inputs and a surrogate for decomposition rate (average wood density of living trees)) and forest structure (biomass), but is better explained by forest dynamics. We propose an improved method to estimate necromass for plots where necromass has not been measured. The estimates, together with other actual measurements of necromass, were scaled-up to project a total Amazonian necromass of 9.6±1.0 Pg C. The ratio of necromass (on average weighted by forest region) to coarse aboveground biomass is 0.127. Overall, we find (1) a strong spatial trend in necromass in parallel with other macroecological gradients and (2) that necromass is a substantial component of the carbon pool in the Amazon.

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Chao, K. J., O. L. Phillips, T. R. Baker, J. Peacock, G. Lopez-Gonzalez, R. Vásquez Martínez, A. Monteagudo, and A. Torres-Lezama. "After trees die: quantities and determinants of necromass across Amazonia." Biogeosciences Discussions 6, no. 1 (February 12, 2009): 1979–2006. http://dx.doi.org/10.5194/bgd-6-1979-2009.

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Abstract. The Amazon basin, one of the most substantial biomass carbon pools on earth, is characterised by strong macroecological gradients in biomass, mortality rates, and wood density from the west to the east. These gradients could affect necromass stocks, but this has not yet been tested. This study aims to assess the stocks and determinants of necromass patterns across Amazonian forests. Field-based and literature data were used to find relationships between necromass and possible determinants. The final regression result was used to estimate and extrapolate the necromass stocks across terra firma Amazonian forests. In eight northwestern and three northeastern Amazonian permanent plots, volumes of coarse woody debris (≥10 cm diameter) were measured in the field and density of each decay class was estimated. Forest structure and historical mortality data were used to determine controlling factors of necromass. Necromass is greater in forests with low stem mortality rates (northeast) rather than forest with high stem mortality rates (northwest) (58.5±10.6 and 27.3±3.2 Mg ha−1, respectively). After integrating all published necromass values, we find that necromass across terra firma forests in Amazonia is positively related to stand biomass, mortality mass input, and average wood density of live trees (ρBA j). We applied these relationships to estimate necromass for plots where necromass has not been measured. The estimates, together with other actual measurements of necromass, were scaled-up to project a total Amazonian necromass of 9.6±1.0 Pg C. The ratio of necromass (on average weighted by forest region) to coarse aboveground biomass is 0.127. Overall, we find (1) a strong spatial trend in necromass in parallel with other macroecological gradients and (2) that necromass is a substantial component of the carbon pool in the Amazon.

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Schneider, Maria Cristina, Joan Aron, Carlos Santos-Burgoa, Wilson Uieda, and Sílvia Ruiz-Velazco. "Common vampire bat attacks on humans in a village of the Amazon region of Brazil." Cadernos de Saúde Pública 17, no. 6 (December 2001): 1531–36. http://dx.doi.org/10.1590/s0102-311x2001000600025.

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Many people in Amazonian communities have reported bat bites in the last decade. Bites by vampire bats can potentially transmit rabies to humans. The objective of this study was to analyze factors associated with bat biting in one of these communities. A cross-sectional survey was conducted in a village of gold miners in the Amazonian region of Brazil (160 inhabitants). Bats were captured near people's houses and sent to a lab. Of 129 people interviewed, 41% had been attacked by a bat at least once, with 92% of the bites located on the lower limbs. A logistic regression found that adults were bitten around four times more often than children (OR = 3.75, CI 95%: 1.46-9.62, p = 0.036). Males were bitten more frequently than females (OR = 2.08, CI 95%: 0.90-4.76, p = 0.067). Nine Desmodus rotundus and three frugivorous bats were captured and tested negative for rabies. The study suggests that, in an area of gold miners, common vampire bats are more likely to attack adults and males. The control strategy for human rabies developed in this region should therefore place special emphasis on adult males. There should also be more research on how the search for gold in the Amazonian region places people and the environment at risk.

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LEHR, EDGAR, Alessandro Catenazzi, and DANIEL RODRÍGUEZ. "A new species of Pristimantis (Anura: Strabomantidae) from the Amazonian lowlands of northern Peru (Region Loreto and San Martín)." Zootaxa 1990, no. 1 (January 30, 2009): 30–40. http://dx.doi.org/10.11646/zootaxa.1990.1.2.

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A new species of Pristimantis from the Amazonian lowlands of northern Peru (Regions of Loreto and San Martín) is described. The new species has a snout-vent length of 32.6–36.5 mm (n = 3) in adult females, and 20.0–25.1 mm (n = 4) in adult males. It differs from all Pristimantis of the Amazonian lowlands in having a contrasting life coloration pattern of black with white or whitish blue blotches in axilla, groin, anterior and posterior surfaces of the thighs and concealed surfaces of the tibia.

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Malhado, A. C. M., Y. Malhi, R. J. Whittaker, R. J. Ladle, H. ter Steege, L. E. O. C. Aragão, C. A. Quesada, et al. "Spatial trends in leaf size of Amazonian rainforest trees." Biogeosciences Discussions 6, no. 1 (February 23, 2009): 2125–62. http://dx.doi.org/10.5194/bgd-6-2125-2009.

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Abstract. Leaf size influences many aspects of tree function such as rates of transpiration and photosynthesis and, consequently, often varies in a predictable way in response to environmental gradients. The recent development of pan-Amazonian databases based on permanent botanical plots (e.g. RAINFOR, ATDN) has now made it possible to assess trends in leaf size across environmental gradients in Amazonia. Previous plot-based studies have shown that the community structure of Amazonian trees breaks down into at least two major ecological gradients corresponding with variations in soil fertility (decreasing south to northeast) and length of the dry season (increasing from northwest to south and east). Here we describe the results of the geographic distribution of leaf size categories based on 121 plots distributed across eight South American countries. We find that, as predicted, the Amazon forest is predominantly populated by tree species and individuals in the mesophyll size class (20.25–182.25 cm2). The geographic distribution of species and individuals with large leaves (>20.25 cm2) is complex but is generally characterized by a higher proportion of such trees in the north-west of the region. Spatially corrected regressions reveal weak correlations between the proportion of large-leaved species and metrics of water availability. We also find a significant negative relationship between leaf size and wood density.

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Heckenberger, Michael. "Archaeology as Indigenous Advocacy in Amazonia." Practicing Anthropology 26, no. 3 (July 1, 2004): 35–39. http://dx.doi.org/10.17730/praa.26.3.j3x06m427k558232.

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Not so long ago, most anthropologists held a view of pre-Columbian Amazonian peoples as fairly uniform across the region and roughly identical to 20th century ethnographic groups- a view based on very scanty direct evidence. Attention was therefore directed at contemporary social forms and singlesited ethnography, which seemed well suited to studying the small, dispersed, and autonomous villages of the region. In recent decades, archaeology and ethnohistory document much greater variability through time and space, notably complex, regional social formations and broad regional social networks. At the same time, contemporary issues of cultural ‘property’ rights have drawn attention to the agency and dynamism of indigenous social formations. In light of new views on Amazonia, as dynamic, diverse, and unpredictable, the unique ability of archaeologists to consider longterm change provides a critical perspective in regional ethnology, although in-depth archaeological investigations are rare.

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Katz, Esther, Claudia L. Lopez, Marie Fleury, Robert Miller, Valeria Payê, Teresinha Dias, Franklin Silva, Zelandes Oliveira, and Elaine Moreira. "No greens in the forest? Note on the limited consumption of greens in the Amazon." Acta Societatis Botanicorum Poloniae 81, no. 4 (2012): 283–93. http://dx.doi.org/10.5586/asbp.2012.048.

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The consumption of greens is reported as being very minor among Amazonian Indians. The authors of this article present a new review of this subject, based on fieldwork with Amerindians and other populations in different parts of the Brazilian Amazon and French Guiana. Written sources on Brazilian, Peruvian, Columbian and Venezuelan Amazon were also reviewed. The consumption of cultivated, semi-cultivated and wild species of greens was taken into account here, as the data specific to wild greens is very scarce. It is confirmed that greens are not commonly eaten among native Amazonians and that some ethnic groups do not consume them at all. The consumed species are usually young shoots of weeds or cassava leaves. Common in the Belém region are some specific aromatic plants, which have been diffused to other parts of the Amazon, together with introduced plants such as kale and coriander. Migrants from Northeastern Brazil settled in the Amazon consume some cultivated greens, especially aromatic plants. Maroons are the ones who use more greens in their diet. Native Amazonian people, who supplement agriculture with game and fish, follow a hunter-gatherer pattern, preferring wild fruit and tubers to greens.

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Felippe-Bauer, Maria Luiza, Abraham Cáceres, Cristiane Santos da Silva, William Valderrama-Bazan, Antero Gonzales-Perez, and Janira Martins Costa. "New records of Culicoides Latreille (Diptera: Ceratopogonidae) from Peruvian Amazonian region." Biota Neotropica 8, no. 2 (June 2008): 33–38. http://dx.doi.org/10.1590/s1676-06032008000200002.

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Ten species of Culicoides Latreille are reported for the first time from Peruvian Departments of Amazonas, Cajamarca, Loreto, Madre de Dios, Piura and San Martin. The synonymy and distribution of the species in the New World are given.

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Journal articles on the topic 'Amazonian region'

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