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Sample records for amazon tree boa

  1. Predation of a squirrel monkey (Saimiri sciureus) by an Amazon tree boa (Corallus hortulanus): even small boids may be a potential threat to small-bodied platyrrhines.

    PubMed

    Ribeiro-Júnior, Marco Antônio; Ferrari, Stephen Francis; Lima, Janaina Reis Ferreira; da Silva, Claudia Regina; Lima, Jucivaldo Dias

    2016-07-01

    Predation has been suggested to play a major role in the evolution of primate ecology, although reports of predation events are very rare. Mammalian carnivores, raptors, and snakes are known predators of Neotropical primates, and most reported attacks by snakes are attributed to Boa constrictor (terrestrial boas). Here, we document the predation of a squirrel monkey (Saimiri sciureus) by an Amazon tree boa (Corallus hortulanus), the first record of the predation of a platyrrhine primate by this boid. The event was recorded during a nocturnal herpetological survey in the Piratuba Lake Biological Reserve, in the north-eastern Brazilian Amazon. The snake was encountered at 20:00 hours on the ground next to a stream, at the final stage of ingesting the monkey. The C. hortulanus specimen was 1620 mm in length (SVL) and weighed 650 g, while the S. sciureus was a young adult female weighing 600 g, 92 % of the body mass of the snake and the largest prey item known to have been ingested by a C. hortulanus. The evidence indicates that the predation event occurred at the end of the afternoon or early evening, and that, while capable of capturing an agile monkey like Saimiri, C. hortulanus may be limited to capturing small platyrrhines such as callitrichines. PMID:27165689

  2. IDENTIFICATION OF CHLAMYDOPHILA PNEUMONIAE IN AN EMERALD TREE BOA, CORALLUS CANINUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multiple tissues were evaluated from dead emerald tree boas, Corallus caninus, that were from a collection where chlamydiosis was diagnosed. To determine the strain of chlamydia infecting these snakes, tissue samples from 5 frozen snakes were tested by a TaqMan PCR test and a PCR-sequence analysis ...

  3. Morphological and molecular identification of ticks infesting Boa constrictor (Squamata, Boidae) in Manaus (Central Brazilian Amazon).

    PubMed

    Fiorini, Leonardo Costa; Craveiro, Adriana Bentes; Mendes, Márcia Cristina; Chiesorin Neto, Laerzio; Silveira, Ronis Da

    2014-01-01

    The Boa constrictor is one of the world's largest vertebrate carnivores and is often found in urban areas in the city of Manaus, Brazil. The morphological identification of ticks collected from 27 snakes indicated the occurrence of Amblyomma dissimile Koch 1844 on all individuals sampled. In contrast, Amblyomma rotundatum Koch was found on only two snakes. An analysis of the 16S rRNA molecular marker confirmed the morphological identification of these ectoparasites. PMID:25517537

  4. Intracoelomic anaplastic sarcoma in an intersex Madagascar tree boa (Sanzinia madagascariensis).

    PubMed

    Sharpe, Sam; Lamm, Catherine G; Killick, Rowena

    2013-01-01

    An adult Madagascar tree boa (Sanzinia madagascariensis) underwent coeliotomy for investigation of a coelomic mass. At surgery, a large mass originating from the peri-pancreatic adipose tissue and involving the gall bladder was removed. The snake did not recover from general anesthesia. A complete postmortem was performed, and samples were submitted to the University of Glasgow for histopathology. On histological examination, the mass was composed of adipose tissue infiltrated with a poorly demarcated spindle cell neoplasm. The neoplastic cells were highly pleomorphic with abundant cytoplasm and frequent clear cytoplasmic vacuoles, suggestive of adipocyte origin. Immunohistochemical characterization of the mass was inconclusive. Metastatic neoplastic cells were present within vessels in the liver, lungs, and brain. As an incidental finding, the gonads contained both maturing ovarian follicles and seminiferous tubules with intact germinal epithelium and evidence of spermatogenesis, along with other features of male and female gonad anatomy. The current report describes a rare neoplasm in snakes within an intersex Madagascar tree boa. PMID:23345276

  5. Methane emissions from floodplain trees of the Amazon basin

    NASA Astrophysics Data System (ADS)

    Pangala, Sunitha; Bastviken, David; Enrich-Prast, Alex; Gauci, Vincent

    2016-04-01

    Wetlands are the largest source of methane to the atmosphere, but emission estimates are highly uncertain leading to large discrepancies between emission inventories and much larger estimates of the Amazon methane source derived at larger scales. We examined methane emissions from all emission pathways including aquatic surfaces, emergent soils and herbaceous vegetation and more than 2000 trees from 13 locations across the central Amazon floodplain in 2014. Our data are the first measurements of stem emission from emergent portions of inundated trees in the Amazon and they demonstrate that regionally, tree stems are the dominant means of emissions for soil produced methane to the atmosphere. Emissions via the range of egress pathways varied substantially between sample locations and water-table exerted some control over emissions from ~2m below the soil surface upto 0.5-1m of inundation. Higher water (upto ~10m of inundation) exerted no further control over emissions. Applying our measurements to models of whole tree emission and scaling to the entire Amazon lowland basin demonstrates the significant contribution of trees to regional emissions that can close the Amazon basin methane budget.

  6. Extreme Drought Events Revealed in Amazon Tree Ring Records

    NASA Astrophysics Data System (ADS)

    Jenkins, H. S.; Baker, P. A.; Guilderson, T. P.

    2010-12-01

    The Amazon basin is a center of deep atmospheric convection and thus acts as a major engine for global hydrologic circulation. Yet despite its significance, a full understanding of Amazon rainfall variability remains elusive due to a poor historical record of climate. Temperate tree rings have been used extensively to reconstruct climate over the last thousand years, however less attention has been given to the application of dendrochronology in tropical regions, in large part due to a lower frequency of tree species known to produce annual rings. Here we present a tree ring record of drought extremes from the Madre de Dios region of southeastern Peru over the last 190 years. We confirm that tree ring growth in species Cedrela odorata is annual and show it to be well correlated with wet season precipitation. This correlation is used to identify extreme dry (and wet) events that have occurred in the past. We focus on drought events identified in the record as drought frequency is expected to increase over the Amazon in a warming climate. The Cedrela chronology records historic Amazon droughts of the 20th century previously identified in the literature and extends the record of drought for this region to the year 1816. Our analysis shows that there has been an increase in the frequency of extreme drought (mean recurrence interval = 5-6 years) since the turn of the 20th century and both Atlantic and Pacific sea surface temperature (SST) forcing mechanisms are implicated.

  7. Contrasting Strategies of Tree Function in a Seasonal Amazon Rainforest

    NASA Astrophysics Data System (ADS)

    Ivanov, V. Y.; Oliveira, R.; Agee, E.; Brum, M., Jr.; Saleska, S. R.; Fatichi, S.; Ewing, G.

    2015-12-01

    The increased frequency and severity of drought conditions in the Amazon Basin region have emphasized the question of rainforest vulnerability and resilience to heat and drought-induced stresses. However, what emerges from much research is that the impacts of droughts, essential controlling factors of the rainforest function, and variability of tree-scale strategies are yet to be fully understood. We present here a preliminary analysis of hydraulic relations of a seasonal Amazon rainforest using a set of ecohydrologic data collected through the GoAmazon project over dry and wet seasons. Expressions of different hydraulic strategies are identified that convey different implications for tree resilience during short- (diurnal) and longer-term (seasonal) stress periods. These hydraulic strategies appear to be inter-related with the tree growth and non-structural carbohydrate dynamics, contributing to the understanding of trait coordination at the whole-plant scale. Integration of individual responses is conducted over a range of wood density and exposure conditions. The results of this research thus shed light on the implication of variations in the rainforest function for future stresses, vital for predictive models of ecosystem dynamics of next generation.

  8. Neogene origins and implied warmth tolerance of Amazon tree species

    PubMed Central

    Dick, Christopher W; Lewis, Simon L; Maslin, Mark; Bermingham, Eldredge

    2013-01-01

    Tropical rain forest has been a persistent feature in South America for at least 55 million years. The future of the contemporary Amazon forest is uncertain, however, as the region is entering conditions with no past analogue, combining rapidly increasing air temperatures, high atmospheric carbon dioxide concentrations, possible extreme droughts, and extensive removal and modification by humans. Given the long-term Cenozoic cooling trend, it is unknown whether Amazon forests can tolerate air temperature increases, with suggestions that lowland forests lack warm-adapted taxa, leading to inevitable species losses. In response to this uncertainty, we posit a simple hypothesis: the older the age of a species prior to the Pleistocene, the warmer the climate it has previously survived, with Pliocene (2.6–5 Ma) and late-Miocene (8–10 Ma) air temperature across Amazonia being similar to 2100 temperature projections under low and high carbon emission scenarios, respectively. Using comparative phylogeographic analyses, we show that 9 of 12 widespread Amazon tree species have Pliocene or earlier lineages (>2.6 Ma), with seven dating from the Miocene (>5.6 Ma) and three >8 Ma. The remarkably old age of these species suggest that Amazon forests passed through warmth similar to 2100 levels and that, in the absence of other major environmental changes, near-term high temperature-induced mass species extinction is unlikely. PMID:23404439

  9. Pattern and process in Amazon tree turnover, 1976-2001.

    PubMed Central

    Phillips, O L; Baker, T R; Arroyo, L; Higuchi, N; Killeen, T J; Laurance, W F; Lewis, S L; Lloyd, J; Malhi, Y; Monteagudo, A; Neill, D A; Vargas, P Núñez; Silva, J N M; Terborgh, J; Martínez, R Vásquez; Alexiades, M; Almeida, S; Brown, S; Chave, J; Comiskey, J A; Czimczik, C I; Di Fiore, A; Erwin, T; Kuebler, C; Laurance, S G; Nascimento, H E M; Olivier, J; Palacios, W; Patiño, S; Pitman, N C A; Quesada, C A; Saldias, M; Lezama, A Torres; Vinceti, B

    2004-01-01

    Previous work has shown that tree turnover, tree biomass and large liana densities have increased in mature tropical forest plots in the late twentieth century. These results point to a concerted shift in forest ecological processes that may already be having significant impacts on terrestrial carbon stocks, fluxes and biodiversity. However, the findings have proved controversial, partly because a rather limited number of permanent plots have been monitored for rather short periods. The aim of this paper is to characterize regional-scale patterns of 'tree turnover' (the rate with which trees die and recruit into a population) by using improved datasets now available for Amazonia that span the past 25 years. Specifically, we assess whether concerted changes in turnover are occurring, and if so whether they are general throughout the Amazon or restricted to one region or environmental zone. In addition, we ask whether they are driven by changes in recruitment, mortality or both. We find that: (i) trees 10 cm or more in diameter recruit and die twice as fast on the richer soils of southern and western Amazonia than on the poorer soils of eastern and central Amazonia; (ii) turnover rates have increased throughout Amazonia over the past two decades; (iii) mortality and recruitment rates have both increased significantly in every region and environmental zone, with the exception of mortality in eastern Amazonia; (iv) recruitment rates have consistently exceeded mortality rates; (v) absolute increases in recruitment and mortality rates are greatest in western Amazonian sites; and (vi) mortality appears to be lagging recruitment at regional scales. These spatial patterns and temporal trends are not caused by obvious artefacts in the data or the analyses. The trends cannot be directly driven by a mortality driver (such as increased drought or fragmentation-related death) because the biomass in these forests has simultaneously increased. Our findings therefore indicate that

  10. Basin-Wide Amazon Forest Tree Mortality From a Large 2005 Storm

    NASA Astrophysics Data System (ADS)

    Negron Juarez, R. I.; Chambers, J. Q.; Guimaraes, G.; Zeng, H.; Raupp, C.; Marra, D. M.; Ribeiro, G.; Saatchi, S. S.; Higuchi, N.

    2010-12-01

    Blowdowns are a recurrent characteristic of Amazon forests and are produced, among others, by squall lines. Squall lines are aligned clusters (typical length of 1000 km, width of 200 km) of deep convective cells that produce heavy rainfall during the dry season and significant rainfall during the wet season. These squall lines (accompanied by intense downbursts from convective cells) have been associated with large blowdowns characterized by uprooted, snapped trees, and trees being dragged down by other falling trees. Most squall lines in Amazonia form along the northeastern coast of South America as sea breeze-induced instability lines and propagate inside the continent. They occur frequently (~4 times per month), and can reach the central and even extreme western parts of Amazonia. Squall lines can also be generated inside the Amazon and propagate toward the equator. In January 2005 a squall line propagated from south to north across the entire Amazon basin producing widespread forest tree mortality and contributed to the elevated mortality observed that year. Over the Manaus region (3.4 x104 km2), disturbed forest patches generated by the squall produced a mortality of 0.3-0.5 million trees, equivalent to 30% of the observed annual deforestation reported in 2005 over the same area. The elevated mortality observed in the Central Amazon in 2005 is unlikely to be related to the 2005 Amazon drought since drought did not affect Central or Eastern Amazonia. Assuming a similar rate of forest mortality across the basin, the squall line could have potentially produced tree mortality estimated at 542 ± 121 million trees, equivalent to 23% of the mean annual biomass accumulation estimated for these forests. Our results highlight the vulnerability of Amazon trees to wind-driven mortality associated with convective storms. This vulnerability is likely to increase in a warming climate with models projecting an increase in storm intensity.

  11. Identification, Characterization, and In Vitro Culture of Highly Divergent Arenaviruses from Boa Constrictors and Annulated Tree Boas: Candidate Etiological Agents for Snake Inclusion Body Disease

    PubMed Central

    Stenglein, Mark D.; Sanders, Chris; Kistler, Amy L.; Ruby, J. Graham; Franco, Jessica Y.; Reavill, Drury R.; Dunker, Freeland; DeRisi, Joseph L.

    2012-01-01

    ABSTRACT Inclusion body disease (IBD) is an infectious fatal disease of snakes typified by behavioral abnormalities, wasting, and secondary infections. At a histopathological level, the disease is identified by the presence of large eosinophilic cytoplasmic inclusions in multiple tissues. To date, no virus or other pathogen has been definitively characterized or associated with the disease. Using a metagenomic approach to search for candidate etiologic agents in snakes with confirmed IBD, we identified and de novo assembled the complete genomic sequences of two viruses related to arenaviruses, and a third arenavirus-like sequence was discovered by screening an additional set of samples. A continuous boa constrictor cell line was established and used to propagate and isolate one of the viruses in culture. Viral nucleoprotein was localized and concentrated within large cytoplasmic inclusions in infected cells in culture and tissues from diseased snakes. In total, viral RNA was detected in 6/8 confirmed IBD cases and 0/18 controls. These viruses have a typical arenavirus genome organization but are highly divergent, belonging to a lineage separate from that of the Old and New World arenaviruses. Furthermore, these viruses encode envelope glycoproteins that are more similar to those of filoviruses than to those of other arenaviruses. These findings implicate these viruses as candidate etiologic agents of IBD. The presence of arenaviruses outside mammals reveals that these viruses infect an unexpectedly broad range of species and represent a new reservoir of potential human pathogens. PMID:22893382

  12. Wind Disturbance Produced Changes in Tree Species Assemblage in the Peruvian Amazon

    NASA Astrophysics Data System (ADS)

    Rifai, S. W.; Chambers, J. Q.; Negron Juarez, R. I.; Ramirez, F.; Tello, R.; Alegria Muñoz, W.

    2010-12-01

    Wind disturbance has been a frequently overlooked abiotic cause of mass tree mortality in the Amazon basin. In the Peruvian Amazon these wind disturbances are produced by meteorological events such as convective systems. Downbursts for example produce short term descendent wind speeds that can be in excess of 30 m s-1. These are capable of producing tree blowdowns which have been reported to be as large as 33 km2 in the Amazon basin. We used the chronosequence of Landsat Satellite imagery to find and locate where these blowdowns have occurred in the Loreto region of the Peruvian Amazon. Spectral Mixture Analysis was used to estimate the proportion landcover of green vegetation, non-photosynthetic vegetation (NPV), soil and shade in each pixel. The change in NPV was calculated by subtracting the NPV signal in the Landsat image prior to the blowdown occurrence, from the image following the disturbance. Our prior research has established a linear relationship between tree mortality and change in NPV. It is hypothesized that these mass tree mortality events result in changes in the tree species assemblage of affected forests. Here we present preliminary tree species assemblage data from two sites in the Peruvian Amazon near Iquitos, Peru. The site (ALP) at the Allpahuayo Mishana reserve (3.945 S, 73.455 W) is 30 km south of Iquitos, Peru, and hosts the remnants of a 50 ha blowdown that occurred in either 1992 or 1993. Another site (NAPO) on the Napo river about 60 km north of Iquitos, is the location of an approximately 300 ha blowdown that occurred in 1998. At each site, a 3000 m x 10 m transect encompassing non disturbed and disturbed areas was installed, and trees greater than 10 cm diameter at breast height were measured for diameter, height and were identified to the species. Stem density of trees with diameter at breast height > 10 cm, and tree height appear to be similar both inside and outside the blowdown affected areas of the forests at both sites. At the ALP

  13. Deforestation, fire susceptibility, and potential tree responses to fire in the eastern Amazon

    SciTech Connect

    Uhl, C. Agropecuria do Tropico Umnido, Para ); Kauffman, J.B. )

    1990-04-01

    In the state of Para, Brazil, in the eastern Amazon, the authors studied the potential for sustained fire events within four dominant vegetation cover types (undisturbed rain forest, selectively logged forest, second-growth forest, and open pasture), by measuring fuel availability, microclimate, and rates of fuel moisture loss. They also estimated the potential tree mortality that might result from a wide-scale Amazon forest fire by measuring the thermal properties of bark for all trees in a 5-ha stand of mature forest, followed by measurements of heat flux through bark during simulated fires. In pastures the average midday temperature was almost 10{degree}C greater and the average midday relative humidity was 30% lower than in primary forest. The most five-prone ecosystem was the open pasture followed by selectively logged forest, second growth forest, and undisturbed rain forest in which sustained combustion was not possible even after prolonged rainless periods. Even though the autogenic factors in primary forest of the eastern Amazon create a microclimate that virtually eliminates the probability of fire, they are currently a common event in disturbed areas of Amazonia. As many as 8 {times} 10{sup 6} ha burned in the Amazon Basin of Brazil in 1987 alone. In terms of current land-use patterns, altered microclimates, and fuel mass, there are also striking similarities between the eastern Amazon and East Kalimantan, Indonesia (the site of recent rain forest wildfires that burned 3.5 {times} 10{sup 6} ha).

  14. Contribution of litter and tree diameter increment in the eastern Amazon rainforest

    NASA Astrophysics Data System (ADS)

    Camargo, P. B.; Ferreira, M.; De Oliveira, R., Jr.; Saleska, S. R.; Alves, L. F.

    2013-12-01

    Tropical forests have a great importance in the global carbon cycle, especially with regard to biomass. Some models predict that these forests can be vulnerable to carbon loss due to global warming-induced drought increases, while others contradict this theory. So, it is necessary to assess changes in carbon storage over time to better understand the future trends of this scenario. In this sense, this work has as its main objective the evaluation of tree diameter increment and the amount of litter, in a region of the eastern Amazon rainforest. 1000 dendometric trees bands were installed in different taxonomic families and size classes over four transects represent 4 ha each, as well as 60 collectors (litter traps). The trees of the forest had a higher growth in November and a smaller diameter increment in the month of September. The trees of the size class 55-90 cm were the most grown up followed by class > 90 cm trees. A likely factor that drove this episode was the height of the canopy of these trees. Pearson's correlation analysis showed correlation of 55-90 cm class with temperature and precipitation. The production of litter has an average production within the range found in the literature between 200 and 1700 kg.ha.ano-1. Further studies are needed in order to understand more clearly, what are the key factors that drive or limit the growth of tree species in the Amazon.

  15. Penicillium excelsum sp. nov from the Brazil Nut Tree Ecosystem in the Amazon Basin’

    PubMed Central

    Taniwaki, Marta Hiromi; Pitt, John I.; Iamanaka, Beatriz T.; Massi, Fernanda P.; Fungaro, Maria Helena P.; Frisvad, Jens C.

    2015-01-01

    A new Penicillium species, P. excelsum, is described here using morphological characters, extrolite and partial sequence data from the ITS, β-tubulin and calmodulin genes. It was isolated repeatedly using samples of nut shells and flowers from the brazil nut tree, Bertolletia excelsa, as well as bees and ants from the tree ecosystem in the Amazon rainforest. The species produces andrastin A, curvulic acid, penicillic acid and xanthoepocin, and has unique partial β-tubulin and calmodulin gene sequences. The holotype of P. excelsum is CCT 7772, while ITAL 7572 and IBT 31516 are cultures derived from the holotype. PMID:26717519

  16. Penicillium excelsum sp. nov from the Brazil Nut Tree Ecosystem in the Amazon Basin'.

    PubMed

    Taniwaki, Marta Hiromi; Pitt, John I; Iamanaka, Beatriz T; Massi, Fernanda P; Fungaro, Maria Helena P; Frisvad, Jens C

    2015-01-01

    A new Penicillium species, P. excelsum, is described here using morphological characters, extrolite and partial sequence data from the ITS, β-tubulin and calmodulin genes. It was isolated repeatedly using samples of nut shells and flowers from the brazil nut tree, Bertolletia excelsa, as well as bees and ants from the tree ecosystem in the Amazon rainforest. The species produces andrastin A, curvulic acid, penicillic acid and xanthoepocin, and has unique partial β-tubulin and calmodulin gene sequences. The holotype of P. excelsum is CCT 7772, while ITAL 7572 and IBT 31516 are cultures derived from the holotype. PMID:26717519

  17. Widespread Amazon forest tree mortality from a single cross-basin squall line event

    NASA Astrophysics Data System (ADS)

    Negrón-Juárez, Robinson I.; Chambers, Jeffrey Q.; Guimaraes, Giuliano; Zeng, Hongcheng; Raupp, Carlos F. M.; Marra, Daniel M.; Ribeiro, Gabriel H. P. M.; Saatchi, Sassan S.; Nelson, Bruce W.; Higuchi, Niro

    2010-08-01

    Climate change is expected to increase the intensity of extreme precipitation events in Amazonia that in turn might produce more forest blowdowns associated with convective storms. Yet quantitative tree mortality associated with convective storms has never been reported across Amazonia, representing an important additional source of carbon to the atmosphere. Here we demonstrate that a single squall line (aligned cluster of convective storm cells) propagating across Amazonia in January, 2005, caused widespread forest tree mortality and may have contributed to the elevated mortality observed that year. Forest plot data demonstrated that the same year represented the second highest mortality rate over a 15-year annual monitoring interval. Over the Manaus region, disturbed forest patches generated by the squall followed a power-law distribution (scaling exponent α = 1.48) and produced a mortality of 0.3-0.5 million trees, equivalent to 30% of the observed annual deforestation reported in 2005 over the same area. Basin-wide, potential tree mortality from this one event was estimated at 542 ± 121 million trees, equivalent to 23% of the mean annual biomass accumulation estimated for these forests. Our results highlight the vulnerability of Amazon trees to wind-driven mortality associated with convective storms. Storm intensity is expected to increase with a warming climate, which would result in additional tree mortality and carbon release to the atmosphere, with the potential to further warm the climate system.

  18. Functional and biological diversity of foliar spectra in tree canopies throughout the Andes to Amazon region.

    PubMed

    Asner, Gregory P; Martin, Roberta E; Carranza-Jiménez, Loreli; Sinca, Felipe; Tupayachi, Raul; Anderson, Christopher B; Martinez, Paola

    2014-10-01

    Spectral properties of foliage express fundamental chemical interactions of canopies with solar radiation. However, the degree to which leaf spectra track chemical traits across environmental gradients in tropical forests is unknown. We analyzed leaf reflectance and transmittance spectra in 2567 tropical canopy trees comprising 1449 species in 17 forests along a 3400-m elevation and soil fertility gradient from the Amazonian lowlands to the Andean treeline. We developed quantitative links between 21 leaf traits and 400-2500-nm spectra, and developed classifications of tree taxa based on spectral traits. Our results reveal enormous inter-specific variation in spectral and chemical traits among canopy trees of the western Amazon. Chemical traits mediating primary production were tightly linked to elevational changes in foliar spectral signatures. By contrast, defense compounds and rock-derived nutrients tracked foliar spectral variation with changing soil fertility in the lowlands. Despite the effects of abiotic filtering on mean foliar spectral properties of tree communities, the spectra were dominated by phylogeny within any given community, and spectroscopy accurately classified 85-93% of Amazonian tree species. Our findings quantify how tropical tree canopies interact with sunlight, and indicate how to measure the functional and biological diversity of forests with spectroscopy. PMID:24942328

  19. Predation of Alouatta puruensis by Boa constrictor.

    PubMed

    Quintino, Erika Patrícia; Bicca-Marques, Júlio César

    2013-10-01

    Reports of successful predator attacks on primates are rare. Primates from all major radiations are particularly susceptible to raptors, carnivores, and snakes. Among New World primates, reports of snake predation are limited to medium- and small-bodied species. Here, we report the first documented case of successful predation of an atelid by a snake-an adult female Purús red howler monkey, Alouatta puruensis, that was subdued by a ca. 2-m-long Boa constrictor in an arboreal setting at a height of 7.5 m above the ground. The victim belonged to a group composed of six individuals (one adult male, two adult females, two juveniles, and one infant) that inhabited a ca. 2.5-ha forest fragment in the State of Rondônia, western Brazilian Amazon. The boa applied the species' typical hunting behavior of striking and immediately coiling around its prey and then killing it through constriction (probably in less than 5 min), but the entire restraint period lasted 38 min. The attack occurred around noon. The howler was swallowed head-first in 76 min. The only group member to respond to the distress vocalization emitted by the victim was the other adult female, which was closest to the location where the attack occurred. This female ran toward the snake, also vocalizing, and hit it with her hands several times, but the snake did not react and she moved off to a nearby tree from where she watched most of the interaction. The remaining group members stayed resting at a height approximately 15 m above the victim in a nearby tree without showing any overt signs of stress, except for a single whimper vocalization. This event indicates that even large-bodied atelids are vulnerable to predation by large snakes and suggests that B. constrictor may be a more common predator of primates. PMID:23917944

  20. Large-Scale Wind Disturbances Promote Tree Diversity in a Central Amazon Forest

    PubMed Central

    Marra, Daniel Magnabosco; Chambers, Jeffrey Q.; Higuchi, Niro; Trumbore, Susan E.; Ribeiro, Gabriel H. P. M.; dos Santos, Joaquim; Negrón-Juárez, Robinson I.; Reu, Björn; Wirth, Christian

    2014-01-01

    Canopy gaps created by wind-throw events, or blowdowns, create a complex mosaic of forest patches varying in disturbance intensity and recovery in the Central Amazon. Using field and remote sensing data, we investigated the short-term (four-year) effects of large (>2000 m2) blowdown gaps created during a single storm event in January 2005 near Manaus, Brazil, to study (i) how forest structure and composition vary with disturbance gradients and (ii) whether tree diversity is promoted by niche differentiation related to wind-throw events at the landscape scale. In the forest area affected by the blowdown, tree mortality ranged from 0 to 70%, and was highest on plateaus and slopes. Less impacted areas in the region affected by the blowdown had overlapping characteristics with a nearby unaffected forest in tree density (583±46 trees ha−1) (mean±99% Confidence Interval) and basal area (26.7±2.4 m2 ha−1). Highly impacted areas had tree density and basal area as low as 120 trees ha−1 and 14.9 m2 ha−1, respectively. In general, these structural measures correlated negatively with an index of tree mortality intensity derived from satellite imagery. Four years after the blowdown event, differences in size-distribution, fraction of resprouters, floristic composition and species diversity still correlated with disturbance measures such as tree mortality and gap size. Our results suggest that the gradients of wind disturbance intensity encompassed in large blowdown gaps (>2000 m2) promote tree diversity. Specialists for particular disturbance intensities existed along the entire gradient. The existence of species or genera taking an intermediate position between undisturbed and gap specialists led to a peak of rarefied richness and diversity at intermediate disturbance levels. A diverse set of species differing widely in requirements and recruitment strategies forms the initial post-disturbance cohort, thus lending a high resilience towards wind disturbances at the

  1. Large-scale wind disturbances promote tree diversity in a Central Amazon forest.

    PubMed

    Marra, Daniel Magnabosco; Chambers, Jeffrey Q; Higuchi, Niro; Trumbore, Susan E; Ribeiro, Gabriel H P M; Dos Santos, Joaquim; Negrón-Juárez, Robinson I; Reu, Björn; Wirth, Christian

    2014-01-01

    Canopy gaps created by wind-throw events, or blowdowns, create a complex mosaic of forest patches varying in disturbance intensity and recovery in the Central Amazon. Using field and remote sensing data, we investigated the short-term (four-year) effects of large (>2000 m(2)) blowdown gaps created during a single storm event in January 2005 near Manaus, Brazil, to study (i) how forest structure and composition vary with disturbance gradients and (ii) whether tree diversity is promoted by niche differentiation related to wind-throw events at the landscape scale. In the forest area affected by the blowdown, tree mortality ranged from 0 to 70%, and was highest on plateaus and slopes. Less impacted areas in the region affected by the blowdown had overlapping characteristics with a nearby unaffected forest in tree density (583 ± 46 trees ha(-1)) (mean ± 99% Confidence Interval) and basal area (26.7 ± 2.4 m(2) ha(-1)). Highly impacted areas had tree density and basal area as low as 120 trees ha(-1) and 14.9 m(2) ha(-1), respectively. In general, these structural measures correlated negatively with an index of tree mortality intensity derived from satellite imagery. Four years after the blowdown event, differences in size-distribution, fraction of resprouters, floristic composition and species diversity still correlated with disturbance measures such as tree mortality and gap size. Our results suggest that the gradients of wind disturbance intensity encompassed in large blowdown gaps (>2000 m(2)) promote tree diversity. Specialists for particular disturbance intensities existed along the entire gradient. The existence of species or genera taking an intermediate position between undisturbed and gap specialists led to a peak of rarefied richness and diversity at intermediate disturbance levels. A diverse set of species differing widely in requirements and recruitment strategies forms the initial post-disturbance cohort, thus lending a high resilience towards wind

  2. Colloquium paper: how many tree species are there in the Amazon and how many of them will go extinct?

    PubMed

    Hubbell, Stephen P; He, Fangliang; Condit, Richard; Borda-de-Agua, Luís; Kellner, James; Ter Steege, Hans

    2008-08-12

    New roads, agricultural projects, logging, and mining are claiming an ever greater area of once-pristine Amazonian forest. The Millennium Ecosystems Assessment (MA) forecasts the extinction of a large fraction of Amazonian tree species based on projected loss of forest cover over the next several decades. How accurate are these estimates of extinction rates? We use neutral theory to estimate the number, relative abundance, and range size of tree species in the Amazon metacommunity and estimate likely tree-species extinctions under published optimistic and nonoptimistic Amazon scenarios. We estimate that the Brazilian portion of the Amazon Basin has (or had) 11,210 tree species that reach sizes >10 cm DBH (stem diameter at breast height). Of these, 3,248 species have population sizes >1 million individuals, and, ignoring possible climate-change effects, almost all of these common species persist under both optimistic and nonoptimistic scenarios. At the rare end of the abundance spectrum, however, neutral theory predicts the existence of approximately 5,308 species with <10,000 individuals each that are expected to suffer nearly a 50% extinction rate under the nonoptimistic deforestation scenario and an approximately 37% loss rate even under the optimistic scenario. Most of these species have small range sizes and are highly vulnerable to local habitat loss. In ensembles of 100 stochastic simulations, we found mean total extinction rates of 20% and 33% of tree species in the Brazilian Amazon under the optimistic and nonoptimistic scenarios, respectively. PMID:18695228

  3. Tree Regeneration Under Different Land-Use Mosaics in the Brazilian Amazon's "Arc of Deforestation"

    NASA Astrophysics Data System (ADS)

    Do Vale, Igor; Miranda, Izildinha Souza; Mitja, Danielle; Grimaldi, Michel; Nelson, Bruce Walker; Desjardins, Thierry; Costa, Luiz Gonzaga Silva

    2015-08-01

    We studied the tree-regeneration patterns in three distinct agricultural settlements in the Eastern Amazon to test the influence of land-use mosaics. The following questions are addressed: are the floristic structure and composition of regenerating trees affected by the various land-use types applied in the agricultural settlements? Do tree-regeneration patterns respond similarly to distinct land-use mosaics? Is there a relationship between tree regeneration and soil characteristics among the land-use types? The regeneration was inventoried at 45 sampling points in each settlement. At each sampling point, fourteen soil variables were analyzed. Nine different land-use types were considered. The floristic structure and composition of the settlements showed differences in the density of individuals and species and high species heterogeneity among the land-use types. The maximum Jaccard similarity coefficient found between land-use types was only 29 %. Shade-tolerant species were the most diverse functional group in most land-use types, including pasture and annual crops, ranging from 91 % of the number of species in the conserved and exploited forests of Travessão 338-S to 53 % in the invaded pastures of Maçaranduba. The land-use types influenced significantly the floristic structure and composition of regenerating trees in two agricultural settlements, but not in third the settlement, which had greater forest cover. This finding demonstrates that the composition of each land-use mosaic, established by different management approaches, affects regeneration patterns. Tree regeneration was related to soil characteristics in all mosaics. Preparation of the area by burning was most likely the determining factor in the differences in soil characteristics between forests and agricultural areas.

  4. Tree Regeneration Under Different Land-Use Mosaics in the Brazilian Amazon's "Arc of Deforestation".

    PubMed

    Do Vale, Igor; Miranda, Izildinha Souza; Mitja, Danielle; Grimaldi, Michel; Nelson, Bruce Walker; Desjardins, Thierry; Costa, Luiz Gonzaga Silva

    2015-08-01

    We studied the tree-regeneration patterns in three distinct agricultural settlements in the Eastern Amazon to test the influence of land-use mosaics. The following questions are addressed: are the floristic structure and composition of regenerating trees affected by the various land-use types applied in the agricultural settlements? Do tree-regeneration patterns respond similarly to distinct land-use mosaics? Is there a relationship between tree regeneration and soil characteristics among the land-use types? The regeneration was inventoried at 45 sampling points in each settlement. At each sampling point, fourteen soil variables were analyzed. Nine different land-use types were considered. The floristic structure and composition of the settlements showed differences in the density of individuals and species and high species heterogeneity among the land-use types. The maximum Jaccard similarity coefficient found between land-use types was only 29%. Shade-tolerant species were the most diverse functional group in most land-use types, including pasture and annual crops, ranging from 91% of the number of species in the conserved and exploited forests of Travessão 338-S to 53% in the invaded pastures of Maçaranduba. The land-use types influenced significantly the floristic structure and composition of regenerating trees in two agricultural settlements, but not in third the settlement, which had greater forest cover. This finding demonstrates that the composition of each land-use mosaic, established by different management approaches, affects regeneration patterns. Tree regeneration was related to soil characteristics in all mosaics. Preparation of the area by burning was most likely the determining factor in the differences in soil characteristics between forests and agricultural areas. PMID:25948152

  5. Seeing the pasture through the trees: A household model explaining silvo-pastoral landscapes in the Ecuadorian Amazon

    NASA Astrophysics Data System (ADS)

    Lerner, A. M.; Rudel, T.; Schneider, L.; Burbano, D.; McGroddy, M.

    2012-12-01

    In the Amazon basin the destruction of old growth forests has meant, for the most part, the expansion of pastures for livestock and destruction of a global carbon sink. As these pastures have grown in extent and age, questions about what happens to the biodiversity and carbon sequestration in these pastoral landscapes has assumed more importance. In the research reported here, we offer a preliminary answer to these questions. Our study focuses on the southern Ecuadorian Amazon, where there have recently been trends of spontaneous silvo-pastoral landscapes. These landscapes are a result of land managers allowing trees to grow in cattle pastures, potentially leading to seed sources for native species regeneration and carbon sequestration. This paper discusses demographic, economic and cultural shifts, potentially in light of the expansion of urban areas and off-farm employment, which could impact pasture management in Morona Santiago, Ecuador. Tree cover in pastures is modeled against household demographic, economic and environmental variables that demonstrate which variables affect tree cover in managed landscapes. This analysis sheds light into current processes affecting pasture management in the Amazon, and in turn important landscape outcomes such as dual management systems that include pastures and tree regeneration.

  6. Linking canopy leaf area and light environments with tree size distributions to explain Amazon forest demography.

    PubMed

    Stark, Scott C; Enquist, Brian J; Saleska, Scott R; Leitold, Veronika; Schietti, Juliana; Longo, Marcos; Alves, Luciana F; Camargo, Plinio B; Oliveira, Raimundo C

    2015-07-01

    Forest biophysical structure - the arrangement and frequency of leaves and stems - emerges from growth, mortality and space filling dynamics, and may also influence those dynamics by structuring light environments. To investigate this interaction, we developed models that could use LiDAR remote sensing to link leaf area profiles with tree size distributions, comparing models which did not (metabolic scaling theory) and did allow light to influence this link. We found that a light environment-to-structure link was necessary to accurately simulate tree size distributions and canopy structure in two contrasting Amazon forests. Partitioning leaf area profiles into size-class components, we found that demographic rates were related to variation in light absorption, with mortality increasing relative to growth in higher light, consistent with a light environment feedback to size distributions. Combining LiDAR with models linking forest structure and demography offers a high-throughput approach to advance theory and investigate climate-relevant tropical forest change. PMID:25963522

  7. Toward detection of CO2 fertilization of tree growth and biomass accumulation in Amazon forests

    NASA Astrophysics Data System (ADS)

    Chambers, J. Q.; Negron Juarez, R. I.; Di Vittorio, A. V.; Marra, D.; Rifai, S. W.; Ribeiro, G.; Higuchi, N.

    2012-12-01

    Synthesis studies of old-growth tropical forest plot networks indicate a pantropical net carbon sink of more than 1 Pg C/yr. However a number of confounding factors limit our ability to attribute these changes to direct CO2 fertilization of tree growth and forest productivity. Of primary importance is determining if the plots adequately sample natural disturbance and recovery gradients, and the larger landscape successional mosaic. In addition, forest biomass dynamics which include tree growth, recruitment and mortality can interact in complex ways with changes in forest productivity and biomass accumulation. This study represents a novel approach to determine the sensitivity of different sampling strategies for detecting tropical forest CO2 fertilization while accounting for these confounding factors. Our approach, developed for Amazon forests in Brazil and Peru, combines extensive field plot data on biomass dynamics, remote sensing analyses to generate disturbance probability distribution functions, and individual-based simulation modeling for placing plot-level results into a landscape context. Results indicate that forest plots significantly larger than 10 ha are required to maximize the signal-to-noise ratio for detecting CO2 fertilization. We also present a field sampling strategy for quantifying site-to-site differences in forest biomass accumulation rates, which is useful for detecting regional differences in tropical forest sensitivity to rising atmospheric CO2 concentration. Overall, this approach is useful in developing field campaigns that explicitly account for landscape heterogeneity in testing key predictions of Earth system models.

  8. Hyperspectral remote detection of niche partitioning among canopy trees driven by blowdown gap disturbances in the Central Amazon.

    PubMed

    Chambers, Jeffrey Q; Robertson, Amanda L; Carneiro, Vilany M C; Lima, Adriano J N; Smith, Marie-Louise; Plourde, Lucie C; Higuchi, Niro

    2009-05-01

    Advanced recruitment and neutral processes play important roles in determining tree species composition in tropical forest canopy gaps, with few gaps experiencing clear secondary successional processes. However, most studies are limited to the relatively limited spatial scales provided by forest inventory plots, and investigations over the entire range of gap size are needed to better understand how ecological processes vary with tree mortality events. This study employed a landscape approach to test the hypothesis that tree species composition and forest structural attributes differ between large blowdown gaps and relatively undisturbed primary forest. Spectral mixture analysis on hyperspectral satellite imagery was employed to direct field sampling to widely distributed sites, and blowdown plots were compared with undisturbed primary forest plots. Tree species composition and forest structural attributes differed markedly between gap and non-gap sites, providing evidence of niche partitioning in response to disturbance across the region. Large gaps were dominated by classic Neotropical pioneer genera such as Cecropia and Vismia, and average tree size was significantly smaller. Mean wood density of trees recovering in large gaps (0.55 g cm(-3)) was significantly lower than in primary forest plots (0.71 g cm(-3)), a difference similar to that found when comparing less dynamic (i.e., tree recruitment, growth, and mortality) Central Amazon forests with more dynamic Western Amazon forests. Based on results, we hypothesize that the importance of neutral processes weaken, and niche processes strengthen, in determining community assembly along a gradient in gap size and tree mortality intensity. Over evolutionary time scales, pervasive dispersal among colonizers could result in the loss of tree diversity in the pioneer guild through competitive exclusion. Results also underscore the importance of considering disturbance processes across the landscape when addressing

  9. Revisiting mechanisms underlying tree mortality induced by drought in the Amazon: from observation to modeling

    NASA Astrophysics Data System (ADS)

    Joetzjer, E.; Poulter, B.; Ciais, P.; Sala, A.; Sack, L.; Bartlett, M.

    2015-12-01

    In the past decade, two extreme droughts experienced by the Amazon rainforest led to a perturbation of carbon cycle dynamics and forest structure, partly through an increase in tree mortality. While there is a relatively strong consensus in CMIP5 projections for an increase in both frequency and intensity of droughts across the Amazon, the potential for forest die-off constitutes a large uncertainty in projections of climate impacts on terrestrial ecosystems and carbon cycle feedbacks. Two long-term through fall exclusion experiments (TFE) provided novel observations of Amazonian ecosystem responses under drought. These experiments also provided a great opportunity to evaluate and improve models' behavior under drought by comparing simulations and observations. While current DGVM use a wide array of algorithms to represent mortality, most are associated with large uncertainty for representing drought-induced mortality, and require updating to include current information of physiological processes. During very strong droughts, the leaves desiccate and stems may undergo catastrophic embolism. However, even before that point, stomata close, to minimize excessive water loss and risk of hydraulic failure, which reduces carbon assimilation. To maintain respiration and other functions, plants may eventually deplete stored non-structural carbon compounds (NSC), which may have negative impacts on plant and eventually increase the probability of mortality.Here, we describe a new parameterization of the mortality process induced by drought using the ORCHIDEE-CAN dynamic vegetation model and test it using the two TFE results. We first updated and evaluated both the representation of hydraulic architecture and the NSC pool dynamics using in situ data. We implemented a direct climate effect on mortality through catastrophic stem embolism, based on hydraulic vulnerability curves. In addition, we explored the role of NSC on hydraulic failure and mortality by coupling in the model

  10. Canopy spectral and chemical diversity from lowland to tree line in the Western Amazon using CAO-VSWIR

    NASA Astrophysics Data System (ADS)

    Martin, R. E.; Asner, G. P.

    2012-12-01

    Canopy chemistry and spectroscopy offer insight into community assembly and ecosystem processes in high-diversity tropical forests. Results from one lowland site in the Peruvian Amazon suggests both an environmental and an evolutionary component of canopy trait development however, the degree to which larger environmental differences influence diversity in canopy traits and their respective spectroscopic signatures across remains poorly understood. The spectranomics approach explicitly connects phylogenetic, chemical and spectral patterns in tropical canopies providing the basis for analysis, while high-fidelity, airborne remote sensing measurements extend plot-level data to landscape-scale, achieving a comprehensive view of the region. In 2011, the Carnegie Airborne Observatory (CAO) was used to sample a large region of the Western Amazon Basin in southeastern Peru, extending from lowlands to tree line in the Andean mountains. The CAO Visible-Shortwave Imaging Spectrometer (VSWIR) collected 480-band high-fidelity imaging spectroscopy data of the forest canopy, while its high-resolution LiDAR captured information on canopy structure and the underlying terrain. The data were used to quantify relationships between environmental gradients and canopy chemical and spectral diversity. Results suggest strong environmental control with additional phylogenetic influence over canopy spectral and chemical properties, particularly those related to structure, defense and metabolic function. Data from CAO-VSWIR extends the large range in canopy chemical and spectral diversity related to environmental factors across the Western Amazon Basin.

  11. Palms versus trees: water use characteristics of native fruit-bearing plant species in the Central Amazon

    NASA Astrophysics Data System (ADS)

    Kunert, N.; Barros, P.; Higuchi, N.

    2012-12-01

    Native fruiting plants are widely cultivated in the Amazon but only little information on their water use characteristics can be found in the literature. Due to the growing local consumption and the increasing popularity for new "exotic" fruits all over Brazil and worldwide, additional new plantations cultivating such fruit-bearing species might be established in the Amazon in the future. These new plantations will affect the water table of the cultivated areas, however, the impact of these changes on the regional hydrology are not known. We, therefore, decided to study plant water use characteristics of two native fruit plants commonly occurring in the Amazon region, a tree species (Cupuaçu, Theobroma grandiflorum, (Willd. ex Spreng.) Schum., Malvaceae) and a palm species (Açai, Euterpe oleraceae Mart., Arecaceae). This study was conducted in a fruit plantation close to the city of Manaus, in the Central Amazon, Brazil. The objectives of our study were 1) to compare variables controlling plant water use and 2) to identify differences in water use between woody monocot and dicot plant species. We chose three representative individuals with well-sun-exposed crowns for each species, which were equipped with Granier-type thermal dissipation probes to measure sap flux density continuously for six weeks from August 1st 2011 until September 6th 2011. We used a simple sap flux model with two environmental variables, photosynthetic photon flux density and vapor pressure deficit, to compare sap flux densities between species. We achieved a good model fit and modeled sap flux densities corresponded very well with the actual measured values. No significant differences among species in sap flux densities were indicated by the model. Overall, palms had a 3.5 fold higher water consumption compared to trees with similar diameter. Water use scaled independent from species with the size of the conductive xylem area (r2 = 0.85), so that the higher water use of the palms was

  12. Boa constrictor (Boa constrictor): foraging behavior

    USGS Publications Warehouse

    Sorrell, G.G.; Boback, M.S.; Reed, R.N.; Green, S.; Montgomery, Chad E.; DeSouza, L.S.; Chiaraviglio, M.

    2011-01-01

    Boa constrictor is often referred to as a sit-and-wait or ambush forager that chooses locations to maximize the likelihood of prey encounters (Greene 1983. In Janzen [ed.], Costa Rica Natural History, pp. 380-382. Univ. Chicago Press, Illinois). However, as more is learned about the natural history of snakes in general, the dichotomy between active versus ambush foraging is becoming blurred. Herein, we describe an instance of diurnal active foraging by a B. constrictor, illustrating that this species exhibits a range of foraging behaviors.

  13. Using empirical measurements of tree branching architecture to scale whole-tree metabolism along a 4000 m elevation transect in the Peruvian Andes and Amazon

    NASA Astrophysics Data System (ADS)

    Bentley, L. P.; Shenkin, A.; Enquist, B.; Malhi, Y.

    2014-12-01

    Plant scaling models use measurements of architecture (i.e., length, width, and order of branch or xylem segments) to ultimately predict whole-plant metabolism via mass and water-use allometries. The application of plant scaling models is broad, and holds potential to simplify forest modelling efforts. However little is known regarding the influence of the environment (e.g., temperature, light, etc) on variation in branching architecture traits and how this variation affects scaling. Furthermore, scaling model assumptions of a self-similar and symmetric branching network have not been extensively tested, especially in tropical forests. As such, it is still unclear to what extent tree communities can be approximated by simple geometrical models, and where important functional divergences from theory exist. Here we analyse novel tree architecture data from diverse species along a 4000m elevational gradient spanning the Andes to the Amazon in Peru. Specifically, we calculate and compare inter- and intra-specific scaling exponents related to branch segment length and width within a hierarchical Bayesian framework. Preliminary results indicate that branching architecture significantly varies among and within species especially with respect to light environments. As such, we explore the role of light in driving tree geometry by also analysing differences in light environment and crown shape. Then, we attempt to link branch architecture and crown shape. Using 6 branch-level and whole-tree traits (path length fraction, crown depth, crown width, crown volume, crown depth/width and crown width/depth) we are able to cluster 68 species of trees into 6 unique groups related to architecture and explain ~60% variability in these data. In the future, it will be important to relate these architectural groups to variation in leaf-level traits and physiology. Lastly, we discuss the implications of using these results to understand tropical forest responses to environmental change.

  14. Oxygen isotopes in tree rings are a good proxy for Amazon precipitation and El Nino-Southern Oscillation variability.

    PubMed

    Brienen, Roel J W; Helle, Gerd; Pons, Thijs L; Guyot, Jean-Loup; Gloor, Manuel

    2012-10-16

    We present a unique proxy for the reconstruction of variation in precipitation over the Amazon: oxygen isotope ratios in annual rings in tropical cedar (Cedrela odorata). A century-long record from northern Bolivia shows that tree rings preserve the signal of oxygen isotopes in precipitation during the wet season, with weaker influences of temperature and vapor pressure. Tree ring δ(18)O correlates strongly with δ(18)O in precipitation from distant stations in the center and west of the basin, and with Andean ice core δ(18)O showing that the signal is coherent over large areas. The signal correlates most strongly with basin-wide precipitation and Amazon river discharge. We attribute the strength of this (negative) correlation mainly to the cumulative rainout processes of oxygen isotopes (Rayleigh distillation) in air parcels during westward transport across the basin. We further find a clear signature of the El Niño-Southern Oscillation (ENSO) in the record, with strong ENSO influences over recent decades, but weaker influence from 1925 to 1975 indicating decadal scale variation in the controls on the hydrological cycle. The record exhibits a significant increase in δ(18)O over the 20th century consistent with increases in Andean δ(18)O ice core and lake records, which we tentatively attribute to increased water vapor transport into the basin. Taking these data together, our record reveals a fresh path to diagnose and improve our understanding of variation and trends of the hydrological cycle of the world's largest river catchment. PMID:23027960

  15. Mortality of large trees and lianas following experimental drought in an Amazon forest.

    PubMed

    Nepstad, Daniel C; Tohver, Ingrid Marisa; Ray, David; Moutinho, Paulo; Cardinot, Georgina

    2007-09-01

    Severe drought episodes such as those associated with El Niño Southern Oscillation (ENSO) events influence large areas of tropical forest and may become more frequent in the future. One of the most important forest responses to severe drought is tree mortality, which alters forest structure, composition, carbon content, and flammability, and which varies widely. This study tests the hypothesis that tree mortality increases abruptly during drought episodes when plant-available soil water (PAW) declines below a critical minimum threshold. It also examines the effect of tree size, plant life form (palm, liana, tree) and potential canopy position (understory, midcanopy, overstory) on drought-induced plant mortality. A severe, four-year drought episode was simulated by excluding 60% of incoming throughfall during each wet season using plastic panels installed in the understory of a 1-ha forest treatment plot, while a 1-ha control plot received normal rainfall. After 3.2 years, the treatment resulted in a 38% increase in mortality rates across all stems >2 cm dbh. Mortality rates increased 4.5-fold among large trees (>30 cm dbh) and twofold among medium trees (10-30 cm dbh) in response to the treatment, whereas the smallest stems were less responsive. Recruitment rates did not compensate for the elevated mortality of larger-diameter stems in the treatment plot. Overall, lianas proved more susceptible to drought-induced mortality than trees or palms, and potential overstory tree species were more vulnerable than midcanopy and understory species. Large stems contributed to 90% of the pretreatment live aboveground biomass in both plots. Large-tree mortality resulting from the treatment generated 3.4 times more dead biomass than the control plot. The dramatic mortality response suggests significant, adverse impacts on the global carbon cycle if climatic changes follow current trends. PMID:17918404

  16. Amazon tree stems respiration: Is the O2 influx a better measure?

    NASA Astrophysics Data System (ADS)

    Angert, A.; Muhr, J.; Negron Juarez, R.; Alegria Muñoz, W.; Chambers, J. Q.; Trumbore, S. E.

    2012-04-01

    Respiration in tree stems strongly controls the tree carbon use efficiency. The rate of CO2 efflux from the stem has often been assumed to be a measure of stem respiration. However, recent work has demonstrated that stem CO2 efflux can either overestimate or underestimate respiration rate, because of emission or removal of CO2 by transport in xylem water. Here, we have used high precision measurements of O2 to estimate the ratio between local stem respiration and local CO2 efflux, in tropical forest trees. This approach is based on the much lower solubility of O2 in water relatively to CO2. The measured ratios between the stems CO2 efflux and O2 influx indicated that a large portion of the respired CO2 (~35% on average) is not emitted locally, and is probably transported upward in the stem. Our results indicate the existence of a considerable internal flux of CO2 in the stem. If the transported CO2 is used in the canopy as a substrate for photosynthesis, it could account for several percent of the carbon fixed by the tree, and perhaps serve as a mechanism that buffers the response of the tree to changing CO2 levels or to drought stress. We have also demonstrated that measurements of O2 uptake, while are more difficult to make, can be a more appropriate method to estimate stem respiration rates.

  17. Are ecologically important tree species the most useful? A case study from indigenous people in the Bolivian Amazon

    PubMed Central

    Guèze, Maximilien; Luz, Ana Catarina; Paneque-Gálvez, Jaime; Macía, Manuel J.; Orta-Martínez, Martí; Pino, Joan; Reyes-García, Victoria

    2015-01-01

    Researchers have argued that indigenous peoples preferably use the most apparent plant species, particularly for medicinal uses. However, the association between the ecological importance of a species and its usefulness remains unclear. In this paper we quantify such association for six use categories (firewood, construction, materials, food, medicines and other uses). We collected data on the uses of 58 tree species, as reported by 93 informants in 22 villages in the Tsimane’ territory (Bolivian Amazon). We calculated the ecological importance of the same species by deriving their importance value index (IVI) in 48 0.1-ha old-growth forest plots. Matching both data sets, we found a positive relation between the IVI of a species and its overall use value (UV) as well as with its UV for construction and materials. We found a negative relation between IVI and UV for species that were reportedly used for medicine and food uses, and no clear pattern for the other categories. We hypothesize that species used for construction or crafting purposes because of their physical properties are more easily substitutable than species used for medicinal or edible purposes because of their chemical properties. PMID:26097243

  18. Internal respiration of Amazon tree stems greatly exceeds external CO2 efflux

    NASA Astrophysics Data System (ADS)

    Angert, A.; Muhr, J.; Negron Juarez, R.; Alegria Muñoz, W.; Kraemer, G.; Ramirez Santillan, J.; Barkan, E.; Mazeh, S.; Chambers, J. Q.; Trumbore, S. E.

    2012-12-01

    Respiration in tree stems is an important component of forest carbon balance. The rate of CO2 efflux from the stem has often been assumed to be a measure of stem respiration. However, recent work in temperate forests has demonstrated that stem CO2 efflux can either overestimate or underestimate respiration rate because of emission or removal of CO2 by transport in xylem water. Here, we studied gas exchange from stems of tropical forest trees using a new approach to better understand respiration in an ecosystem that plays a key role in the global carbon cycle. Our main questions were (1) is internal CO2 transport important in tropical trees, and, if so, (2) does this transport result in net release of CO2 respired in the roots at the stem, or does it cause the opposite effect of net removal of stem-respired CO2? To answer these questions, we measured the ratio of stem CO2 efflux to O2 influx. This ratio, defined here as apparent respiratory quotient (ARQ), is expected to equal 1.0 if carbohydrates are the substrate for respiration, and the net transport of CO2 in the xylem water is negligible. Using a stem chamber approach to quantifying ARQ, we found values of 0.66 ± 0.18. These low ARQ values indicate that a large portion of respired CO2 (~ 35%) is not emitted locally, and is probably transported upward in the stem. ARQ values of 0.21 ± 0.10 were found for the steady-state gas concentration within the stem, sampled by in-stem equilibration probes. These lower values may result from the proximity to the xylem water stream. In contrast, we found ARQ values of 1.00 ± 0.13 for soil respiration. Our results indicate the existence of a considerable internal flux of CO2 in the stems of tropical trees. If the transported CO2 is used in the canopy as a substrate for photosynthesis, it could account for up to 10% of the C fixed by the tree, and perhaps serve as a mechanism that buffers the response of the tree to changing CO2 levels. Our results also indicate, in

  19. Internal respiration of Amazon tree stems greatly exceeds external CO2 efflux

    NASA Astrophysics Data System (ADS)

    Angert, A.; Muhr, J.; Negron Juarez, R.; Alegria Muñoz, W.; Kraemer, G.; Ramirez Santillan, J.; Barkan, E.; Mazeh, S.; Chambers, J. Q.; Trumbore, S. E.

    2012-08-01

    Respiration in tree stems is an important component of forest carbon balance. The rate of CO2 efflux from the stem has often been assumed to be a measure of stem respiration. However, recent work in temperate forests has demonstrated that stem CO2 efflux can either overestimate or underestimate respiration rate, because of emission or removal of CO2 by transport in xylem water. Here we used the ratio between CO2 efflux and O2 influx in stems of tropical forest trees to better understand respiration in an ecosystem that plays a key role in the global carbon cycle. This ratio, which we defined here as apparent respiratory quotient (ARQ), is expected to equal 1.0 if carbohydrates are the substrate for respiration, and the net transport of CO2 in the xylem water is negligible. However, using a stem chamber approach to quantifying ARQ we found values of 0.66 ± 0.18. These low ARQ values indicate that a large portion of respired CO2 (~35%) is not emitted locally, and is probably transported upward in the stem. ARQ values of 0.21 ± 0.10 were found for the steady-state gas concentration within the tree, sampled by in-stem equilibration probes. These lower values may result from the proximity to the xylem water stream. In contrast, we found ARQ values of 1.00 ± 0.13 for soil respiration. Our results indicate, for the first time, the existence of a~considerable internal flux of CO2in the stem of tropical trees. If the transported CO2 is used in the canopy as a substrate for photosynthesis, it could account for several percent of the C fixed by the tree, and perhaps serve as a mechanism that buffers the response of the tree to changing CO2 levels. Our results also indicate, in agreement with previous work, that the widely used CO2 efflux approach for determining stem respiration is unreliable. We demonstrate here a field applicable approach for measuring the O2 uptake rate, which we suggest to be a more appropriate method to estimate stem respiration rates.

  20. Hydrogen Isotope Biogeochemistry of Plant Biomarkers in Tropical Trees from the Andes to Amazon

    NASA Astrophysics Data System (ADS)

    Feakins, S. J.; Ponton, C.; West, A. J.; Malhi, Y.; Goldsmith, G.; Salinas, N.; Bentley, L. P.

    2014-12-01

    Plant leaf waxes are well known biomarkers for terrestrial vegetation. Generally, their hydrogen isotopic composition (D/H) records the isotopic composition of precipitation, modulated by leaf water processes and a large biosynthetic fractionation. In addition, the D/H of methoxyl groups on tree wood lignin is an emerging technique thought to record the D/H of source waters, without leaf water complications. Using each of these biomarkers as proxies requires understanding D/H fractionations in plant systems, but few studies have directly studied hydrogen isotope biogeochemistry in tropical plants. An approach that has proven helpful is the paired analysis of plant waters and plant biomarkers: in order that fractionations can be directly computed rather than assumed. This presents logistical challenges in remote tropical forest environments. We report on a unique dataset collected by tree-climbers from 6 well-studied vegetation plots across a 4km elevation transect in the Peruvian Andes and Amazonia. We have measured the D/H of stem water and leaf water, and we compare these to precipitation isotopes and stream waters. The goal of the plant water studies is to understand plant water uptake and stem-leaf water isotopic offsets which can vary due to both transpiration and foliar uptake of water in tropical montane forests. We are in the process of measuring the D/H of plant biomarkers (n-alkanoic acids, n-alkanes and lignin methoxyl) in order to assess how these water isotopic signals are encoded in plant biomarkers. We compare the species-specific modern plant insights to the plant leaf wax n-alkanoic acid D/H that we have recently reported from soils and river sediments from the same region, in order to understand how signals of plant biogeochemistry are integrated into geological sedimentary archives. Progress and open questions in tropical isotope biogeochemistry will be discussed at the meeting.

  1. Oxygen isotopes in tree rings are a good proxy for Amazon precipitation and El Niño-Southern Oscillation variability

    NASA Astrophysics Data System (ADS)

    Brienen, Roel J. W.; Helle, Gerd; Pons, Thijs L.; Guyot, Jean-Loup; Gloor, Manuel

    2012-10-01

    We present a unique proxy for the reconstruction of variation in precipitation over the Amazon: oxygen isotope ratios in annual rings in tropical cedar (Cedrela odorata). A century-long record from northern Bolivia shows that tree rings preserve the signal of oxygen isotopes in precipitation during the wet season, with weaker influences of temperature and vapor pressure. Tree ring δ18O correlates strongly with δ18O in precipitation from distant stations in the center and west of the basin, and with Andean ice core δ18O showing that the signal is coherent over large areas. The signal correlates most strongly with basin-wide precipitation and Amazon river discharge. We attribute the strength of this (negative) correlation mainly to the cumulative rainout processes of oxygen isotopes (Rayleigh distillation) in air parcels during westward transport across the basin. We further find a clear signature of the El Niño-Southern Oscillation (ENSO) in the record, with strong ENSO influences over recent decades, but weaker influence from 1925 to 1975 indicating decadal scale variation in the controls on the hydrological cycle. The record exhibits a significant increase in δ18O over the 20th century consistent with increases in Andean δ18O ice core and lake records, which we tentatively attribute to increased water vapor transport into the basin. Taking these data together, our record reveals a fresh path to diagnose and improve our understanding of variation and trends of the hydrological cycle of the world's largest river catchment.

  2. Boas, Darwin, science, and anthropology.

    PubMed

    Lewis, H S

    2001-06-01

    This paper presents a new reading of Franz Boas's philosophy of science and his approach to the understanding of culture and behavior. It points out that his approach had important parallels with the worldview of the major figures associated with pragmatism and suggests that a similar perspective can be useful today. PMID:14992220

  3. Correlation between populations of Rhodnius and presence of palm trees as risk factors for the emergence of Chagas disease in Amazon region, Brazil.

    PubMed

    Ricardo-Silva, Alice Helena; Lopes, Catarina M; Ramos, Leandro B; Marques, William A; Mello, Cícero B; Duarte, Rosemere; de la Fuente, Ana Laura Carbajal; Toma, Helena K; Reboredo-Oliveira, Luciana; Kikuchi, Simone A; Baptista, Thaiana F; Santos-Mallet, Jacenir R; Junqueira, Angela Cristina V; Gonçalves, Teresa Cristina M

    2012-09-01

    Among the states that comprise the legally defined Amazon region of Brazil, Pará has presented the highest occurrences of acute cases of Chagas disease over the last two decades. These cases have been attributed to consumption of fruits from native palm trees. In surveys in rural and wild areas of the municipality of Oriximiná, Pará, triatomine fauna, their main ecotopes and the infection rate due to Trypanosoma cruzi were identified using active and passive search methods: manual capture and Noireau traps, respectively. A total of 582 ecotopes were surveyed using 1496 Noireau traps. Out of 442 specimens collected, 289 were identified as Rhodnius robustus and 153 as Rhodnius pictipes. The infection rate caused by T. cruzi was 17.4%. The food sources of the triatomines were found to be birds, hemolymph, horses, and rodents. The association between R. robustus and inajá palm trees (Attalea marita), which are abundant in rural areas, was confirmed. On the other hand, R. pictipes is found in several palm tree species, such as inajá (A. marita), mucajá (Acrocomia aculeata), murumuru (Astrocaryum murumuru) and patauá (Oenocarpus bataua), and in bromeliads in wild areas. These occurrences of triatomine species in regions with or without T. cruzi infection, in the vicinity of the main settlement of the municipality, suggest that there is a need for entomological and epidemiological surveillance in this region. PMID:22664419

  4. Oxygen isotopes in tree rings are a good proxy for Amazon precipitation and El Niño-Southern Oscillation variability

    PubMed Central

    Brienen, Roel J. W.; Helle, Gerd; Pons, Thijs L.; Guyot, Jean-Loup; Gloor, Manuel

    2012-01-01

    We present a unique proxy for the reconstruction of variation in precipitation over the Amazon: oxygen isotope ratios in annual rings in tropical cedar (Cedrela odorata). A century-long record from northern Bolivia shows that tree rings preserve the signal of oxygen isotopes in precipitation during the wet season, with weaker influences of temperature and vapor pressure. Tree ring δ18O correlates strongly with δ18O in precipitation from distant stations in the center and west of the basin, and with Andean ice core δ18O showing that the signal is coherent over large areas. The signal correlates most strongly with basin-wide precipitation and Amazon river discharge. We attribute the strength of this (negative) correlation mainly to the cumulative rainout processes of oxygen isotopes (Rayleigh distillation) in air parcels during westward transport across the basin. We further find a clear signature of the El Niño-Southern Oscillation (ENSO) in the record, with strong ENSO influences over recent decades, but weaker influence from 1925 to 1975 indicating decadal scale variation in the controls on the hydrological cycle. The record exhibits a significant increase in δ18O over the 20th century consistent with increases in Andean δ18O ice core and lake records, which we tentatively attribute to increased water vapor transport into the basin. Taking these data together, our record reveals a fresh path to diagnose and improve our understanding of variation and trends of the hydrological cycle of the world’s largest river catchment. PMID:23027960

  5. [Remembering Ismar Boas (1858 - 1938)].

    PubMed

    Hansen, W E

    2013-04-01

    Ismar Boas is revered as one of the pioneers of modern gastroenterology. 75 years after his suicide due to Nazism it is appropriate to remember the great clinician and scientist. Moreover in a newly detected report from his hands some information on his thinking and handling of medical problems can be derived and his view of medial progress until today can be assessed. PMID:23585267

  6. Inferring the phylogenetic position of Boa constrictor among the Boinae.

    PubMed

    Burbrink, Frank T

    2005-01-01

    Snakes of the subfamily Boinae are found in Madagascar, the Papuan-Pacific Islands, and the Neotropics. It has been suggested that genera within each of these particular areas do not form monophyletic groups. Further, it was proposed that the New World Boa constrictor is more closely related to boine genera in Madagascar than to boines in the Neotropics. Along with inferring the relationship of all boine genera using data from the cytochrome b gene and morphology, the placement of Boa was also examined. Phylogenetic inferences using maximum likelihood and Bayesian (BI) methods for combined data analyses and separate analyses of DNA sequence and morphological data were conducted. Priors, parametric bootstraps, and the Shimodaira-Hasegawa test were used to examine the previously proposed placement of Boa with Madagascan taxa using these DNA data. DNA data and combined data analyses strongly reject the hypothesis that Boa is more closely related to Old World genera than to other New World genera. Additionally, strong tree support suggests that all species within Madagascar, the Papuan-Pacific Islands, and the Neotropics each form a monophyletic group with respect to their geographic region. PMID:15579390

  7. Seed size influence on germination responses to light and temperature of seven pioneer tree species from the Central Amazon.

    PubMed

    Aud, Fabiana F; Ferraz, Isolde D K

    2012-09-01

    In Amazon secondary forests are dominated by pioneer species that typically produce large amounts of small and dormant seeds that are able to form a persistent soil seed bank. Seed dormancy in this group of species is overcome by environmental conditions found in open areas, such as high irradiation or alternating temperatures. Nevertheless, a variety of germination responses to environmental factors is known among pioneers; some of them may germinate in diffuse light or in darkness condition at constant temperature. Seed mass can be considered as one of the factors that promotes this variety. Regarding species with very small seeds, it seems that the trigger for germination is light and for larger seeds temperature alternation may be a more important stimulus. In this study we established a relationship between seed mass and germination response to light and alternating temperature for a group of seven woody pioneer species from the Amazon forest. We found that an increase in seed mass was followed by a decrease in the need for light and an increase in the tolerance to alternating temperatures. Understanding germination strategies may contribute with the knowledge of species coexistence in high diverse environments and also may assist those involved in forest management and restoration. PMID:22886162

  8. Shifts in indigenous culture relate to forest tree diversity: a case study from the Tsimane’, Bolivian Amazon

    PubMed Central

    Guèze, Maximilien; Luz, Ana Catarina; Paneque-Gálvez, Jaime; Macía, Manuel J.; Orta-Martínez, Martí; Pino, Joan; Reyes-García, Victoria

    2015-01-01

    Understanding how indigenous peoples’ management practices relate to biological diversity requires addressing contemporary changes in indigenous peoples’ way of life. This study explores the association between cultural change among a Bolivian Amazonian indigenous group, the Tsimane’, and tree diversity in forests surrounding their villages. We interviewed 86 informants in six villages about their level of attachment to traditional Tsimane’ values, our proxy for cultural change. We estimated tree diversity (Fisher’s Alpha index) by inventorying trees in 48 0.1-ha plots in old-growth forests distributed in the territory of the same villages. We used multivariate models to assess the relation between cultural change and alpha tree diversity. Cultural change was associated with alpha tree diversity and the relation showed an inverted U-shape, thus suggesting that tree alpha diversity peaked in villages undergoing intermediate cultural change. Although the results do not allow for testing the direction of the relation, we propose that cultural change relates to tree diversity through the changes in practices and behaviors that affect the traditional ecological knowledge of Tsimane’ communities; further research is needed to determine the causality. Our results also find support in the intermediate disturbance hypothesis, and suggest that indigenous management can be seen as an intermediate form of anthropogenic disturbance affecting forest communities in a subtle, non-destructive way. PMID:26097240

  9. Seasonal variations in the stable oxygen isotope ratio of wood cellulose reveal annual rings of trees in a Central Amazon terra firme forest.

    PubMed

    Ohashi, Shinta; Durgante, Flávia M; Kagawa, Akira; Kajimoto, Takuya; Trumbore, Susan E; Xu, Xiaomei; Ishizuka, Moriyoshi; Higuchi, Niro

    2016-03-01

    In Amazonian non-flooded forests with a moderate dry season, many trees do not form anatomically definite annual rings. Alternative indicators of annual rings, such as the oxygen (δ(18)Owc) and carbon stable isotope ratios of wood cellulose (δ(13)Cwc), have been proposed; however, their applicability in Amazonian forests remains unclear. We examined seasonal variations in the δ(18)Owc and δ(13)Cwc of three common species (Eschweilera coriacea, Iryanthera coriacea, and Protium hebetatum) in Manaus, Brazil (Central Amazon). E. coriacea was also sampled in two other regions to determine the synchronicity of the isotopic signals among different regions. The annual cyclicity of δ(18)Owc variation was cross-checked by (14)C dating. The δ(18)Owc showed distinct seasonal variations that matched the amplitude observed in the δ(18)O of precipitation, whereas seasonal δ(13)Cwc variations were less distinct in most cases. The δ(18)Owc variation patterns were similar within and between some individual trees in Manaus. However, the δ(18)Owc patterns of E. coriacea differed by region. The ages of some samples estimated from the δ(18)Owc cycles were offset from the ages estimated by (14)C dating. In the case of E. coriacea, this phenomenon suggested that missing or wedging rings may occur frequently even in well-grown individuals. Successful cross-dating may be facilitated by establishing δ(18)Owc master chronologies at both seasonal and inter-annual scales for tree species with distinct annual rings in each region. PMID:26621690

  10. Amazon River

    Atmospheric Science Data Center

    2013-04-17

    article title:  Mouth of the Amazon River     View Larger Image ... over 6450 kilometers eastward across Brazil, the Amazon River originates in the Peruvian Andes as tiny mountain streams that eventually ...

  11. Emerging Chagas disease: trophic network and cycle of transmission of Trypanosoma cruzi from palm trees in the Amazon.

    PubMed Central

    Teixeira, A. R.; Monteiro, P. S.; Rebelo, J. M.; Argañaraz, E. R.; Vieira, D.; Lauria-Pires, L.; Nascimento, R.; Vexenat, C. A.; Silva, A. R.; Ault, S. K.; Costa, J. M.

    2001-01-01

    A trophic network involving molds, invertebrates, and vertebrates, ancestrally adapted to the palm tree (Attalaea phalerata) microhabitat, maintains enzootic Trypanosoma cruzi infections in the Amazonian county Paço do Lumiar, state of Maranhão, Brazil. We assessed seropositivity for T. cruzi infections in the human population of the county, searched in palm trees for the triatomines that harbor these infections, and gathered demographic, environmental, and socioeconomic data. Rhodnius pictipes and R. neglectus in palm-tree frond clefts or in houses were infected with T. cruzi (57% and 41%, respectively). Human blood was found in 6.8% of R. pictipes in houses, and 9 of 10 wild Didelphis marsupialis had virulent T. cruzi infections. Increasing human population density, rain forest deforestation, and human predation of local fauna are risk factors for human T. cruzi infections. PMID:11266300

  12. New estimates of temperature response of leaf photosynthesis in Amazon forest trees, its acclimation to mean temperature change and consequences for modelling climate response to rain forests.

    NASA Astrophysics Data System (ADS)

    Kruijt, B.; Jans, W.; Vasconcelos, S.; Tribuzy, E. S.; Felsemburgh, C.; Eliane, M.; Rowland, L.; da Costa, A. C. L.; Meir, P.

    2014-12-01

    In many dynamic vegetation models, degradation of the tropical forests is induced because they assume that productivity falls rapidly when temperatures rise in the region of 30-40°C. Apart plant respiration, this is due to the assumptions on the temperature optima of photosynthetic capacity, which are low and can differ widely between models, where in fact hardly any empirical information is available for tropical forests. Even less is known about the possibility that photosynthesis will acclimate to changing temperatures. The objective of this study to is to provide better estimates for optima, as well as to determine whether any acclimation to temperature change is to be expected. We present both new and hitherto unpublished data on the temperature response of photosynthesis of Amazon rainforest trees, encompassing three sites, several species and five field campaigns. Leaf photosynthesis and its parameters were determined at a range of temperatures. To study the long-term (seasonal) acclimation of this response, this was combined with an artificial, in situ, multi-season leaf heating experiment. The data show that, on average for all non-heated cases, the photosynthetic parameter Vcmax weakly peaks between 35 and 40 ˚C, while heating does not have a clearly significant effect. Results for Jmax are slightly different, with sharper peaks. Scatter was relatively high, which could indicate weak overall temperature dependence. The combined results were used to fit new parameters to the various temperature response curve functions in a range of DGVMs. The figure shows a typical example: while the default Jules model assumes a temperature optimum for Vcmax at around 33 ˚C, the data suggest that Vcmax keeps rising up to at least 40 ˚C. Of course, calculated photosynthesis, obtained by applying this Vcmax in the Farquhar model, peaks at lower temperature. Finally, the implication of these new model parameters for modelled climate change impact on modelled Amazon

  13. Trees

    ERIC Educational Resources Information Center

    Al-Khaja, Nawal

    2007-01-01

    This is a thematic lesson plan for young learners about palm trees and the importance of taking care of them. The two part lesson teaches listening, reading and speaking skills. The lesson includes parts of a tree; the modal auxiliary, can; dialogues and a role play activity.

  14. Amazon River

    Atmospheric Science Data Center

    2013-04-17

    ... the Rio Solimoes and the Rio Negro converge to form the Amazon River. This image from the Multi-angle Imaging SpectroRadiometer (MISR) ... date:  Jul 23, 2000 Images:  Amazon River location:  South America thumbnail:  ...

  15. Franz Boas and Native American biological variability.

    PubMed

    Jantz, R L

    1995-06-01

    The contributions to physical anthropology with which Franz Boas is usually credited are in the areas of growth, plasticity of head and body form, and biometric genetics. Such a listing of Boas's contributions overlooks the tremendous amount of research he did with biological variability of Native American populations. The rediscovery of his anthropometric data documents the tremendous investment in time, money, and effort Boas devoted to the topic and provides the opportunity to rediscover his insights into a subject that is of continuing interest. The design of his massive anthropometric survey of native North Americans reveals a concern for population analyses and a rejection of the typological framework of the time. If Boas's ideas had been adopted at the turn of the century, the development of physical anthropology in America might have been much different. PMID:7607632

  16. The anthropometric legacy of Franz Boas.

    PubMed

    Jantz, Richard L

    2003-06-01

    Franz Boas was responsible for obtaining anthropometric data from approximately 27,000 subjects living around the turn-of-the-century. The subjects are of Native American, Siberian and European ancestry. These data have been entered into databases and are available for research. This paper describes the circumstances under which these data were collected and discusses their research potential. PMID:15463979

  17. Progress on the Big Optical Array (BOA)

    NASA Astrophysics Data System (ADS)

    Armstrong, John T.

    1994-06-01

    The Navy Prototype Optical Interferometer (NPOI) is nearing the completion of the first phase of construction at the Lowell Observatory on Anderson Mesa, AZ. The NPOI comprises two sub- arrays, the Big Optical Array (BOA) and the USNO Astrometric Interferometer (AI), which share delay lines, the optics laboratory, the control system, and parts of the feed optics. We describe the design of and progress on the BOA, the imaging component of the NPOI. The AI is described elsewhere (Hutter, these proceedings). As of the date of this symposium, most of the civil engineering is complete, including the control and laboratory buildings and the concrete piers for the initial array. Three AI siderostats and associated feed pipes, three delay lines, the initial three-way beam combiner, and much of the control system are in place. First fringes are anticipated in April. By the end of 1994, four AI and two BOA siderostats, as well as three more delay lines, will be installed, making imaging with all six siderostats possible. The complete BOA will consist of six 50 cm siderostats and 30 siderostat stations in a Y with 251 m arms, with baseline lengths from 4 m to 437 m. Nearly redundant baseline lengths will allow fringe tracking on long baselines on which the visibilities are too low for detection in real time. A six-way beam combiner (Mozurkewich, these proceedings) will allow simultaneous measurements of 15 visibilities and nine of 10 independent closure phases. The output beams will feed 32-channel spectrometers covering the range from 450 to 900 nm. We anticipate tracking fringes on stars brighter than 10(superscript m), imaging surfaces of stars brighter than 4(superscript m), measuring stellar diameters to 0.18 milliarcsec (mas), and measuring binary orbits with major axes as small as 0.4 mas.

  18. Valvulopathy consistent with endocarditis in an Argentine boa (Boa constrictor occidentalis).

    PubMed

    Wernick, Morena B; Novo-Matos, José; Ebling, Alessia; Kühn, Karolin; Ruetten, Maja; Hilbe, Monika; Howard, Judith; Chang, Rita; Prohaska, Sarah; Hatt, Jean-Michel

    2015-03-01

    An Argentine boa (Boa constrictor occidentalis) of 5 yr 7 mo of age was presented for respiratory problems and regurgitation. Radiographs revealed evidence of cardiomegaly and pneumonia. Blood smear examination revealed the presence of intracytoplasmic inclusion bodies in peripheral lymphocytes, consistent with inclusion body disease. Cultures of a tracheal wash sample resulted in growth of Ochrobactrum intermedium and Pseudomonas putida. Echocardiographic examination revealed a large vegetative lesion on the right atrioventricular valve with valvular insufficiency, a mildly dilated right atrium, and pulmonary hypertension. Postmortem examination confirmed the presence of pneumonia and bacterial endocarditis with dystrophic mineralization of the right atrioventricular valve, associated with different bacteria than those cultured from the tracheal wash. The present case is the first report of endocarditis in a boa constrictor and contributes to the rare reports of cardiac disease in snakes. PMID:25831585

  19. BOA: Pipe asbestos insulation removal robot system

    SciTech Connect

    Schempf, H.; Bares, J.; Schnorr, W.

    1995-12-31

    The BOA system is a mobile pipe-external robotic crawler used to remotely strip and bag asbestos-containing lagging and insulation materials (ACLIM) from various diameter pipes in (primarily) industrial installations. Steam and process lines within the DOE weapons complex warrant the use of a remote device due to the high labor costs and high level of radioactive contamination, making manual removal extremely costly and highly inefficient. Currently targeted facilities for demonstration and remediation are Fernald in Ohio and Oak Ridge in Tennessee.

  20. Ecology of Rhodnius robustus Larrousse, 1927 (Hemiptera, Reduviidae, Triatominae) in Attalea palm trees of the Tapajós River Region (Pará State, Brazilian Amazon)

    PubMed Central

    2014-01-01

    Background The rising number of acute cases of Chagas disease in the State of Pará, reported in the past two decades, has been associated, in part, with the ingestion of juice of local palm tree fruits, mainly açaí berry and bacaba. Near the study area, in Santarém, Pará State, an outbreak of Chagas disease has been notified and investigations suggest the consumption of bacaba juice as the main source of infection with T. cruzi. The purpose of this study is to assess the aspects associated to the ecology of Rhodnius robustus in palm trees of three communities of the Tapajós region, in the State of Pará, Brazil. Methods Palm trees were cut down and dissected to search for triatomines. DNA from triatomines was extracted to investigate natural infection by Trypanosoma cruzi and T. rangeli. For statistical analyzes, data from infestation of palm trees, as well as the rates of natural infection by T. cruzi and T. rangeli were compared by Chi-square test. Triatomine density values were analyzed by the nonparametric Kruskal Wallis test and then comparisons between each pair of variables were made by the Mann–Whitney test assuming a confidence interval of 95%. Results We dissected 136 palm trees, 60 at the end of the rainy period and 76 at the end of the dry period. Seventy-three of them (53.7%) were infested with triatomines and three species were found, namely: Rhodnius robustus, Rhodnius pictipes and Panstrongylus lignarius. We collected 743 triatomines, and R. robustus was predominant (n = 739). The identification of natural infection of the insects by trypanosomatids revealed that 125 triatomines were infected by T. cruzi, 69 by T. rangeli and 14 presented both parasites, indicating the presence of mixed infection in the same vector. Conclusion The results suggest that São Tomé is the community with greater density of triatomines and infestation of palm trees; also, it demonstrates the existence of an intense sylvatic cycle in the region, which demands

  1. BILATERALLY SYMMETRICAL ORAL AMELANOTIC MELANOMA IN A BOA CONSTRICTOR (BOA CONSTRICTOR CONSTRICTOR).

    PubMed

    Thompson, Kimberly A; Campbell, Mark; Levens, Gregory; Agnew, Dalen

    2015-09-01

    A 17-yr-old boa constrictor (Boa constrictor constrictor) presented initially with diffuse gingival swelling, loose teeth, and loss of body condition. Examination under anesthesia revealed two firm pink masses within the oral cavity. The largest mass was removed for biopsy. Histopathology and Melan-A-positive immunohistochemistry labeling confirmed a diagnosis of amelanotic melanoma. Secondary stomatitis was treated with antibiotics to improve quality of life, but the snake's condition deteriorated quickly over the next 2 mo. Euthanasia was elected and a gross postmortem examination was performed. Gross postmortem examination and histopathology results demonstrated that the neoplastic cells had spread in an unusual symmetrical pattern along all four dental arcades: the right and left sides of both the mandible and maxilla. Histopathology confirmed metastasis throughout the liver and spleen, despite the lack of gross lesions. PMID:26352976

  2. Diagnosis and treatment of a pharyngeal squamous cell carcinoma in a Madagascar ground boa (Boa madagascariensis).

    PubMed

    Steeil, James C; Schumacher, Juergen; Hecht, Silke; Baine, Katherine; Ramsay, Edward C; Ferguson, Sylvia; Miller, Debra; Lee, Nathan D

    2013-03-01

    A 15-yr-old female Madagascar ground boa (Boa madagascariensis) presented with a history of anorexia, wheezing, and occasional open-mouth breathing. On oral examination, a firm, caseous mass was noted in the right caudoventral pharyngeal region, which was confirmed as a carcinoma on incisional biopsy. Advanced imaging (computed tomography and magnetic resonance imaging) was performed to evaluate local tumor invasion and to plan for palliative radiation therapy. However, following the second treatment (10 Gy), the mass had increased in size, and the snake was euthanatized. Radiation-associated vasculitis was noted within the soft tissues surrounding the mass and within muscles and the lung, which was verified on histopathology. The squamous cell carcinoma of the snake in this report was resistant to palliative radiation therapy. PMID:23505715

  3. Franz Boas, geographer, and the problem of disciplinary identity.

    PubMed

    Koelsch, William A

    2004-01-01

    This paper examines Franz Boas as an aspiring professional geographer during the 1880s: his Baffin Land research, his publications, his participation in geography organizations, and his struggle to attain a university appointment in geography. Frustrated by a seeming lack of opportunity for advancement in Germany, Boas explored career opportunities as a geographer in America and launched a series of unsuccessful but meaningful attempts to dominate the intellectual direction of American geography. Finally, the article reviews the circumstances surrounding Boas's appointment as an anthropologist at Clark University in 1889. Through examining Boas's own words and actions, the paper demonstrates that his professional identification with geography was lengthier and stronger than earlier accounts have suggested. It also critiques the myth of a Baffin Land "conversion" to anthropology, and delineates the circumstances of his shift from German human geography to his Americanist recasting of anthropology after 1889. PMID:14724914

  4. Effect of biometric variables on two-dimensional echocardiographic measurements in the red-tailed boa (Boa constrictor constrictor).

    PubMed

    Conceicão, Maria Eduarda B A M; Monteiro, Frederico O B; Andrade, Rafael S; Margalho, Viviane E; Filho, Ednaldo S; Monteiro, Maria Vivina B; Castro, Paulo Henrique G; Stone, Anita; Rahal, Sheila C; Melchert, Alessandra

    2014-09-01

    The effects of body biometrics on cardiac measurements and description of cardiac anatomy were performed in red-tailed boas (Boa constrictor constrictor) (n = 29) using real-time B-mode ultrasonography. Statistical comparison of measured cardiac metrics according to sex and body measurements demonstrated no significant difference between sexes but a highly significant linear increase between body length and mass and all cardiac metrics. PMID:25314841

  5. Experimental study of induced inflammation in the Brazilian Boa (Boa constrictor constrictor).

    PubMed

    Tucunduva, M; Borelli, P; Silva, J R

    2001-01-01

    The objective of this work was to identify the cellular types present in inflammatory processes in the Brazilian snake, Boa constrictor constrictor. Blood smears were first made from three normal snakes and stained by several methods to identify the cell types present, thus facilitating the identification of cells in inflammatory processes induced in 16 further snakes by the subcutaneous implantation of cotton suture threads and circular coverslips. Implanted threads induced migration of heterophils and monocytes after 4 h, more intense monocyte migration after 24 h, an intense granulocytic migration inside and around the thread after 48 h, heterophilic granulocytes, macrophages and giant cells after 7 days, and giant cells with a typical granuloma response and persistence of heterophilic cells after 15, 69 and 117 days. The cell population attached to the implanted coverslips after 4 h was composed of heterophils, thrombocytes, erythrocytes and macrophages; after 24 and 48 h heterophils predominated, and after 7 days heterophils, macrophages and giant cells predominated. PMID:11578134

  6. A reassessment of human cranial plasticity: Boas revisited.

    PubMed

    Sparks, Corey S; Jantz, Richard L

    2002-11-12

    In 1912, Franz Boas published a study demonstrating the plastic nature of the human body in response to changes in the environment. The results of this study have been cited for the past 90 years as evidence of cranial plasticity. These findings, however, have never been critiqued thoroughly for their statistical and biological validity. This study presents a reassessment of Boas' data within a modern statistical and quantitative genetic framework. The data used here consist of head and face measurements on over 8,000 individuals of various European ethnic groups. By using pedigree information contained in Boas' data, narrow sense heritabilities are estimated by the method of maximum likelihood. In addition, a series of t tests and regression analyses are performed to determine the statistical validity of Boas' original findings on differentiation between American and European-born children and the prolonged effect of the environment on cranial form. Results indicate the relatively high genetic component of the head and face diameters despite the environmental differences during development. Results point to very small and insignificant differences between European- and American-born offspring, and no effect of exposure to the American environment on the cranial index in children. These results contradict Boas' original findings and demonstrate that they may no longer be used to support arguments of plasticity in cranial morphology. PMID:12374854

  7. A reassessment of human cranial plasticity: Boas revisited

    PubMed Central

    Sparks, Corey S.; Jantz, Richard L.

    2002-01-01

    In 1912, Franz Boas published a study demonstrating the plastic nature of the human body in response to changes in the environment. The results of this study have been cited for the past 90 years as evidence of cranial plasticity. These findings, however, have never been critiqued thoroughly for their statistical and biological validity. This study presents a reassessment of Boas' data within a modern statistical and quantitative genetic framework. The data used here consist of head and face measurements on over 8,000 individuals of various European ethnic groups. By using pedigree information contained in Boas' data, narrow sense heritabilities are estimated by the method of maximum likelihood. In addition, a series of t tests and regression analyses are performed to determine the statistical validity of Boas' original findings on differentiation between American and European-born children and the prolonged effect of the environment on cranial form. Results indicate the relatively high genetic component of the head and face diameters despite the environmental differences during development. Results point to very small and insignificant differences between European- and American-born offspring, and no effect of exposure to the American environment on the cranial index in children. These results contradict Boas' original findings and demonstrate that they may no longer be used to support arguments of plasticity in cranial morphology. PMID:12374854

  8. Phytotoxic effect of 2-benzoxazolinone (BOA) against some vegetable crops.

    PubMed

    Chum, Mukta; Batish, Daizy R; Singh, Harminder Pal; Kohli, Ravinder Kumar

    2012-01-01

    Benzoxazolin-2(3H)-one (BOA) is a well known allelochemical that is being explored for its herbicidal activity. However, not much is known about its effect on crop plants. The present study investigated the effect of BOA on germination and early growth of four vegetable crops viz. Pisum sativum L., Raphanus sativus L., Brassica oleracea L. var. botrytis and Brassica oleracea L. var. capitata. At 1000 microM, germination of P. sativum, R. sativus and B. oleracea var. botrytis was reduced by more than 50%, whereas that of B. oleracea var. capitata was completely suppressed. Further, BOA reduced the root and shoot length of the test plants by approximately 40-82% and approximately 55-85%, respectively. In general, the effect was more pronounced on the root (approximately 82% in B. oleracea var. botrytis) than on the shoot growth (approximately 73% B. oleracea var, botrytis). 2-Benzoxazolinone significantly enhanced the contents of proteins (by 6-28%) and carbohydrates (by 61-189%) in B. oleracea var. capitata and decreased the activities of related enzymes like proteases (by 13-36%), alpha-amylases (19-60%) and beta-amylase (25-70%). The observed decline in the activities of hydrolytic enzymes amylases suggest that BOA interferes with the vital metabolic processes in the germinating seedlings leading to growth reduction. The study reveals that BOA interferes with the germination and early seedling growth of vegetable crops and induces biochemical alterations. PMID:23033638

  9. Crop damage of Eriotheca gracilipes (Bombacaceae) by the Blue-Fronted Amazon (Amazona aestiva, Psittacidae), in the Brazilian Cerrado.

    PubMed

    Ragusa-Netto, J

    2014-11-01

    Seed predation has major effects on the reproductive success of individuals, spatial patterns of populations, genetic variability, interspecific interactions and ultimately in the diversity of tree communities. At a Brazilian savanna, I evaluated the proportional crop loss of Eriotheca gracilipes due the Blue-Fronted Amazon (Amazona aestiva) during a fruiting period. Also, I analyzed the relationship between proportional crop loss to Amazons and both fruit crop size and the distance from the nearest damaged conspecific. Trees produced from 1 to 109 fruits, so that Amazons foraged more often on trees bearing larger fruit crop size, while seldom visited less productive trees. Moreover, the relationship between fruit crop sizes and the number of depredated fruits was significant. However, when only damaged trees were assessed, I found a negative and significant relation between fruit crop size and proportional crop loss to Blue-Fronted Amazons. Taking into account this as a measure more directly related to the probability of seed survival, a negative density dependent effect emerged. Also, Amazons similarly damaged the fruit crops of either close or distant neighboring damaged trees. Hence, in spite of Blue-Fronted Amazons searched for E. gracilipes bearing large fruit crops, they were swamped due to the presence of more fruits than they could eat. Moderate seed predation by Blue-Fronted Amazons either at trees with large fruit crops or in areas where fruiting trees were aggregated implies in an enhanced probability of E. gracilipes seed survival and consequent regeneration success. PMID:25627593

  10. An ecological risk assessment of nonnative boas and pythons as potentially invasive species in the United States.

    PubMed

    Reed, Robert N

    2005-06-01

    The growing international trade in live wildlife has the potential to result in continuing establishment of nonnative animal populations in the United States. Snakes may pose particularly high risks as potentially invasive species, as exemplified by the decimation of Guam's vertebrate fauna by the accidentally introduced brown tree snake. Herein, ecological and commercial predictors of the likelihood of establishment of invasive populations were used to model risk associated with legal commercial imports of 23 species of boas, pythons, and relatives into the United States during the period 1989-2000. Data on ecological variables were collected from multiple sources, while data on commercial variables were collated from import records maintained by the U.S. Fish and Wildlife Service. Results of the risk-assessment models indicate that species including boa constrictors (Boa constrictor), ball pythons (Python regius), and reticulated pythons (P. reticulatus) may pose particularly high risks as potentially invasive species. Recommendations for reducing risk of establishment of invasive populations of snakes and/or pathogens include temporary quarantine of imports to increase detection rates of nonnative pathogens, increasing research attention to reptile pathogens, reducing the risk that nonnative snakes will reach certain areas with high numbers of federally listed species (such as the Florida Keys), and attempting to better educate individuals purchasing reptiles. PMID:16022706

  11. FREUD, JUNG AND BOAS: THE PSYCHOANALYTIC ENGAGEMENT WITH ANTHROPOLOGY REVISITED.

    PubMed

    Kenny, Robert

    2015-06-20

    Sigmund Freud's and C. G. Jung's turn to evolutionist anthropological material after 1909 is usually seen as a logical progression of their long-term interest in such material. It is also seen that they used this material ignorant of the significant challenges to the evolutionist paradigm underpinning such material, in particular the challenges led by Franz Boas. This paper argues otherwise: that both psychologists' turnings to such material was a new development, that neither had shown great interest in such material before 1909, and that their turnings to such material, far from being taken in ignorance of the challenges to evolutionist anthropology, were engagements with those challenges, because the evolutionist paradigm lay at the base of psychoanalysis. It argues that it is no coincidence that this engagement occurred after their return from America in 1909, where they had come into first-hand contact with the challenges of Franz Boas. PMID:26665301

  12. Variation among North Amerindians: analysis of Boas's anthropometric data.

    PubMed

    Jantz, R L; Hunt, D R; Falsetti, A B; Key, P J

    1992-06-01

    In the late nineteenth century Franz Boas was responsible for assembling anthropometric data from North Amerindians. Approximately 15,000 subjects were measured, but the data have never been systematically analyzed. Here we describe our efforts to develop a computerized database from Boas's data and present the first systematic analysis of these data. In addition to a general analysis of North Amerindian anthropometric variation, we also present a more detailed analysis of anthropometric variation among tribes located in the American Northwest. In the general analysis we find that anthropometric variation is strongly patterned along geographic lines. We examine geographic and language patterning by grouping tribes by culture area and language phylum. Both have high explanatory power, culture area being the higher. The Northwest analysis shows that both language and geographic location are important in explaining anthropometric variation. PMID:1607187

  13. Freud, Jung and Boas: the psychoanalytic engagement with anthropology revisited

    PubMed Central

    Kenny, Robert

    2015-01-01

    Sigmund Freud's and C. G. Jung's turn to evolutionist anthropological material after 1909 is usually seen as a logical progression of their long-term interest in such material. It is also seen that they used this material ignorant of the significant challenges to the evolutionist paradigm underpinning such material, in particular the challenges led by Franz Boas. This paper argues otherwise: that both psychologists' turnings to such material was a new development, that neither had shown great interest in such material before 1909, and that their turnings to such material, far from being taken in ignorance of the challenges to evolutionist anthropology, were engagements with those challenges, because the evolutionist paradigm lay at the base of psychoanalysis. It argues that it is no coincidence that this engagement occurred after their return from America in 1909, where they had come into first-hand contact with the challenges of Franz Boas. PMID:26665301

  14. Osteomyelitis caused by Salmonella enterica serovar derby in boa constrictor.

    PubMed

    de Souza, Suyene O; Casagrande, Renata A; Guerra, Priscila R; Cruz, Cláudio E F; Veit, Evandro; Cardoso, Marisa R I; Driemeier, David

    2014-09-01

    After demonstrating chronic weight loss, prostration, and muscle flaccidness, a captive-bred 9-mo-old boa constrictor (Boa constrictor constrictor) died and was submitted for necropsy. Along the spinal column there were multiple, yellowish white, macroscopic nodules of 1-5 mm in diameter in the ventral side of the vertebral body and in the intervertebral spaces. Severe multifocal necrotizing osteomyelitis associated with granulomatous inflammation was the main histologic finding in the vertebral column. In the liver, there was discrete but similar granulomatous changes. Positive anti-Salmonella immunostaining was observed in the spinal column and in the liver. Salmonella enterica serovar Derby was isolated from fragments of the spinal column. These bacteria are important cause of disease in captive reptiles. PMID:25314834

  15. Evidence for viable, non-clonal but fatherless Boa constrictors.

    PubMed

    Booth, Warren; Johnson, Daniel H; Moore, Sharon; Schal, Coby; Vargo, Edward L

    2011-04-23

    Parthenogenesis in vertebrates is considered an evolutionary novelty. In snakes, all of which exhibit genetic sex determination with ZZ : ZW sex chromosomes, this rare form of asexual reproduction has failed to yield viable female WW offspring. Only through complex experimental manipulations have WW females been produced, and only in fish and amphibians. Through microsatellite DNA fingerprinting, we provide the first evidence of facultative parthenogenesis in a Boa constrictor, identifying multiple, viable, non-experimentally induced females for the first time in any vertebrate lineage. Although the elevated homozygosity of the offspring in relation to the mother suggests that the mechanism responsible may be terminal fusion automixis, no males were produced, potentially indicating maternal sex chromosome hemizygosity (WO). These findings provide the first evidence of parthenogenesis in the family Boidae (Boas), and suggest that WW females may be more common within basal reptilian lineages than previously assumed. PMID:21047849

  16. Did Franz Boas witness an act of cannibalism?

    PubMed

    Maud, R

    1986-01-01

    Franz Boas has been used as an authority for the existence of cannibalism among the Kwakiutl of British Columbia, as cited in Patterns of Culture. There is reason to think, however, that all his evidence is hearsay, and that he himself never witnessed an act of cannibalism. One indication is that he eliminated all references to such acts in his final overview, published posthumously as Kwakiutl Ethnology. PMID:3511138

  17. BOA II: pipe-asbestos insulation removal system

    SciTech Connect

    Schempf, H.; Mutschler; Boehmke, S.; Chemel, B.; Piepgras, C.

    1996-12-31

    BOA system is a mobile pipe-external robotic crawler used to remotely strip and bag asbestos-containing lagging and insulation materials from various diameter pipes in (primarily) industrial installations. Steam and process lines within the DOE weapons complex warrant the use of a remote device due to high labor costs and high level of radioactive contamination, making manual removal costly and inefficient. Currently targeted facilities for demonstration and remediation are Fernald in Ohio and Oak Ridge in Tennessee.

  18. BOA, Beam Optics Analyzer A Particle-In-Cell Code

    SciTech Connect

    Thuc Bui

    2007-12-06

    The program was tasked with implementing time dependent analysis of charges particles into an existing finite element code with adaptive meshing, called Beam Optics Analyzer (BOA). BOA was initially funded by a DOE Phase II program to use the finite element method with adaptive meshing to track particles in unstructured meshes. It uses modern programming techniques, state-of-the-art data structures, so that new methods, features and capabilities are easily added and maintained. This Phase II program was funded to implement plasma simulations in BOA and extend its capabilities to model thermal electrons, secondary emissions, self magnetic field and implement a more comprehensive post-processing and feature-rich GUI. The program was successful in implementing thermal electrons, secondary emissions, and self magnetic field calculations. The BOA GUI was also upgraded significantly, and CCR is receiving interest from the microwave tube and semiconductor equipment industry for the code. Implementation of PIC analysis was partially successful. Computational resource requirements for modeling more than 2000 particles begin to exceed the capability of most readily available computers. Modern plasma analysis typically requires modeling of approximately 2 million particles or more. The problem is that tracking many particles in an unstructured mesh that is adapting becomes inefficient. In particular memory requirements become excessive. This probably makes particle tracking in unstructured meshes currently unfeasible with commonly available computer resources. Consequently, Calabazas Creek Research, Inc. is exploring hybrid codes where the electromagnetic fields are solved on the unstructured, adaptive mesh while particles are tracked on a fixed mesh. Efficient interpolation routines should be able to transfer information between nodes of the two meshes. If successfully developed, this could provide high accuracy and reasonable computational efficiency.

  19. BOA: Asbestos pipe insulation removal robot system. Phase 1

    SciTech Connect

    Schempf, H.; Bares, J.E.

    1995-02-01

    The project described in this report targets the development of a mechanized system for safe, cost-efficient and automated abatement of asbestos containing materials used as pipe insulation. Based on several key design criteria and site visits, a proof-of-concept prototype robot system, dubbed BOA, was designed and built, which automatically strips the lagging and insulation from the pipes, and encapsulates them under complete vacuum operation. The system can operate on straight runs of piping in horizontal or vertical orientations. Currently we are limited to four-inch diameter piping without obstacles as well as a somewhat laborious emplacement and removal procedure -- restrictions to be alleviated through continued development. BOA removed asbestos at a rate of 4-5 ft./h compared to 3 ft./h for manual removal of asbestos with a 3-person crew. The containment and vacuum system on BOA was able to achieve the regulatory requirement for airborne fiber emissions of 0.01 fibers/ccm/ 8-hr. shift. This program consists of two phases. The first phase was completed and a demonstration was given to a review panel, consisting of DOE headquarters and site representatives as well as commercial abatement industry representatives. Based on the technical and programmatic recommendations drafted, presented and discussed during the review meeting, a new plan for the Phase II effort of this project was developed. Phase 11 will consist of a 26-month effort, with an up-front 4-month site-, market-, cost/benefit and regulatory study before the next BOA robot (14 months) is built, and then deployed and demonstrated (3 months) at a DOE site (such as Fernald or Oak Ridge) by the beginning of FY`97.

  20. Computed tomography-guided bone biopsies for evaluation of proliferative vertebral lesions in two boa constrictors (Boa constrictor imperator).

    PubMed

    Di Girolamo, Nicola; Selleri, Paolo; Nardini, Giordano; Corlazzoli, Daniele; Fonti, Paolo; Rossier, Christophe; Della Salda, Leonardo; Schilliger, Lionel; Vignoli, Massimo; Bongiovanni, Laura

    2014-12-01

    Two boa constrictors (Boa constrictor imperator) presented with paresis of the trunk originating cranial to the cloaca. Radiographs were consistent with proliferative bone lesions involving several vertebrae. Computed tomography (CT) demonstrated the presence of lytic/expansile lesions. Computed tomography-guided biopsies of the lesions were performed without complications. Histology was consistent with bacterial osteomyelitis and osteoarthritis. Gram-negative bacteria (Salmonella sp. and Pseudomonas sp.) were isolated from cultures of the biopsies. Medical treatment with specific antibiotics was attempted for several weeks in both cases without clinical or radiographic improvements. The animals were euthanized, and necropsy confirmed the findings observed upon CT. To the authors' knowledge, this is the first report of the use of CT-guided biopsies to evaluate proliferative vertebral lesions in snakes. In the present report, CT-guided biopsies were easily performed, and both histologic and microbiologic results were consistent with the final diagnosis. PMID:25632696

  1. Lymphoblastic lymphoma and leukemic blood profile in a red-tail boa (Boa constrictor constrictor) with concurrent inclusion body disease.

    PubMed

    Schilliger, Lionel; Selleri, Paolo; Frye, Fredric L

    2011-01-01

    An adult male wild-caught true red-tail boa (Boa constrictor constrictor), imported from Surinam, was presented for anorexia, extreme lethargy, and coelomic swelling in the cranial third of the body, in the anatomic location of the thymus. The snake died a few minutes after blood sampling via cardiocentesis. Hematology revealed anemia and extreme leukocytosis (820 × 10(3)/ml) characterized by a predominance (95%) of lymphocytes. Necropsy revealed enlargement of most of the visceral organs. Histology confirmed lymphoblastic lymphoma with a leukemic blood profile and diffuse infiltration of some of the heart, thymus, bone marrow, kidney, spleen, lung, and liver. Several large intracytoplasmic eosinophilic inclusion bodies surrounded by narrow clear "halos" were identified within gastric mucosal cells, proximal and distal convoluted tubule epithelial cells, and splenic cells. The final diagnosis was lymphoblast lymphoma with a leukemic blood profile and concurrent inclusion body disease. PMID:21217051

  2. Detection of arenavirus in a peripheral odontogenic fibromyxoma in a red tail boa (Boa constrictor constrictor) with inclusion body disease.

    PubMed

    Hellebuyck, Tom; Pasmans, Frank; Ducatelle, Richard; Saey, Veronique; Martel, An

    2015-03-01

    A captive bred red tail boa (Boa constrictor constrictor) was presented with a large intraoral mass originating from the buccal gingiva, attached to the right dentary teeth row. Based on the clinical features and histological examination, the diagnosis of a peripheral odontogenic fibromyxoma was made. Sections of liver biopsies and circulating lymphocytes contained relatively few eosinophilic intracytoplasmic inclusion bodies, indistinguishable from those observed in inclusion body disease-affected snakes. Inclusion bodies were not observed in cells comprising the neoplastic mass. Using reverse transcription polymerase chain reaction (RT-PCR), arenavirus was detected in the neoplastic tissue. Two years after surgical removal of the mass, recurrence of the neoplastic lesion was observed. Numerous large inclusion body disease inclusions were abundantly present in the neoplastic cells of the recurrent fibromyxoma. Sections of liver biopsies and circulating lymphocytes contained relatively few intracytoplasmic inclusions. The RT-PCR revealed the presence of arenavirus in blood, a liver biopsy, and neoplastic tissue. The present case describes the co-occurrence of an arenavirus infection and an odontogenic fibromyxoma in a red tail boa. PMID:25776548

  3. The Amazon and climate

    NASA Technical Reports Server (NTRS)

    Nobre, C. A.

    1984-01-01

    The climatologies of cloudiness and precipitation for the Amazon, are reviewed and the physical causes of some of the observed features and those which are not well known are explained. The atmospheric circulation over the Amazon is discussed on the large scale tropical circulations forced by deep diabatic heating sources. Weather deforestation which leads to a reduction in evapotranspiration into the atmosphere, and a reduction in precipitation and its implicated for the gobal climate is discussed. It is indicated that a large scale clearing of tropical rainforests there would be a reduction in rainfall which would have global effects on climate and weather both in the tropical and extratropical regions.

  4. Amazon basin: a system in equilibrium

    SciTech Connect

    Salati, E.; Vose, P.B.

    1984-07-13

    Despite very active deforestation in the last decade, the Amazon Basin is still primarily covered with trees and is a system in equilibrium. The Andes form a barrier at the western end of the basin and, coupled with the prevailing easterly winds, ensure an almost unique precipitation and water-recycling regime. On average 50% of the precipitation is recycled, and in some areas even more. The soils are poor. Most of the nitrogen and phosphorus is found in the soil, and the remaining nutrient elements are found in the standing biomass. There is some nutrient recycling and little loss from the intact ecosystem, and the small input of nutrients from precipitation maintains a small positive nutrient balance. Continued large-scale deforestation is likely to lead to increased erosion and water runoff with initial flooding in the lower Amazon, together with reduced evapotranspiration and ultimately reduced precipitation. Reduced precipitation in the Amazon could increase the tendency toward continentality and adversely affect climate and the present agriculture in south-central Brazil. 83 references, 1 figure, 5 tables.

  5. Amazon basin: a system in equilibrium.

    PubMed

    Salati, E; Vose, P B

    1984-07-13

    Despite the very active deforestation of the last decade, the Amazon Basin is still primarily covered with trees and is a system in equilibrium. The Andes form a barrier at the western end of the basin and, coupled with the prevailing easterly winds, ensure an almost unique precipitation and water-recycling regime. On average 50 percent of the precipitation is recycled, and in some areas even more. The soils are poor. Most of the nitrogen and phosphorus is found in the soil, and the remaining nutrient elements are found in the standing biomass. There is some nutrient recycling and little loss from the intact ecosystem, and the small input of nutrients from precipitation maintains a small positive nutrient balance. Continued large-scale deforestation is likely to lead to increased erosion and water runoff with initial flooding in the lower Amazon, together with reduced evapotranspiration and ultimately reduced precipitation. Reduced precipitation in the Amazon could increase the tendency toward continentality and adversely affect climate and the present agriculture in south-central Brazil. PMID:17837908

  6. BOA: Pipe-asbestos insulation removal robot system

    SciTech Connect

    Schempf, H.; Bares, J.; Schnorr, W.

    1995-10-01

    The BOA system is a mobile pipe-external robotic crawler used to remotely strip and bag asbestos-containing lagging and insulation materials (ACLIM) from various diameter pipes in (primarily) industrial installations. Steam and process lines within the DOE weapons complex warrant the use of a remote device due to the high labor costs and high level of radioactive contamination, making manual removal extremely costly and highly inefficient. Currently targeted facilities for demonstration and remediation are Fernald in Ohio and Oak Ridge in Tennessee.

  7. BOA: Asbestos Pipe-Insulation Abatement Robot System

    SciTech Connect

    Schempf, H.

    1996-06-01

    The BOA system is a mobile pipe-external robotic crawler used to remotely strip and bag asbestos-containing lagging and insulation materials (ACLIM) from various diameter pipes in (primarily) industrial installations. Steam and process lines within the DOE weapons complex warrant the use of a remote device due to the high labor costs and high level of radioactive contamination, making manual removal extremely costly and highly inefficient. Currently targeted facilities for demonstration and remediation are Fernald in Ohio and Oak Ridge in Tennessee.

  8. BoA: a versatile software for bolometer data reduction

    NASA Astrophysics Data System (ADS)

    Schuller, Frédéric

    2012-09-01

    Together with the development of the Large APEX Bolometer Camera (LABOCA) for the Atacama Pathfinder Experiment (APEX), a new data reduction package has been written. This software naturally interfaces with the telescope control system, and provides all functionalities for the reduction, analysis and visualization of bolometer data. It is used at APEX for real time processing of observations performed with LABOCA and other bolometer arrays, providing feedback to the observer. Written in an easy-to-script language, BoA is also used offline to reduce APEX continuum data. In this paper, the general structure of this software is presented, and its online and offline capabilities are described.

  9. Amazon flood wave hydraulics

    NASA Astrophysics Data System (ADS)

    Trigg, Mark A.; Wilson, Matthew D.; Bates, Paul D.; Horritt, Matthew S.; Alsdorf, Douglas E.; Forsberg, Bruce R.; Vega, Maria C.

    2009-07-01

    SummaryA bathymetric survey of 575 km of the central Amazon River and one of its tributaries, the Purus, are combined with gauged data to characterise the Amazon flood wave, and for hydraulic modelling of the main channel for the period June 1995-March 1997 with the LISFLOOD-FP and HEC-RAS hydraulic models. Our investigations show that the Amazon flood wave is subcritical and diffusive in character and, due to shallow bed slopes, backwater conditions control significant reach lengths and are present for low and high water states. Comparison of the different models shows that it is necessary to include at least the diffusion term in any model, and the RMSE error in predicted water elevation at all cross sections introduced by ignoring the acceleration and advection terms is of the order of 0.02-0.03 m. The use of a wide rectangular channel approximation introduces an error of 0.10-0.15 m on the predicted water levels. Reducing the bathymetry to a simple bed slope and with mean cross section only, introduces an error in the order of 0.5 m. These results show that when compared to the mean annual amplitude of the Amazon flood wave of 11-12 m, water levels are relatively insensitive to the bathymetry of the channel model. The implication for remote sensing studies of the central Amazon channel, such as those proposed with the Surface Water and Ocean Topography mission (SWOT), is that even relatively crude assumptions regarding the channel bathymetry will be valid in order to derive discharge from water surface slope of the main channel, as long as the mean channel area is approximately correct.

  10. BOA: Pipe-asbestos insulation removal robot system

    SciTech Connect

    Schempf, H.; Bares, J.; Mutschler, E.

    1995-12-31

    This paper describes the BOA system, a mobile pipe-external crawler used to remotely strip and bag (possibly contaminated) asbestos-containing lagging and insulation materials (ACLIM) from various diameter pipes in (primarily) industrial installations across the DOE weapons complex. The mechanical removal of ACLIM is very cost-effective due to the relatively low productivity and high cost involved in human removal scenarios. BOA, a mechanical system capable of removing most forms of lagging (paper, plaster, aluminum sheet, clamps, screws and chicken-wire), and insulation (paper, tar, asbestos fiber, mag-block) uses a circular cutter and compression paddles to cut and strip the insulation off the pipe through compression, while a HEPA-filter and encapsulant system maintain a certifiable vacuum and moisture content inside the system and on the pipe, respectively. The crawler system has been built and is currently undergoing testing. Key design parameters and performance parameters are developed and used in performance testing. Since the current system is a testbed, we also discuss future enhancements and outline two deployment scenarios (robotic and manual) for the final system to be designed and completed by the end of FY `95. An on-site demonstration is currently planned for Fernald in Ohio and Oak Ridge in Tennessee.

  11. Ecological specialization and morphological diversification in Greater Antillean boas.

    PubMed

    Reynolds, R Graham; Collar, David C; Pasachnik, Stesha A; Niemiller, Matthew L; Puente-Rolón, Alberto R; Revell, Liam J

    2016-08-01

    Colonization of islands can dramatically influence the evolutionary trajectories of organisms, with both deterministic and stochastic processes driving adaptation and diversification. Some island colonists evolve extremely large or small body sizes, presumably in response to unique ecological circumstances present on islands. One example of this phenomenon, the Greater Antillean boas, includes both small (<90 cm) and large (4 m) species occurring on the Greater Antilles and Bahamas, with some islands supporting pairs or trios of body-size divergent species. These boas have been shown to comprise a monophyletic radiation arising from a Miocene dispersal event to the Greater Antilles, though it is not known whether co-occurrence of small and large species is a result of dispersal or in situ evolution. Here, we provide the first comprehensive species phylogeny for this clade combined with morphometric and ecological data to show that small body size evolved repeatedly on separate islands in association with specialization in substrate use. Our results further suggest that microhabitat specialization is linked to increased rates of head shape diversification among specialists. Our findings show that ecological specialization following island colonization promotes morphological diversity through deterministic body size evolution and cranial morphological diversification that is contingent on island- and species-specific factors. PMID:27345593

  12. A robotic inspection experimental system (ARIES) and BOA

    SciTech Connect

    1998-02-01

    ARIES consists of a 6-wheeled K3A mobile platform, a compact subturret, a sonar imaging system, a laser-based light detection and ranging (lidar) navigation beacon system, and a camera positioning system. It has a sonar imaging system used in navigation and collision avoidance and an automatic docking/charging system. Drum-referencing algorithms and camera-positioning algorithms have been included in the primitive instruction set for the robot. The robot`s navigation is based on Synchro-Drive, a patented design that utilizes concentric shafts to distribute drive and steering power to the six wheels simultaneously. ARIES uses a virtual path concept in which only a limited amount of information needs to be provided to the control computer in order to get the vehicle moving. The safety and health evaluation, during the human factors assessment, found several areas of concern including ergonomics, laser hazards, tripping hazards, fall-from-above and struck-by hazards, electrical hazards, and decontamination of the system. BOA is a self-propelled automated mini-enclosure, able to remove insulation from installed pipes, primarily of 4 inch nominal outside diameter. The system is designed for two operators: one oversees the abatement head operation from a distance of 10 or 15 feet using a pendant control and the other bags the debris at a cyclonic bagging station that is attached by a vacuum hose to the cutting head. Since the abatement head is its own enclosure, there may be no need for further enclosures to be built. The system wets and removes asbestos insulation automatically, cutting the debris into consistent chunks and moving the wave under a strong vacuum to a bagging machine. Prior to reaching the bagging operation, the material passes through a water separator which greatly reduces the weight of the debris and allows recirculation of water, after sufficient filtration. The safety and health evaluation, during the human factors assessment, focused on: noise, dust

  13. The Amazon and climate

    NASA Technical Reports Server (NTRS)

    Nobre, C. A.

    1984-01-01

    The climatologies of cloudiness and precipitation for the Amazon are reviewed. The physical causes of observed features are explained. The question whether deforestation leads to a reduction in evapotranspiration into the atmosphere is examined, as well as the reduction in precipitation and its implication for the global climate. There are indications that for large scale clearing of tropical rain forests there would indeed be a reduction in rainfall, which would have global effects in terms of climate and weather.

  14. Columbia University's Franz Boas: He Led the Undoing of Scientific Racism.

    ERIC Educational Resources Information Center

    Baker, Lee D.

    1999-01-01

    As early as 1887, the anthropologist Franz Boas began to combat scientific racism and the insistence that blacks were of lower intelligence than whites. Throughout his career, Boas guided anthropology to a consensus that people of color were not racially inferior and that they possessed unique and historically specific cultures. (SLD)

  15. Patents on periphery of the Amazon rainforest.

    PubMed

    de Moura, Emanoel G; Araújo, José R G; Monroe, Paulo H M; de O Nascimento, Ivaneide; Aguiar, Alana C F

    2009-06-01

    In the humid tropics, on the edges of the Amazon forest, the technological challenges to establishing and maintaining productive and sustainable agricultural systems have yet to be overcome. The groups involved in agriculture in the north of Brazil still engage in the practice of slash and burn in order to prepare and fertilize the soil. This produces negative effects for the local and global environment, without the counter-effect of providing social benefits to rural communities. Whether this process continues is of fundamental importance to many countries because it means that slash and burn agriculture is advancing on the Amazon rainforest, with a negative effect on every dimension of national policy. Beyond social political problems the biggest challenge for researchers in the field of tropical agriculture is to offer technological alternatives that can sustain agriculture in soils derived from sedimentary rocks that have been subjected to a high degree of weathering. In this article patented information is also discussed. Experiments undertaken in this region recommend taking advantage of the rapid growth of plants in the tropics. We aimed at proposing a suitable alternative system for a sustainable soil management in the particular conditions of humid tropics, named as "no-till in alley cropping using tree leguminous mulch." This system offers the advantages of: bringing together, in the same space and at the same time, the processes of cultivation and the regeneration of soil fertility. PMID:20653534

  16. BOA detoxification of four summer weeds during germination and seedling growth.

    PubMed

    Schulz, Margot; Marocco, Adriano; Tabaglio, Vincenzo

    2012-07-01

    A recent greenhouse study revealed a significant reduction of germination and growth of redroot pigweed (Amaranthus retroflexus) and common purslane (Portulaca oleracea) by rye mulch, whereas velvetleaf (Abutilon theophrasti) and common lambsquarters (Chenopodium album) were not suppressed. Since BOA detoxification by metabolic alteration may influence the relation between the benzoxazinoid content of the soil mulch and weed suppression, we tested the dynamics in BOA detoxification in different plant organs of three and 10-day-old seedlings of four warm season weeds incubated with five BOA concentrations (4, 20, 40, 80, and 200 μmol g(-1) fresh weight). In addition, germination and length of 3-day-old seedlings were measured after exposure to 0, 0.3, 1.5, 3, 6, and 15 μmol BOA. Finally, we tested the influence of the MDR translocator inhibitors verapamil, nifedipine, and the GST inhibitor ethycrynic acid on BOA accumulation and detoxification activity. Due to BOA-detoxification, all weeds were able to grow in environments with low BOA contents. At higher contents, Abutilon theophrasti and Chenopodium album had a better chance to survive because of highly active mechanisms that avoided the uptake of BOA (A. theophrasti) and of efficient detoxification activities in youngest seedlings (C. album). The interpretation of all of the data gave the following sequence of increasing sensitivity: A. theophrasti < C. album < P. oleracea ≤ A. retroflexus. The results were in agreement with recent findings of the suppression of these weeds by rye mulches and their benzoxazinoid contents. Our studies demonstrate for the first time that the detoxification of BOA influences the survival of certain weeds in environments enriched with this allelochemical. Therefore, detoxification processes affect the potential for weed suppression by soil allelochemicals in sustainable weed management. PMID:22614450

  17. Long-term decline of the Amazon carbon sink.

    PubMed

    Brienen, R J W; Phillips, O L; Feldpausch, T R; Gloor, E; Baker, T R; Lloyd, J; Lopez-Gonzalez, G; Monteagudo-Mendoza, A; Malhi, Y; Lewis, S L; Vásquez Martinez, R; Alexiades, M; Álvarez Dávila, E; Alvarez-Loayza, P; Andrade, A; Aragão, L E O C; Araujo-Murakami, A; Arets, E J M M; Arroyo, L; Aymard C, G A; Bánki, O S; Baraloto, C; Barroso, J; Bonal, D; Boot, R G A; Camargo, J L C; Castilho, C V; Chama, V; Chao, K J; Chave, J; Comiskey, J A; Cornejo Valverde, F; da Costa, L; de Oliveira, E A; Di Fiore, A; Erwin, T L; Fauset, S; Forsthofer, M; Galbraith, D R; Grahame, E S; Groot, N; Hérault, B; Higuchi, N; Honorio Coronado, E N; Keeling, H; Killeen, T J; Laurance, W F; Laurance, S; Licona, J; Magnussen, W E; Marimon, B S; Marimon-Junior, B H; Mendoza, C; Neill, D A; Nogueira, E M; Núñez, P; Pallqui Camacho, N C; Parada, A; Pardo-Molina, G; Peacock, J; Peña-Claros, M; Pickavance, G C; Pitman, N C A; Poorter, L; Prieto, A; Quesada, C A; Ramírez, F; Ramírez-Angulo, H; Restrepo, Z; Roopsind, A; Rudas, A; Salomão, R P; Schwarz, M; Silva, N; Silva-Espejo, J E; Silveira, M; Stropp, J; Talbot, J; ter Steege, H; Teran-Aguilar, J; Terborgh, J; Thomas-Caesar, R; Toledo, M; Torello-Raventos, M; Umetsu, R K; van der Heijden, G M F; van der Hout, P; Guimarães Vieira, I C; Vieira, S A; Vilanova, E; Vos, V A; Zagt, R J

    2015-03-19

    Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models. PMID:25788097

  18. Long-term decline of the Amazon carbon sink

    NASA Astrophysics Data System (ADS)

    Brienen, R. J. W.; Phillips, O. L.; Feldpausch, T. R.; Gloor, E.; Baker, T. R.; Lloyd, J.; Lopez-Gonzalez, G.; Monteagudo-Mendoza, A.; Malhi, Y.; Lewis, S. L.; Vásquez Martinez, R.; Alexiades, M.; Álvarez Dávila, E.; Alvarez-Loayza, P.; Andrade, A.; Aragão, L. E. O. C.; Araujo-Murakami, A.; Arets, E. J. M. M.; Arroyo, L.; Aymard C., G. A.; Bánki, O. S.; Baraloto, C.; Barroso, J.; Bonal, D.; Boot, R. G. A.; Camargo, J. L. C.; Castilho, C. V.; Chama, V.; Chao, K. J.; Chave, J.; Comiskey, J. A.; Cornejo Valverde, F.; da Costa, L.; de Oliveira, E. A.; di Fiore, A.; Erwin, T. L.; Fauset, S.; Forsthofer, M.; Galbraith, D. R.; Grahame, E. S.; Groot, N.; Hérault, B.; Higuchi, N.; Honorio Coronado, E. N.; Keeling, H.; Killeen, T. J.; Laurance, W. F.; Laurance, S.; Licona, J.; Magnussen, W. E.; Marimon, B. S.; Marimon-Junior, B. H.; Mendoza, C.; Neill, D. A.; Nogueira, E. M.; Núñez, P.; Pallqui Camacho, N. C.; Parada, A.; Pardo-Molina, G.; Peacock, J.; Peña-Claros, M.; Pickavance, G. C.; Pitman, N. C. A.; Poorter, L.; Prieto, A.; Quesada, C. A.; Ramírez, F.; Ramírez-Angulo, H.; Restrepo, Z.; Roopsind, A.; Rudas, A.; Salomão, R. P.; Schwarz, M.; Silva, N.; Silva-Espejo, J. E.; Silveira, M.; Stropp, J.; Talbot, J.; Ter Steege, H.; Teran-Aguilar, J.; Terborgh, J.; Thomas-Caesar, R.; Toledo, M.; Torello-Raventos, M.; Umetsu, R. K.; van der Heijden, G. M. F.; van der Hout, P.; Guimarães Vieira, I. C.; Vieira, S. A.; Vilanova, E.; Vos, V. A.; Zagt, R. J.

    2015-03-01

    Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.

  19. Spatial Pattern of Standing Timber Value across the Brazilian Amazon

    PubMed Central

    Ahmed, Sadia E.; Ewers, Robert M.

    2012-01-01

    The Amazon is a globally important system, providing a host of ecosystem services from climate regulation to food sources. It is also home to a quarter of all global diversity. Large swathes of forest are removed each year, and many models have attempted to predict the spatial patterns of this forest loss. The spatial patterns of deforestation are determined largely by the patterns of roads that open access to frontier areas and expansion of the road network in the Amazon is largely determined by profit seeking logging activities. Here we present predictions for the spatial distribution of standing value of timber across the Amazon. We show that the patterns of timber value reflect large-scale ecological gradients, determining the spatial distribution of functional traits of trees which are, in turn, correlated with timber values. We expect that understanding the spatial patterns of timber value across the Amazon will aid predictions of logging movements and thus predictions of potential future road developments. These predictions in turn will be of great use in estimating the spatial patterns of deforestation in this globally important biome. PMID:22590520

  20. Spatial pattern of standing timber value across the Brazilian Amazon.

    PubMed

    Ahmed, Sadia E; Ewers, Robert M

    2012-01-01

    The Amazon is a globally important system, providing a host of ecosystem services from climate regulation to food sources. It is also home to a quarter of all global diversity. Large swathes of forest are removed each year, and many models have attempted to predict the spatial patterns of this forest loss. The spatial patterns of deforestation are determined largely by the patterns of roads that open access to frontier areas and expansion of the road network in the Amazon is largely determined by profit seeking logging activities. Here we present predictions for the spatial distribution of standing value of timber across the Amazon. We show that the patterns of timber value reflect large-scale ecological gradients, determining the spatial distribution of functional traits of trees which are, in turn, correlated with timber values. We expect that understanding the spatial patterns of timber value across the Amazon will aid predictions of logging movements and thus predictions of potential future road developments. These predictions in turn will be of great use in estimating the spatial patterns of deforestation in this globally important biome. PMID:22590520

  1. Monte-Carlo Opening Books for Amazons

    NASA Astrophysics Data System (ADS)

    Kloetzer, Julien

    Automatically creating opening books is a natural step towards the building of strong game-playing programs, especially when there is little available knowledge about the game. However, while recent popular Monte-Carlo Tree-Search programs showed strong results for various games, we show here that programs based on such methods cannot efficiently use opening books created using algorithms based on minimax. To overcome this issue, we propose to use an MCTS-based technique, Meta-MCTS, to create such opening books. This method, while requiring some tuning to arrive at the best opening book possible, shows promising results to create an opening book for the game of the Amazons, even if this is at the cost of removing its Monte-Carlo part.

  2. Ecological diversity of Trypanosoma cruzi transmission in the Amazon basin. The main scenaries in the Brazilian Amazon.

    PubMed

    Coura, J R; Junqueira, A C V

    2015-11-01

    The ecological diversity of Trypanosoma cruzi transmission in the Brazilian Amazon region is directly interlinked with the parasite's extensive reservoir, composed of 33 species of wild mammals within the following orders: Marsupialia, Chiroptera, Rodentia, Xenarthra, Carnivora and Primates; and of 16 species of wild triatomines, of which ten may be infected with T. cruzi. Four scenarios for the diversity of T. cruzi transmission in the Brazilian Amazon region are evident: (i) T. cruzi transmission between vectors and wild mammals, which is characterized as a wild enzooty encompassing the entire Amazon basin; (ii) accidental T. cruzi transmission from vectors and wild mammals to humans, when they invade the wild ecotope or when these vectors and wild mammals invade human homes; (iii) occupational Chagas disease among piassava (Leopoldinia piassaba) palm fiber gatherers, transmitted by the vector Rhodnius brethesi, for which these palm trees are the specific ecotope; (IV) oral T. cruzi transmission to humans through food contamination, particularly in juices from plants such as assai, which today is considered to be endemic in the Brazilian Amazon region, with more than 1500 cases notified. PMID:26254002

  3. Retinal photoreceptors and visual pigments in Boa constrictor imperator.

    PubMed

    Sillman, A J; Johnson, J L; Loew, E R

    2001-09-01

    The photoreceptors of Boa constrictor, a boid snake of the subfamily Boinae, were examined with scanning electron microscopy and microspectrophotometry. The retina of B. constrictor is duplex but highly dominated by rods, cones comprising 11% of the photoreceptor population. The rather tightly packed rods have relatively long outer segments with proximal ends that are somewhat tapered. There are two morphologically distinct, single cones. The most common cone by far has a large inner segment and a relatively stout outer segment. The second cone, seen only infrequently, has a substantially smaller inner segment and a finer outer segment. The visual pigments of B. constrictor are virtually identical to those of the pythonine boid, Python regius. Three different visual pigments are present, all based on vitamin A(1.) The visual pigment of the rods has a wavelength of peak absorbance (lambda(max)) at 495 +/- 2 nm. The visual pigment of the more common, large cone has a lambda(max) at 549 +/- 1 nm. The small, rare cone contains a visual pigment with lambda(max) at 357 +/- 2 nm, providing the snake with sensitivity in the ultraviolet. We suggest that B. constrictor might employ UV sensitivity to locate conspecifics and/or to improve hunting efficiency. The data indicate that wavelength discrimination above 430 nm would not be possible without some input from the rods. PMID:11550183

  4. Chemosensory age discrimination in the snake Boa constrictor (Serpentes: Boidae).

    PubMed

    Gabirot, Marianne; Picerno, Pablo; Valencia, Jorge; Lopez, Pilar; Martin, José

    2012-12-01

    Many snakes are able to use their chemosensory system to detect scent of conspecifics, which is important in many social contexts. Age discrimination based on chemical cues may be especially important to ensure access to sexually mature potential partners. In this study, we used 24 individual Boa constrictor snakes (12 adults mature and 12 non-mature individuals) that had been captured in different areas of Ecuador, and were maintained in captivity at the Vivarium of Quito. We used tongue-flick experiments to examine whether these snakes were able to discriminate between scents from mature and non-mature individuals. Results showed that B. constrictor snakes used chemical cues to recognize conspecifics and that the scent of individuals of different ages elicited chemosensory responses of different magnitudes. The scents from adult conspecifics elicited the quickest and highest chemosensory responses (i.e., short latency times and high tongue-flick rates), although we did not find differential responses to scent of males and females. The magnitude of the responses was lower to scent of sub adult individuals, and then even lower to scent of juvenile snakes, but in all cases the scent of snakes was discriminated from a blank control. We discuss the potential chemical mechanisms that may allow age recognition and its implications for social and sexual behavior of this snake species. PMID:23342514

  5. Slow Growth Rates of Amazonian Trees: Consequences for Carbon Sequestration and Forest Management.

    NASA Astrophysics Data System (ADS)

    Vieira, S. A.; Camargo, P. B.; Selhorst, D.; Chambers, J.; Higuchi, N.; Martinelli, L. A.; Trumbore, S.

    2004-12-01

    Growth rates for tropical forest trees estimated from radiocarbon ages and dendrometer measurements illustrate differences in forest age and structure among three sites located in the eastern, central and western Amazon basin. Although growth rates vary dramatically among individual trees overall the slowest growing trees (averaging \\sim0.1mm yr-1 as opposed to 0.3mm yr-1 diameter increment) are found in the central Amazon. Small individuals (DBH \\<30cm) have slower growth rates than larger diameter trees, and trees in this size class with radiocarbon ages >500 yr are encountered at all sites. Only \\sim2MgC ha-1 year-1, or \\SIM7% of annual photosynthesis, is allocated to growth of living wood at the eastern and central Amazon sites. Rates of C allocation to stem growth are similar across the three sites we studied because slowest growth occurs at the central Amazon site that has highest stem density and greatest biomass. Extrapolating our growth increment data to forest stand, we estimate the mean age of individual trees is \\SIM350 years in the central Amazon but \\SIM200\\-250 years in the other two areas. The mean age of C making up the trees has a smaller range of \\SIM250\\-310 years, because of the greater fraction of biomass in larger individuals in the eastern and western Amazon sites. These residence times for C are longer than those of 100\\-180 years obtained by simply dividing the total biomass C by the rate of C allocation to new wood for the same reason. We estimate that >20% of trees at all sites should have ages >300 years, and that maximum tree ages of >1000 years, though not common, are in accord with the growth rates we find. The fact that many Amazon trees attain ages greater than several centuries should be accounted for in management practices in these forests.

  6. Second COS FUV Lifetime Calibration Program: Verification of FUV BOA Operations {FCAL4}

    NASA Astrophysics Data System (ADS)

    Debes, John

    2011-10-01

    This program will obtain one external orbit of G191B2B, a previous SMOV4 BOA target. We will obtain spectra in the G130M, G160M, and G140L gratings at one cenwave each to 1} spot-check spectral performance, 2} obtain spatial profiles, and 3} complete updated target acquisition parameters. We will also test auto- wavecals within a BOA observation.

  7. Analogical reasoning in amazons.

    PubMed

    Obozova, Tanya; Smirnova, Anna; Zorina, Zoya; Wasserman, Edward

    2015-11-01

    Two juvenile orange-winged amazons (Amazona amazonica) were initially trained to match visual stimuli by color, shape, and number of items, but not by size. After learning these three identity matching-to-sample tasks, the parrots transferred discriminative responding to new stimuli from the same categories that had been used in training (other colors, shapes, and numbers of items) as well as to stimuli from a different category (stimuli varying in size). In the critical testing phase, both parrots exhibited reliable relational matching-to-sample (RMTS) behavior, suggesting that they perceived and compared the relationship between objects in the sample stimulus pair to the relationship between objects in the comparison stimulus pairs, even though no physical matches were possible between items in the sample and comparison pairs. The parrots spontaneously exhibited this higher-order relational responding without having ever before been trained on RMTS tasks, therefore joining apes and crows in displaying this abstract cognitive behavior. PMID:26084679

  8. Highly reactive light-dependent monoterpenes in the Amazon

    SciTech Connect

    Jardine, A. B.; Jardine, K. J.; Fuentes, J. D.; Martin, S. T.; Martins, G.; Durgante, F.; Carneiro, V.; Higuchi, N.; Manzi, A. O.; Chambers, J. Q.

    2015-03-06

    Despite orders of magnitude difference in atmospheric reactivity and great diversity in biological functioning, little is known about monoterpene speciation in tropical forests. Here we report vertically resolved ambient air mixing ratios for 12 monoterpenes in a central Amazon rainforest including observations of the highly reactive cis-β-ocimene (160 ppt), trans-β-ocimene (79 ppt), and terpinolene (32 ppt) which accounted for an estimated 21% of total monoterpene composition yet 55% of the upper canopy monoterpene ozonolysis rate. All 12 monoterpenes showed a mixing ratio peak in the upper canopy, with three demonstrating subcanopy peaks in 7 of 11 profiles. Leaf level emissions of highly reactive monoterpenes accounted for up to 1.9% of photosynthesis confirming light-dependent emissions across several Amazon tree genera. These results suggest that highly reactive monoterpenes play important antioxidant roles during photosynthesis in plants and serve as near-canopy sources of secondary organic aerosol precursors through atmospheric photooxidation via ozonolysis.

  9. Highly reactive light-dependent monoterpenes in the Amazon

    NASA Astrophysics Data System (ADS)

    Jardine, A. B.; Jardine, K. J.; Fuentes, J. D.; Martin, S. T.; Martins, G.; Durgante, F.; Carneiro, V.; Higuchi, N.; Manzi, A. O.; Chambers, J. Q.

    2015-03-01

    Despite orders of magnitude difference in atmospheric reactivity and great diversity in biological functioning, little is known about monoterpene speciation in tropical forests. Here we report vertically resolved ambient air mixing ratios for 12 monoterpenes in a central Amazon rainforest including observations of the highly reactive cis-β-ocimene (160 ppt), trans-β-ocimene (79 ppt), and terpinolene (32 ppt) which accounted for an estimated 21% of total monoterpene composition yet 55% of the upper canopy monoterpene ozonolysis rate. All 12 monoterpenes showed a mixing ratio peak in the upper canopy, with three demonstrating subcanopy peaks in 7 of 11 profiles. Leaf level emissions of highly reactive monoterpenes accounted for up to 1.9% of photosynthesis confirming light-dependent emissions across several Amazon tree genera. These results suggest that highly reactive monoterpenes play important antioxidant roles during photosynthesis in plants and serve as near-canopy sources of secondary organic aerosol precursors through atmospheric photooxidation via ozonolysis.

  10. Generation of Anti-Boa Immunoglobulin Antibodies for Serodiagnostic Applications, and Their Use to Detect Anti-Reptarenavirus Antibodies in Boa Constrictor

    PubMed Central

    Korzyukov, Yegor; Hetzel, Udo; Kipar, Anja; Vapalahti, Olli; Hepojoki, Jussi

    2016-01-01

    Immunoglobulins (Igs), the key effectors of the adaptive immune system, mediate the specific recognition of foreign structures, i.e. antigens. In mammals, IgM production commonly precedes the production of IgG in the response to an infection. The reptilian counterpart of IgG is IgY, but the exact kinetics of the reptilian immune response are less well known. Boid inclusion body disease (BIBD), an often fatal disease of captive boas and pythons has been linked to reptarenavirus infection, and BIBD is believed to be immunosuppressive. However, so far, the study of the serological response towards reptarenaviruses in BIBD has been hampered by the lack of reagents. Thus we set up a purification protocol for boa constrictor IgY and IgM, which should also be applicable for other snake species. We used centrifugal filter units, poly ethylene glycol precipitation and gel permeation chromatography to purify and separate the IgM and IgY fractions from boa constrictor serum, which we further used to immunise rabbits. We affinity purified IgM and IgY specific reagents from the produced antiserum, and labelled the reagents with horseradish peroxidase. Finally, using the sera of snakes with known exposure to reptarenaviruses we demonstrated that the newly generated reagents can be utilised for serodiagnostic purposes, such as immunoblotting and immunofluorescent staining. To our knowledge, this is the first report to show reptarenavirus-specific antibodies in boa constrictors. PMID:27355360

  11. Generation of Anti-Boa Immunoglobulin Antibodies for Serodiagnostic Applications, and Their Use to Detect Anti-Reptarenavirus Antibodies in Boa Constrictor.

    PubMed

    Korzyukov, Yegor; Hetzel, Udo; Kipar, Anja; Vapalahti, Olli; Hepojoki, Jussi

    2016-01-01

    Immunoglobulins (Igs), the key effectors of the adaptive immune system, mediate the specific recognition of foreign structures, i.e. antigens. In mammals, IgM production commonly precedes the production of IgG in the response to an infection. The reptilian counterpart of IgG is IgY, but the exact kinetics of the reptilian immune response are less well known. Boid inclusion body disease (BIBD), an often fatal disease of captive boas and pythons has been linked to reptarenavirus infection, and BIBD is believed to be immunosuppressive. However, so far, the study of the serological response towards reptarenaviruses in BIBD has been hampered by the lack of reagents. Thus we set up a purification protocol for boa constrictor IgY and IgM, which should also be applicable for other snake species. We used centrifugal filter units, poly ethylene glycol precipitation and gel permeation chromatography to purify and separate the IgM and IgY fractions from boa constrictor serum, which we further used to immunise rabbits. We affinity purified IgM and IgY specific reagents from the produced antiserum, and labelled the reagents with horseradish peroxidase. Finally, using the sera of snakes with known exposure to reptarenaviruses we demonstrated that the newly generated reagents can be utilised for serodiagnostic purposes, such as immunoblotting and immunofluorescent staining. To our knowledge, this is the first report to show reptarenavirus-specific antibodies in boa constrictors. PMID:27355360

  12. Projections of future meteorological drought and wet periods in the Amazon.

    PubMed

    Duffy, Philip B; Brando, Paulo; Asner, Gregory P; Field, Christopher B

    2015-10-27

    Future intensification of Amazon drought resulting from climate change may cause increased fire activity, tree mortality, and emissions of carbon to the atmosphere across large areas of Amazonia. To provide a basis for addressing these issues, we examine properties of recent and future meteorological droughts in the Amazon in 35 climate models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5). We find that the CMIP5 climate models, as a group, simulate important properties of historical meteorological droughts in the Amazon. In addition, this group of models reproduces observed relationships between Amazon precipitation and regional sea surface temperature anomalies in the tropical Pacific and the North Atlantic oceans. Assuming the Representative Concentration Pathway 8.5 scenario for future drivers of climate change, the models project increases in the frequency and geographic extent of meteorological drought in the eastern Amazon, and the opposite in the West. For the region as a whole, the CMIP5 models suggest that the area affected by mild and severe meteorological drought will nearly double and triple, respectively, by 2100. Extremes of wetness are also projected to increase after 2040. Specifically, the frequency of periods of unusual wetness and the area affected by unusual wetness are projected to increase after 2040 in the Amazon as a whole, including in locations where annual mean precipitation is projected to decrease. Our analyses suggest that continued emissions of greenhouse gases will increase the likelihood of extreme events that have been shown to alter and degrade Amazonian forests. PMID:26460046

  13. Projections of future meteorological drought and wet periods in the Amazon

    PubMed Central

    Duffy, Philip B.; Brando, Paulo; Asner, Gregory P.; Field, Christopher B.

    2015-01-01

    Future intensification of Amazon drought resulting from climate change may cause increased fire activity, tree mortality, and emissions of carbon to the atmosphere across large areas of Amazonia. To provide a basis for addressing these issues, we examine properties of recent and future meteorological droughts in the Amazon in 35 climate models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5). We find that the CMIP5 climate models, as a group, simulate important properties of historical meteorological droughts in the Amazon. In addition, this group of models reproduces observed relationships between Amazon precipitation and regional sea surface temperature anomalies in the tropical Pacific and the North Atlantic oceans. Assuming the Representative Concentration Pathway 8.5 scenario for future drivers of climate change, the models project increases in the frequency and geographic extent of meteorological drought in the eastern Amazon, and the opposite in the West. For the region as a whole, the CMIP5 models suggest that the area affected by mild and severe meteorological drought will nearly double and triple, respectively, by 2100. Extremes of wetness are also projected to increase after 2040. Specifically, the frequency of periods of unusual wetness and the area affected by unusual wetness are projected to increase after 2040 in the Amazon as a whole, including in locations where annual mean precipitation is projected to decrease. Our analyses suggest that continued emissions of greenhouse gases will increase the likelihood of extreme events that have been shown to alter and degrade Amazonian forests. PMID:26460046

  14. Windthrows increase soil carbon stocks in a Central Amazon forest

    NASA Astrophysics Data System (ADS)

    dos Santos, L. T.; Magnabosco Marra, D.; Trumbore, S.; Camargo, P. B.; Chambers, J. Q.; Negrón-Juárez, R. I.; Lima, A. J. N.; Ribeiro, G. H. P. M.; dos Santos, J.; Higuchi, N.

    2015-12-01

    Windthrows change forest structure and species composition in Central Amazon forests. However, the effects of widespread tree mortality associated with wind-disturbances on soil properties have not yet been described. In this study, we investigated short-term effects (seven years after disturbance) of a windthrow event on soil carbon stocks and concentrations in a Central Amazon terra firme forest. The soil carbon stock (averaged over a 0-30 cm depth profile) in disturbed plots (61.4 ± 4.18 Mg ha-1, mean ± standard error) was marginally higher (p = 0.009) than that from undisturbed plots (47.7 ± 6.95 Mg ha-1). The soil organic carbon concentration in disturbed plots (2.0 ± 0.08 %) was significantly higher (p < 0.001) than that from undisturbed plots (1.36 ± 0.12 %). Moreover, soil carbon stocks were positively correlated with soil clay content (r = 0.575 and p = 0.019) and with tree mortality intensity (r = 0.493 and p = 0.045). Our results indicate that large inputs of plant litter associated with large windthrow events cause a short-term increase in soil carbon content, and the degree of increase is related to soil clay content and tree mortality intensity. Higher nutrient availability in soils from large canopy gaps created by wind disturbance may increase vegetation resilience and favor forest recovery.

  15. Dimethyl sulfide in the Amazon rain forest

    NASA Astrophysics Data System (ADS)

    Jardine, K.; Yañez-Serrano, A. M.; Williams, J.; Kunert, N.; Jardine, A.; Taylor, T.; Abrell, L.; Artaxo, P.; Guenther, A.; Hewitt, C. N.; House, E.; Florentino, A. P.; Manzi, A.; Higuchi, N.; Kesselmeier, J.; Behrendt, T.; Veres, P. R.; Derstroff, B.; Fuentes, J. D.; Martin, S. T.; Andreae, M. O.

    2015-01-01

    Surface-to-atmosphere emissions of dimethyl sulfide (DMS) may impact global climate through the formation of gaseous sulfuric acid, which can yield secondary sulfate aerosols and contribute to new particle formation. While oceans are generally considered the dominant sources of DMS, a shortage of ecosystem observations prevents an accurate analysis of terrestrial DMS sources. Using mass spectrometry, we quantified ambient DMS mixing ratios within and above a primary rainforest ecosystem in the central Amazon Basin in real-time (2010-2011) and at high vertical resolution (2013-2014). Elevated but highly variable DMS mixing ratios were observed within the canopy, showing clear evidence of a net ecosystem source to the atmosphere during both day and night in both the dry and wet seasons. Periods of high DMS mixing ratios lasting up to 8 h (up to 160 parts per trillion (ppt)) often occurred within the canopy and near the surface during many evenings and nights. Daytime gradients showed mixing ratios (up to 80 ppt) peaking near the top of the canopy as well as near the ground following a rain event. The spatial and temporal distribution of DMS suggests that ambient levels and their potential climatic impacts are dominated by local soil and plant emissions. A soil source was confirmed by measurements of DMS emission fluxes from Amazon soils as a function of temperature and soil moisture. Furthermore, light- and temperature-dependent DMS emissions were measured from seven tropical tree species. Our study has important implications for understanding terrestrial DMS sources and their role in coupled land-atmosphere climate feedbacks.

  16. Phylogeographic and population genetic analyses reveal multiple species of Boa and independent origins of insular dwarfism.

    PubMed

    Card, Daren C; Schield, Drew R; Adams, Richard H; Corbin, Andrew B; Perry, Blair W; Andrew, Audra L; Pasquesi, Giulia I M; Smith, Eric N; Jezkova, Tereza; Boback, Scott M; Booth, Warren; Castoe, Todd A

    2016-09-01

    Boa is a Neotropical genus of snakes historically recognized as monotypic despite its expansive distribution. The distinct morphological traits and color patterns exhibited by these snakes, together with the wide diversity of ecosystems they inhabit, collectively suggest that the genus may represent multiple species. Morphological variation within Boa also includes instances of dwarfism observed in multiple offshore island populations. Despite this substantial diversity, the systematics of the genus Boa has received little attention until very recently. In this study we examined the genetic structure and phylogenetic relationships of Boa populations using mitochondrial sequences and genome-wide SNP data obtained from RADseq. We analyzed these data at multiple geographic scales using a combination of phylogenetic inference (including coalescent-based species delimitation) and population genetic analyses. We identified extensive population structure across the range of the genus Boa and multiple lines of evidence for three widely-distributed clades roughly corresponding with the three primary land masses of the Western Hemisphere. We also find both mitochondrial and nuclear support for independent origins and parallel evolution of dwarfism on offshore island clusters in Belize and Cayos Cochinos Menor, Honduras. PMID:27241629

  17. An assessment of the impact of the pet trade on five CITES-Appendix II case studies - Boa constrictor imperator

    USGS Publications Warehouse

    Montgomery, Chad E.; Boback, Scott M.; Reed, Robert N.; Frazier, Julius A.

    2015-01-01

    Boa constrictor is a wide ranging snake species that is common in the pet trade and is currently listed in CITES Appendix II. Hog Island boas, or Cayos Cochinos boas, are a dwarf, insular race of Boa constrictor imperator endemic to the Cayos Cochinos Archipelago, Honduras. Cayos Cochinos boas are prized in the international pet trade for their light pink dorsal coloration, as well as for being much smaller and more docile than mainland boas (Porras, 1999; Russo, 2007). The boa population in the Cayos Cochinos was heavily exploited for the pet trade from 1979 to 1993, and researchers reported finding no boas on the islands during a five day herpetological survey trip in the early 1990s (Wilson and CruzDiaz, 1993), leading to the speculation that the population had been extirpated (e.g., Russo, 2007). The Cayos Cochinos Archipelago Natural Marine Monument has been managed by the Honduran Coral Reef Foundation since 1994 and prohibits removal of boas from the area. Poaching for the pet trade continues today, although at a lower level. Due to the endemic nature of this island morph of B. c. imperator it is imperative that we understand the dynamics of the populations and the ongoing threats that could negatively impact their long-term survival.

  18. Mixing in the Amazon estuary

    NASA Astrophysics Data System (ADS)

    Bezerra, M. O.

    2010-05-01

    The research area of this work is located at the estuary of the Amazon River (Brazil), near the river mouth. The results of air movement analysis on the surface atmospheric circulation over the Mouth of the Amazonas River, salinity and temperature measures as well as measurements of currents, carried out along a longitudinal section in the navigation canal region of the Northern Bar of the Amazon River (Barra Norte do Rio Amazonas) in June 2006, during the river flood season in the quadrature tide. The dynamics effects affect hydrodynamic,meteorological and hydrographical parameters at the river mouth. The conclusion drawn include that: a) the saline wedge-type stratification can be detected approximately 100km away from the mouth of the Amazon River during the end of the rainy season in the quadrature tide; b) probably, at the Amazon estuary the quadrature entrainment processes are dominant and they are the ones responsible for increased salinity detected in the surface layer, whereas turbulence scattering mixing is not so important. c) The large flow of fresh water from the Amazon River at the end of the rainy season implies the displacement of the saline front position over the internal Amazon continental platform, and d) The tidal wave shows a positive asymmetry in the canal, with floods lasting less than in the ebb tide. This asymmetry decreases towards the ocean, eventually becoming reversed in the presence of a saline wedge. The speeds, however, have a negative asymmetry, with more intense ebb tides, due to the river flow and is more evident by the existence of quadrature tides.

  19. Parallel selective pressures drive convergent diversification of phenotypes in pythons and boas.

    PubMed

    Esquerré, Damien; Scott Keogh, J

    2016-07-01

    Pythons and boas are globally distributed and distantly related radiations with remarkable phenotypic and ecological diversity. We tested whether pythons, boas and their relatives have evolved convergent phenotypes when they display similar ecology. We collected geometric morphometric data on head shape for 1073 specimens representing over 80% of species. We show that these two groups display strong and widespread convergence when they occupy equivalent ecological niches and that the history of phenotypic evolution strongly matches the history of ecological diversification, suggesting that both processes are strongly coupled. These results are consistent with replicated adaptive radiation in both groups. We argue that strong selective pressures related to habitat-use have driven this convergence. Pythons and boas provide a new model system for the study of macro-evolutionary patterns of morphological and ecological evolution and they do so at a deeper level of divergence and global scale than any well-established adaptive radiation model systems. PMID:27264195

  20. Fatal attack on black-tufted-ear marmosets (Callithrix penicillata) by a Boa constrictor: a simultaneous assault on two juvenile monkeys.

    PubMed

    Teixeira, Danilo Simonini; dos Santos, Edmilson; Leal, Silvana Gomes; de Jesus, Andrea Karla; Vargas, Waldemir Paixão; Dutra, Irapuan; Barros, Marilia

    2016-01-01

    Here we report the first witnessed attack on a marmoset by a constrictor snake. The incident occurred mid-morning in a gallery forest within an altered landscape of the Cerrado region of central Brazil and refers to a fatal attack by a Boa constrictor on two juvenile black-tufted-ear marmosets (Callithrix penicillata) simultaneously. The snake captured both individuals at a height of ~ 4 m while a group of eight marmosets traveled through the subcanopy. The actual strike was not seen. After 2 min, the boa fell to the ground with both marmosets in its coils and proceeded to kill one animal at a time through constriction. Two adult marmosets immediately descended to where the snake held its victims on the ground and attacked it. The snake showed no apparent reaction, and after ~ 1-2 min, the adults rejoined the remaining group members that were mobbing and vocalizing from 5 to 6 m above. The group left the scene ~ 7 min after the onset of the attack and was not seen again. The snake loosened its coils 10 min after its initial strike, left the two carcasses on the ground and stayed behind a nearby tree. Thus, we are not sure if the victims were in fact ingested. This report confirms that marmosets are vulnerable to boid snakes and capable of highly organized and cooperative antipredation behavior. It also suggests that snakes pose a greater threat to callitrichids than previously thought. PMID:26467338

  1. Diphtheroid colitis in a Boa constrictor infected with amphibian Entamoeba sp.

    PubMed

    Richter, Barbara; Kübber-Heiss, Anna; Weissenböck, Herbert

    2008-05-01

    A female boa (Boa constrictor) from a zoological collection was submitted for necropsy after sudden death. Prominent pathological findings included a diphtheroid colitis, endoparasitism, focal pneumonia and inclusion bodies typical for inclusion body disease (IBD). In the colon entamoebae were identified, which differed in size and distribution from Entamoeba invadens. Gene sequence analysis of the 18S ribosomal RNA revealed 100% similarity with an Entamoeba species from the African bullfrog (Pyxicephalus adspersus), probably Entamoeba ranarum. The snake was possibly immunosuppressed, and the source of infection remains unclear. This is the first report of an infection with an amphibian Entamoeba species associated with colitis in a snake. PMID:18291588

  2. 75 FR 13264 - Meeting of the Board of Advisors (BOA) to the President, Naval Postgraduate School (NPS)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE Department of the Navy Meeting of the Board of Advisors (BOA) to the President, Naval Postgraduate School... NPS BOA, contact Ms. Jaye Panza, Naval Postgraduate School, 1 University Circle, Monterey, CA...

  3. Tree Scanning

    PubMed Central

    Templeton, Alan R.; Maxwell, Taylor; Posada, David; Stengård, Jari H.; Boerwinkle, Eric; Sing, Charles F.

    2005-01-01

    We use evolutionary trees of haplotypes to study phenotypic associations by exhaustively examining all possible biallelic partitions of the tree, a technique we call tree scanning. If the first scan detects significant associations, additional rounds of tree scanning are used to partition the tree into three or more allelic classes. Two worked examples are presented. The first is a reanalysis of associations between haplotypes at the Alcohol Dehydrogenase locus in Drosophila melanogaster that was previously analyzed using a nested clade analysis, a more complicated technique for using haplotype trees to detect phenotypic associations. Tree scanning and the nested clade analysis yield the same inferences when permutation testing is used with both approaches. The second example is an analysis of associations between variation in various lipid traits and genetic variation at the Apolipoprotein E (APOE) gene in three human populations. Tree scanning successfully identified phenotypic associations expected from previous analyses. Tree scanning for the most part detected more associations and provided a better biological interpretative framework than single SNP analyses. We also show how prior information can be incorporated into the tree scan by starting with the traditional three electrophoretic alleles at APOE. Tree scanning detected genetically determined phenotypic heterogeneity within all three electrophoretic allelic classes. Overall, tree scanning is a simple, powerful, and flexible method for using haplotype trees to detect phenotype/genotype associations at candidate loci. PMID:15371364

  4. Windthrows increase soil carbon stocks in a central Amazon forest

    NASA Astrophysics Data System (ADS)

    dos Santos, Leandro T.; Magnabosco Marra, Daniel; Trumbore, Susan; de Camargo, Plínio B.; Negrón-Juárez, Robinson I.; Lima, Adriano J. N.; Ribeiro, Gabriel H. P. M.; dos Santos, Joaquim; Higuchi, Niro

    2016-03-01

    Windthrows change forest structure and species composition in central Amazon forests. However, the effects of widespread tree mortality associated with wind disturbances on soil properties have not yet been described in this vast region. We investigated short-term effects (7 years after disturbance) of widespread tree mortality caused by a squall line event from mid-January of 2005 on soil carbon stocks and concentrations in a central Amazon terra firme forest. The soil carbon stock (averaged over a 0-30 cm depth profile) in disturbed plots (61.4 ± 8.2 Mg ha-1, mean ±95 % confidence interval) was marginally higher (p = 0.09) than that from undisturbed plots (47.7 ± 13.6 Mg ha-1). The soil organic carbon concentration in disturbed plots (2.0 ± 0.17 %) was significantly higher (p < 0.001) than that from undisturbed plots (1.36 ± 0.24 %). Moreover, soil carbon stocks were positively correlated with soil clay content (r2 = 0.332, r = 0.575 and p = 0.019) and with tree mortality intensity (r2 = 0.257, r = 0.506 and p = 0.045). Our results indicate that large inputs of plant litter associated with large windthrow events cause a short-term increase in soil carbon content, and the degree of increase is related to soil clay content and tree mortality intensity. The higher carbon content and potentially higher nutrient availability in soils from areas recovering from windthrows may favor forest regrowth and increase vegetation resilience.

  5. A new species of Tropidopedia from the Amazon rainforest, Brazil (Hymenoptera: Apidae), with a revised phylogenetic overview of the genus.

    PubMed

    Mahlmann, Thiago; De Oliveira, Marcio L

    2015-01-01

    We describe a new species of the bee tribe Tapinotaspidini, Tropidopedia guaranae Mahlmann & Oliveira sp. n. from the Amazon rainforest, Amazonas, Brazil. We emend the phylogenetic tree of Aguiar & Melo (2007) to include the new species and comment upon some characters presented by those authors. PMID:26624352

  6. Bacillus mojavensis transforms BOA into fungitoxic APO in the presence of fusarium verticillioides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Benzoxazolin-2(3H)-one (BOA) is an important transformation product of cyclic hydroxamic acids of maize. This natural product has the potential of providing resistance to maize from Fusarium verticillioides, a major pathogen of maize. However, it has been demonstrated that this maize pathogen and ...

  7. High resolution neutron imaging capabilities at BOA beamline at Paul Scherrer Institut

    NASA Astrophysics Data System (ADS)

    Tremsin, A. S.; Morgano, M.; Panzner, T.; Lehmann, E.; Filgers, U.; Vallerga, J. V.; McPhate, J. B.; Siegmund, O. H. W.; Feller, W. B.

    2015-06-01

    The cold neutron spectrum of the Beamline for neutron Optics and other Applications (BOA) at Paul Scherrer Institut enables high contrast neutron imaging because neutron cross sections for many materials increase with neutron wavelength. However, for many neutron imaging applications, spatial resolution can be as important as contrast. In this paper the neutron transmission imaging capabilities of an MCP/Timepix detector installed at the BOA beamline are presented, demonstrating the possibilities for studying sub-20 μm features in various samples. In addition to conventional neutron radiography and microtomography, the high degree of neutron polarization at the BOA beamline can be very attractive for imaging of magnetic fields, as demonstrated by our measurements. We also show that a collimated cold neutron beamline combined with a high resolution detector can produce image artifacts, (e.g. edge enhancements) due to neutron refraction and scattering. The results of our experiments indicate that the BOA beamline is a valuable addition to neutron imaging facilities, providing improved and sometimes unique capabilities for non-destructive studies with cold neutrons.

  8. Physicochemical, antimicrobial and anti-inflammatory evaluation of fixed oil from Boa constrictor.

    PubMed

    Falodun, Abiodun; Owolabi, Omonkhelin Josephine; Osahon, Obasuyi

    2008-01-01

    Boa constrictor is one of the snakes found in the riverine areas of Nigeria, especially in the Niger Delta regions. The fat obtained from the snake is used ethno-medicinally for the treatment of burns and inflammatory conditions. The purpose of this study was to validate the traditional use of this crude fat and oil. The fat obtained from the Boa snake was subjected to some physiochemical screening tests. A systematic chemical and antimicrobial investigation was carried out using some bacterial found in wound such as Staphylococcus aureus, B. subtilis and Streptococcus pyrogenes. The degree of zone of inhibition was a measure of the antimicrobial activity of the fat and oil. The maximal inhibitory dilution was determined for significant zone. The anti-inflammatory investigation was done using the croton oil induced ear edema. The results of the study revealed a potent anti-inflammatory and a significant antimicrobial activity of the fat from Boa constrictor against S. aureus and S. pyrogenes organisms, thus, justifying the traditional usage of the fat of Boa constrictor. PMID:19051590

  9. Interactions of Bacillus mojavensis and Fusarium verticillioides with a benzoxazolinone (BOA) and its transformation product, APO.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The benzoxazolinones, specifically benzoxazolin-2(3H)-one (BOA), are important transformation products of cyclic hydroxamic acids that serve as allelochemicals, which provide resistance to maize from pathogenic bacteria and fungi, and insects. However, several maize pathogens such as Fusarium verti...

  10. Tree Lifecycle.

    ERIC Educational Resources Information Center

    Nature Study, 1998

    1998-01-01

    Presents a Project Learning Tree (PLT) activity that has students investigate and compare the lifecycle of a tree to other living things and the tree's role in the ecosystem. Includes background material as well as step-by-step instructions, variation and enrichment ideas, assessment opportunities, and student worksheets. (SJR)

  11. Genetic variability in three Amazon parrot species.

    PubMed

    Lopes, I F; Del Lama, M A; Del Lama, S N

    2007-12-01

    Parrots of the genus Amazona are among the most threatened species of the Order Pscittaciformes. This work describes allozyme polymorphisms in three Amazon parrot species--the Blue-fronted Amazon (Amazona aestiva), the Orange-winged Amazon (Amazona amazonica), and the Festive Amazon (Amazona festiva) -, and provides useful data for the evaluation of their genetic variability. We electrophoretically analyzed blood samples from 68 wild-caught individuals, maintained in captivity in three Brazilian zoos. Eight of the ten studied enzyme loci exhibited polymorphism. Glucosephosphate isomerase (Gpi) proved to be a diagnostic locus for the identification of these Amazon species. The expected average heterozygosity of the Blue-fronted Amazon (0.060) differed significantly from the expected heterozygosities of the Orange-winged Amazon and the Festive Amazon (0.040 and 0.039, respectively). This result was discussed as a consequence of hybridization between two geographic A. aestiva subspecies, and alternatively as a particular trait of this species. Genetic variability of the Blue-fronted Amazon compared to birds in general is not low on a species-wide level, despite the fact that this parrot is one of the most illegally traded species. Allozyme analysis proved to be an useful tool in monitoring the genetic variation within the genus Amazona and can be applied in the management program of other threatened species of this genus. PMID:18278355

  12. Dimethyl sulfide in the Amazon rain forest: DMS in the Amazon

    DOE PAGESBeta

    Jardine, K.; Yañez-Serrano, A. M.; Williams, J.; Kunert, N.; Jardine, A.; Taylor, T.; Abrell, L.; Artaxo, P.; Guenther, A.; Hewitt, C. N.; et al

    2015-01-08

    Surface-to-atmosphere emissions of dimethyl sulfide (DMS) may impact global climate 44 through the formation of gaseous sulfuric acid, which can yield secondary sulfate 45 aerosols and contribute to new particle formation. While oceans are generally 46 considered the dominant source of DMS, a shortage of ecosystem observations prevents 47 an accurate analysis of terrestrial DMS sources. Using mass spectrometry, we quantified 48 ambient DMS mixing ratios within and above a primary rainforest ecosystem in the 49 central Amazon Basin in real-time (2010-2011) and at high vertical resolution (2013-50 2014). Elevated but highly variable DMS mixing ratios were observed within themore » 51 canopy, showing clear evidence of a net ecosystem source to the atmosphere during 52 both day and night in both the dry and wet seasons. Periods of high DMS mixing ratios 53 lasting up to 8 hours (up to 160 ppt) often occurred within the canopy and near the 54 surface during many evenings and nights. Daytime gradients showed mixing ratios (up 55 to 80 ppt) peaking near the top of the canopy as well as near the ground following a rain 56 event. The spatial and temporal distribution of DMS suggests that ambient levels and 57 their potential climatic impacts are dominated by local soil and plant emissions. A soil 58 source was confirmed by measurements of DMS emission fluxes from Amazon soils as 59 a function of temperature and soil moisture. Furthermore, light and temperature 60 dependent DMS emissions were measured from seven tropical tree species. Our study 61 has important implications for understanding terrestrial DMS sources and their role in 62 coupled land-atmosphere climate feedbacks. 63« less

  13. Dimethyl sulfide in the Amazon rain forest: DMS in the Amazon

    SciTech Connect

    Jardine, K.; Yañez-Serrano, A. M.; Williams, J.; Kunert, N.; Jardine, A.; Taylor, T.; Abrell, L.; Artaxo, P.; Guenther, A.; Hewitt, C. N.; House, E.; Florentino, A. P.; Manzi, A.; Higuchi, N.; Kesselmeier, J.; Behrendt, T.; Veres, P. R.; Derstroff, B.; Fuentes, J. D.; Martin, S. T.; Andreae, M. O.

    2015-01-08

    Surface-to-atmosphere emissions of dimethyl sulfide (DMS) may impact global climate 44 through the formation of gaseous sulfuric acid, which can yield secondary sulfate 45 aerosols and contribute to new particle formation. While oceans are generally 46 considered the dominant source of DMS, a shortage of ecosystem observations prevents 47 an accurate analysis of terrestrial DMS sources. Using mass spectrometry, we quantified 48 ambient DMS mixing ratios within and above a primary rainforest ecosystem in the 49 central Amazon Basin in real-time (2010-2011) and at high vertical resolution (2013-50 2014). Elevated but highly variable DMS mixing ratios were observed within the 51 canopy, showing clear evidence of a net ecosystem source to the atmosphere during 52 both day and night in both the dry and wet seasons. Periods of high DMS mixing ratios 53 lasting up to 8 hours (up to 160 ppt) often occurred within the canopy and near the 54 surface during many evenings and nights. Daytime gradients showed mixing ratios (up 55 to 80 ppt) peaking near the top of the canopy as well as near the ground following a rain 56 event. The spatial and temporal distribution of DMS suggests that ambient levels and 57 their potential climatic impacts are dominated by local soil and plant emissions. A soil 58 source was confirmed by measurements of DMS emission fluxes from Amazon soils as 59 a function of temperature and soil moisture. Furthermore, light and temperature 60 dependent DMS emissions were measured from seven tropical tree species. Our study 61 has important implications for understanding terrestrial DMS sources and their role in 62 coupled land-atmosphere climate feedbacks. 63

  14. Recent Amazon climate as background for possible ongoing and future changes of Amazon humid forests

    NASA Astrophysics Data System (ADS)

    Gloor, M.; Barichivich, J.; Ziv, G.; Brienen, R.; Schöngart, J.; Peylin, P.; Ladvocat Cintra, B. Barcante; Feldpausch, T.; Phillips, O.; Baker, J.

    2015-09-01

    forests are mainly expected in the southwest and south, which have become slightly drier and hotter, consistent with tree mortality trends observed at the RAINFOR Amazon forest plot network established in the early 1980s consisting of approximately 150 regularly censused 1ha plots in intact forests located across the whole basin.

  15. Could the STARS detect deforestation in the Brazilian Amazon?

    NASA Astrophysics Data System (ADS)

    Mello, M. P.; Trabaquini, K.; Rudorff, B. F.; Oliveira, J. C.

    2013-05-01

    The Brazilian National Institute for Space Research (INPE) has been monitoring the Brazilian Legal Amazon deforestation through the PRODES project since 1988, providing yearly deforestation maps based on about 60 m spatial resolution. Additionally, INPE's Real Time Deforestation Detection System (DETER) has monthly indicating, based on high temporal resolution satellite data, where and when the forest is being felled. However, those monitoring processes are mainly based on visual interpretation, which is accurate but a hard and time consuming task. The Spectral-Temporal Analysis by Response Surface (STARS), which synthesizes the full information content of a multitemporal-multispectral remote sensing image dataset to represent the spectral variation over time of features on the Earth's surface, comes as an alternative for applications in land cover change detection, such as deforestation in the Brazilian Amazon. Thus, since deforestation process presents particular spectral changes over time, spectral-temporal response surfaces could be fitted to describe its change patterns, allowing to detect deforested areas. In this context, this work aims to apply the STARS to detect deforestation in the Brazilian Amazon, using Landsat-5 multitemporal-multispectral images. Four georeferenced images covering about 3.400 square kilometres within the Mato Grosso State, Brazil (13°17'S; 55°50'W to 14°20'S; 55°10'W) were used: one Multispectral Scanner (MSS) image from 1980 (bands 4, 5, 6 and 7 - 60 m spatial resolution); and three Thematic Mapper (TM) images from 1990, 2000 and 2010 (bands 1, 2, 3, 4, 5 and 7 - 30 m spatial resolution). The MSS image was resampled to 30 m to match the TM spatial resolution. All images were then used as input for STARS resulting in a Multi-Coefficient Image (MCI) with 10 synthetic bands formed by the 10 fitted coefficients of a Polynomial Trend Surface (PTS) model with degree equal to three. The MCI was used as input for a decision tree (DT

  16. Extratropical Respones to Amazon Deforestation

    NASA Astrophysics Data System (ADS)

    Badger, A.; Dirmeyer, P.

    2014-12-01

    Land-use change (LUC) is known to impact local climate conditions through modifications of land-atmosphere interactions. Large-scale LUC, such as Amazon deforestation, could have a significant effect on the local and regional climates. The question remains as to what the global impact of large-scale LUC could be, as previous modeling studies have shown non-local responses due to Amazon deforestation. A common shortcoming in many previous modeling studies is the use of prescribed ocean conditions, which can act as a boundary condition to dampen the global response with respect to changes in the mean and variability. Using fully coupled modeling simulations with the Community Earth System Model version 1.2.0, the Amazon rainforest has been replaced with a distribution of representative tropical crops. Through the modifications of local land-atmosphere interactions, a significant change in the region, both at the surface and throughout the atmosphere, can be quantified. Accompanying these local changes are significant changes to the atmospheric circulation across all scales, thus modifying regional climates in other locales. Notable impacts include significant changes in precipitation, surface fluxes, basin-wide sea surface temperatures and ENSO behavior.

  17. Green Leaf Volatile Emissions during High Temperature and Drought Stress in a Central Amazon Rainforest.

    PubMed

    Jardine, Kolby J; Chambers, Jeffrey Q; Holm, Jennifer; Jardine, Angela B; Fontes, Clarissa G; Zorzanelli, Raquel F; Meyers, Kimberly T; de Souza, Vinicius Fernadez; Garcia, Sabrina; Gimenez, Bruno O; Piva, Luani R de O; Higuchi, Niro; Artaxo, Paulo; Martin, Scot; Manzi, Antônio O

    2015-01-01

    Prolonged drought stress combined with high leaf temperatures can induce programmed leaf senescence involving lipid peroxidation, and the loss of net carbon assimilation during early stages of tree mortality. Periodic droughts are known to induce widespread tree mortality in the Amazon rainforest, but little is known about the role of lipid peroxidation during drought-induced leaf senescence. In this study, we present observations of green leaf volatile (GLV) emissions during membrane peroxidation processes associated with the combined effects of high leaf temperatures and drought-induced leaf senescence from individual detached leaves and a rainforest ecosystem in the central Amazon. Temperature-dependent leaf emissions of volatile terpenoids were observed during the morning, and together with transpiration and net photosynthesis, showed a post-midday depression. This post-midday depression was associated with a stimulation of C₅ and C₆ GLV emissions, which continued to increase throughout the late afternoon in a temperature-independent fashion. During the 2010 drought in the Amazon Basin, which resulted in widespread tree mortality, green leaf volatile emissions (C₆ GLVs) were observed to build up within the forest canopy atmosphere, likely associated with high leaf temperatures and enhanced drought-induced leaf senescence processes. The results suggest that observations of GLVs in the tropical boundary layer could be used as a chemical sensor of reduced ecosystem productivity associated with drought stress. PMID:27135346

  18. Green Leaf Volatile Emissions during High Temperature and Drought Stress in a Central Amazon Rainforest

    PubMed Central

    Jardine, Kolby J.; Chambers, Jeffrey Q.; Holm, Jennifer; Jardine, Angela B.; Fontes, Clarissa G.; Zorzanelli, Raquel F.; Meyers, Kimberly T.; de Souza, Vinicius Fernadez; Garcia, Sabrina; Gimenez, Bruno O.; de O. Piva, Luani R.; Higuchi, Niro; Artaxo, Paulo; Martin, Scot; Manzi, Antônio O.

    2015-01-01

    Prolonged drought stress combined with high leaf temperatures can induce programmed leaf senescence involving lipid peroxidation, and the loss of net carbon assimilation during early stages of tree mortality. Periodic droughts are known to induce widespread tree mortality in the Amazon rainforest, but little is known about the role of lipid peroxidation during drought-induced leaf senescence. In this study, we present observations of green leaf volatile (GLV) emissions during membrane peroxidation processes associated with the combined effects of high leaf temperatures and drought-induced leaf senescence from individual detached leaves and a rainforest ecosystem in the central Amazon. Temperature-dependent leaf emissions of volatile terpenoids were observed during the morning, and together with transpiration and net photosynthesis, showed a post-midday depression. This post-midday depression was associated with a stimulation of C5 and C6 GLV emissions, which continued to increase throughout the late afternoon in a temperature-independent fashion. During the 2010 drought in the Amazon Basin, which resulted in widespread tree mortality, green leaf volatile emissions (C6 GLVs) were observed to build up within the forest canopy atmosphere, likely associated with high leaf temperatures and enhanced drought-induced leaf senescence processes. The results suggest that observations of GLVs in the tropical boundary layer could be used as a chemical sensor of reduced ecosystem productivity associated with drought stress. PMID:27135346

  19. Wet- and dry-season steroid hormone profiles and stress reactivity of an insular dwarf snake, the Hog Island boa (Boa constrictor imperator).

    PubMed

    Holding, Matthew L; Frazier, Julius A; Dorr, Scott W; Pollock, Nicholas B; Muelleman, P J; Branske, Amber; Henningsen, Sloane N; Eikenaar, Cas; Escallón, Camilo; Montgomery, Chad E; Moore, Ignacio T; Taylor, Emily N

    2014-01-01

    Field endocrine studies providing new comparisons for inference into the evolutionary and ecological factors shaping organismal physiology are important, often yielding novel physiological insights. Here, we explored factors associated with the sex steroid hormone concentrations and adrenocortical response to capture stress in Hog Island boas (Boa constrictor imperator) in the Cayos Cochinos archipelago of Honduras to generate comparative field hormone data from a tropical reptile and test the island tameness hypothesis. Baseline concentrations of testosterone, corticosterone, estradiol, and progesterone were measured during the wet and dry seasons, and an acute stressor of 1 h in a cloth bag was used to assess the stress response. Plasma steroid concentrations in these snakes were generally low in comparison to other taxa. Higher testosterone concentrations in males and higher estradiol and corticosterone concentrations in females were observed during the wet season compared to the dry season, which may be indicative of mating activities and vitellogenesis during this period. Snakes displayed a 15-fold increase in corticosterone concentrations in response to capture stress, a rise that was not impacted by whether a snake had been captured during previous years. The adrenocortical stress response was greater in males and positively related to body temperature. We suggest that this system merits future inquiries into the physiology and behavior of B. c. imperator, particularly as a model for studying insular impacts on diverse life history characters. PMID:24769701

  20. Slow growth rates of Amazonian trees: Consequences for carbon cycling

    PubMed Central

    Vieira, Simone; Trumbore, Susan; Camargo, Plinio B.; Selhorst, Diogo; Chambers, Jeffrey Q.; Higuchi, Niro; Martinelli, Luiz Antonio

    2005-01-01

    Quantifying age structure and tree growth rate of Amazonian forests is essential for understanding their role in the carbon cycle. Here, we use radiocarbon dating and direct measurement of diameter increment to document unexpectedly slow growth rates for trees from three locations spanning the Brazilian Amazon basin. Central Amazon trees, averaging only ≈1mm/year diameter increment, grow half as fast as those from areas with more seasonal rainfall to the east and west. Slow growth rates mean that trees can attain great ages; across our sites we estimate 17-50% of trees with diameter >10 cm have ages exceeding 300 years. Whereas a few emergent trees that make up a large portion of the biomass grow faster, small trees that are more abundant grow slowly and attain ages of hundreds of years. The mean age of carbon in living trees (60-110 years) is within the range of or slightly longer than the mean residence time calculated from C inventory divided by annual C allocation to wood growth (40-100 years). Faster C turnover is observed in stands with overall higher rates of diameter increment and a larger fraction of the biomass in large, fast-growing trees. As a consequence, forests can recover biomass relatively quickly after disturbance, whereas recovering species composition may take many centuries. Carbon cycle models that apply a single turnover time for carbon in forest biomass do not account for variations in life strategy and therefore may overestimate the carbon sequestration potential of Amazon forests. PMID:16339903

  1. Franz Boas and his plans for an International School of American Archaeology and Ethnology in Mexico.

    PubMed

    Godoy, R

    1977-07-01

    The expansionist policy of the United States at the turn of the century widened the horizons of American anthropology. The International School of American Archaeology and Ethnology was one of the first attempts by American anthropologists to carry out systematic research in foreign lands. Motivated partly by a wish to strengthen the quality of American anthropology, Franz Boas succeeded in gaining the cooperation of several European and American institutions. The purpose of the school was to conduct rigorous anthropological investigations in Mexico. Obsessed with professionalizing the discipline, Boas failed to take into account the turbulent political climate of Mexico when planning the school. Although it did good work for a number of years (1910-1914), the school was broken up forever in 1914 because of the Mexican revolution. Attempts at resurrection failed for numerous reasons. PMID:332760

  2. Habitat association, size, stomach contents, and reproductive condition of Puerto Rican boas (Epicrates inornatus)

    USGS Publications Warehouse

    Wiley, J.W.

    2003-01-01

    The Puerto Rican boa occurs in a variety of habitats, including wet montane forest, lowland wet forest, mangrove forest, wet limestone karst, and offshore cays, and from sea level to 480 m. Mean SVL of 49 encountered boas (live and road-killed) was 136.9 ?? 35.1 (range = 38.8-205 cm), with a mean mass of 952.1 ?? 349.0 g (n = 47; range = 140-1662 g). Prey in digestive tracts (n = 29) included remains of black rats, house mice, three species of anoles, bats, common ground-doves, domestic fowl chicks, and invertebrates. Females were in reproductive condition in late April through mid-August and had an average brood size of 21.8 ?? 6.0 (n = 9, range = 13-30 ).

  3. BOA II: Asbestos Pipe-Insulation Removal Robot System. Innovative Technology Summary Report.

    SciTech Connect

    2001-09-01

    The objective of this task is to develop and demonstrate a mechanical, asbestos-removal system that can be remotely operated without a containment area. The technology, known as BOA, consists of a pipe-crawler removal head and a boom vehicle system with dual robots. BOA's removal head can be remotely placed on the outside of the pipe and can crawl along the pipe, removing lagging and insulation. The lagging and insulation is cut using a hybrid endmill water-jet cutter and then diced into 2-inch cube sections of ACM. These ACM sections are then removed from the pipe using a set of blasting fan- spray nozzles, vacuumed off through a vacuum hose, and bagged. Careful attention to vacuum and entrapment air flow ensures that the system can operate without a containment area while meeting local and federal standards for fiber count.

  4. Neutron imaging options at the BOA beamline at Paul Scherrer Institut

    NASA Astrophysics Data System (ADS)

    Morgano, M.; Peetermans, S.; Lehmann, E. H.; Panzner, T.; Filges, U.

    2014-08-01

    The BOA beamline at the Swiss spallation neutron source SINQ at Paul Scherrer Institut is a flexible instrument used mainly for testing novel techniques and devices for neutron scattering and optics, but, due to the large and relatively homogeneous field of view, it can be successfully used for experiments in the field of neutron imaging. The beamline allows also for the exploitation of advanced imaging concepts such as polarized neutron imaging and diffractive neutron imaging. In this paper we present the characterization of the BOA beamline in the light of its neutron imaging capabilities. We show also the different techniques that can be employed there as user-friendly plugins for non-standard neutron imaging experiments.

  5. Experimental infection of Boa constrictor with an orthoreovirus isolated from a snake with inclusion body disease.

    PubMed

    Darke, Sabina; Marschang, Rachel E; Hetzel, Udo; Reinacher, Manfred

    2014-06-01

    Orthoreoviruses have been associated with disease in reptiles, but have not previously been isolated from snakes with inclusion body disease (IBD). An orthoreovirus was isolated from a Boa constrictor diagnosed with IBD and then used to conduct a transmission study to determine the clinical importance of this virus. For the transmission study, 10 juvenile boas were experimentally infected with the isolated orthoreovirus and compared to 5 sham-infected control animals. Orthoreovirus was reisolated for a period of 18 wk after infection and weight gain was reduced in infected snakes. Histological examination showed a mild hepatitis in three of four virologically positive snakes up to 12 wk after infection. Results indicated that the orthoreovirus was moderately pathogenic, but, no evidence was found to indicate that it was the causal agent of IBD. In the light of the discovery of Arenaviruses in some snakes with IBD, it was proposed that orthoreoviruses may play a role in synergistic infection. PMID:25000715

  6. Sperm motility parameters to evaluate the seminal quality of Boa constrictor occidentalis, a threatened snake species.

    PubMed

    Tourmente, M; Cardozo, G A; Guidobaldi, H A; Giojalas, L C; Bertona, M; Chiaraviglio, M

    2007-02-01

    Semen quality analysis constitutes a powerful tool to evaluate the fertility potential of males in threatened species. The Argentine boa constrictor or lampalagua (Boa constrictor occidentalis) is a threatened snake species and has been included in Appendix I of CITES. The objective of this work is to characterize the sperm of B. c. occidentalis on the bases of dynamic parameters to improve this species conservation. Dynamic parameters were measured in sperm samples using videomicroscopy and image analysis software. The sperm population showed a high degree of heterogeneity in velocity parameter values and 95% of the cells showed a linear pattern of movement. Studies in other species indicate that the number of motile spermatozoa and their movement speed is directly correlated with fertilization success. This work will help to establish basic parameter values for the evaluation of the reproductive potential of populations of B. c. occidentalis and to resolve questions referred to its reproductive strategies. PMID:16857223

  7. Confluence of the Amazon and Topajos Rivers, Brazil, South America

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This view shows the confluence of the Amazon and the Topajos Rivers at Santarem, Brazil (2.0S, 55.0W). The Am,azon flows from lower left to upper right of the photo. Below the river juncture of the Amazon and Tapajos, there is considerable deforestation activity along the Trans-Amazon Highway.

  8. BOA: Asbestos pipe-insulation removal robot system. Phase I. Topical report, November 1993--December 1994

    SciTech Connect

    Schempf, H.; Bares, J.E.

    1995-01-01

    Based on several key design criteria and site visits, we developed a Robot design and built a system which automatically strips the lagging and insulation from the pipes, and encapsulates them under complete vacuum operation. The system can operate on straight runs of piping in horizontal or vertical orientations. Currently we are limited to four-inch diameter piping without obstacles as well as a somewhat laborious emplacement and removal procedure. Experimental results indicated that the current robotic abatement process is sound yet needs to be further expanded and modified. One of the main discoveries was that a longitudinal cut to fully allow the paddles to dig in and compress the insulation off the pipe is essential. Furthermore, a different cutting method might be explored to alleviate the need for a deeper cut and to enable a combination of certain functions such as compression and cutting. Unfortunately due to a damaged mechanism caused by extensive testing, we were unable to perform vertical piping abatement experiments, but foresee no trouble in implementing them in the next proposed Phase. Other encouraging results have BOA removing asbestos at a rate of 4-5 ft./h compared to 3 ft./h for manual removal of asbestos with a 3-person crew. However, we feel confident that we can double the asbestos removal rate by improving cutting speed, and increasing the length of the BOA robot. The containment and vacuum system on BOA is able to achieve the regulatory requirement for airborne fiber emissions of 0.01 fibers/ccm/8-hr. shift. Currently, BOA weighs about 117 pounds which is more than a human is permitted to lift overhead under OSHA requirements (i.e., 25 pounds). We are considering designing the robot into two components (i.e., locomotor section and cutter/removal section) to aid human installation as well as incorporating composite materials. A more detailed list of all the technical modifications is given in this topical report.

  9. AMS Observations over Coastal California from the Biological and Oceanic Atmospheric Study (BOAS)

    NASA Astrophysics Data System (ADS)

    Bates, K. H.; Coggon, M. M.; Hodas, N.; Negron, A.; Ortega, A. M.; Crosbie, E.; Sorooshian, A.; Nenes, A.; Flagan, R. C.; Seinfeld, J.

    2015-12-01

    In July 2015, fifteen research flights were conducted on a US Navy Twin Otter aircraft as part of the Biological and Oceanic Atmospheric Study (BOAS) campaign. The flights took place near the California coast at Monterey, to investigate the effects of sea surface temperature and algal blooms on oceanic particulate emissions, the diurnal mixing of urban pollution with other airmasses, and the impacts of biological aerosols on the California atmosphere. The aircraft's payload included an aerosol mass spectrometer (AMS), a differential mobility analyzer, a cloud condensation nuclei counter, a counterflow virtual impactor, a cloudwater collector, and two instruments designed to detect biological aerosols - a wideband integrated biological spectrometer and a SpinCon II - as well as a number of meteorology and aerosol probes, two condensation particle counters, and instruments to measure gas-phase CO, CO2, O3, and NOx. Here, we describe in depth the objectives and outcomes of BOAS and report preliminary results, primarily from the AMS. We detail the spatial characteristics and meteorological variability of speciated aerosol components over a strong and persistent bloom of Pseudo-Nitzschia, the harmful algae that cause 'red tide', and report newly identified AMS markers for biological particles. Finally, we compare these results with data collected during BOAS over urban, forested, and agricultural environments, and describe the mixing observed between oceanic and terrestrial airmasses.

  10. Distribution of Aboveground Live Biomass in the Amazon Basin

    NASA Technical Reports Server (NTRS)

    Saatchi, S. S.; Houghton, R. A.; DosSantos Alvala, R. C.; Soares, J. V.; Yu, Y.

    2007-01-01

    The amount and spatial distribution of forest biomass in the Amazon basin is a major source of uncertainty in estimating the flux of carbon released from land-cover and land-use change. Direct measurements of aboveground live biomass (AGLB) are limited to small areas of forest inventory plots and site-specific allometric equations that cannot be readily generalized for the entire basin. Furthermore, there is no spaceborne remote sensing instrument that can measure tropical forest biomass directly. To determine the spatial distribution of forest biomass of the Amazon basin, we report a method based on remote sensing metrics representing various forest structural parameters and environmental variables, and more than 500 plot measurements of forest biomass distributed over the basin. A decision tree approach was used to develop the spatial distribution of AGLB for seven distinct biomass classes of lowland old-growth forests with more than 80% accuracy. AGLB for other vegetation types, such as the woody and herbaceous savanna and secondary forests, was directly estimated with a regression based on satellite data. Results show that AGLB is highest in Central Amazonia and in regions to the east and north, including the Guyanas. Biomass is generally above 300Mgha(sup 1) here except in areas of intense logging or open floodplains. In Western Amazonia, from the lowlands of Peru, Ecuador, and Colombia to the Andean mountains, biomass ranges from 150 to 300Mgha(sup 1). Most transitional and seasonal forests at the southern and northwestern edges of the basin have biomass ranging from 100 to 200Mgha(sup 1). The AGLB distribution has a significant correlation with the length of the dry season. We estimate that the total carbon in forest biomass of the Amazon basin, including the dead and below ground biomass, is 86 PgC with +/- 20% uncertainty.

  11. Talking Trees

    ERIC Educational Resources Information Center

    Tolman, Marvin

    2005-01-01

    Students love outdoor activities and will love them even more when they build confidence in their tree identification and measurement skills. Through these activities, students will learn to identify the major characteristics of trees and discover how the pace--a nonstandard measuring unit--can be used to estimate not only distances but also the…

  12. Tree Amigos.

    ERIC Educational Resources Information Center

    Center for Environmental Study, Grand Rapids, MI.

    Tree Amigos is a special cross-cultural program that uses trees as a common bond to bring the people of the Americas together in unique partnerships to preserve and protect the shared global environment. It is a tangible program that embodies the philosophy that individuals, acting together, can make a difference. This resource book contains…

  13. Amazon deforestation and climate change

    SciTech Connect

    Shukla, J.; Nobre, C.; Sellers, P. )

    1990-03-16

    A coupled numerical model of the global atmosphere and biosphere has been used to assess the effects of Amazon deforestation on the regional and global climate. When the tropical forests in the model were replaced by degraded grass (pasture), there was a significant increase in surface temperature and a decrease in evapotranspiration and precipitation over Amazonia. In the simulation, the length of the dry season also increased; such an increase could make reestablishment of the tropical forests after massive deforestation particularly difficult. 31 refs., 3 figs., 2 tabs.

  14. Up-regulation of Amazon forest photosynthesis precedes elevated mortality under drought

    NASA Astrophysics Data System (ADS)

    Saleska, S. R.; Christoffersen, B. O.; Longo, M.; Restrepo-Coupe, N.; Alves, L. F.; Wiedemann, K. T.; Stark, S. C.; Hayek, M.; Wu, J.; Munger, J. W.; Meir, P.; Oliveira Junior, R. C.; da Silva, R.; Camargo, P. B. D.

    2015-12-01

    Coupled climate-carbon cycle models indicate that Amazon forests may be vulnerable to drought, with some predicting drought-induced collapse of the Amazon forest and conversion to savanna, under future climate change. While much progress has been made in understanding tropical forest drought response, a holistic picture encompassing both short-term physiological (e.g., photosynthesis) and longer term demographic responses (e.g., mortality) remains elusive, mainly due to the rarity of coinciding relevant measurements and drought events. Here we address this knowledge gap by analyzing the response of an eastern Amazonian forest at both timescales to the El Nino-induced drought of late 2009 / early 2010 (distinct from the Atlantic SST-induced drought to hit Western Amazonia in mid/late 2010) using eddy flux measurements of carbon exchange and periodic tree demographic surveys. We partitioned the drought response of GPP into environmental (light, vapor pressure deficit (VPD), diffuse light) and biological responses. Based on environmental conditions alone (high VPD), we expected GPP to be 1-2 umol CO2 m-2 s-1 less than average during drought. In contrast, GPP was elevated by 2-4 umol CO2 m-2 s-1 above this expected negative response over a period of ~45 days, consistent with previously observed green-up from satelliltes during the 2005 Amazon drought. At the same time, drought significantly elevated 2009-2011 tree mortality, by ~50% above that during non-drought periods, consistent with a quantitative drought-mortality relationship reported for other Amazon forests. This work suggests that observations of "green-up" of forest canopies during drought may be consistent with subsequent drought-induced tree mortality, in contrast to expectation. More importantly, it highlights endogenous biological regulation of photosynthesis as an important mechanism, neglected by models, in mediating drought responses in tropical forests.

  15. Preliminary Genetic Analysis Supports Cave Populations as Targets for Conservation in the Endemic Endangered Puerto Rican Boa (Boidae: Epicrates inornatus)

    PubMed Central

    Revell, Liam J.

    2013-01-01

    The endemic Puerto Rican boa (Epicrates inornatus) has spent 42 years on the Endangered Species List with little evidence for recovery. One significant impediment to effective conservation planning has been a lack of knowledge of the distribution of genetic variability in the species. It has previously been suggested that boas might best be protected around caves that harbor large populations of bats. Prior study has found Puerto Rican boas at relatively high densities in and around bat caves, which they use both to feed and seek shelter. However, it is unknown whether these behaviorally distinctive populations represent a distinct evolutionary lineage, or (conversely) whether caves harbor representative genetic diversity for the species across the island. We provide the first genetic study of the Puerto Rican boa, and we examine and compare genetic diversity and divergence among two cave populations and two surface populations of boas. We find three haplogroups and an apparent lack of phylogeographic structure across the island. In addition, we find that the two cave populations appear no less diverse than the two surface populations, and harbor multiple mtDNA lineages. We discuss the conservation implications of these findings, including a call for the immediate protection of the remaining cave-associated populations of boas. PMID:23691110

  16. Modelling basin-wide variations in Amazon forest photosynthesis

    NASA Astrophysics Data System (ADS)

    Mercado, Lina; Lloyd, Jon; Domingues, Tomas; Fyllas, Nikolaos; Patino, Sandra; Dolman, Han; Sitch, Stephen

    2010-05-01

    Given the importance of Amazon rainforest in the global carbon and hydrological cycles, there is a need to use parameterized and validated ecosystem gas exchange and vegetation models for this region in order to adequately simulate present and future carbon and water balances. Recent research has found major differences in above-ground net primary productivity (ANPP), above ground biomass and tree dynamics across Amazonia. West Amazonia is more dynamic, with younger trees, higher stem growth rates and lower biomass than central and eastern Amazon (Baker et al. 2004; Malhi et al. 2004; Phillips et al. 2004). A factor of three variation in above-ground net primary productivity has been estimated across Amazonia by Malhi et al. (2004). Different hypotheses have been proposed to explain the observed spatial variability in ANPP (Malhi et al. 2004). First, due to the proximity to the Andes, sites from western Amazonia tend to have richer soils than central and eastern Amazon and therefore soil fertility could possibly be highly related to the high wood productivity found in western sites. Second, if GPP does not vary across the Amazon basin then different patterns of carbon allocation to respiration could also explain the observed ANPP gradient. However since plant growth depends on the interaction between photosynthesis, transport of assimilates, plant respiration, water relations and mineral nutrition, variations in plant gross photosynthesis (GPP) could also explain the observed variations in ANPP. In this study we investigate whether Amazon GPP can explain variations of observed ANPP. We use a sun and shade canopy gas exchange model that has been calibrated and evaluated at five rainforest sites (Mercado et al. 2009) to simulate gross primary productivity of 50 sites across the Amazon basin during the period 1980-2001. Such simulation differs from the ones performed with global vegetation models (Cox et al. 1998; Sitch et al. 2003) where i) single plant functional

  17. The complete mitochondrial genome of the Poecilia formosa (Amazon molly).

    PubMed

    Dang, Xiao; Xia, Yan; Xu, Qiwu; Zhang, Jianguo

    2016-09-01

    The Amazon molly, Poecilia formosa, a member of the Poeciliidae family, is a freshwater fish reproducing through gynogenesis. The complete mitochondrial genome of the P. formosa is determined for the first time in this study. It is a circular molecule of 16 542 bp in length, including 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 1 putative control region. The overall base composition of the genome is A (29.59%), T (27.57%), C (28.27%), and G (14.57%) with 42.84% GC content, which is lower than the content of AT. Most protein-coding genes started with a traditional ATG codon except for COX2, ND5 and ND6, which initiated with ATA, GTG and TTA, respectively. The stop codon was a single T- - base in most of the protein-coding genes, but COX2 and ATP8 both employed TAA and ND2 terminated with AGG codon. Phylogenetic tree was constructed based on the complete mitogenome of P. formosa and closely related 11 chondrichthian species to assess their phylogenic relationship and evolution. The complete mitochondrial genome of the amazon molly would help to study the evolution of Poeciliidae family. PMID:26260185

  18. Highly reactive light-dependent monoterpenes in the Amazon

    DOE PAGESBeta

    Jardine, A. B.; Jardine, K. J.; Fuentes, J. D.; Martin, S. T.; Martins, G.; Durgante, F.; Carneiro, V.; Higuchi, N.; Manzi, A. O.; Chambers, J. Q.

    2015-03-06

    Despite orders of magnitude difference in atmospheric reactivity and great diversity in biological functioning, little is known about monoterpene speciation in tropical forests. Here we report vertically resolved ambient air mixing ratios for 12 monoterpenes in a central Amazon rainforest including observations of the highly reactive cis-β-ocimene (160 ppt), trans-β-ocimene (79 ppt), and terpinolene (32 ppt) which accounted for an estimated 21% of total monoterpene composition yet 55% of the upper canopy monoterpene ozonolysis rate. All 12 monoterpenes showed a mixing ratio peak in the upper canopy, with three demonstrating subcanopy peaks in 7 of 11 profiles. Leaf level emissionsmore » of highly reactive monoterpenes accounted for up to 1.9% of photosynthesis confirming light-dependent emissions across several Amazon tree genera. These results suggest that highly reactive monoterpenes play important antioxidant roles during photosynthesis in plants and serve as near-canopy sources of secondary organic aerosol precursors through atmospheric photooxidation via ozonolysis.« less

  19. Logging Concessions Enable Illegal Logging Crisis in the Peruvian Amazon

    NASA Astrophysics Data System (ADS)

    Finer, Matt; Jenkins, Clinton N.; Sky, Melissa A. Blue; Pine, Justin

    2014-04-01

    The Peruvian Amazon is an important arena in global efforts to promote sustainable logging in the tropics. Despite recent efforts to achieve sustainability, such as provisions in the US-Peru Trade Promotion Agreement, illegal logging continues to plague the region. We present evidence that Peru's legal logging concession system is enabling the widespread illegal logging via the regulatory documents designed to ensure sustainable logging. Analyzing official government data, we found that 68.3% of all concessions supervised by authorities were suspected of major violations. Of the 609 total concessions, nearly 30% have been cancelled for violations and we expect this percentage to increase as investigations continue. Moreover, the nature of the violations indicate that the permits associated with legal concessions are used to harvest trees in unauthorized areas, thus threatening all forested areas. Many of the violations pertain to the illegal extraction of CITES-listed timber species outside authorized areas. These findings highlight the need for additional reforms.

  20. Logging concessions enable illegal logging crisis in the Peruvian Amazon.

    PubMed

    Finer, Matt; Jenkins, Clinton N; Sky, Melissa A Blue; Pine, Justin

    2014-01-01

    The Peruvian Amazon is an important arena in global efforts to promote sustainable logging in the tropics. Despite recent efforts to achieve sustainability, such as provisions in the US-Peru Trade Promotion Agreement, illegal logging continues to plague the region. We present evidence that Peru's legal logging concession system is enabling the widespread illegal logging via the regulatory documents designed to ensure sustainable logging. Analyzing official government data, we found that 68.3% of all concessions supervised by authorities were suspected of major violations. Of the 609 total concessions, nearly 30% have been cancelled for violations and we expect this percentage to increase as investigations continue. Moreover, the nature of the violations indicate that the permits associated with legal concessions are used to harvest trees in unauthorized areas, thus threatening all forested areas. Many of the violations pertain to the illegal extraction of CITES-listed timber species outside authorized areas. These findings highlight the need for additional reforms. PMID:24743552

  1. COS Imaging TA and Spectroscopic WCA-PSA/BOA offset verifications

    NASA Astrophysics Data System (ADS)

    Penton, Steven

    2012-10-01

    This program builds upon the monitoring and calibration of the FGSs. The list of proposals, cycles, and the order in which the alignment is checked is given below.11878->12399->12781->13171C17->C18->C19->C20STIS->WFC3->ACS->COSVisit 01 of the C20 SIAF verification program, 13171, executed on Mar 2, 2012, and Visit 02 is scheduled for Sep 1, 2103. This program performs a PSA/MIRRORA ACQ/IMAGE on a target that should already be centered in the aperture. This verifies the COS NUV PSA aperture position in the SIAF. After this PSA+MIRRORA ACQ/IMAGE, a PSA+MIRRORB ACQ/IMAGE is then performed. This exposure bootstraps the PSA+MIRRORB centering to the PSA+MIRROR SIAF verification. This allows us to monitor the properties of the PSA+MIRRORB image in a controlled way on a centered target. No spectra are taken in 13171 due to time constrains.This program extends the SIAF verification of 13171 to the other two ACQ/IMAGE combinations {BOA+MIRRORA & BOA+MIRRORB} by bootstraping from the PSA+MIRRORB verification of 13171.Visit 1 of this program begins with a PSA+MIRRORB NUV ACQ/IMAGE followed by a BOA+MIRRORA ACQ/IMAGE. Both observations are high S/N to get the most accurate centering information possible. The program then takes a PSA+MIRRORB IMAGE to ensure that we are still properly centered. We prefer that Visit 01 of this program executes after Visit 02 of 13171, but more than 17, but less than 45 days after to ensure that no long term instrument or telescope focus changes impart our results.After the Imaging verification Visit 1 of this program will obtain a S/N > 60 NUV spectrum using the most popular NUV grating {G230L, G185M, & G285M}, and FUV Spectra using G130M/1309 and G140L/1280. This allows the direct verification of the NUV and FUV WCA-to-PSA cross-dispersion offsets used by ACQ/PEAKXD.Visit 02 of this program follows the style of Visit 01, but the initial ACQ/IMAGE is a BOA+MIRRORA and the second ACQ/IMAGE is BOA/MIRRORB. Visit 02 should occur after Visit 01 by

  2. COS Imaging TA and Spectroscopic WCA-PSA/BOA offset verifications

    NASA Astrophysics Data System (ADS)

    Penton, Steven

    2013-10-01

    This program builds upon the monitoring and calibration of the FGSs (13616 - HST Cycle 21 Focal Plane Calibration (SI-FGS Alignment)). HST 13616 performs back-to-back PSA/MIRRORA & PSA/MIRRORB ACQ/IMAGES, from which all the results herein are bootstrapped.The list of proposals, cycles, and the order in which the alignment is checked is given below. 11878->12399->12781->13171->13616 C17->C18 ->C19->C20->C21 STIS->WFC3->ACS->COSThis program will be repeated every cycle and we will once again use it's COS exposures as the baseline for this program.This program performs a PSA/MIRRORA ACQ/IMAGE on a target that should already be centered in the aperture. This verifies the COS NUV PSA aperture position in the SIAF. After this PSA+MIRRORA ACQ/IMAGE, a PSA+MIRRORB ACQ/IMAGE is then performed. This exposure bootstraps the PSA+MIRRORB centering to the PSA+MIRROR SIAF verification. This allows us to monitor the properties of the PSA+MIRRORB image in a controlled way on a centered target. No spectra are taken in 13616 due to time constraints.This program extends the SIAF verification of 13616 to the other two ACQ/IMAGE combinations (BOA+MIRRORA & BOA+MIRRORB) by bootstraping from the PSA+MIRRORB verification of 13616.Visit 1 of this program begins with a PSA+MIRRORB NUV ACQ/IMAGE followed by a BOA+MIRRORA ACQ/IMAGE. Both observations are high S/N to get the most accurate centering information possible. The program then takes a PSA+MIRRORB IMAGE to ensure that we are still properly centered. We prefer that Visit 01 of this program executes within 45 days of Visit 02 of 13616, to ensure that no long term instrument or telescope focus changes impart our results.After the Imaging verification , Visit 1 of this program will obtain a S/N > 60 NUV spectrum using the most popular NUV grating (G230L, G185M, & G285M), and FUV Spectra using G130M/1309 and G140L/1280. This allows the direct verification of the NUV and FUV WCA-to-PSA cross-dispersion offsets used by ACQ/PEAKXD.Visit 02 of

  3. Fast demographic traits promote high diversification rates of Amazonian trees

    PubMed Central

    Baker, Timothy R; Pennington, R Toby; Magallon, Susana; Gloor, Emanuel; Laurance, William F; Alexiades, Miguel; Alvarez, Esteban; Araujo, Alejandro; Arets, Eric J M M; Aymard, Gerardo; de Oliveira, Atila Alves; Amaral, Iêda; Arroyo, Luzmila; Bonal, Damien; Brienen, Roel J W; Chave, Jerome; Dexter, Kyle G; Di Fiore, Anthony; Eler, Eduardo; Feldpausch, Ted R; Ferreira, Leandro; Lopez-Gonzalez, Gabriela; van der Heijden, Geertje; Higuchi, Niro; Honorio, Eurídice; Huamantupa, Isau; Killeen, Tim J; Laurance, Susan; Leaño, Claudio; Lewis, Simon L; Malhi, Yadvinder; Marimon, Beatriz Schwantes; Marimon Junior, Ben Hur; Monteagudo Mendoza, Abel; Neill, David; Peñuela-Mora, Maria Cristina; Pitman, Nigel; Prieto, Adriana; Quesada, Carlos A; Ramírez, Fredy; Ramírez Angulo, Hirma; Rudas, Agustin; Ruschel, Ademir R; Salomão, Rafael P; de Andrade, Ana Segalin; Silva, J Natalino M; Silveira, Marcos; Simon, Marcelo F; Spironello, Wilson; ter Steege, Hans; Terborgh, John; Toledo, Marisol; Torres-Lezama, Armando; Vasquez, Rodolfo; Vieira, Ima Célia Guimarães; Vilanova, Emilio; Vos, Vincent A; Phillips, Oliver L; Wiens, John

    2014-01-01

    The Amazon rain forest sustains the world's highest tree diversity, but it remains unclear why some clades of trees are hyperdiverse, whereas others are not. Using dated phylogenies, estimates of current species richness and trait and demographic data from a large network of forest plots, we show that fast demographic traits – short turnover times – are associated with high diversification rates across 51 clades of canopy trees. This relationship is robust to assuming that diversification rates are either constant or decline over time, and occurs in a wide range of Neotropical tree lineages. This finding reveals the crucial role of intrinsic, ecological variation among clades for understanding the origin of the remarkable diversity of Amazonian trees and forests. PMID:24589190

  4. The dispersal of the Amazon's water

    NASA Technical Reports Server (NTRS)

    Muller-Karger, Frank E.; Mcclain, Charles R.; Richardson, Philip L.

    1988-01-01

    New information obtained with NASA's Coastal Zone Color Scanner and with drifting buoys reveals that the discharge of the Amazon is carried offshore around a retroflection of the North Brazil Current and into the North Equatorial Countercurrent towards Africa between June and January each year. From about February to May, the countercurrent and the retroflection weaken or vanish, and Amazon water flows northwestward toward the Caribbean Sea.

  5. Amazon Forest Responses to Drought and Fire

    NASA Astrophysics Data System (ADS)

    Morton, D. C.

    2015-12-01

    Deforestation and agricultural land uses provide a consistent source of ignitions along the Amazon frontier during the dry season. The risk of understory fires in Amazon forests is amplified by drought conditions, when fires at the forest edge may spread for weeks before rains begin. Fire activity also impacts the regional response of intact forests to drought through diffuse light effects and nutrient redistribution, highlighting the complexity of feedbacks in this coupled human and natural system. This talk will focus on recent advances in our understanding of fire-climate feedbacks in the Amazon, building on research themes initiated under NASA's Large-scale Biosphere-Atmosphere Experiment in Amazonia (LBA). NASA's LBA program began in the wake of the 1997-1998 El Niño, a strong event that exposed the vulnerability of Amazon forests to drought and fire under current climate and projections of climate change. With forecasts of another strong El Niño event in 2015-2016, this talk will provide a multi-scale synthesis of Amazon forest responses to drought and fire based on field measurements, airborne lidar data, and satellite observations of fires, rainfall, and terrestrial water storage. These studies offer new insights into the mechanisms governing fire season severity in the southern Amazon and regional variability in carbon losses from understory fires. The contributions from remote sensing to our understanding of drought and fire in Amazon forests reflect the legacy of NASA's LBA program and the sustained commitment to interdisciplinary research across the Amazon region.

  6. Greenhouse trees

    SciTech Connect

    Hanover, J.W.; Hart, J.W.

    1980-05-09

    Michigan State University has been conducting research on growth control of woody plants with emphasis on commercial plantations. The objective was to develop the optimum levels for the major factors that affect tree seedling growth and development so that high quality plants can be produced for a specific use. This article describes the accelerated-optimal-growth (AOG) concept, describes precautions to take in its application, and shows ways to maximize the potential of AOG for producing ornamental trees. Factors considered were container growing system; protective culture including light, temperature, mineral nutrients, water, carbon dioxide, growth regulators, mycorrhizae, growing media, competition, and pests; size of seedlings; and acclamation. 1 table. (DP)

  7. The thermal biology of digestion in rubber boas (Charina bottae): physiology, behavior, and environmental constraints.

    PubMed

    Dorcas, M E; Peterson, C R; Flint, M E

    1997-01-01

    Coadaptation predicts a match between the thermal physiology and thermoregulatory behavior of reptiles. We tested this prediction by studying the digestive biology of rubber boas (Charina bottae). We measured the thermal dependence of gastric digestive rate and passage rate in rubber boas from 10 degrees C to 35 degrees C. We examined the effect of digestion on their thermal preference by measuring the temperatures of C. bottae in a thermal gradient before and after feeding. While the passage rates calculated from the body temperatures of digesting snakes were higher than the passage rates calculated from the body temperatures of nondigesting snakes, there was no difference in calculated digestive rates. These results indicate that the thermoregulatory behavior of C. bottae may be more tightly correlated with factors affecting passage rate than with digestive rate alone. Results of simulating the constraints of the thermal environment on the digestive biology of C. bottae showed that digestion would take more than twice as long in the spring as in the summer. In addition, during the summer, snakes thermoregulating as digesting snakes would pass food 12% faster than those thermoregulating as nondigesting snakes. These results demonstrate how interpretation of laboratory studies can be improved when combined with measurements of appropriate environmental conditions. PMID:9231403

  8. Substrate diameter and compliance affect the gripping strategies and locomotor mode of climbing boa constrictors.

    PubMed

    Byrnes, Greg; Jayne, Bruce C

    2010-12-15

    Arboreal habitats pose unique challenges for locomotion as a result of their narrow cylindrical surfaces and discontinuities between branches. Decreased diameter of branches increases compliance, which can pose additional challenges, including effects on stability and energy damping. However, the combined effects of substrate diameter and compliance are poorly understood for any animal. We quantified performance, kinematics and substrate deformation while boa constrictors (Boa constrictor) climbed vertical ropes with three diameters (3, 6 and 9 mm) and four tensions (0.5, 1.0, 1.5 and 2.0 body weights). Mean forward velocity decreased significantly with both decreased diameter and increased compliance. Both diameter and compliance had numerous effects on locomotor kinematics, but diameter had larger and more pervasive effects than compliance. Locomotion on the largest diameter had a larger forward excursion per cycle, and the locomotor mode and gripping strategy differed from that on the smaller diameters. On larger diameters, snakes primarily applied opposing forces at the same location on the rope to grip. By contrast, on smaller diameters forces were applied in opposite directions at different locations along the rope, resulting in increased rope deformation. Although energy is likely to be lost during deformation, snakes might use increased surface deformation as a strategy to enhance their ability to grip. PMID:21113006

  9. Audubon Tree Study Program.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    Included are an illustrated student reader, "The Story of Trees," a leaders' guide, and a large tree chart with 37 colored pictures. The student reader reviews several aspects of trees: a definition of a tree; where and how trees grow; flowers, pollination and seed production; how trees make their food; how to recognize trees; seasonal changes;…

  10. Visualizing phylogenetic trees using TreeView.

    PubMed

    Page, Roderic D M

    2002-08-01

    TreeView provides a simple way to view the phylogenetic trees produced by a range of programs, such as PAUP*, PHYLIP, TREE-PUZZLE, and ClustalX. While some phylogenetic programs (such as the Macintosh version of PAUP*) have excellent tree printing facilities, many programs do not have the ability to generate publication quality trees. TreeView addresses this need. The program can read and write a range of tree file formats, display trees in a variety of styles, print trees, and save the tree as a graphic file. Protocols in this unit cover both displaying and printing a tree. Support protocols describe how to download and install TreeView, and how to display bootstrap values in trees generated by ClustalX and PAUP*. PMID:18792942

  11. The Amazon Tall Tower Observatory (ATTO) in the remote Amazon Basin: overview of first results from ecosystem ecology, meteorology, trace gas, and aerosol measurements

    NASA Astrophysics Data System (ADS)

    Andreae, M. O.; Acevedo, O. C.; Araùjo, A.; Artaxo, P.; Barbosa, C. G. G.; Barbosa, H. M. J.; Brito, J.; Carbone, S.; Chi, X.; Cintra, B. B. L.; da Silva, N. F.; Dias, N. L.; Dias-Júnior, C. Q.; Ditas, F.; Ditz, R.; Godoi, A. F. L.; Godoi, R. H. M.; Heimann, M.; Hoffmann, T.; Kesselmeier, J.; Könemann, T.; Krüger, M. L.; Lavric, J. V.; Manzi, A. O.; Moran-Zuloaga, D.; Nölscher, A. C.; Santos Nogueira, D.; Piedade, M. T. F.; Pöhlker, C.; Pöschl, U.; Rizzo, L. V.; Ro, C.-U.; Ruckteschler, N.; Sá, L. D. A.; Sá, M. D. O.; Sales, C. B.; Santos, R. M. N. D.; Saturno, J.; Schöngart, J.; Sörgel, M.; de Souza, C. M.; de Souza, R. A. F.; Su, H.; Targhetta, N.; Tóta, J.; Trebs, I.; Trumbore, S.; van Eijck, A.; Walter, D.; Wang, Z.; Weber, B.; Williams, J.; Winderlich, J.; Wittmann, F.; Wolff, S.; Yáñez-Serrano, A. M.

    2015-04-01

    The Amazon Basin plays key roles in the carbon and water cycles, climate change, atmospheric chemistry, and biodiversity. It already has been changed significantly by human activities, and more pervasive change is expected to occur in the next decades. It is therefore essential to establish long-term measurement sites that provide a baseline record of present-day climatic, biogeochemical, and atmospheric conditions and that will be operated over coming decades to monitor change in the Amazon region as human perturbations increase in the future. The Amazon Tall Tower Observatory (ATTO) has been set up in a pristine rain forest region in the central Amazon Basin, about 150 km northeast of the city of Manaus. An ecological survey including a biodiversity assessment has been conducted in the forest region surrounding the site. Two 80 m towers have been operated at the site since 2012, and a 325 m tower is nearing completion in mid-2015. Measurements of micrometeorological and atmospheric chemical variables were initiated in 2012, and their range has continued to broaden over the last few years. The meteorological and micrometeorological measurements include temperature and wind profiles, precipitation, water and energy fluxes, turbulence components, soil temperature profiles and soil heat fluxes, radiation fluxes, and visibility. A tree has been instrumented to measure stem profiles of temperature, light intensity, and water content in cryptogamic covers. The trace gas measurements comprise continuous monitoring of carbon dioxide, carbon monoxide, methane, and ozone at 5 to 8 different heights, complemented by a variety of additional species measured during intensive campaigns (e.g., VOC, NO, NO2, and OH reactivity). Aerosol optical, microphysical, and chemical measurements are made above the canopy as well as in the canopy space. They include light scattering and absorption, aerosol fluorescence, number and volume size distributions, chemical composition, cloud

  12. A volcanological and geochemical investigation of Boa Vista, Cape Verde Islands; 40Ar/ 39Ar geochronology and field constraints

    NASA Astrophysics Data System (ADS)

    Dyhr, Charlotte T.; Holm, Paul M.

    2010-01-01

    Boa Vista, the easternmost island in the Cape Verde archipelago, consists of volcanic products, minor intrusions and a thin partial sedimentary cover. The first 15 age results from 40Ar/ 39Ar incremental heating analysis of groundmass separates from volcanic and plutonic rocks from Boa Vista are presented. The combination of age results and field observations demonstrates that the volcanic activity that formed the island occurred in three main stages: (1) > 16 Ma, (2) 15-12.5 Ma and (3) 9.5-4.5 Ma. The first stage, restricted to the north eastern part of the island, is dominated by ankaramitic lavas. The second stage, consisting of evolved lavas of phonolitic-trachytic compositions and nepheline syenites, makes up large central parts of the island. The large volume of evolved rocks and the extended eruption period of several Ma make stage 2 in Boa Vista unique to Cape Verde. Mainly basanites and nephelinites were erupted during the third stage, initially dominated by eruption of subaerial mafic lavas around 9 Ma. Pillow lavas are erupted around 7 Ma whereupon dominantly subaerial mafic lavas were erupted. Stage 3 saw volcanism in many centres distributed mainly along the present coastline and with activity partly overlapping in time. The volcanic evolution of Boa Vista constrains the initiation of volcanic activity in the Cape Verde archipelago to the eastern islands. Major and trace element geochemistry of 160 volcanic and plutonic rocks representing the entire exposed chronological sequence on Boa Vista is presented, revealing an extremely well developed Daly Gap. Only a little was modified from the mafic magmas that rose in small batches from the mantle. Compositional variation distinguishes each volcanic complex and was to a large extent present in the mantle melts. The highly evolved stage 2 phonolites and trachytes are related through the fractional crystallization of three compositionally distinct magmas. Two of these may have been derived by crystal

  13. Climate response to Amazon forest replacement by heterogeneous crop cover

    NASA Astrophysics Data System (ADS)

    Badger, A. M.; Dirmeyer, P. A.

    2015-11-01

    Previous modeling studies with atmospheric general circulation models and basic land surface schemes to balance energy and water budgets have shown that by removing the natural vegetation over the Amazon, the region's climate becomes warmer and drier. In this study we use a fully coupled Earth system model and replace tropical forests by a distribution of six common tropical crops with variable planting dates, physiological parameters and irrigation. There is still general agreement with previous studies as areal averages show a warmer (+1.4 K) and drier (-0.35 mm day-1) climate. Using an interactive crop model with a realistic crop distribution shows that regions of vegetation change experience different responses dependent upon the initial tree coverage and whether the replacement vegetation is irrigated, with seasonal changes synchronized to the cropping season. Areas with initial tree coverage greater than 80 % show an increase in coupling with the atmosphere after deforestation, suggesting land use change could heighten sensitivity to climate anomalies, while irrigation acts to dampen coupling with the atmosphere.

  14. Climate response to Amazon forest replacement by heterogeneous crop cover

    NASA Astrophysics Data System (ADS)

    Badger, A. M.; Dirmeyer, P. A.

    2015-01-01

    Previous modeling studies with atmospheric general circulation models and basic land surface schemes to balance energy and water budgets have shown that by removing the natural vegetation over the Amazon, the region's climate becomes warmer and drier. In this study we use a fully coupled Earth System Model and replace tropical forests by a distribution of six common tropical crops with variable planting dates, physiological parameters and irrigation. There is still general agreement with previous studies as areal averages show a warmer (+1.4 K) and drier (-0.35 mm day-1) climate. Using an interactive crop model with a realistic crop distribution shows that regions of vegetation change experience different responses dependent upon the initial tree coverage and whether the replacement vegetation is irrigated, with seasonal changes synchronized to the cropping season. Areas with initial tree coverage greater than 80% show an increase in coupling with atmosphere after deforestation, suggesting land use change could heighten sensitivity to climate anomalies, while irrigation acts to dampen coupling with atmosphere.

  15. Amazon old-growth forest wind disturbance and the regional carbon balance

    NASA Astrophysics Data System (ADS)

    Chambers, J. Q.; Negron Juarez, R. I.; Marra, D. M.; Roberts, D. A.; Hurtt, G. C.; Lima, A.; Higuchi, N.

    2010-12-01

    Estimating the carbon balance of a landscape is challenging. A key problem is determining whether or not measurements made in plots are representative of the carbon state of a larger region. A key parameter for calculating landscape carbon balance is the return frequency of episodic disturbances. If disturbances are clustered and occur more frequently than the time required for biomass recovery, a spatial mixture of patches in different stages of recovery occurs. Under these shifting steady-state mosaic conditions, quantifying the mean state of ecosystem attributes such as carbon balance or tree species diversity is difficult. In this study, satellite remote sensing (Landsat) was coupled with field investigations to create ~25 year landscape-scale disturbance chronosequence for old-growth forest in the Central Amazon. The detected disturbances were caused by strong storms which resulted in tree mortality events ranging from small clusters of 7-10 downed trees, to large contiguous blowdowns larger than 30 ha in size. Using the chronosequence, a cumulative probability distribution function was developed, which followed a power law, and was used to parameterize a forest carbon balance model. Results demonstrate that for power law exponents less than about 2.0, the spatial scale at which forest carbon balance establishes is much larger than generally expected. Ultimately, an increase in wind disturbance frequency and/or intensity with a warming climate has the potential to cause a net loss of carbon from Amazon forests to the atmosphere.

  16. Business as Usual: Amazon.com and the Academic Library

    ERIC Educational Resources Information Center

    Van Ullen, Mary K.; Germain, Carol Anne

    2002-01-01

    In 1999, Steve Coffman proposed that libraries form a single interlibrary loan based entity patterned after Amazon.com. This study examined the suitability of Amazon.com's Web interface and record enhancements for academic libraries. Amazon.com could not deliver circulating monographs in the University at Albany Libraries' collection quickly…

  17. Modelling conservation in the Amazon basin

    NASA Astrophysics Data System (ADS)

    Soares-Filho, Britaldo Silveira; Nepstad, Daniel Curtis; Curran, Lisa M.; Cerqueira, Gustavo Coutinho; Garcia, Ricardo Alexandrino; Ramos, Claudia Azevedo; Voll, Eliane; McDonald, Alice; Lefebvre, Paul; Schlesinger, Peter

    2006-03-01

    Expansion of the cattle and soy industries in the Amazon basin has increased deforestation rates and will soon push all-weather highways into the region's core. In the face of this growing pressure, a comprehensive conservation strategy for the Amazon basin should protect its watersheds, the full range of species and ecosystem diversity, and the stability of regional climates. Here we report that protected areas in the Amazon basin-the central feature of prevailing conservation approaches-are an important but insufficient component of this strategy, based on policy-sensitive simulations of future deforestation. By 2050, current trends in agricultural expansion will eliminate a total of 40% of Amazon forests, including at least two-thirds of the forest cover of six major watersheds and 12 ecoregions, releasing 32 +/- 8Pg of carbon to the atmosphere. One-quarter of the 382 mammalian species examined will lose more than 40% of the forest within their Amazon ranges. Although an expanded and enforced network of protected areas could avoid as much as one-third of this projected forest loss, conservation on private lands is also essential. Expanding market pressures for sound land management and prevention of forest clearing on lands unsuitable for agriculture are critical ingredients of a strategy for comprehensive conservation.

  18. Modelling conservation in the Amazon basin.

    PubMed

    Soares-Filho, Britaldo Silveira; Nepstad, Daniel Curtis; Curran, Lisa M; Cerqueira, Gustavo Coutinho; Garcia, Ricardo Alexandrino; Ramos, Claudia Azevedo; Voll, Eliane; McDonald, Alice; Lefebvre, Paul; Schlesinger, Peter

    2006-03-23

    Expansion of the cattle and soy industries in the Amazon basin has increased deforestation rates and will soon push all-weather highways into the region's core. In the face of this growing pressure, a comprehensive conservation strategy for the Amazon basin should protect its watersheds, the full range of species and ecosystem diversity, and the stability of regional climates. Here we report that protected areas in the Amazon basin--the central feature of prevailing conservation approaches--are an important but insufficient component of this strategy, based on policy-sensitive simulations of future deforestation. By 2050, current trends in agricultural expansion will eliminate a total of 40% of Amazon forests, including at least two-thirds of the forest cover of six major watersheds and 12 ecoregions, releasing 32 +/- 8 Pg of carbon to the atmosphere. One-quarter of the 382 mammalian species examined will lose more than 40% of the forest within their Amazon ranges. Although an expanded and enforced network of protected areas could avoid as much as one-third of this projected forest loss, conservation on private lands is also essential. Expanding market pressures for sound land management and prevention of forest clearing on lands unsuitable for agriculture are critical ingredients of a strategy for comprehensive conservation. PMID:16554817

  19. Forest Understory Fire in the Brazilian Amazon in ENSO and Non-ENSO Years: Area Burned and Committed Carbon Emissions

    NASA Technical Reports Server (NTRS)

    Alencar, A.; Nepstad, D.; Ver-Diaz, M. Del. C.

    2004-01-01

    "Understory fires" that burn the floor of standing forests are one of the most important types of forest impoverishment in the Amazon, especially during the severe droughts of El Nino Southern Oscillation (ENSO) episodes. However, we are aware of no estimates of the areal extent of these fires for the Brazilian Amazon and, hence, of their contribution to Amazon carbon fluxes to the atmosphere. We calculated the area of forest understory fires for the Brazilian Amazon region during an El Nino (1998) and a non El Nino (1995) year based on forest fire scars mapped with satellite images for three locations in eastern and southern Amazon, where deforestation is concentrated. The three study sites represented a gradient of both forest types and dry season severity. The burning scar maps were used to determine how the percentage of forest that burned varied with distance from agricultural clearings. These spatial functions were then applied to similar forest/climate combinations outside of the study sites to derive an initial estimate for the Brazilian Amazon. Ninety-one percent of the forest area that burned in the study sites was within the first kilometer of a clearing for the non ENSO year and within the first four kilometers for the ENSO year. The area of forest burned by understory forest fire during the severe drought (ENSO) year (3.9 millions of hectares) was 13 times greater than the area burned during the average rainfall year (0.2 million hectares), and twice the area of annual deforestation rate. Dense forest was, proportionally, the forest area most affected by understory fires during the El Nino year, while understory fires were concentrated in transitional forests during the year of average rainfall. Our estimate of aboveground tree biomass killed by fire ranged from 0.06 Pg to 0.38 Pg during the ENSO and from 0,004 Pg to 0,024 Pg during the non ENSO.

  20. A new felsic cone-sheet swarm in the Central Atlantic Islands: The cone-sheet swarm of Boa Vista (Cape Verde)

    NASA Astrophysics Data System (ADS)

    Ancochea, Eumenio; Huertas, María José; Hernán, Francisco; Brändle, José Luis

    2014-03-01

    The island of Boa Vista is one of the oceanic islands with the largest amount of felsic rocks reported in the world (50% of the total outcropping igneous rocks of Boa Vista). The felsic rocks are trachytes and phonolites generated within the second main stage of the volcanic activity that lasted about four million years.

  1. Ecology of the Sand Boa, Eryx jayakari in Riyadh Region of Saudi Arabia

    PubMed Central

    Al-Sadoon, Mohammed K.; Al-Otaibi, Fahed S.

    2014-01-01

    The ecology, feeding habits and sexual dimorphism in Arabian Sand Boa, Eryx jayakari from the Central region of Saudi Arabia, were studied. In this study the E. jayakari was recorded for the first time from several sites. Significant differences were noted in total length of body and tail, and body diameter of male and female. The females were of larger size. The mean number of the dorsal body scales, ventrals and subcaudal for both sexes were not significantly different. The mean number of the dorsal body scales, ventral body scales and subcaudal scales for the females was 43, 169 and 18 scales which were not significantly different from respectively ones in males 42, 168 and 18 scales. Frequent prey consumed were lizards (50%), rodents (25%) and arthropods (12.5%). PMID:25313272

  2. Seasonal influence on hematologic values and hemoglobin electrophoresis in Brazilian boa constrictor amarali.

    PubMed

    Machado, Carla C; Silva, Luis F N; Ramos, Paulo R R; Takahira, Regina K

    2006-12-01

    As ectothermic animals, snakes depend exclusively on the environment for proper temperature maintenance, which may greatly influence their activity. Twenty-five adult Boa constrictor amarali snakes maintained in captivity were used to determine the influence of seasons on their hematologic values and electrophoretic profile of hemoglobin. A complete blood cell count (CBC) and examination for hemoparasites were performed in the summer and winter of 2004. Hemoglobin was stored for later electrophoresis. Significant differences (P < 0.05) were obtained in RBC, WBC, lymphocyte, thrombocyte, and monocyte counts, demonstrating the importance of the period of the year in the interpretation of reference values in these animals. Two snakes were detected with blood parasites (Hepatozoon sp.) in the winter and four in the summer, although it appears that their presence did not cause any significant alterations in the CBC. The electrophoretic analysis of the samples demonstrated two-four hemoglobin bands in this species. PMID:17315433

  3. Technical Tree Climbing.

    ERIC Educational Resources Information Center

    Jenkins, Peter

    Tree climbing offers a safe, inexpensive adventure sport that can be performed almost anywhere. Using standard procedures practiced in tree surgery or rock climbing, almost any tree can be climbed. Tree climbing provides challenge and adventure as well as a vigorous upper-body workout. Tree Climbers International classifies trees using a system…

  4. Challenges encountered using standard vector control measures for dengue in Boa Vista, Brazil

    PubMed Central

    Valle, Denise

    2014-01-01

    Abstract Problem In 2010, dengue virus (DENV) serotype–4 was detected during a dengue outbreak in the Amazonian city of Boa Vista. At that time Brazil was already endemic for DENV-1, DENV-2 and DENV-3. This was the first time DENV-4 was observed in the country after it was initially detected and eliminated in 1981. Approach To hinder the spread of DENV-4 throughout Brazil, standard vector control measures were intensified. Vector control professionals visited 56 837 households in 22 out of 31 districts of Boa Vista, to eliminate mosquito-breeding sites. Water storage containers were treated with the larvicide diflubenzuron, and deltamethrin was sprayed for adult Aedes aegypti mosquitoes. Fifteen days later, a second larvae survey and additional deltamethrin applications were performed. Local setting In Brazil, dengue vector control is managed at all three government levels. Regular surveillance of Aedes aegypti is done four to six times a year to strengthen mosquito control activities in areas with high-vector density. Educational dengue control campaigns in communities are scarce, especially between outbreaks. Relevant changes In spite of extensive implementation of all standard control actions recommended by the Brazilian dengue control programme, only a slight decrease in mosquito density was detected. Lessons learnt There is a need to redesign all levels of dengue control. Public consultation and engagement, behaviour change and actions that go beyond technical impositions are required. Vector control programme managers need to reflect on what constitutes good practices and whether intermittent information campaigns are effective measures for dengue prevention and control. PMID:25378760

  5. Position around a tree: consequences for pheromone detection.

    PubMed

    Miller, Ginger L; Loudon, Catherine; Freed, Sarah

    2007-03-01

    The air flow pattern expected around a cylindrical object such as a tree in slow wind, is predicted from fluid mechanics to have areas of faster flow (upwind) and slower recirculating flow with eddies (downwind). An organism located on the surface of a tree would experience different flow depending on its circumferential position. If that organism was searching for a chemical signal, such as a pheromone plume, it might maximize its probability of chemodetection by placing itself in areas of greatest flow speed (the upwind surface of the cylinder, i.e., in front of the separation points). We tested whether wood cockroaches in the genus Parcoblatta exhibit such upwind positioning; they live in forests, and males actively fly from tree to tree, while searching for females releasing sex pheromone. In contrast to an expectation of upwind preference, male cockroaches were evenly distributed around trees relative to upwind (measured with a novel "feather boa" flow visualization technique), even though the wind direction was relatively steady. We investigated whether sex pheromone could be detected at any location around a cylindrical surface in a laboratory flow chamber by using Bombyx mori wing fanning as a bioassay. Although upwind moths arrayed on the surface detected pheromone more rapidly, pheromone detection occurred at least a third of the time at any position, which could explain the even distribution of Parcoblatta males around trees. PMID:17252213

  6. "Different by Degree": Ella Cara Deloria, Zora Neale Hurston, and Franz Boas Contend with Race and Ethnicity.

    ERIC Educational Resources Information Center

    Hoefel, Roseanne

    2001-01-01

    American Indian ethnographer and linguist Ella Cara Deloria and African American folklorist and writer Zora Neale Hurston did fieldwork for Franz Boas, the father of modern anthropology. Both were shocked by how American racism empowered white people's historical actions. By correcting stereotypes through their work, they reasserted the role of…

  7. Use of an osteoconductive compound as an aid in the management of a maxillary fracture in a boa constrictor.

    PubMed

    Rahal, Sheila C; Teixeira, Carlos R; Vulcano, Luiz C; Aguiar, Antonio J A

    2011-03-01

    A boa constrictor was presented with a short oblique compound fracture of the rostral third of the right maxilla. The fracture was reduced and biomaterial was placed around the fracture. A computed tomography scan at 1.5 mo post-surgery showed that the fracture had healed with slight displacement of the bone fragments. PMID:21629425

  8. The Amazon, measuring a mighty river

    USGS Publications Warehouse

    U.S. Geological Survey

    1967-01-01

    The Amazon, the world's largest river, discharges enough water into the sea each day to provide fresh water to the City of New York for over 9 years. Its flow accounts for about 15 percent of all the fresh water discharged into the oceans by all the rivers of the world. By comparison, the Amazon's flow is over 4 times that of the Congo River, the world's second largest river. And it is 10 times that of the Mississippi, the largest river on the North American Continent.

  9. Size and frequency of natural forest disturbances and the Amazon forest carbon balance

    NASA Astrophysics Data System (ADS)

    Espírito-Santo, Fernando D. B.; Gloor, Manuel; Keller, Michael; Malhi, Yadvinder; Saatchi, Sassan; Nelson, Bruce; Junior, Raimundo C. Oliveira; Pereira, Cleuton; Lloyd, Jon; Frolking, Steve; Palace, Michael; Shimabukuro, Yosio E.; Duarte, Valdete; Mendoza, Abel Monteagudo; López-González, Gabriela; Baker, Tim R.; Feldpausch, Ted R.; Brienen, Roel J. W.; Asner, Gregory P.; Boyd, Doreen S.; Phillips, Oliver L.

    2014-03-01

    Forest inventory studies in the Amazon indicate a large terrestrial carbon sink. However, field plots may fail to represent forest mortality processes at landscape-scales of tropical forests. Here we characterize the frequency distribution of disturbance events in natural forests from 0.01 ha to 2,651 ha size throughout Amazonia using a novel combination of forest inventory, airborne lidar and satellite remote sensing data. We find that small-scale mortality events are responsible for aboveground biomass losses of ~1.7 Pg C y-1 over the entire Amazon region. We also find that intermediate-scale disturbances account for losses of ~0.2 Pg C y-1, and that the largest-scale disturbances as a result of blow-downs only account for losses of ~0.004 Pg C y-1. Simulation of growth and mortality indicates that even when all carbon losses from intermediate and large-scale disturbances are considered, these are outweighed by the net biomass accumulation by tree growth, supporting the inference of an Amazon carbon sink.

  10. Size and frequency of natural forest disturbances and the Amazon forest carbon balance.

    PubMed

    Espírito-Santo, Fernando D B; Gloor, Manuel; Keller, Michael; Malhi, Yadvinder; Saatchi, Sassan; Nelson, Bruce; Junior, Raimundo C Oliveira; Pereira, Cleuton; Lloyd, Jon; Frolking, Steve; Palace, Michael; Shimabukuro, Yosio E; Duarte, Valdete; Mendoza, Abel Monteagudo; López-González, Gabriela; Baker, Tim R; Feldpausch, Ted R; Brienen, Roel J W; Asner, Gregory P; Boyd, Doreen S; Phillips, Oliver L

    2014-01-01

    Forest inventory studies in the Amazon indicate a large terrestrial carbon sink. However, field plots may fail to represent forest mortality processes at landscape-scales of tropical forests. Here we characterize the frequency distribution of disturbance events in natural forests from 0.01 ha to 2,651 ha size throughout Amazonia using a novel combination of forest inventory, airborne lidar and satellite remote sensing data. We find that small-scale mortality events are responsible for aboveground biomass losses of ~1.7 Pg C y(-1) over the entire Amazon region. We also find that intermediate-scale disturbances account for losses of ~0.2 Pg C y(-1), and that the largest-scale disturbances as a result of blow-downs only account for losses of ~0.004 Pg C y(-1). Simulation of growth and mortality indicates that even when all carbon losses from intermediate and large-scale disturbances are considered, these are outweighed by the net biomass accumulation by tree growth, supporting the inference of an Amazon carbon sink. PMID:24643258

  11. Succession-inducing disturbances and the old-growth forest mosaic of a Central Amazon landscape

    NASA Astrophysics Data System (ADS)

    Chambers, J. Q.; Negron Juarez, R. I.; Marra, D.; Roberts, D. A.; Di Vittorio, A. V.; Higuchi, N.; Trumbore, S.

    2011-12-01

    Old-growth forest ecosystems comprise a mosaic of patches in different successional stages, with the fraction of the landscape in any particular state relatively constant over large temporal and spatial scales. Tropical forest studies commonly assume that plots covering only a small fraction of the landscape representatively sample this mosaic, and that departures from steady-state represent trends. Here a critical test of this equilibrium assumption for a Central Amazon old-growth forest landscape is carried out by combining extensive forest field plot data, remote sensing analysis to generate disturbance probability distribution functions, and simulation modeling to place plot-level results into a landscape context. Results show that succession-inducing disturbances had a return frequency of ~100 years, and that these episodic events have been poorly sampled by existing forest sample plots. Overall, key ecosystem attributes of small patches are expected to constantly change in the Central Amazon, and long significant trends can result from purely stochastic processes. The role of episodic disturbances will be discussed in terms of Amazon forest carbon balance, and regional tree diversity patterns.

  12. Polycystic Echinococcosis in Pacas, Amazon Region, Peru

    PubMed Central

    Mayor, Pedro; Baquedano, Laura E.; Sanchez, Elisabeth; Aramburu, Javier; Gomez-Puerta, Luis A.; Mamani, Victor J.

    2015-01-01

    In the Peruvian Amazon, paca meat is consumed by humans. To determine human risk for polycystic echinococcosis, we examined wild pacas from 2 villages; 15 (11.7%) of 128 were infected with Echinococcus vogeli tapeworms. High E. vogeli prevalence among pacas indicates potential risk for humans living in E. vogeli–contaminated areas. PMID:25695937

  13. Principal Connection / Amazon and the Whole Teacher

    ERIC Educational Resources Information Center

    Hoerr, Thomas R.

    2015-01-01

    A recent controversy over Amazon's culture has strong implications for the whole child approach, and it offers powerful lessons for principals. A significant difference between the culture of so many businesses today and the culture at good schools is that in good schools, the welfare of the employees is very important. Student success is the…

  14. The turbidity behavior in an Amazon floodplain

    NASA Astrophysics Data System (ADS)

    Alcântara, E.; Novo, E.; Stech, J.; Lorenzzetti, J.; Barbosa, C.; Assireu, A.; Souza, A.

    2009-05-01

    The main objective of this study is to understand the turbidity behavior of an Amazon Floodplain Lake. Observations of turbidity provide quantitative information about water quality. However, the number of available in situ measurements for water quality determination is usually limited in time and space. Here, we present an analysis of the temporal and spatial variability using two approaches: (i) the first is based on wavelet analysis of a turbidity time series measured by an automatic monitoring system; (ii) the second is based on turbidity samples measured in different locations and then interpolated by an ordinary kriging algorithm. The space/time turbidity variability is clearly related to the Amazon River flood pulses in the floodplain. When the water level in the floodplain is rising or receding, the exchange between the Amazon River and the floodplain is the major driving force in turbidity variability. At high water level, the turbidity variability is controlled by the lake bathymetry. Finally, when the water level is low, the wind action and lake morphometry are the main causes of turbidity variability. The combined use of temporal and spatial data showed a great potential for understanding the turbidity behavior in a complex aquatic system, like the Amazon floodplain.

  15. Amazon Flooded Forest. Teacher Resource Guide.

    ERIC Educational Resources Information Center

    Duvall, Todd

    This teacher's resource guide was created to accompany the Amazon Flooded Forest exhibit at the Oregon Zoo. The enclosed lessons and activities are designed to extend into several aspects of daily curriculum including science, math, reading, writing, speaking, and geography. The materials are intended for use in grades 3-6 although most activities…

  16. Relating tree growth to rainfall in Bolivian rain forests: a test for six species using tree ring analysis.

    PubMed

    Brienen, Roel J W; Zuidema, Pieter A

    2005-11-01

    Many tropical regions show one distinct dry season. Often, this seasonality induces cambial dormancy of trees, particularly if these belong to deciduous species. This will often lead to the formation of annual rings. The aim of this study was to determine whether tree species in the Bolivian Amazon region form annual rings and to study the influence of the total amount and seasonal distribution of rainfall on diameter growth. Ring widths were measured on stem discs of a total of 154 trees belonging to six rain forest species. By correlating ring width and monthly rainfall data we proved the annual character of the tree rings for four of our study species. For two other species the annual character was proved by counting rings on trees of known age and by radiocarbon dating. The results of the climate-growth analysis show a positive relationship between tree growth and rainfall in certain periods of the year, indicating that rainfall plays a major role in tree growth. Three species showed a strong relationship with rainfall at the beginning of the rainy season, while one species is most sensitive to the rainfall at the end of the previous growing season. These results clearly demonstrate that tree ring analysis can be successfully applied in the tropics and that it is a promising method for various research disciplines. PMID:16012820

  17. A long-term perspective on deforestation rates in the Brazilian Amazon

    NASA Astrophysics Data System (ADS)

    Velasco Gomez, M. D.; Beuchle, R.; Shimabukuro, Y.; Grecchi, R.; Simonetti, D.; Eva, H. D.; Achard, F.

    2015-04-01

    Monitoring tropical forest cover is central to biodiversity preservation, terrestrial carbon stocks, essential ecosystem and climate functions, and ultimately, sustainable economic development. The Amazon forest is the Earth's largest rainforest, and despite intensive studies on current deforestation rates, relatively little is known as to how these compare to historic (pre 1985) deforestation rates. We quantified land cover change between 1975 and 2014 in the so-called Arc of Deforestation of the Brazilian Amazon, covering the southern stretch of the Amazon forest and part of the Cerrado biome. We applied a consistent method that made use of data from Landsat sensors: Multispectral Scanner (MSS), Thematic Mapper (TM), Enhanced Thematic Mapper Plus (ETM+) and Operational Land Imager (OLI). We acquired suitable images from the US Geological Survey (USGS) for five epochs: 1975, 1990, 2000, 2010, and 2014. We then performed land cover analysis for each epoch using a systematic sample of 156 sites, each one covering 10 km x 10 km, located at the confluence point of integer degree latitudes and longitudes. An object-based classification of the images was performed with five land cover classes: tree cover, tree cover mosaic, other wooded land, other land cover, and water. The automatic classification results were corrected by visual interpretation, and, when available, by comparison with higher resolution imagery. Our results show a decrease of forest cover of 24.2% in the last 40 years in the Brazilian Arc of Deforestation, with an average yearly net forest cover change rate of -0.71% for the 39 years considered.

  18. Regression based modeling of vegetation and climate variables for the Amazon rainforests

    NASA Astrophysics Data System (ADS)

    Kodali, A.; Khandelwal, A.; Ganguly, S.; Bongard, J.; Das, K.

    2015-12-01

    Both short-term (weather) and long-term (climate) variations in the atmosphere directly impact various ecosystems on earth. Forest ecosystems, especially tropical forests, are crucial as they are the largest reserves of terrestrial carbon sink. For example, the Amazon forests are a critical component of global carbon cycle storing about 100 billion tons of carbon in its woody biomass. There is a growing concern that these forests could succumb to precipitation reduction in a progressively warming climate, leading to release of significant amount of carbon in the atmosphere. Therefore, there is a need to accurately quantify the dependence of vegetation growth on different climate variables and obtain better estimates of drought-induced changes to atmospheric CO2. The availability of globally consistent climate and earth observation datasets have allowed global scale monitoring of various climate and vegetation variables such as precipitation, radiation, surface greenness, etc. Using these diverse datasets, we aim to quantify the magnitude and extent of ecosystem exposure, sensitivity and resilience to droughts in forests. The Amazon rainforests have undergone severe droughts twice in last decade (2005 and 2010), which makes them an ideal candidate for the regional scale analysis. Current studies on vegetation and climate relationships have mostly explored linear dependence due to computational and domain knowledge constraints. We explore a modeling technique called symbolic regression based on evolutionary computation that allows discovery of the dependency structure without any prior assumptions. In symbolic regression the population of possible solutions is defined via trees structures. Each tree represents a mathematical expression that includes pre-defined functions (mathematical operators) and terminal sets (independent variables from data). Selection of these sets is critical to computational efficiency and model accuracy. In this work we investigate

  19. The Tree Worker's Manual.

    ERIC Educational Resources Information Center

    Smithyman, S. J.

    This manual is designed to prepare students for entry-level positions as tree care professionals. Addressed in the individual chapters of the guide are the following topics: the tree service industry; clothing, eqiupment, and tools; tree workers; basic tree anatomy; techniques of pruning; procedures for climbing and working in the tree; aerial…

  20. A basic radial dike swarm of Boa Vista (Cape Verde Archipelago); its significance in the evolution of the island

    NASA Astrophysics Data System (ADS)

    Ancochea, Eumenio; Hernán, Francisco; Huertas, María José; Brändle, José Luis

    2012-10-01

    A basic radial dike swarm unrelated to other basic units of Boa Vista (Cape Verde Archipelago) has been localized and characterized in the central sector of the island. According to new radiometric data three main stages in the evolution of Boa Vista are distinguished: the earlier (the Old Volcanic Complex: 17-16 Ma) is equivalent to the shield building stage of Hawaii and the later (the Recent Volcanics (8-4 Ma) is in some aspects comparable to the post-erosional stage. An important intermediate essentially felsic stage (the Trachytic-Phonolitic Complex: 14.3-12.8 Ma) followed the basaltic shield stage. This felsic stage has equivalents in some other oceanic islands as the Canary Islands, specially Gran Canaria, Tenerife, and La Gomera. The central sector of Boa Vista is also occupied by the Felsic Subvolcanic Complex, a unit consisting of phonolitic breccias, syenites and monzonites that represent the Trachytic-Phonolitic Complex hypabyssal roots. The felsic rocks as a whole constitute half of the total amount of igneous rocks on the island making up Boa Vista, the island with the highest percentage of felsic rocks in the Central Atlantic Ocean. More than 200 dikes of the basic radial swarm intruding the Felsic Subvolcanic Complex have been measured. The intensity of the multiple dike injection is sometimes rather high, roughly a dike every 5 m. The individual dikes have an observable mean length of about 300 m. The composition of these dikes is always foiditic (nephelinites, melilitites, and limburgites), slightly different in composition (more alkaline and richer in incompatible elements) to the other basic units of the island (the Old Volcanic Complex and the Recent Volcanics). The radial dikes converge in an area located NW of the geometrical center of Boa Vista, a zone where the hypothetical center of the Old Volcanic Complex and the Trachytic-Phonolitic Complex edifices must also have been situated. The ages obtained from the dikes (between 14.8 and 11.5 Ma

  1. Do farmers reduce genetic diversity when they domesticate tropical trees? A case study from Amazonia.

    PubMed

    Hollingsworth, P M; Dawson, I K; Goodall-Copestake, W P; Richardson, J E; Weber, J C; Sotelo Montes, C; Pennington, R T

    2005-02-01

    Agroforestry ecosystems may be an important resource for conservation and sustainable use of tropical trees, but little is known of the genetic diversity they contain. Inga edulis, a widespread indigenous fruit tree in South America, is used as a model to assess the maintenance of genetic diversity in five planted vs. five natural stands in the Peruvian Amazon. Analysis of five SSR (simple sequence repeat) loci indicated lower allelic variation in planted stands [mean corrected allelic richness 31.3 (planted) and 39.3 (natural), P = 0.009]. Concerns regarding genetic erosion in planted Amazonian tree stands appear valid, although allelic variation on-farm is still relatively high. PMID:15660940

  2. Evaluation of the Amazon River delta as a barrier to gene flow for the regional malaria vector, Anopheles aquasalis (Diptera: Culicidae) in northeastern Brazil.

    PubMed

    Fairley, T L; Póvoa, M M; Conn, J E

    2002-11-01

    The Neotropical malaria vector Anopheles aquasalis Curry is distributed predominantly along the Atlantic and Pacific Coasts because of its tolerance for breeding in salt water. We tested the hypothesis that the freshwater Amazon River acts as a barrier to gene flow in northeastern Brazil, by examining variation at a 588-nucleotide fragment of the mitochondrial cytochrome oxidase Igene from five populations. We identified 15 haplotypes of which 5 were shared both (1) between sample localities and (2) across the Amazon River Delta. Sequence divergence ranged from 0.0017-0.0272 (average = 0.0137). Estimates of genetic subdivision based on the presence of the Amazon Riverwere greatest within localities (phi = 0.029) and among regions (phi = 0.018), followed by among localities (phi = 0.011), but none were significant. Parsimony, neighbor-joining, and Nested Clade Analyses were used to estimate relationships among populations and infer evolutionary processes. Two phylogenetically distinct clusters of populations were moderately supported by parsimony. Neighbor-joining trees were poorly resolved, thus providing no geographical resolution and no support for the Amazon River as a barrier to migration. Phylogeographic structure as detected by the Nested Clade Analysis was consistent with restricted gene flow coupled with isolation by distance. Taken together, these analyses suggest that the localities within this region of northeastern Brazil constitute a single large population of An. aquasalis that spans the Amazon Delta. PMID:12495184

  3. Biomass Change of the Landless Peasants' Settlements in Lower Amazon

    NASA Astrophysics Data System (ADS)

    Yoshikawa, S.; Ishimaru, K.

    2014-12-01

    Land use/land cover (LU/LC) changes have been reported to occur over large areas in Legal Amazon due to the introduction of large-scale mechanized agriculture, extensive cattle ranching and uncontrolled slash-and-burn cultivation since the 1980s. Around the same time, movements which poor peoples or landless peasants settle into abandoned land have been very active in Brazil. In many cases, these people lack agricultural experiences to yield sufficient production for livelihoods. Thus, it leads to abandon the land and repeat forest clearance. In recent year, education by NGOs to these people encourage spreading of agroforestry which is a land use management system in which trees are grown around or among crops or pasture land. In this study, we specifically aimed at clarifying changes in LULC and these biomass using ground observation data, remotely-sensed LANDSAT data and GIS techniques. We focus on four different settlements: old-established settlement (around 30 years), established settlement (around 20 years), productive settlement (7 year) and unproductive settlement (7 years). These four settelements were located at Santa Barbará province, about 40 km northeast from the center of Belém, the Pará state capital, in the northern part of Brazil. We clarify that the biomass change varied according to whether the settlement are productive or not.

  4. Second COS FUV Lifetime Position: Verification of FUV Bright Object Aperture (BOA) Operations (FCAL4)

    NASA Astrophysics Data System (ADS)

    Debes, John H.

    2013-05-01

    As part of the calibration of the second lifetime position on the Cosmic Origins Spectrograph (COS) far-ultraviolet (FUV) detectors, observations of the external target, G191-B2B, were obtained with the G130M, G160M, and G140L gratings in combi- nation with the Bright Object Aperture. The observations were designed to verify the performance of these spectroscopic modes by reproducing similar observations taken during the SM4 Servicing Mission Observatory Verification (SMOV) of COS. These observations allowed for a detailed determination of the spatial location and profile of the spectra from the three gratings, as well as a determination of the spectral resolution of the G130M grating prior to and after the lifetime move. In general, the negligi- ble differences which exist between the two lifetime positions can be attributed to slight differences in the optical path. In particular, the spectral resolution appears to be slightly improved. The stability of the absolute and relative flux calibration was investigated for G130M as well using STIS echelle data of G191-B2B. We determine that the COS ab- solute flux calibration with the BOA is accurate to 10%, and flux calibrated data are reproducible at the 1-2% level since SMOV.

  5. Mitochondrial DNA variation reveals recent evolutionary history of main Boa constrictor clades.

    PubMed

    Hynková, Ivana; Starostová, Zuzana; Frynta, Daniel

    2009-09-01

    We sequenced a 1114-bp fragment of cytochrome b gene in six subspecies (115 samples) of Boa constrictor and detected 67 haplotypes. Our analyses revealed the presence of two distinct clades, one from Central America (CA) including the neighboring part of South America west of the Andes, and the other covering the rest of South America (SA). Sequence divergence between CA and SA clades is about 5-7%, which roughly corresponds to a separation at the time of uplift of the Colombian Andes following formation of the Panama Isthmus before 3.5 Myr Sequence divergence within the SA and CA clades is only 2-3%, suggesting a fairly recent spread of these clades Into their current geographic ranges. Thus, we may not be dealing with taxa with a markedly old evolutionary history. Because juveniles of B. constrictor feed mostly on small rodents, we hypothesized that spread of this species was allowed by a new food source represented by murold rodents that appeared after closure of the Panama portal. With respect to the taxonomy, B. c. imperator may be elevated to full species rank. Within the SA clade, a haplotype of Argentinian B. c. occidentalis is markedly distinct, while the remaining haplotype groups analyzed are distributed throughout large ranges and may all belong to a single nominotypic subspecies. PMID:19799513

  6. Climate Change Impacts in the Amazon. Review of scientific literature

    SciTech Connect

    2006-04-15

    The Amazon's hydrological cycle is a key driver of global climate, and global climate is therefore sensitive to changes in the Amazon. Climate change threatens to substantially affect the Amazon region, which in turn is expected to alter global climate and increase the risk of biodiversity loss. In this literature review the following subjects can be distinguished: Observed Climatic Change and Variability, Predicted Climatic Change, Impacts, Forests, Freshwater, Agriculture, Health, and Sea Level Rise.

  7. Can accelerometers detect mass variations in Amazonian trees?

    NASA Astrophysics Data System (ADS)

    van Emmerik, Tim; Steele-Dunne, Susan; Gentine, Pierre; Guerin, Marceau; Hut, Rolf; Oliveira, Rafael; van de Giesen, Nick

    2016-04-01

    The mass of trees is influenced by physiological processes within the tree (e.g. transpiration and root water uptake), as well as external loads (e.g. intercepted precipitation). Recent studies have found diurnal variations in radar backscatter over vegetated areas, which might be attributed to mass changes of the vegetation layer. Field measurements are required to study the driving processes. This study aims to use measured three-dimensional displacement and acceleration of trees, to detect and quantify their diurnal (bio)mass variations. Accelerometers and dendrometers were installed on seven different tree species in the Amazon rainforest. Trees were selected to cover a broad range of wood density. Using spectral analysis, the governing frequencies in the acceleration time series were found. The governing frequencies showed a diurnal pattern, as well as a change during precipitation events. Our results suggest that we can separate and potentially quantify tree mass changes due to (1) internal water redistribution and (2) intercepted precipitation. This will allow further investigation of the effect of precipitation and water stress on tree dynamics in forest canopies.

  8. Selective Logging in the Brazilian Amazon

    NASA Astrophysics Data System (ADS)

    Asner, Gregory P.; Knapp, David E.; Broadbent, Eben N.; Oliveira, Paulo J. C.; Keller, Michael; Silva, Jose N.

    2005-10-01

    Amazon deforestation has been measured by remote sensing for three decades. In comparison, selective logging has been mostly invisible to satellites. We developed a large-scale, high-resolution, automated remote-sensing analysis of selective logging in the top five timber-producing states of the Brazilian Amazon. Logged areas ranged from 12,075 to 19,823 square kilometers per year (+/-14%) between 1999 and 2002, equivalent to 60 to 123% of previously reported deforestation area. Up to 1200 square kilometers per year of logging were observed on conservation lands. Each year, 27 million to 50 million cubic meters of wood were extracted, and a gross flux of ~0.1 billion metric tons of carbon was destined for release to the atmosphere by logging.

  9. Suspected Lead Poisoning in an Amazon Parrot

    PubMed Central

    McDonald, Lawrence J.

    1986-01-01

    A double yellow headed Amazon parrot (Amazona ochrocephala tresmariae) of unknown age and sex was examined for an acute onset of anorexia, listlessness, central nervous system signs and diarrhea. A tentative diagnosis of lead toxicosis was achieved based on radiographs, clinical pathology and response to therapy. Chelation therapy (Calcium EDTA) and supportive measures resulted in an uneventful recovery. ImagesFigure 1.Figure 2.Figure 3. PMID:17422638

  10. Petrobras eyes LNG project in Amazon region

    SciTech Connect

    1995-08-07

    The Brazilian state oil company has proved gas reserves in the Rio Urucu area of the Amazon jungle totaling 1.84 tcf. That compares with 3.08 tcf contained in the offshore Campos basin, source of most of Brazil`s oil and gas production. The environmentally sensitive Urucu region is one of the most dense, remote jungles in the world. Because of environmental concerns about pipelines in the rain forest and a government emphasis on boosting the natural gas share of Brazil`s energy mix, a small liquefied natural gas project is shaping up as the best option for developing and marketing Urucu gas. The amazon campaign underscores a government initiative to boost Brazilian consumption of natural gas. In Brazil natural gas accounts for only 4% of primary energy consumption. Some years ago, the government set an official goal of boosting the gas share of the primary energy mix to 10% by 2000. The paper discusses current drilling activities, gas production and processing, the logistics of the upper Amazon, and gas markets.

  11. Chagas disease and globalization of the Amazon.

    PubMed

    Briceño-León, Roberto

    2007-01-01

    The increasing number of autochthonous cases of Chagas disease in the Amazon since the 1970s has led to fear that the disease may become a new public health problem in the region. This transformation in the disease's epidemiological pattern in the Amazon can be explained by environmental and social changes in the last 30 years. The current article draws on the sociological theory of perverse effects to explain these changes as the unwanted result of the shift from the "inward" development model prevailing until the 1970s to the "outward" model that we know as globalization, oriented by industrial forces and international trade. The current article highlights the implementation of five new patterns in agriculture, cattle-raising, mining, lumbering, and urban occupation that have generated changes in the environment and the traditional indigenous habitat and have led to migratory flows, deforestation, sedentary living, the presence of domestic animals, and changes in the habitat that facilitate colonization of human dwellings by vectors and the domestic and work-related transmission of the disease. The expansion of Chagas disease is thus a perverse effect of the globalization process in the Amazon. PMID:17308715

  12. Carbon isotopic composition of Amazon shelf sediments

    SciTech Connect

    Showers, W.J.; Angle, D.G.; Nittrouer, C.A.; Demaster, D.J.

    1985-02-01

    The distribution of carbon isotopes in Amazon shelf sediment is controlled by the same processes that are forming the modern subaqueous delta. The terrestrial (-27 to -25 per thousand) isotopic carbon signal observed in surficial sediments near the river mouth extends over 400 km northwest along the shelf. Terrestrial carbon is associated with areas of rapid sediment accumulation (topset and foreset regions). A sharp boundary between terrestrial (-27 to -25 per thousand) and marine (-23 to -22 per thousand) isotopic carbon values in surficial sediments is associated with a change in depositional conditions (foreset to bottomset regions) and a decrease in sediment accumulation rate. POC water-column isotopic values (-27 per thousand) near the river mouth are similar to the underlying surficial-sediment TOC isotopic values, but POC water-column samples collected 20 km off the river mouth have marine carbon isotopic values (-22 to -19 per thousand) and differ from the underlying surficial-sediment TOC isotopic values. These water column observations are related to variations in turbidity and productivity. Down-core isotopic variation is only observed in cores taken in areas of lower sediment accumulation rates. These observations indicate that the organic carbon in Amazon shelf sediment is dominantly terrestrial in composition, and the location of deposition of this carbon is controlled by modern processes of sediment accumulation. The modern Amazon shelf is similar to large clinoform shale deposits of the Cretaceous in North America. Thus, the stratigraphic setting may help predict the isotopic variations of carbon in ancient deposits.

  13. Sustainable settlement in the Brazilian Amazon

    SciTech Connect

    Almeida, A.L.O.; Campari, J.S.

    1996-02-01

    Presents and analyzes the largest and most complete data set ever produced on the economic variables that influence deforestation by small farmers in the Amazon. This landmark study presents the largest and most analytically complete data set ever produced on the economic variables that influence deforestation by small farmers in the Amazon. The authors examine the changing character of the Amazon frontier based on field surveys conducted during twenty years of settlement experience. By observing the economic behavior of small farmers from colonization during the 1970s until the chaotic aftermath of the early 1990s, the authors are able to pinpoint a central paradox: unsuccessful farmers tend to be unstable, moving on to new frontiers where they will again destroy forests. Successful farmers tend to increase deforestation in the places where they remain. The findings reveal that much of the Amazonian frontier land cleared by pioneers in the 1970s is becoming agriculturally unproductive. Small farmers should be rewarded for staying where they are and for pursuing sustainable farming. Good farming methods must be promoted, and deforestation must be penalized. The authors recommend the implementation of innovative economic policies and new forms of cooperation between environmental and economic agencies, including the World Bank, at both local and international levels. The aim of these policies should be to raise agricultural incomes and reduce environmental aggression.

  14. Biomarkers of Mercury Exposure in the Amazon

    PubMed Central

    de Castro, Nathália Santos Serrão; Lima, Marcelo de Oliveira

    2014-01-01

    Mercury exposure in the Amazon has been studied since the 1980s decade and the assessment of human mercury exposure in the Amazon is difficult given that the natural occurrence of this metal is high and the concentration of mercury in biological samples of this population exceeds the standardized value of normality established by WHO. Few studies have focused on the discovery of mercury biomarkers in the region's population. In this way, some studies have used genetics as well as immunological and cytogenetic tools in order to find a molecular biomarker for assessing the toxicological effect of mercury in the Amazonian population. Most of those studies focused attention on the relation between mercury exposure and autoimmunity and, because of that, they will be discussed in more detail. Here we introduce the general aspects involved with each biomarker that was studied in the region in order to contextualize the reader and add information about the Amazonian life style and health that may be considered for future studies. We hope that, in the future, the toxicological studies in this field use high technological tools, such as the next generation sequencing and proteomics skills, in order to comprehend basic questions regarding the metabolic route of mercury in populations that are under constant exposure, such as in the Amazon. PMID:24895619

  15. Tree Tectonics

    NASA Astrophysics Data System (ADS)

    Vogt, Peter R.

    2004-09-01

    Nature often replicates her processes at different scales of space and time in differing media. Here a tree-trunk cross section I am preparing for a dendrochronological display at the Battle Creek Cypress Swamp Nature Sanctuary (Calvert County, Maryland) dried and cracked in a way that replicates practically all the planform features found along the Mid-Oceanic Ridge (see Figure 1). The left-lateral offset of saw marks, contrasting with the right-lateral ``rift'' offset, even illustrates the distinction between transcurrent (strike-slip) and transform faults, the latter only recognized as a geologic feature, by J. Tuzo Wilson, in 1965. However, wood cracking is but one of many examples of natural processes that replicate one or several elements of lithospheric plate tectonics. Many of these examples occur in everyday venues and thus make great teaching aids, ``teachable'' from primary school to university levels. Plate tectonics, the dominant process of Earth geology, also occurs in miniature on the surface of some lava lakes, and as ``ice plate tectonics'' on our frozen seas and lakes. Ice tectonics also happens at larger spatial and temporal scales on the Jovian moons Europa and perhaps Ganymede. Tabletop plate tectonics, in which a molten-paraffin ``asthenosphere'' is surfaced by a skin of congealing wax ``plates,'' first replicated Mid-Oceanic Ridge type seafloor spreading more than three decades ago. A seismologist (J. Brune, personal communication, 2004) discovered wax plate tectonics by casually and serendipitously pulling a stick across a container of molten wax his wife and daughters had used in making candles. Brune and his student D. Oldenburg followed up and mirabile dictu published the results in Science (178, 301-304).

  16. Cardiovascular Risk in Men Aged Over 40 in Boa Vista, Brazil

    PubMed Central

    de Lima Junior, Mário Maciel; Bezerra, Emanuel Araújo; Ticianeli, José Geraldo

    2016-01-01

    Background: Cardiovascular disease is the most common cause of disease in the developed world. Early detection and risk prediction are a key component in reducing cardiovascular mortality. The Framingham Risk Score uses age, sex, cholesterol, blood pressure, diabetes, and smoking to calculate the 10-year risk probability of developing cardiovascular disease for a given patient. The aim of this study was to examine cardiovascular disease risk in men aged over 40 years in Boa Vista, Brazil and identify socioeconomic factors contributing to the risk. Methods: This was an epidemiological, cross-sectional, descriptive study. Physical examination and questionnaire survey were conducted on the participants. Results: Of the 598 participants (average age = 55.38 ± 10.77 years), 346 completed all the examinations and answered the survey, while 252 completed the survey and the physical examinations but did not undertake the laboratory tests. A large proportion of participants were overweight (42.6%) or obese (23.6%), 14.5% were hypertensive, and 71.9% were prehypertensive. Consumption of red meat and junk food was high, while participation in the exercise was low. Framingham scores ranged from −3 to 13 (mean score: 3.86 ± 3.16). A total of 204 participants (34.1%) had a low risk of cardiovascular disease, 98 (16.4%) had a medium risk, and 44 (7.4%) possessed high risk. Increased abdominal circumference (P = 0.013), resting pulse (P = 0.002), and prostate-specific antigen levels (P < 0.001) were associated with increased risk of cardiovascular disease. Conclusions: Our study highlights a worrying trend in increasing obesity and hypertension, most likely associated with increasingly poor diet and reduced participation in exercises. As the Brazilian population ages, this will drive increasing rates of cardiovascular mortality unless these trends are reversed. This study suggests that such campaigns should focus on men over the age of 40, who are married or divorced and of

  17. Ventilatory compensation of the alkaline tide during digestion in the snake Boa constrictor.

    PubMed

    Andrade, Denis V; De Toledo, Luis Felipe; Abe, Augusto S; Wang, Tobias

    2004-03-01

    The increased metabolic rate during digestion is associated with changes in arterial acid-base parameters that are caused by gastric acid secretion (the 'alkaline tide'). Net transfer of HCl to the stomach lumen causes an increase in plasma HCO3- levels, but arterial pH does not change because of a ventilatory compensation that counters the metabolic alkalosis. It seems, therefore, that ventilation is controlled to preserve pH and not PCO2 during the postprandial period. To investigate this possibility, we determined arterial acid-base parameters and the metabolic response to digestion in the snake Boa constrictor, where gastric acid secretion was inhibited pharmacologically by oral administration of omeprazole. The increase in oxygen consumption of omeprazole-treated snakes after ingestion of 30% of their own body mass was quantitatively similar to the response in untreated snakes, although the peak of the metabolic response occurred later (36 h versus 24 h). Untreated control animals exhibited a large increase in arterial plasma HCO3- concentration of approximately 12 mmol l(-1), but arterial pH only increased by 0.12 pH units because of a simultaneous increase in arterial PCO2 by about 10 mmHg. Omeprazole virtually abolished the changes in arterial pH and plasma HCO3- concentration during digestion and there was no increase in arterial PCO2. The increased arterial PCO2 during digestion is not caused, therefore, by the increased metabolism during digestion or a lower ventilatory responsiveness to ventilatory stimuli during a presumably relaxed state in digestion. Furthermore, the constant arterial PCO2, in the absence of an alkaline tide, of omeprazole-treated snakes strongly suggests that pH rather than PCO2 normally affects chemoreceptor activity and ventilatory drive. PMID:15010489

  18. Abrupt increases in Amazonian tree mortality due to drought-fire interactions.

    PubMed

    Brando, Paulo Monteiro; Balch, Jennifer K; Nepstad, Daniel C; Morton, Douglas C; Putz, Francis E; Coe, Michael T; Silvério, Divino; Macedo, Marcia N; Davidson, Eric A; Nóbrega, Caroline C; Alencar, Ane; Soares-Filho, Britaldo S

    2014-04-29

    Interactions between climate and land-use change may drive widespread degradation of Amazonian forests. High-intensity fires associated with extreme weather events could accelerate this degradation by abruptly increasing tree mortality, but this process remains poorly understood. Here we present, to our knowledge, the first field-based evidence of a tipping point in Amazon forests due to altered fire regimes. Based on results of a large-scale, long-term experiment with annual and triennial burn regimes (B1yr and B3yr, respectively) in the Amazon, we found abrupt increases in fire-induced tree mortality (226 and 462%) during a severe drought event, when fuel loads and air temperatures were substantially higher and relative humidity was lower than long-term averages. This threshold mortality response had a cascading effect, causing sharp declines in canopy cover (23 and 31%) and aboveground live biomass (12 and 30%) and favoring widespread invasion by flammable grasses across the forest edge area (80 and 63%), where fires were most intense (e.g., 220 and 820 kW ⋅ m(-1)). During the droughts of 2007 and 2010, regional forest fires burned 12 and 5% of southeastern Amazon forests, respectively, compared with <1% in nondrought years. These results show that a few extreme drought events, coupled with forest fragmentation and anthropogenic ignition sources, are already causing widespread fire-induced tree mortality and forest degradation across southeastern Amazon forests. Future projections of vegetation responses to climate change across drier portions of the Amazon require more than simulation of global climate forcing alone and must also include interactions of extreme weather events, fire, and land-use change. PMID:24733937

  19. Abrupt increases in Amazonian tree mortality due to drought–fire interactions

    PubMed Central

    Brando, Paulo Monteiro; Balch, Jennifer K.; Nepstad, Daniel C.; Morton, Douglas C.; Putz, Francis E.; Coe, Michael T.; Silvério, Divino; Macedo, Marcia N.; Davidson, Eric A.; Nóbrega, Caroline C.; Alencar, Ane; Soares-Filho, Britaldo S.

    2014-01-01

    Interactions between climate and land-use change may drive widespread degradation of Amazonian forests. High-intensity fires associated with extreme weather events could accelerate this degradation by abruptly increasing tree mortality, but this process remains poorly understood. Here we present, to our knowledge, the first field-based evidence of a tipping point in Amazon forests due to altered fire regimes. Based on results of a large-scale, long-term experiment with annual and triennial burn regimes (B1yr and B3yr, respectively) in the Amazon, we found abrupt increases in fire-induced tree mortality (226 and 462%) during a severe drought event, when fuel loads and air temperatures were substantially higher and relative humidity was lower than long-term averages. This threshold mortality response had a cascading effect, causing sharp declines in canopy cover (23 and 31%) and aboveground live biomass (12 and 30%) and favoring widespread invasion by flammable grasses across the forest edge area (80 and 63%), where fires were most intense (e.g., 220 and 820 kW⋅m−1). During the droughts of 2007 and 2010, regional forest fires burned 12 and 5% of southeastern Amazon forests, respectively, compared with <1% in nondrought years. These results show that a few extreme drought events, coupled with forest fragmentation and anthropogenic ignition sources, are already causing widespread fire-induced tree mortality and forest degradation across southeastern Amazon forests. Future projections of vegetation responses to climate change across drier portions of the Amazon require more than simulation of global climate forcing alone and must also include interactions of extreme weather events, fire, and land-use change. PMID:24733937

  20. Impact of Atmospheric Albedo on Amazon Evapotranspiration

    NASA Astrophysics Data System (ADS)

    Lopes, A. V.; Thompson, S. E.; Dracup, J. A.

    2013-12-01

    The vulnerability of the Amazon region to climate and anthropogenic driven disturbances has been the subject of extensive research efforts, given its importance in the global and regional climate and ecologic systems. The evaluation of such vulnerabilities requires the proper understanding of physical mechanisms controlling water and energy balances and how the disturbances change them. Among those mechanisms, the effects of atmospheric albedo on evapotranspiration have not been fully explored yet and are explored in this study. Evapotranspiration in the Amazon is sustained at high levels across all seasons and represents a large fraction of water and energy surface budgets. In this study, statistical analysis of data from four flux towers installed at Amazon primary forest sites was employed to quantify the impact of atmospheric albedo, mostly resulted from cloudiness, on evapotranspiration and to compare it to the effect of water limitation. Firstly, the difference in eddy-flux derived evapotranspiration at the flux towers under rainy and non-rainy antecedent conditions was tested for significance. Secondly, the same statistical comparison was performed under cloudy and clear sky conditions at hourly and daily time scales, using the reduction in incoming solar radiation as an indicator of cloudiness. Finally, the sensitivity of seasonal evapotranspiration totals to atmospheric albedo resulted from rainfall patterns is evaluated. That was done by sampling daily evapotranspiration estimates from empirical probability distribution functions conditioned to rainfall occurrence and then varying the number of dry days in each season. It was found that light limitation is much more important than water limitation in the Amazon, resulting in up to 43% reduction in daily evapotranspiration. Also, this effect varies by location and by season, the largest impact being in wet season, from December do January. Moreover, seasonal evapotranspiration totals were found to be

  1. Benzoxazolin-2(3H)-one (BOA) induced changes in leaf water relations, photosynthesis and carbon isotope discrimination in Lactuca sativa.

    PubMed

    Hussain, M Iftikhar; González, L; Chiapusio, G; Reigosa, M J

    2011-08-01

    The effects are reported here of Benzoxazolin-2(3H)-one (BOA), an allelopathic compound, on plant water relations, growth, components of chlorophyll fluorescence, and carbon isotope discrimination in lettuce (Lactuca sativa L.). Lettuce seedlings were grown in 1:1 Hoagland solution in perlite culture medium in environmentally controlled glasshouse. After 30 days, BOA was applied at concentration of 0.1, 0.5, 1.0 and 1.5 mM and distilled water (control). BOA, in the range (0.1-1.5 mM), decreased the shoot length, root length, leaf and root fresh weight. Within this concentration range, BOA significantly reduced relative water content while leaf osmotic potential remained unaltered. Stress response of lettuce was evaluated on the basis of six days of treatment with 1.5 mM BOA by analyzing several chlorophyll fluorescence parameters determined under dark-adapted and steady state conditions. There was no change in initial fluorescence (F₀) in response to BOA treatment while maximum chlorophyll fluorescence (F(m)) was significantly reduced. BOA treatment significantly reduced variable fluorescence (F(v)) on first, second, third, fourth, fifth and sixth day. Quantum efficiency of open PSII reaction centers (F(v)/F(m)) in the dark-adapted state was significantly reduced in response to BOA treatment. Quantum yield of photosystem II (ΦPSII) electron transport was significantly reduced because of decrease in the efficiency of excitation energy trapping of PSII reaction centers. Maximum fluorescence in light-adapted leaves (F'(m)) was significantly decreased but there was no change in initial fluorescence in light-adapted state (F'₀) in response to 1.5 mM BOA treatment. BOA application significantly reduced photochemical fluorescence quenching (qP) indicating that the balance between excitation rate and electron transfer rate has changed leading to a more reduced state of PSII reaction centers. Non photochemical quenching (NPQ) was also significantly reduced by BOA

  2. Simulating Amazon forest carbon cycling using an individual- and trait-based model.

    NASA Astrophysics Data System (ADS)

    Fauset, S.; Fyllas, N.; Galbraith, D.; Christoffersen, B. O.; Baker, T. R.; Johnson, M. O.; Malhi, Y.; Phillips, O. L.; Lloyd, J.; Gloor, E. U.

    2014-12-01

    The Amazon forest, a regional and global regulator of climate and store of enormous biodiversity, is an incredibly complex ecosystem. Just one ha of forest can contain 300 different species of tree, with an estimated 16,000 tree species present in the region. Different tree species, and even different individuals of a species, vary in their functional traits, influencing how they behave in response to the environment. Dynamic global vegetation models (DGVMs) are commonly used to simulate the response of the Amazon forest to global environmental change. Yet, such DGVMs typically use a plant functional type (PFT) approach where variation between individuals and species are not represented, which inherently limits the range of outcomes for Amazonia under climate change. Here, we report on recent advances in an alternative approach to tropical forest modeling that represents the size structure and variation of traits within a community, which we term the Trait-based Forest Simulator (TFS). As originally proposed, TFS was strictly a steady-state model and here we present an extension of TFS which includes full forest dynamics, and has been evaluated with data collected from intensive carbon cycling inventory plots from the GEM (Global Ecosystems Monitoring) network. Specifically, we compare the model output to stand-level data on productivity and respiration of the canopy, stems and roots. The model development process has highlighted ecological tradeoffs that are necessary to integrate into trait-based models, such as a shorter leaf lifetime with a lower leaf mass per area. The adapted TFS model simulates carbon cycling in forest plots, including variation in productivity between sites. These results lend confidence to the ability of next-generation vegetation models to accurately simulate forest sensitivity to future changes.

  3. The Needs of Trees

    ERIC Educational Resources Information Center

    Boyd, Amy E.; Cooper, Jim

    2004-01-01

    Tree rings can be used not only to look at plant growth, but also to make connections between plant growth and resource availability. In this lesson, students in 2nd-4th grades use role-play to become familiar with basic requirements of trees and how availability of those resources is related to tree ring sizes and tree growth. These concepts can…

  4. Introduction: Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5)

    NASA Astrophysics Data System (ADS)

    Martin, S. T.; Artaxo, P.; Machado, L. A. T.; Manzi, A. O.; Souza, R. A. F.; Schumacher, C.; Wang, J.; Andreae, M. O.; Barbosa, H. M. J.; Fan, J.; Fisch, G.; Goldstein, A. H.; Guenther, A.; Jimenez, J. L.; Pöschl, U.; Silva Dias, M. A.; Smith, J. N.; Wendisch, M.

    2016-04-01

    The Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) Experiment was carried out in the environs of Manaus, Brazil, in the central region of the Amazon basin for 2 years from 1 January 2014 through 31 December 2015. The experiment focused on the complex interactions among vegetation, atmospheric chemistry, and aerosol production on the one hand and their connections to aerosols, clouds, and precipitation on the other. The objective was to understand and quantify these linked processes, first under natural conditions to obtain a baseline and second when altered by the effects of human activities. To this end, the pollution plume from the Manaus metropolis, superimposed on the background conditions of the central Amazon basin, served as a natural laboratory. The present paper, as the introduction to the special issue of GoAmazon2014/5, presents the context and motivation of the GoAmazon2014/5 Experiment. The nine research sites, including the characteristics and instrumentation of each site, are presented. The sites range from time point zero (T0) upwind of the pollution, to T1 in the midst of the pollution, to T2 just downwind of the pollution, to T3 furthest downwind of the pollution (70 km). In addition to the ground sites, a low-altitude G-159 Gulfstream I (G-1) observed the atmospheric boundary layer and low clouds, and a high-altitude Gulfstream G550 (HALO) operated in the free troposphere. During the 2-year experiment, two Intensive Operating Periods (IOP1 and IOP2) also took place that included additional specialized research instrumentation at the ground sites as well as flights of the two aircraft. GoAmazon2014/5 IOP1 was carried out from 1 February to 31 March 2014 in the wet season. GoAmazon2014/5 IOP2 was conducted from 15 August to 15 October 2014 in the dry season. The G-1 aircraft flew during both IOP1 and IOP2, and the HALO aircraft flew during IOP2. In the context of the Amazon basin, the two IOPs also correspond to the clean and

  5. Introduction: Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5)

    NASA Astrophysics Data System (ADS)

    Martin, S. T.; Artaxo, P.; Machado, L. A. T.; Manzi, A. O.; Souza, R. A. F.; Schumacher, C.; Wang, J.; Andreae, M. O.; Barbosa, H. M. J.; Fan, J.; Fisch, G.; Goldstein, A. H.; Guenther, A.; Jimenez, J. L.; Pöschl, U.; Silva Dias, M. A.; Smith, J. N.; Wendisch, M.

    2015-11-01

    The Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) Experiment was carried out in the environs of Manaus, Brazil, in the central region of the Amazon basin during two years from 1 January 2014 through 31 December 2015. The experiment focused on the complex interactions among vegetation, atmospheric chemistry, and aerosol production on the one hand and their connections to aerosols, clouds, and precipitation on the other. The objective was to understand and quantify these linked processes, first under natural conditions to obtain a baseline and second when altered by the effects of human activities. To this end, the pollution plume from the Manaus metropolis, superimposed on the background conditions of the central Amazon basin, served as a natural laboratory. The present paper, as the Introduction to the GoAmazon2014/5 Special Issue, presents the context and motivation of the GoAmazon2014/5 Experiment. The nine research sites, including the characteristics and instrumentation of each site, are presented. The sites range from time point zero (T0) upwind of the pollution, to T1 in the midst of the pollution, to T2 just downwind of the pollution, to T3 furthest downwind of the pollution (70 km). In addition to the ground sites, a low-altitude G-159 Gulfstream I (G1) observed the atmospheric boundary layer and low clouds, and a high-altitude Gulfstream G550 (HALO) operated in the free troposphere. During the two-year experiment, two Intensive Operating Periods (IOP1 and IOP2) also took place that included additional specialized research instrumentation at the ground sites as well as flights of the two aircraft. GoAmazon2014/5 IOP1 was carried out from 1 February to 31 March 2014 in the wet season. GoAmazon2014/5 IOP2 was conducted from 15 August to 15 October 2014 in the dry season. The G1 aircraft flew during both IOP1 and IOP2, and the HALO aircraft flew during IOP2. In the context of the Amazon basin, the two IOPs also correspond to the clean

  6. Modeling the complex impacts of timber harvests to find optimal management regimes for Amazon tidal floodplain forests

    USGS Publications Warehouse

    Fortini, Lucas; Cropper, Wendell P.; Zarin, Daniel J.

    2015-01-01

    At the Amazon estuary, the oldest logging frontier in the Amazon, no studies have comprehensively explored the potential long-term population and yield consequences of multiple timber harvests over time. Matrix population modeling is one way to simulate long-term impacts of tree harvests, but this approach has often ignored common impacts of tree harvests including incidental damage, changes in post-harvest demography, shifts in the distribution of merchantable trees, and shifts in stand composition. We designed a matrix-based forest management model that incorporates these harvest-related impacts so resulting simulations reflect forest stand dynamics under repeated timber harvests as well as the realities of local smallholder timber management systems. Using a wide range of values for management criteria (e.g., length of cutting cycle, minimum cut diameter), we projected the long-term population dynamics and yields of hundreds of timber management regimes in the Amazon estuary, where small-scale, unmechanized logging is an important economic activity. These results were then compared to find optimal stand-level and species-specific sustainable timber management (STM) regimes using a set of timber yield and population growth indicators. Prospects for STM in Amazonian tidal floodplain forests are better than for many other tropical forests. However, generally high stock recovery rates between harvests are due to the comparatively high projected mean annualized yields from fast-growing species that effectively counterbalance the projected yield declines from other species. For Amazonian tidal floodplain forests, national management guidelines provide neither the highest yields nor the highest sustained population growth for species under management. Our research shows that management guidelines specific to a region’s ecological settings can be further refined to consider differences in species demographic responses to repeated harvests. In principle, such fine

  7. Modeling the Complex Impacts of Timber Harvests to Find Optimal Management Regimes for Amazon Tidal Floodplain Forests.

    PubMed

    Fortini, Lucas B; Cropper, Wendell P; Zarin, Daniel J

    2015-01-01

    At the Amazon estuary, the oldest logging frontier in the Amazon, no studies have comprehensively explored the potential long-term population and yield consequences of multiple timber harvests over time. Matrix population modeling is one way to simulate long-term impacts of tree harvests, but this approach has often ignored common impacts of tree harvests including incidental damage, changes in post-harvest demography, shifts in the distribution of merchantable trees, and shifts in stand composition. We designed a matrix-based forest management model that incorporates these harvest-related impacts so resulting simulations reflect forest stand dynamics under repeated timber harvests as well as the realities of local smallholder timber management systems. Using a wide range of values for management criteria (e.g., length of cutting cycle, minimum cut diameter), we projected the long-term population dynamics and yields of hundreds of timber management regimes in the Amazon estuary, where small-scale, unmechanized logging is an important economic activity. These results were then compared to find optimal stand-level and species-specific sustainable timber management (STM) regimes using a set of timber yield and population growth indicators. Prospects for STM in Amazonian tidal floodplain forests are better than for many other tropical forests. However, generally high stock recovery rates between harvests are due to the comparatively high projected mean annualized yields from fast-growing species that effectively counterbalance the projected yield declines from other species. For Amazonian tidal floodplain forests, national management guidelines provide neither the highest yields nor the highest sustained population growth for species under management. Our research shows that management guidelines specific to a region's ecological settings can be further refined to consider differences in species demographic responses to repeated harvests. In principle, such fine

  8. Modeling the Complex Impacts of Timber Harvests to Find Optimal Management Regimes for Amazon Tidal Floodplain Forests

    PubMed Central

    Fortini, Lucas B.; Cropper, Wendell P.; Zarin, Daniel J.

    2015-01-01

    At the Amazon estuary, the oldest logging frontier in the Amazon, no studies have comprehensively explored the potential long-term population and yield consequences of multiple timber harvests over time. Matrix population modeling is one way to simulate long-term impacts of tree harvests, but this approach has often ignored common impacts of tree harvests including incidental damage, changes in post-harvest demography, shifts in the distribution of merchantable trees, and shifts in stand composition. We designed a matrix-based forest management model that incorporates these harvest-related impacts so resulting simulations reflect forest stand dynamics under repeated timber harvests as well as the realities of local smallholder timber management systems. Using a wide range of values for management criteria (e.g., length of cutting cycle, minimum cut diameter), we projected the long-term population dynamics and yields of hundreds of timber management regimes in the Amazon estuary, where small-scale, unmechanized logging is an important economic activity. These results were then compared to find optimal stand-level and species-specific sustainable timber management (STM) regimes using a set of timber yield and population growth indicators. Prospects for STM in Amazonian tidal floodplain forests are better than for many other tropical forests. However, generally high stock recovery rates between harvests are due to the comparatively high projected mean annualized yields from fast-growing species that effectively counterbalance the projected yield declines from other species. For Amazonian tidal floodplain forests, national management guidelines provide neither the highest yields nor the highest sustained population growth for species under management. Our research shows that management guidelines specific to a region’s ecological settings can be further refined to consider differences in species demographic responses to repeated harvests. In principle, such fine

  9. Nitrous oxide and methane fluxes in six different land use systems in the Peruvian Amazon

    NASA Astrophysics Data System (ADS)

    Palm, C. A.; Alegre, J. C.; Arevalo, L.; Mutuo, P. K.; Mosier, A. R.; Coe, R.

    2002-12-01

    The contribution of different land-use systems in the humid tropics to increasing atmospheric trace gases has focused on forests, pastures, and crops with few measurements from managed, tree-based systems that dominate much of the landscape. This study from the Peruvian Amazon includes monthly nitrous oxide and methane fluxes from two cropping systems, three tree-based systems, and a 23-year secondary forest control. Average N2O fluxes from the cropping systems were two to three times higher than the secondary forest control (9.1 μg N m-2 h-1), while those of the tree-based systems were similar to the secondary forest. Increased fluxes in the cropping systems were attributed to N fertilization, while fluxes from the tree-based systems were related to litterfall N. Average CH4 consumption was reduced by up to half that of the secondary forest (-30.0 μg C m-2 h-1) in the tree-based and low-input cropping systems. There was net CH4 production in the high-input cropping system. This switch to net production was a result of increased bulk density and increased soil respiration resulting in anaerobic conditions. Reduced rates of N2O emissions, similar CH4 consumption, and high C sequestration rates in these tree-based systems compared with mature forests, coupled with the large area of these systems in the humid tropics, may partially offset the past effects of deforestation on increased atmospheric trace gas concentrations. In contrast, cropping systems with higher N2O emissions, substantially reduced CH4 consumption or even net CH4 emissions, and little C sequestration exacerbate those effects.

  10. Disruption of hydroecological equilibrium in southwest Amazon mediated by drought

    NASA Astrophysics Data System (ADS)

    Maeda, Eduardo Eiji; Kim, Hyungjun; Aragão, Luiz E. O. C.; Famiglietti, James S.; Oki, Taikan

    2015-09-01

    The impacts of droughts on the Amazon ecosystem have been broadly discussed in recent years, but a comprehensive understanding of the consequences is still missing. In this study, we show evidence of a fragile hydrological equilibrium in the western Amazon. While drainage systems located near the equator and the western Amazon do not show water deficit in years with average climate conditions, this equilibrium can be broken during drought events. More importantly, we show that this effect is persistent, taking years until the normal hydrological patterns are reestablished. We show clear links between persistent changes in forest canopy structure and changes in hydrological patterns, revealing physical evidence of hydrological mechanisms that may lead to permanent changes in parts of the Amazon ecosystem. If prospects of increasing drought frequency are confirmed, a change in the current hydroecological patterns in the western Amazon could take place in less than a decade.

  11. The atmospheric sulfur cycle over the Amazon Basin. 2. Wet season

    SciTech Connect

    Andreae, M.O.; Berresheim, H.; Lewis, B.L.; Li, S. ); Jacob, D.J. ); Talbot, R.W. ); Bingemer, H.

    1990-09-20

    The authors determined the fluxes and concentrations of atmospheric sulfur species at ground level and from aircraft over the Amazon Basin during the 1987 wet season, providing a comprehensive description of the sulfur cycle over a remote tropical region. The vertical profile of dimethylsulfide (DMS) during the wet season was found to be very similar to that measured during the dry season. The concentrations of hydrogen sulfide (H{sub 2}S) were almost an order of magnitude higher than those of DMS, which makes H{sub 2}S the most important biogenic source species in the atmospheric sulfur cycle over the Amazon Basin. Using the gradient-flux approach, estimated the flux of DMS at the top of the tree canopy. The canopy was a source of DMS during the day, and a weak sink during the night. Measurements of sulfur gas emissions from soils, using the chamber method, showed very small fluxes, consistent with the hypothesis that the forest canopy is the major source of sulfur gases. The observed soil and canopy emission fluxes are similar to those measured in temperate regions. The concentrations of SO{sub 2} and sulfate aerosol in the wet season atmosphere were similar to dry season values. The sulfate concentration in rainwater, on the other hand, was lower by about a factor of 5 during the wet season. Due to the higher precipitation rate, however, the wet deposition flux of sulfate was not significantly different between the seasons. The measured fluxes and concentrations of DMS, H{sub 2}S, and SO{sub 2} were consistent with a model describing transport and chemistry of these sulfur species in the boundary layer. The concentrations of aerosol and the sulfate deposition rate, on the other hand, could only be explained by import of significant amounts of marine and anthropogenic sulfate aerosol into the Amazon Basin.

  12. Amazon forest structure generates diurnal and seasonal variability in light utilization

    NASA Astrophysics Data System (ADS)

    Morton, D. C.; Rubio, J.; Cook, B. D.; Gastellu-Etchegorry, J.-P.; Longo, M.; Choi, H.; Hunter, M. O.; Keller, M.

    2015-12-01

    The complex three-dimensional (3-D) structure of tropical forests generates a diversity of light environments for canopy and understory trees. Understanding diurnal and seasonal changes in light availability is critical for interpreting measurements of net ecosystem exchange and improving ecosystem models. Here, we used the Discrete Anisotropic Radiative Transfer (DART) model to simulate leaf absorption of photosynthetically active radiation (lAPAR) for an Amazon forest. The 3-D model scene was developed from airborne lidar data, and local measurements of leaf reflectance, aerosols, and PAR were used to model lAPAR under direct and diffuse illumination conditions. Simulated lAPAR under clear sky and cloudy conditions was corrected for light saturation effects to estimate light utilization, the fraction of lAPAR available for photosynthesis. Although the fraction of incoming PAR absorbed by leaves was consistent throughout the year (0.80-0.82), light utilization varied seasonally (0.67-0.74), with minimum values during the Amazon dry season. Shadowing and light saturation effects moderated potential gains in forest productivity from increasing PAR during dry season months when the diffuse fraction from clouds and aerosols was low. Comparisons between DART and other models highlighted the role of 3-D forest structure to account for seasonal changes in light utilization. Our findings highlight how directional illumination and forest 3-D structure combine to influence diurnal and seasonal variability in light utilization, independent of further changes in leaf area, leaf age, or environmental controls on canopy photosynthesis. Changing illumination geometry constitutes an alternative biophysical explanation for observed seasonality in Amazon forest productivity without changes in canopy phenology.

  13. Amazon forest structure generates diurnal and seasonal variability in light utilization

    NASA Astrophysics Data System (ADS)

    Morton, Douglas C.; Rubio, Jérémy; Cook, Bruce D.; Gastellu-Etchegorry, Jean-Philippe; Longo, Marcos; Choi, Hyeungu; Hunter, Maria; Keller, Michael

    2016-04-01

    The complex three-dimensional (3-D) structure of tropical forests generates a diversity of light environments for canopy and understory trees. Understanding diurnal and seasonal changes in light availability is critical for interpreting measurements of net ecosystem exchange and improving ecosystem models. Here, we used the Discrete Anisotropic Radiative Transfer (DART) model to simulate leaf absorption of photosynthetically active radiation (lAPAR) for an Amazon forest. The 3-D model scene was developed from airborne lidar data, and local measurements of leaf reflectance, aerosols, and PAR were used to model lAPAR under direct and diffuse illumination conditions. Simulated lAPAR under clear-sky and cloudy conditions was corrected for light saturation effects to estimate light utilization, the fraction of lAPAR available for photosynthesis. Although the fraction of incoming PAR absorbed by leaves was consistent throughout the year (0.80-0.82), light utilization varied seasonally (0.67-0.74), with minimum values during the Amazon dry season. Shadowing and light saturation effects moderated potential gains in forest productivity from increasing PAR during dry-season months when the diffuse fraction from clouds and aerosols was low. Comparisons between DART and other models highlighted the role of 3-D forest structure to account for seasonal changes in light utilization. Our findings highlight how directional illumination and forest 3-D structure combine to influence diurnal and seasonal variability in light utilization, independent of further changes in leaf area, leaf age, or environmental controls on canopy photosynthesis. Changing illumination geometry constitutes an alternative biophysical explanation for observed seasonality in Amazon forest productivity without changes in canopy phenology.

  14. Proliferation of Hydroelectric Dams in the Andean Amazon and Implications for Andes-Amazon Connectivity

    PubMed Central

    Finer, Matt; Jenkins, Clinton N.

    2012-01-01

    Due to rising energy demands and abundant untapped potential, hydropower projects are rapidly increasing in the Neotropics. This is especially true in the wet and rugged Andean Amazon, where regional governments are prioritizing new hydroelectric dams as the centerpiece of long-term energy plans. However, the current planning for hydropower lacks adequate regional and basin-scale assessment of potential ecological impacts. This lack of strategic planning is particularly problematic given the intimate link between the Andes and Amazonian flood plain, together one of the most species rich zones on Earth. We examined the potential ecological impacts, in terms of river connectivity and forest loss, of the planned proliferation of hydroelectric dams across all Andean tributaries of the Amazon River. Considering data on the full portfolios of existing and planned dams, along with data on roads and transmission line systems, we developed a new conceptual framework to estimate the relative impacts of all planned dams. There are plans for 151 new dams greater than 2 MW over the next 20 years, more than a 300% increase. These dams would include five of the six major Andean tributaries of the Amazon. Our ecological impact analysis classified 47% of the potential new dams as high impact and just 19% as low impact. Sixty percent of the dams would cause the first major break in connectivity between protected Andean headwaters and the lowland Amazon. More than 80% would drive deforestation due to new roads, transmission lines, or inundation. We conclude with a discussion of three major policy implications of these findings. 1) There is a critical need for further strategic regional and basin scale evaluation of dams. 2) There is an urgent need for a strategic plan to maintain Andes-Amazon connectivity. 3) Reconsideration of hydropower as a low-impact energy source in the Neotropics. PMID:22529979

  15. Proliferation of hydroelectric dams in the Andean Amazon and implications for Andes-Amazon connectivity.

    PubMed

    Finer, Matt; Jenkins, Clinton N

    2012-01-01

    Due to rising energy demands and abundant untapped potential, hydropower projects are rapidly increasing in the Neotropics. This is especially true in the wet and rugged Andean Amazon, where regional governments are prioritizing new hydroelectric dams as the centerpiece of long-term energy plans. However, the current planning for hydropower lacks adequate regional and basin-scale assessment of potential ecological impacts. This lack of strategic planning is particularly problematic given the intimate link between the Andes and Amazonian flood plain, together one of the most species rich zones on Earth. We examined the potential ecological impacts, in terms of river connectivity and forest loss, of the planned proliferation of hydroelectric dams across all Andean tributaries of the Amazon River. Considering data on the full portfolios of existing and planned dams, along with data on roads and transmission line systems, we developed a new conceptual framework to estimate the relative impacts of all planned dams. There are plans for 151 new dams greater than 2 MW over the next 20 years, more than a 300% increase. These dams would include five of the six major Andean tributaries of the Amazon. Our ecological impact analysis classified 47% of the potential new dams as high impact and just 19% as low impact. Sixty percent of the dams would cause the first major break in connectivity between protected Andean headwaters and the lowland Amazon. More than 80% would drive deforestation due to new roads, transmission lines, or inundation. We conclude with a discussion of three major policy implications of these findings. 1) There is a critical need for further strategic regional and basin scale evaluation of dams. 2) There is an urgent need for a strategic plan to maintain Andes-Amazon connectivity. 3) Reconsideration of hydropower as a low-impact energy source in the Neotropics. PMID:22529979

  16. Fault tree handbook

    SciTech Connect

    Haasl, D.F.; Roberts, N.H.; Vesely, W.E.; Goldberg, F.F.

    1981-01-01

    This handbook describes a methodology for reliability analysis of complex systems such as those which comprise the engineered safety features of nuclear power generating stations. After an initial overview of the available system analysis approaches, the handbook focuses on a description of the deductive method known as fault tree analysis. The following aspects of fault tree analysis are covered: basic concepts for fault tree analysis; basic elements of a fault tree; fault tree construction; probability, statistics, and Boolean algebra for the fault tree analyst; qualitative and quantitative fault tree evaluation techniques; and computer codes for fault tree evaluation. Also discussed are several example problems illustrating the basic concepts of fault tree construction and evaluation.

  17. Seasonal influence on biochemical profile and serum protein electrophoresis for Boa constrictor amarali in captivity.

    PubMed

    Silva, L F N; Riani-Costa, C C M; Ramos, P R R; Takahira, R K

    2011-05-01

    Similarly to other reptiles, snakes are ectothermic animals and depend exclusively on the environment for the maintenance of their physiological, biochemical and immunological processes. Thus, changes in biochemical values can be expected due to seasonal influence. Twenty-two adult specimens of Boa constrictor amarali kept in captivity were used. Blood collections were done in two different seasons: winter (July 2004) and summer (January 2005) for the following assays: uric acid, aspartate aminotransferase (AST), glucose, cholesterol, total protein, and serum protein electrophoresis. The mean biochemical results found in summer and winter, respectively, were: 6.3 ± 3.4 and 11.3 ± 6.2 mg/dL for uric acid; 28.7 ± 12.4 and 20.7 ± 16.2 UI/L for AST; 26.3 ± 17 and 17.4 ± 6.8 mg/dL for glucose; 67.3 ± 30.2 and 69.7 ± 38.5 mg/dL for cholesterol; and 5.9 ± 1.6 and 5.9 ± 1.4 g/dL for total protein. Results regarding electrophoresis in summer and winter, respectively, were: 1.9 ± 0.7 and 2.4 ± 0.6 g/dL for albumin; 0.7 ± 0.2 and 0.5 ± 0.2 g/dL for α-globulin; 1.5 ± 0.5 and 1.7 ± 0.6 g/dL for β-globulin; and 1.8 ± 0.5 and 1.5 ± 0.5 g/dL for γ-globulin. In the summer, there was a significant increase in AST and a decrease in uric acid (p < 0.05). Serum protein electrophoresis showed a significant increase in α-globulin fraction (p < 0.05) in the same season. There were not significant differences between seasons for the remaining variables. Based on these results, the period of the year must be considered in the interpretation of some biochemical values for these animals. PMID:21755171

  18. Autonomic control of heart rate during forced activity and digestion in the snake Boa constrictor.

    PubMed

    Wang, T; Taylor, E W; Andrade, D; Abe, A S

    2001-10-01

    Reptiles, particularly snakes, exhibit large and quantitatively similar increments in metabolic rate during muscular exercise and following a meal, when they are apparently inactive. The cardiovascular responses are similar during these two states, but the underlying autonomic control of the heart remains unknown. We describe both adrenergic and cholinergic tonus on the heart during rest, during enforced activity and during digestion (24-36 h after ingestion of 30 % of their body mass) in the snake Boa constrictor. The snakes were equipped with an arterial catheter for measurements of blood pressure and heart rate, and autonomic tonus was determined following infusion of the beta-adrenergic antagonist propranolol (3 mg kg(-1)) and the muscarinic cholinoceptor antagonist atropine (3 mg kg(-1)). The mean heart rate of fasting animals at rest was 26.4+/-1.4 min(-1), and this increased to 36.1+/-1.4 min(-1) (means +/- S.E.M.; N=8) following double autonomic block (atropine and propranolol). The calculated cholinergic and adrenergic tones were 60.1+/-9.3 % and 19.8+/-2.2 %, respectively. Heart rate increased to 61.4+/-1.5 min(-1) during enforced activity, and this response was significantly reduced by propranolol (maximum values of 35.8+/-1.6 min(-1)), but unaffected by atropine. The cholinergic and adrenergic tones were 2.6+/-2.2 and 41.3+/-1.9 % during activity, respectively. Double autonomic block virtually abolished tachycardia associated with enforced activity (heart rate increased significantly from 36.1+/-1.4 to 37.6+/-1.3 min(-1)), indicating that non-adrenergic, non-cholinergic effectors are not involved in regulating heart rate during activity. Blood pressure also increased during activity. Digestion was accompanied by an increase in heart rate from 25.6+/-1.3 to 47.7+/-2.2 min(-1) (N=8). In these animals, heart rate decreased to 44.2+/-2.7 min(-1) following propranolol infusion and increased to 53.9+/-1.8 min(-1) after infusion of atropine, resulting in small

  19. Isoprene photochemistry over the Amazon rainforest

    NASA Astrophysics Data System (ADS)

    Liu, Yingjun; Brito, Joel; Dorris, Matthew R.; Rivera-Rios, Jean C.; Seco, Roger; Bates, Kelvin H.; Artaxo, Paulo; Duvoisin, Sergio; Keutsch, Frank N.; Kim, Saewung; Goldstein, Allen H.; Guenther, Alex B.; Manzi, Antonio O.; Souza, Rodrigo A. F.; Springston, Stephen R.; Watson, Thomas B.; McKinney, Karena A.; Martin, Scot T.

    2016-05-01

    Isoprene photooxidation is a major driver of atmospheric chemistry over forested regions. Isoprene reacts with hydroxyl radicals (OH) and molecular oxygen to produce isoprene peroxy radicals (ISOPOO). These radicals can react with hydroperoxyl radicals (HO2) to dominantly produce hydroxyhydroperoxides (ISOPOOH). They can also react with nitric oxide (NO) to largely produce methyl vinyl ketone (MVK) and methacrolein (MACR). Unimolecular isomerization and bimolecular reactions with organic peroxy radicals are also possible. There is uncertainty about the relative importance of each of these pathways in the atmosphere and possible changes because of anthropogenic pollution. Herein, measurements of ISOPOOH and MVK + MACR concentrations are reported over the central region of the Amazon basin during the wet season. The research site, downwind of an urban region, intercepted both background and polluted air masses during the GoAmazon2014/5 Experiment. Under background conditions, the confidence interval for the ratio of the ISOPOOH concentration to that of MVK + MACR spanned 0.4–0.6. This result implies a ratio of the reaction rate of ISOPOO with HO2 to that with NO of approximately unity. A value of unity is significantly smaller than simulated at present by global chemical transport models for this important, nominally low-NO, forested region of Earth. Under polluted conditions, when the concentrations of reactive nitrogen compounds were high (>1 ppb), ISOPOOH concentrations dropped below the instrumental detection limit (<60 ppt). This abrupt shift in isoprene photooxidation, sparked by human activities, speaks to ongoing and possible future changes in the photochemistry active over the Amazon rainforest.

  20. Isoprene photochemistry over the Amazon rainforest.

    PubMed

    Liu, Yingjun; Brito, Joel; Dorris, Matthew R; Rivera-Rios, Jean C; Seco, Roger; Bates, Kelvin H; Artaxo, Paulo; Duvoisin, Sergio; Keutsch, Frank N; Kim, Saewung; Goldstein, Allen H; Guenther, Alex B; Manzi, Antonio O; Souza, Rodrigo A F; Springston, Stephen R; Watson, Thomas B; McKinney, Karena A; Martin, Scot T

    2016-05-31

    Isoprene photooxidation is a major driver of atmospheric chemistry over forested regions. Isoprene reacts with hydroxyl radicals (OH) and molecular oxygen to produce isoprene peroxy radicals (ISOPOO). These radicals can react with hydroperoxyl radicals (HO2) to dominantly produce hydroxyhydroperoxides (ISOPOOH). They can also react with nitric oxide (NO) to largely produce methyl vinyl ketone (MVK) and methacrolein (MACR). Unimolecular isomerization and bimolecular reactions with organic peroxy radicals are also possible. There is uncertainty about the relative importance of each of these pathways in the atmosphere and possible changes because of anthropogenic pollution. Herein, measurements of ISOPOOH and MVK + MACR concentrations are reported over the central region of the Amazon basin during the wet season. The research site, downwind of an urban region, intercepted both background and polluted air masses during the GoAmazon2014/5 Experiment. Under background conditions, the confidence interval for the ratio of the ISOPOOH concentration to that of MVK + MACR spanned 0.4-0.6. This result implies a ratio of the reaction rate of ISOPOO with HO2 to that with NO of approximately unity. A value of unity is significantly smaller than simulated at present by global chemical transport models for this important, nominally low-NO, forested region of Earth. Under polluted conditions, when the concentrations of reactive nitrogen compounds were high (>1 ppb), ISOPOOH concentrations dropped below the instrumental detection limit (<60 ppt). This abrupt shift in isoprene photooxidation, sparked by human activities, speaks to ongoing and possible future changes in the photochemistry active over the Amazon rainforest. PMID:27185928

  1. The phenology pattern of rubber trees in plantation and its impacts on rubber tree structure, water and carbon cycles

    NASA Astrophysics Data System (ADS)

    Liu, W.; Giambelluca, T. W.; Mudd, R. G.

    2012-12-01

    Commercial rubber (Hevea Brasiliensis) is originally native to the Amazon rainforest and it has become one of the important commercial crops in Mainland Southeast Asia. Similarly to some trees species in Amazon but quite distinctly from other native forests in Southeast Asia, rubber tree sheds its leaves in the middle of dry season and flushes new leaves before the onset of the wet season. Moreover, the mountane mainland Southeast Asia is heavily influenced by the monsoon climate which has most the precipitation in the wet season while almost no rainfall in the dry season. It is believed that the phenology pattern of rubber interacted with local climate would not only regulate the seasonal rubber plantation structures but also further alter the local energy and water budget. However, it is still lack of solid understandings of how the phenology patterns in terms of the leaf area index (LAI) changes of the rubber tree response to environmental drivers. The study tries to shed lights on the issue from analyses of a various types of in-situ field data combined with 3 years' tower flux measurements collected within the rubber plantations. It concludes that: 1) Both the monthly tree height increment and the monthly biomass accumulation are highly correlated with the LAI changes, which have the low rate of changes in the dry season versus the relative high rate of changes in the wet season; 2) the daily evapotranspiration (ET) of the rubber tree is very sensitive to the daily LAI changes in the dry season (R2 > 0.9); 3) the LAI changes, especially the leaf drops, are majorly determined by the accumulated precipitation in the past three months.

  2. Imaging Laser Altimetry in the Amazon: Mapping Large Areas of Topography, Vegetation Height and Structure, and Biomass

    NASA Technical Reports Server (NTRS)

    Blair, J. Bryan; Nelson, B.; dosSantos, J.; Valeriano, D.; Houghton, R.; Hofton, M.; Lutchke, S.; Sun, Q.

    2002-01-01

    A flight mission of NASA GSFC's Laser Vegetation Imaging Sensor (LVIS) is planned for June-August 2003 in the Amazon region of Brazil. The goal of this flight mission is to map the vegetation height and structure and ground topography of a large area of the Amazon. This data will be used to produce maps of true ground topography, vegetation height, and estimated above-ground biomass and for comparison with and potential calibration of Synthetic Aperture Radar (SAR) data. Approximately 15,000 sq. km covering various regions of the Amazon will be mapped. The LVIS sensor has the unique ability to accurately sense the ground topography beneath even the densest of forest canopies. This is achieved by using a high signal-to-noise laser altimeter to detect the very weak reflection from the ground that is available only through small gaps in between leaves and between tree canopies. Often the amount of ground signal is 1% or less of the total returned echo. Once the ground elevation is identified, that is used as the reference surface from which we measure the vertical height and structure of the vegetation. Test data over tropical forests have shown excellent correlation between LVIS measurements and biomass, basal area, stem density, ground topography, and canopy height. Examples of laser altimetry data over forests and the relationships to biophysical parameters will be shown. Also, recent advances in the LVIS instrument will be discussed.

  3. Rare earth elements in the Amazon basin

    NASA Astrophysics Data System (ADS)

    Gerard, M.; Seyler, P.; Benedetti, M. F.; Alves, V. P.; Boaventura, G. R.; Sondag, F.

    2003-05-01

    The rare earth element (REE) concentrations of the dissolved and particulate fractions and bed sediment between Manaus and Santarém in the Amazon River, and in some major tributaries, were evaluated. A very important zone in the Amazon basin, the encontro das aguas area where the Rio Solimões and the Rio Negro meet, was especially sampled. Different size fractions were isolated by ultrafiltration. Water samples were collected at different stages of the mixing. Three groups of waters are distinguished: group I has a low pH (<5·5) and is represented by the Negro basin rivers; group II has alkalinity less than 0·2 meq l-1 and is represented by the Rios Tapajós and Trombetas; group III has high alkalinity (>0·2 meq l-1) and higher pH (>6·5) and is represented by the Madeira basin rivers, the Solimões and the Amazon. The highest dissolved REE concentration is in the Rio Negro and the lowest in the Rio Tapajós (dissolved REEs vary by more than a factor of ten). The solubility of REEs is pH dependent: in river waters with a pH < 6 the Ce concentration is twice that of La, whereas in rivers with a higher pH the concentrations of Ce and La are similar. Dissolved REE concentrations are positively correlated with the dissolved organic carbon. Correlations between Fe, Al, and La suggest that La is associated with Al (Fe)-rich organic matter and/or related to dissolved Fe-rich inorganic material. Dissolved REEs normalized to North American shale composite show an enrichment in intermediate/heavy REEs (from Eu to Er), except for the shields rivers (such as Rio Negro and Rio Trombetas). Both of them are depleted in heavy REEs and show a relative Ce enrichment. In contrast, for the Andeans rivers (such as Rio Solimões), light REEs are slightly depleted and a negative Ce relative anomaly occurs. The pattern of the Amazon River at Óbidos confirms the major influence of the Rios Negro and Solimões with REE fractionation. For the Rio Negro, 60 to 70% of REEs are

  4. [The Amazon Sanitation Plan (1940-1942)].

    PubMed

    Andrade, Rômulo de Paula; Hochman, Gilberto

    2007-12-01

    The article addresses the Amazon Sanitation Plan and the political context in which it was formulated between 1940 and 1941. It examines the role of Getúlio Vargas, the activities of the plan's main protagonists (such as Evandro Chagas, João de Barros Barreto, and Valério Konder), its key proposals, and its demise as of 1942 upon creation of the Special Public Health Service (Sesp), which grew out of cooperation agreements between Brazil and the US following both nations' involvement in World War II. A reproduction of the Plan as published in the Arquivos de Higiene in 1941 is included. PMID:18783151

  5. Impacts on regional climate of Amazon deforestation

    SciTech Connect

    Dickinson, R.E.; Kennedy, P. NCAR, Boulder, CO )

    1992-10-01

    A simulation of the climate response to Amazon deforestation has been carried out. Precipitation is decreased on the average by 25 percent or 1.4 mm/day, with ET and runoff both decreasing by 0.7 mm/day. Modifications of surface energy balance through change of albedo and roughness are complicated by cloud feedbacks. The initial decrease of the absorption of solar radiation by higher surface albedos is largely cancelled by a reduction in cloud cover, but consequent reduction in downward longwave has a substantial impact on surface energy balance. Smoke aerosols might have an effect comparable to deforestation during burning season. 8 refs.

  6. Categorizing Ideas about Trees: A Tree of Trees

    PubMed Central

    Fisler, Marie; Lecointre, Guillaume

    2013-01-01

    The aim of this study is to explore whether matrices and MP trees used to produce systematic categories of organisms could be useful to produce categories of ideas in history of science. We study the history of the use of trees in systematics to represent the diversity of life from 1766 to 1991. We apply to those ideas a method inspired from coding homologous parts of organisms. We discretize conceptual parts of ideas, writings and drawings about trees contained in 41 main writings; we detect shared parts among authors and code them into a 91-characters matrix and use a tree representation to show who shares what with whom. In other words, we propose a hierarchical representation of the shared ideas about trees among authors: this produces a “tree of trees.” Then, we categorize schools of tree-representations. Classical schools like “cladists” and “pheneticists” are recovered but others are not: “gradists” are separated into two blocks, one of them being called here “grade theoreticians.” We propose new interesting categories like the “buffonian school,” the “metaphoricians,” and those using “strictly genealogical classifications.” We consider that networks are not useful to represent shared ideas at the present step of the study. A cladogram is made for showing who is sharing what with whom, but also heterobathmy and homoplasy of characters. The present cladogram is not modelling processes of transmission of ideas about trees, and here it is mostly used to test for proximity of ideas of the same age and for categorization. PMID:23950877

  7. [Drawer of boundaries: Franz Boas and the (im)possibility of the concept of culture in anthropology].

    PubMed

    Martínez-Hernáez, Angel

    2011-01-01

    The history of anthropology has tended towards two extremes in its analyses of the works of Franz Boas: aggrandizement or underestimation. This disparity can be explained by the author's liminal relationship with two research approaches in anthropology: universalist theories (evolutionism, difussionism, racialism, etc.) and culturalist theories, prevalent between the late nineteenth and early twentieth centuries. With this argument in mind, the article discusses the emergence of the Boasian concept of culture and endeavors to show how this concept proves both possible and impossible within the author's own work. PMID:22012102

  8. Seasonal variation of Hepatozoon spp. (Apicomplexa, Hepatozoidae) parasitemia from Boa constrictor amarali (Serpentes, Boidae) and Hydrodynastes gigas (Serpentes, Colubridae).

    PubMed

    de Vieira Santos, Mariana Morena; O'Dwyer, Lucia Helena; da Silva, Reinaldo José

    2005-09-01

    The aim of this study was to evaluate the parasitemia variation of three Hepatozoon species in Brazilian snakes. This study was conducted between 2001 and 2003 and included Hepatozoon terzii from Boa constrictor amarali, and Hepatozoon migonei and Hepatozoon cyclagrasi from Hydrodynastes gigas. It was observed that the parasitemia tended to decrease in all three Hepatozoon species but the parasites were not eliminated. This data suggest that Hepatozoon infection may be similar to Toxoplasma gondii infection, in that it persists throughout host life. PMID:15999279

  9. The atmospheric sulfur cycle over the Amazon Basin. II - Wet season

    NASA Technical Reports Server (NTRS)

    Andreae, M. O.; Bingemer, H.; Berresheim, H.; Jacob, D. J.; Lewis, B. L.

    1990-01-01

    The fluxes and concentrations of atmospheric sulfur species were determined at ground level and from aircraft over the Amazon Basin during the 1987 wet season, providing a comprehensive description of the sulfur cycle over a remote tropical region. The vertical profile of dimethylsulfide (DMS) during the wet season was found to be very similar to that measured during the dry season, suggesting little seasonal variation in DMS fluxes. The concentrations of H2S were almost an order of magnitude higher than those of DMS, which makes H2S the most important biogenic source species in the atmosheric sulfur cycle over the Amazon Basin. Using the gradient-flux approach, the flux of DMS at the top of the tree canopy was estimated. The canopy was a source of DMS during the day, and a weak sink during the night. Measurements of sulfur gas emissions from soils, using the chamber method, showed very small fluxes, consistent with the hypothesis that the forest canopy is the major source of sulfur gases. The observed soil and canopy emission fluxes are similar to those measured in temperate regions. The concentrations of SO2 and sulfate aerosol in the wet season atmosphere were similar to dry season values.

  10. Charting the Impacts of Disturbance on Biomass Accumulation in Old-Growth Amazon Forests

    NASA Astrophysics Data System (ADS)

    Chambers, J.; Fisher, J.; Hurtt, G.; Baker, T.; Camargo, P.; Campanella, R.; Dos Santos, J.; Higuchi, N.; Malhi, Y.; Phillips, O.; Plourde, L.; Smith, M.; Trumbore, S.

    2006-12-01

    Observed increases in intact Amazon forest biomass, averaging ~0.6 Mg C ha-1 yr-1, have led to suggestions that a forest sink may be of a magnitude large enough to substantially offset Amazonian land- use sources. The mechanism which explains the biomass increase remains unclear. Here we use a synthetic approach, combining remote sensing, intensive field observations, and simulation modeling to elucidate the impact of disturbance on forest structure and changes in biomass. EO-1 Hyperion data and existing field data will be analyzed to generate broad scale disturbance maps. These maps will integrate information from field and remote sensing investigations, spanning a gradient from individual trees to landscape-scale events. Intensive field work will quantify the mortality from these disturbance events. Mapped data will be used to parameterize the height-structured Ecosystem Demography model (ED). ED offers a general method of scaling stochastic individual-based models of ecosystem dynamics to regional scales. Model runs of ED with synthetic mortality rates brackets the range of potential carbon flux attributable to disturbance, mortality, and recovery. The parameterization of the model with generated disturbance maps will provide a best estimate biomass gain due to disturbance patterns across the Amazon.