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Background: Previous work has shown that Amazonian tropical forests have experienced two widespread changes in dynamics over recent decades, increases in both tree stem turnover and above-ground biomass. However, data from an Amazonian monodominant forest dominated by Peltogyne gracilipes have shown that the above-ground biomass of this forest type has declined slightly (<5%) over an 11-year period. Aims: To determine whether the tree communities in three types of forest, with or without Peltogyne gracilipes (Peltogyne-rich forest (PRF), Peltogyne-poor (PPF) and forest without Peltogyne (FWP)) on Maracá Island, Roraima, have experienced a change in structure and floristic composition over a 20-year period. Methods: We have quantified the variation in the occurrence and abundance of tree species, the above-ground biomass (AGB) and change in total stand biomass from mortality, recruitment and growth for trees, palms and large lianas, ≥10 cm diameter at breast height, in three plots of 0.25 ha in each of the three forest types. Results: Floristic composition showed little change, with no shift in the rank abundance amongst the 10 most important tree species, although in FWP there was a reduction in species richness from 51 to 43. Recruitment is shown to offset the losses caused by mortality in PRF and FWP. The annual mean mortality rates were low, at around 1%. In 2011 AGB in the three forest types varied from 434 Mg ha-1 (PPF) to 363 Mg ha-1 (FWP). PRF experienced an AGB decline of 4.1%, associated with the death of large trees, while FWP showed a slight increase in biomass (2.6%). Conclusions: Over the last 20 years Maracá forest stands appear to have been stable in terms of their floristic composition and structure, some showing a persistent monodominance by Peltogyne gracilipes. © 2014 Copyright 2013 Botanical Society of Scotland and Taylor & Francis.


News Article | November 2, 2016
Site: www.eurekalert.org

GOAmazon researchers describe in Nature the role of clouds as transporters of particles between the ground and the upper atmosphere. New knowledge will enhance climate models A study published in the journal Nature solves a mystery that has puzzled scientists for over a decade: the origin of the atmospheric aerosols that contribute to cloud formation above the Amazon rainforest in the absence of local sources of pollution. Aerosols are microscopic particles suspended in the atmosphere. They play several essential roles in the climate system. For example, most clouds owe their existence to aerosols, because the water vapor in the atmosphere condenses on them to form cloud droplets that eventually precipitate as rain. These seed-like aerosol particles are called cloud condensation nuclei, the authors explain. According to the latest findings of the research project, conducted with FAPESP's support as part of the Green Ocean Amazon Experiment (GOAmazon), particles that serve as precursors of cloud condensation nuclei form in the upper atmosphere and are carried down toward the ground by clouds and rain. "We tried for at least 15 years to measure the formation of new aerosol particles in the Amazon at ground level and the result was always zero. The new nanometric particles simply didn't turn up there. Measurements were made on the surface or in aircraft flying no higher than 3,000 m. We only found the answer when we looked much higher up," said Paulo Artaxo, a professor at the University of São Paulo's Physics Institute (IF-USP) and a co-author of the article. According to Artaxo, the Amazon rainforest naturally emits gases known as volatile organic compounds (VOCs), including terpene and isoprene. They are swept into the upper atmosphere by cloud convection and can soar as high as 15,000 m, where the temperature is about minus 55 degrees Celsius. "At these very low temperatures, the VOCs condense and form tiny particles measuring 1-5 nm," Artaxo explained. "These nanoparticles absorb gases and collide with each other, rapidly agglomerating and growing to a size large enough to make them cloud condensation nuclei, typically more than 50-70 nm." At high altitudes, he added, particle agglomeration is facilitated by low atmospheric pressure, low temperature, and the vast numbers of particles in circulation there. "Eventually one of these giant convective clouds generates a strong downdraft of air and precipitates as rain, so that the particles plunge down toward the ground," Artaxo said. Some of the measurements presented in the article were made in March 2014 during the Amazon's rainy season by a Grumman Gulfstream-1, a research aircraft capable of flying at 6,000 m, or nearly 20,000 ft, and owned by Pacific Northwest National Laboratory (PNNL) in the US. Another dataset was obtained between March and May 2014 at the Amazon Tall Tower Observatory (ATTO), which is operated by Brazil's National Institute of Amazon Research (INPA). The ATTO is 320 m high and located in the heart of the rainforest on the Uatumã Biological Reserve, some 160 km northeast of Manaus - beyond the reach of urban pollution. Supplementary measurements of aerosols were made at the ZF2 towers around 55 km north of Manaus, and in Manacapuru some 100km west of Manaus at the Atmospheric Radiation Measurement (ARM) mobile facility comprising a number of ground-based and airborne devices developed for climate studies and owned by the US Department of Energy. "Much to our surprise, we found that the amount of particulate matter in the atmosphere increased with altitude. We would have expected higher concentrations nearer to the ground. We found very large amounts of aerosols at around 6,000 m, the highest the Gulfstream-1 can fly," said Luiz Augusto Toledo Machado, a researcher at the National Space Research Institute (INPE) and also a co-author of the article. The initial observation was confirmed by new measurements captured by the German High Altitude & Long Range Research Aircraft (HALO), which can fly at 16,000 m and is operated by a research consortium that includes the German Aerospace Center (DLR), Max Planck Institute (MPI) and German Research Foundation (DFG). "We found that in polluted areas there was an extremely high concentration of particulate matter near ground level, which wasn't the case in pollution-free areas. At high altitudes, however, we found large amounts of particles even in the absence of local pollution sources," Machado said. "This latest study shows how these nanoparticles are swept down toward the ground by rain to form new populations of particulate matter that act as cloud condensation nuclei at low altitudes." According to Artaxo, the observation was surprising because above the planetary boundary layer at 2,500 m there is a temperature inversion that usually inhibits the vertical movement of particules. "But we hadn't taken into account the role of convective clouds as transporters of the gases emitted by the forest," he said. The studies performed under the aegis of GOAmazon are proving that VOCs from plants are part of a fundamental mechanism for the production of aerosols in continental areas, he went on. "The combination of forest-emitted VOCs and clouds makes a very specific dynamic that produces huge amounts of particles at high altitudes, where there weren't thought to be any. It's the biology of the forest interacting with clouds to keep the Amazon's ecosystem functioning," Artaxo said. The VOCs soar into the upper atmosphere where wind speeds are very high, and are redistributed around the planet very efficiently. In the Amazon's case, part goes to the Andes and part to southern Brazil, while some remains in the tropical forest region itself. "At the moment we're modeling all our data to work out more precisely which regions are affected by VOCs from the Amazon that are transported by atmospheric circulation," Artaxo said. Because it was unknown until now, this aerosol production mechanism is not considered by any of the climate models currently in use. "The knowledge will have to be included," Machado said. "It will help make rainfall simulations more precise."


Tarra I.L.C.,National Institute of Amazonian Research | de Luizao F.J.,INPA | Wandelli E.V.,Embrapa CPAA | Teixeira W.G.,Embrapa CPAA | And 2 more authors.
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2010

Soil quality under usage through time, and within agroecosystems, is an important aspect in order to improve soil usage sustainability in tropical regions. In this scenario, quantifying the effects of time of usage in pastures under the different soil components (macropores) is important to determine the management planning and reclamation most adequate for such areas. The objective of this study was to evaluate the time effect in pastures (4, 5 and 8 years) on macropore volume after ten years of abandonment and nine of reclamation through Capoeira and agroecosystems. Macropore volume was measured in three different depths (0-5; 5-10 and 10-15 cm) in 100 cm 3 steel cylinders. Macropore volume dropped significantly with the raise in time usage of the areas as pasture, which in turn makes time usage evident in pastures over macropore volume of soil ≥ 50μ μm, mainly in the first soil layer (0-5 cm), directly affected by animal impact. Therefore, it is suggested that time of soil reclamation should be longer than ten years so that the soil characteristics can be recovered.


Inoue L.A.K.A.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | Boijink C.L.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | Ribeiro P.T.,Centro Universitario Nilton Lins | da Silva A.M.D.,Inpa | Affonso E.G.,Inpa
Acta Amazonica | Year: 2011

Tambaqui is the main farmed fish in the Western Amazon. However, in handling this fish has to be anesthetized for safety purposes, usually when evaluating growth and health conditions. Eugenol, the main component of clove oil, has been reported as an alternative fish anesthetic, because it is an inexpensive natural product. However, continued studies are necessary about the metabolic responses of tropical fish to anesthetics. The present work evaluated metabolic responses of tambaqui to eugenol in simulated anesthetic baths, measuring blood and plasma parameters. Typical metabolic stress responses to handling were detected, but they were not totally reduced by eugenol. On the other hand, the anesthetic dissolved in water did not provoke any extra charge of stress during short-term exposures in concentrations of about 20mg L-1 for 15 min.


Ferreira R.N.C.,National Institute of Amazonian Research | Franklin E.,INPA | de Souza J.L.P.,National Institute of Amazonian Research | de Moraes J.,National Institute of Amazonian Research
Journal of Natural History | Year: 2012

We recorded species abundance and richness of oribatid mites along 16 plots established in semi-deciduous forest fragments in Amazonia. The results were compared with a published dataset consisting of an inventory carried out in 38 plots in the surrounding savanna. Totals of 143 and 91 species were recorded in the forest fragments and savanna, respectively. Sørensen similarity index between both environments was 0.44. Ordination of sites according to oribatid mite species composition showed a clear separation between forest fragments and savanna. Rostrozetes ovulum, Archegozetes longisetosus and Eohypochthonius (Eohypochthonius) becki were abundant and frequent in the forest fragments but exceedingly rare in the savanna. Neoppia (Neoppia) schauenbergi, Pseudoppia sp. C, Microppia sp. A and Cosmochthonius sp. A were limited to the savanna. This study also represents an early step toward knowing which groups of species are exclusive to one or another vegetation type or are sensitive to their inherent environmental conditions. © 2012 Copyright Taylor and Francis Group, LLC.


Baccaro F.B.,National Institute of Amazonian Research | De Souza J.L.P.,Programa de Pos Graduacao em Entomologia | Franklin E.,INPA | Landeiro V.L.,National Institute of Amazonian Research | Magnusson W.E.,INPA
Ecological Entomology | Year: 2012

Ants are highly interactive organisms and dominant species are considered to be able to control the species richness of other ants via competitive exclusion. However, depending on the scale studied, inter-specific competition may or may not structure biological assemblages. To date, ant dominance-richness relationships have only been studied in small sample units, where a few dominant colonies could plausibly control most of the sample unit. We conducted a comprehensive survey of terrestrial ant assemblages using bait, pitfall, and litter-sorting methods in three sites in Brazilian Amazonia. Using a spatially structured rarefaction approach, based on sampling units with linear dimensions ranging from 25 to 250 m, the mesoscale patterns of ant dominance-richness relationships (sampling units covering hundreds of meters separated by kilometers) were investigated. Interference-competition models (parabolic or negative linear relationships between species richness and the abundance of dominant ants) tended to be more frequent in smaller sample units or in assemblages sampled with interactive methods, such as baits. Using more inclusive sampling methods, the relationship was generally asymptotic rather than parabolic, with no reduction in species diversity because of the presence of dominants. Random co-occurrence patterns of species within sites support the interpretation of a limited role for present-day competition in structuring these assemblages. Competition from dominant species may reduce species richness in small areas, especially when artificial baits are used, but appears to be less important than environmental constraints in determining ant species richness across scales of hectares and greater in these Amazon forests. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.


Mendes K.R.,National Institute of Amazonian Research | Marenco R.A.,National Institute of Amazonian Research | Magalhaes N.S.,INPA
Revista Arvore | Year: 2013

In the Amazon Rainforest, photosynthesis and tree growth may be limited by the availability of nutrient. Thus, the objectives of this study were to determine the effect of leaf N and P content on photosynthesis, and to assess plant growth in response to understory light in ten tree species in Central Amazonia. Data were collected in January 2008. The photosynthetic capacity (Apot) of leaves positively increased with foliar N and P content, but it was only responsive to P use efficiency. The contents of N and P increased as understory irradiance increased. In addition, we found a positive relationship between N content and the N/P ratio. On the contrary, the relationship between P content and the N/P ratio was negative. Specific leaf area was negatively correlated with N and P. N use efficiency declined with increases with the N/P ratio, but the N/P ratio had no significant effect on P use efficiency. Growth in diameter increased with understory light. In conclusion, saplings were highly sensitive to variations in light intensity, and P was used with high efficiency in studied species.


Boubli J.P.,Wildlife Conservation Society | Couto-Santos F.R.,INPA | Strier K.B.,University of Wisconsin - Madison
Ecotropica | Year: 2011

This study presents results from the first systematic botanical investigation of the RPPN Feliciano Miguel Abdala (RPPN-FMA, formerly Caratinga Biological Station), a semi-deciduous forest fragment in southeastern Brazil that supports nearly a third of the remaining population of the critically endangered northern muriqui (BrachyteUs hypoxanthus). Here we describe the structure, diversity, and floristic composition of this forest. Our goal was to provide the scientific basis for a management plan that will take into consideration the factors involved in the unusually high muriqui carrying capacity in this fragment. Our sample comes from six 500 × 10 -m plots, totaling 3 ha. We marked and identified all trees with DBH ≥ 10 cm in all of the plots, and all trees of 5 ≤ DBH < 10 cm in half of the plots (1.5 ha). Forest structure was consistent with secondary forest characteristics, inasmuch as large trees were rare, total basal area was small, canopy was discontinuous, average tree height was low, and liana load was heavy. Top-ranking families, based on Importance Value, were Fabaceae, Euphorbiaceae, Annonaceae, Rubiaceae, and Moraceae. Compared with other forests where northern muriquis occur, the RPPN-FMA forest was more floristically diverse (H' = 4.6) and even (J = 0.85). In addition, top- ranking species were known muriqui foods. These factors might contribute to the unusually high density of the primate found at this site. © Society for Tropical Ecology.


News Article | March 2, 2017
Site: www.eurekalert.org

An international team of ecologists and social scientists has shown in a new study published 3 March in the journal Science that tree species domesticated and distributed throughout the Amazon basin by indigenous peoples before 1492 continue to play an important role in modern-day forests. These new findings strongly refute the idea that Amazonian forests have been largely untouched by humans. The study was led by Carolina Levis, a PhD candidate at Brazil's National Institute for Amazonian Research (INPA) and Wageningen University and Research Center in the Netherlands. "For many years, ecological studies ignored the influence of pre-Colombian peoples on the forests we see today. We found that a quarter of Amazonia's domesticated species are widely distributed in the basin and dominate large expanses of forest. These results clearly indicate that the Amazonian flora is in part a surviving heritage of its past inhabitants," says Levis. The team made the discovery by overlaying data from more than 1000 forest surveys of the Amazon Tree Diversity Network on a map of more than 3000 archaeological sites across the Amazon. By comparing forest composition at varying distances from archaeological sites, their analysis generated the first Amazon-wide picture of how pre-Colombian peoples influenced Amazonian biodiversity. The study focused on 85 tree species known to have been domesticated by Amazonian peoples for food, shelter, or other uses over the last several thousand years. The researchers found that throughout the Amazon basin these species were five times more likely to be common in tree surveys than non-domesticated species. Domesticated species were also found to be more common and more diverse in forests closer to archaeological sites. These 85 domesticated trees include well-known commercial species, such as cacao, açaí, and Brazil nut. "The finding promises to heat up a long-simmering debate among scientists about how thousands of years of human occupation in the Amazon basin have influenced modern-day patterns of Amazonian biodiversity, and challenges the view many of us ecologists had and still have of this huge area," says Hans ter Steege, of Naturalis Biodiversity Center and coordinator of the Amazon Tree Diversity Network. The immense size of Amazonian forests has historically hampered archaeological research and given the impression of an untouched landscape, but a large number of new archaeological sites have been discovered in recent years. "This lays to rest the long-standing myth of the 'empty Amazon'," says Charles Clement, senior researcher at INPA, Manaus, and a coauthor of the study. "Early European naturalists reported scattered indigenous populations living in huge and apparently virgin forests, and that idea has continued to fascinate the media, policy makers, development planners and even some scientists. This study confirms that even areas of the Amazon that look empty today are crowded with ancient footprints." The study also pinpointed regions of the Amazon that today concentrate especially high diversities and large populations of domesticated species. Southwestern Amazonia, where large stands of Brazil nut trees remain a foundation of local residents' livelihoods, is one such example. In other regions, like the Guiana Shield, domesticated species are less well represented, and the relationship between domesticated species and archaeological sites is less clear, highlighting the need for more research on the history of Amazonian occupation. The degree to which the recent history of Amazonian settlement has affected the distribution and abundance of domesticated species in the Amazon basin also remains to be studied. While the relatively small number of domesticated tree species used in the study was sufficient to reveal a strong human signal in modern forests, the authors point out that the signal may be even stronger than they documented, since hundreds of other Amazonian tree species were also managed by pre-Colombian peoples but not domesticated. Untangling the complex interplay of historical, environmental, and ecological factors structuring approximately 16,000-species Amazonian tree flora remains a focus of the team's work. The question is pressing, since both types of pre-Columbian heritage--archaeological sites and forests with a strong historical component--are at risk from deforestation, degradation, roadbuilding, mining, and other threats. "Domesticated tree species are still vital nowadays for the livelihood of Amazonian peoples", says André Junqueira, a Post-doc at Wageningen University and Research Center and a co-author of the study. "Results of this study have important implications for conservation. We have shown that the southwestern and eastern regions concentrate the most domesticated species, and these are the regions where most forest degradation and loss is occurring. Southwestern and eastern Amazonia may not be considered classical biodiversity hotspots, but should be top conservation priorities as reservoirs of high value forests for human populations," says Flávia Costa, researcher at INPA and a co-author of the study.


News Article | March 2, 2017
Site: www.chromatographytechniques.com

An international team of ecologists and social scientists has shown in a new study published 3 March in the journal Science that tree species domesticated and distributed throughout the Amazon basin by indigenous peoples before 1492 continue to play an important role in modern-day forests. These new findings strongly refute the idea that Amazonian forests have been largely untouched by humans. The study was led by Carolina Levis, a PhD candidate at Brazil's National Institute for Amazonian Research (INPA) and Wageningen University and Research Center in the Netherlands. "For many years, ecological studies ignored the influence of pre-Colombian peoples on the forests we see today. We found that a quarter of Amazonia's domesticated species are widely distributed in the basin and dominate large expanses of forest. These results clearly indicate that the Amazonian flora is in part a surviving heritage of its past inhabitants," says Levis. The team made the discovery by overlaying data from more than 1000 forest surveys of the Amazon Tree Diversity Network on a map of more than 3,000 archaeological sites across the Amazon. By comparing forest composition at varying distances from archaeological sites, their analysis generated the first Amazon-wide picture of how pre-Colombian peoples influenced Amazonian biodiversity. The study focused on 85 tree species known to have been domesticated by Amazonian peoples for food, shelter, or other uses over the last several thousand years. The researchers found that throughout the Amazon basin these species were five times more likely to be common in tree surveys than non-domesticated species. Domesticated species were also found to be more common and more diverse in forests closer to archaeological sites. These 85 domesticated trees include well-known commercial species, such as cacao, açaí, and Brazil nut. "The finding promises to heat up a long-simmering debate among scientists about how thousands of years of human occupation in the Amazon basin have influenced modern-day patterns of Amazonian biodiversity, and challenges the view many of us ecologists had and still have of this huge area," says Hans ter Steege, of Naturalis Biodiversity Center and coordinator of the Amazon Tree Diversity Network. The immense size of Amazonian forests has historically hampered archaeological research and given the impression of an untouched landscape, but a large number of new archaeological sites have been discovered in recent years. "This lays to rest the long-standing myth of the 'empty Amazon'," says Charles Clement, senior researcher at INPA, Manaus, and a coauthor of the study. "Early European naturalists reported scattered indigenous populations living in huge and apparently virgin forests, and that idea has continued to fascinate the media, policy makers, development planners and even some scientists. This study confirms that even areas of the Amazon that look empty today are crowded with ancient footprints." The study also pinpointed regions of the Amazon that today concentrate especially high diversities and large populations of domesticated species. Southwestern Amazonia, where large stands of Brazil nut trees remain a foundation of local residents' livelihoods, is one such example. In other regions, like the Guiana Shield, domesticated species are less well represented, and the relationship between domesticated species and archaeological sites is less clear, highlighting the need for more research on the history of Amazonian occupation. The degree to which the recent history of Amazonian settlement has affected the distribution and abundance of domesticated species in the Amazon basin also remains to be studied. While the relatively small number of domesticated tree species used in the study was sufficient to reveal a strong human signal in modern forests, the authors point out that the signal may be even stronger than they documented, since hundreds of other Amazonian tree species were also managed by pre-Colombian peoples but not domesticated. Untangling the complex interplay of historical, environmental, and ecological factors structuring approximately 16,000-species Amazonian tree flora remains a focus of the team's work. The question is pressing, since both types of pre-Columbian heritage—archaeological sites and forests with a strong historical component—are at risk from deforestation, degradation, roadbuilding, mining, and other threats. "Domesticated tree species are still vital nowadays for the livelihood of Amazonian peoples", says André Junqueira, a post-doc at Wageningen University and Research Center and a co-author of the study. "Results of this study have important implications for conservation. We have shown that the southwestern and eastern regions concentrate the most domesticated species, and these are the regions where most forest degradation and loss is occurring. Southwestern and eastern Amazonia may not be considered classical biodiversity hotspots, but should be top conservation priorities as reservoirs of high value forests for human populations," says Flávia Costa, researcher at INPA and a co-author of the study.

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