Showing papers in "Acta Amazonica in 2014"
TL;DR: An ethno botanical survey to assess plant knowledge and use of medicinal plants by local people of four riverine communities at the municipality of Manacapuru confirms that populations living in ManacAPuru still use medicinal plants as one of the ways of treating their most frequent ailments.
Abstract: A utilizacao de plantas medicinais e uma pratica comum entre as populacoes humanas. O presente trabalho teve por objetivo efetuar levantamento etnobotânico sobre o conhecimento e uso das plantas medicinais em quatro comunidades ribeirinhas do Municipio de Manacapuru. Foram coletadas informacoes de 164 moradores locais, selecionados aleatoriamente, por meio de entrevistas semi-estruturadas, observacoes participantes e visitas guiadas. Os problemas de saude citados foram classificados de acordo com a Classificacao Estatistica Internacional de Doencas e Problemas Relacionados a Saude (CID-10) e indices de concordância foram utilizados para identificar os principais usos de cada especie. Identificaram-se 171 plantas medicinais, pertencentes a 65 familias. Lamiaceae (14 especies), Asteraceae (9 especies), Fabaceae e Euphorbiaceae (8 especies) foram as familias mais comuns. As especies mais citadas foram Mentha arvensis (hortela), Ruta graveolens (arruda) e Citrus sinensis (laranja). As folhas foram as partes da planta mais utilizadas e a decoccao da folha o procedimento mais comum usado para preparar medicamentos. Os problemas mais comuns citados foram doencas do aparelho digestivo, doencas do aparelho respiratorio e problemas com sintomas nao classificados. Plantas com indices de concordância maior que 25% foram Plectranthus amboinicus, Chenopodium ambrosioides, Citrus aurantiifolia, Acmella oleracea, Plectranthus barbatus, Mentha arvensis, Citrus sinensis, Lippia origanoides, Lippia alba, Cymbopogon citratus e Ruta graveolens. Estes resultados confirmam que as populacoes que vivem em Manacapuru ainda utilizam plantas medicinais como uma das formas de tratar suas doencas mais frequentes.
95 citations
TL;DR: In both suborders, environmental perturbations do not need to be severe to change species composition, indicating that ecosystem services could be lost, even with only partial alterations in physical environment.
Abstract: The removal or substitution of riparian vegetation causes disturbance in physical environment, seasonal water flow and water chemical quality. These modifications can cause decrease in species richness by local extinctions. The aim of this study was to examine the effect of disturbance in the physical environmental on the richness and species composition of Odonata adults in streams with different levels of conservation in the river Suia-Missu basin, Mato Grosso, Brazil. Modifications in the aquatic systems affected the Odonata community, probably because their ecophysiological and behavioral requirements of adults and larvae. Anisoptera species, which require sunny environments because of their body size, had higher species richness in environments with low plant cover. On the other hand, Zygoptera species, which generally inhabit streams with dense vegetation, presented a decrease in richness in disturbed environments, as a result high sunlight radiation and/or variations in temperature. Hence, in both suborders, environmental perturbations do not need to be severe to change species composition, indicating that ecosystem services could be lost, even with only partial alterations in physical environment.
61 citations
TL;DR: In this article, Guenther et al. identify and quantitatively quantify the emissao of isopreno and fotossintese em diferentes niveis of intensidade de luz and temperatura foliar, em tres fases fenologicas (folha madura recente, folha senescente) of Eschweilera coriacea (Matamata verdadeira) of Bacia Amazonica central.
Abstract: O isopreno emitido pelas plantas corresponde em cerca de um terco das emissoes globais de compostos orgânicos volateis anualmente. A maior fonte de emissao de isopreno para a atmosfera global e a Bacia Amazonica. Este estudo objetivou identificar e quantificar a emissao de isopreno e fotossintese em diferentes niveis de intensidade de luz e temperatura foliar, em tres fases fenologicas (folha madura recente, folha madura tardia e folha senescente) de Eschweilera coriacea (Matamata verdadeira) - a especie com maior distribuicao na Amazonia central. In situ, as medidas de fotossintese e emissao de isopreno da folha madura recente apresentaram as maiores taxas em todos os niveis de luz e de temperatura. Adicionalmente, a capacidade de emissao de isopreno (ES) mudou consideravelmente entre as diferentes idades foliares, sugerindo que o envelhecimento reduz a atividade fotossintetica e a producao/emissao de isopreno. O algoritmo de Guenther et al. (1999) demonstrou bom ajuste para a emissao de isopreno em diferentes intensidades de luz, entretanto, diferencas na ES entre as idades foliares influenciaram no rendimento quântico estimado pelo modelo. Em relacao a temperatura foliar, a estimativa do algoritmo nao foi satisfatoria para as temperaturas acima de ~40 °C; isto provavelmente ocorreu pelo fato dos dados nao apresentarem temperatura otima ate 45 °C. Nossos resultados sao consistentes com a hipotese do isopreno ter um papel funcional para proteger as plantas de altas temperaturas e apontam a necessidade de incluir os efeitos da fenologia foliar em modelos de emissao de isopreno.
39 citations
TL;DR: Among 30 species collected in pastures, twelve are present in native open vegetation too, which represents a recent regional colonization, where species of dung beetles, coming from open areas, are invading the Amazonian pastures.
Abstract: The dung beetles are copro-necrophagous insects and use mainly feces and carrion of mammals as food and nesting source. These insects are sensitive to habitat modification mainly related to vegetation cover. The substitution of the Amazon forest by pasture cause drastic changes in the habitat of native species. This reduces richness and modifies assembly species composition. The aim of this work was understand the effects of substitution of native forest by pasture introduced in richness, abundance, species composition and structure of feeding guilds of dung beetle in southwestern Brazilian Amazon. A total of 10,073 individuals of dung beetles were collected, belonging to 84 species in 22 genera. Forests areas (six secondary forest fragments) had 71 species and the pastures areas (neighboring areas where original forest was substitution by introduced pasture) had significantly lower richness (30 species), and community turnover between forests and pasture was very high. In forests the majority of species were generalist, while pastures showed higher abundance of coprophagous species, which shows a change in feeding guilds caused by the substitution of forest by pasture. Among 30 species collected in pastures, twelve are present in native open vegetation too (cerrado e chaco). That represents a recent regional colonization, where species of dung beetles, coming from open areas, are invading the Amazonian pastures.
36 citations
TL;DR: Investigation of population structure and reproductive characteristics of M. amazonicum from two important areas to artisanal prawn fishing located at the mouth of the Amazon River, State of Amapa and Santana Island and Mazagao Velho showed females predominated in the population.
Abstract: Macrobrachium amazonicum is an indigenous prawn vastly distributed in basins of South America, widely exploited by artisanal fisheries in northern and northeastern Brazil and, with great potential for aquaculture. This study aimed to investigate general aspects of population structure and reproductive characteristics (size at first maturity, fecundity and reproductive output) of M. amazonicum from two important areas to artisanal prawn fishing located at the mouth of the Amazon River, State of Amapa. The specimens were captured using 20 handcrafted traps called "matapi". A number of 5,179 prawns were captured, 2,975 females and 2,195 males resulting in 1.35:1 female to male ratio. Santana Island and Mazagao Velho showed females predominated in the population. A reproductive peak period was observed from January to April/2009 and in December/2010, coinciding with the period of higher rainfall. The recruitment peak occurred in June and July/2009. Egg-bearing females ranged in size (carapace length) from 11.10 to 29.6 mm. Fecundity increased with female size and reached up to 7,417 eggs. This amount of eggs is considered low if compared with other Macrobrachium estuarine species. Mean egg volume increased gradually from 0.121 to 0.24 mm3 during embryogenesis, representing 68.5% of overall increase from Stage I to Stage III. Eggs of M. amazonicum are small; this is typical for Macrobrachium species, which depends on brackish water to complete the larval development. Irrespective of female size, reproductive output of M. amazonicum varied between 4.8 and 21.85% of their body weight into eggs production.
33 citations
TL;DR: The results indicated that M. carcinus can be considered omnivorous species, but with an important carnivorous component, similar to that found in other Macrobrachium species.
Abstract: Macrobrachium carcinus is a Brazilian native prawn with recognized potential for use in aquaculture activities. However, there is little information about the natural diet and feeding habits of this species. The aim of this study was the identification of the diet items of M. carcinus based on the analysis of the stomach contents. Specimens were collected in the Amazon River estuary between January 2009 and January 2010. The stomach analysis was carried out by using the frequency of occurrence (FO), methods of points (MP) and feeding index (FI). It was observed that prawns fed on detritus, animals and plant fragments as the most important food items. Sediment accounted for the main stomach content, accounting for 43.2% by the MP, 44.9% by FI and 100% by the FO. Sexual differences in feeding preferences were not found in this study, and seasonal differences in the frequency of items ingested by M. carcinus were not observed. The results indicated that M. carcinus can be considered omnivorous species, but with an important carnivorous component, similar to that found in other Macrobrachium species.
29 citations
TL;DR: The daily analysis of variation indicated an oligomitic pattern during the years in which the lake was permanently connected to the Negro River, which seems to exert the main influence during the rising water period, while the Solimoes River is the principal controlling river during peak water.
Abstract: Lakes play an important role in biogeochemical, ecological and hydrological processes in the river-floodplain system. The aim of this study was to evaluate the dynamics of the limnological conditions of Catalao Lake, an Amazon floodplain lake. Thus, some of the main limnological environment variables (O2, temperature, pH, nutrient, electrical conductivity) of the Catalao Lake were analyzed under temporal and spacial scales. The study was conducted between November/2004 and August/2005. Sampling excursion were carried out every three months; one excursion for each of the four different hydrological periods (low water, rising water, high water and falling water). Sampling points were chosen so that it could be obtained a gradient of the distance from Negro River. Limnological profiles in Catalao Lake showed generally acidic to slightly alcaline water, with low levels of dissolved oxygen and low concentrations of soluble reactive phosphorous. The Negro River seems to exert the main influence during the rising water period, while the Solimoes River is the principal controlling river during peak water. The Principal Component Analysis (PCA) grouped the seasonal collections by hydrological period, showing the formation of a north-south spatial gradient within the lake in relation to the limnological variables. Multivariate dispersion analysis based on distance-to-centroid method demonstrated an increase in similarity over the course of the hydrological cycle, as the lake was inundated in response to the flood pulse of the main river channels. However, the largest spatial homogeneity in the lake was observed in the epilimnion layer, during the falling water period. The daily analysis of variation indicated an oligomitic pattern during the years in which the lake was permanently connected to the Negro River. Although Catalao Lake receives large quantities of both black water from the Negro River and sediment-filled water from the Solimoes River, the physical and chemical characteristics of the lake are more similar to those of the Solimoes (varzea lake) than the Negro (blackwater lake).
27 citations
TL;DR: In this article, two maps of deforestation hot spots were generated on the basis of MODIS data, one using digital techniques and the other by means of direct visual interpretation by experts.
Abstract: Land cover changes over time as a result of human activity. Nowadays deforestation may be considered one of the main environmental problems. The objective of this study was to identify and characterize changes to forest cover in Venezuela between 2005-2010. Two maps of deforestation hot spots were generated on the basis of MODIS data, one using digital techniques and the other by means of direct visual interpretation by experts. These maps were validated against Landsat ETM+ images. The accuracy of the map obtained digitally was estimated by means of a confusion matrix. The overall accuracy of the maps obtained digitally was 92.5%. Expert opinions regarding the hot spots permitted the causes of deforestation to be identified. The main processes of deforestation were concentrated to the north of the Orinoco River, where 8.63% of the country’s forests are located. In this region, some places registered an average annual forest change rate of between 0.72% and 2.95%, above the forest change rate for the country as a whole (0.61%). The main causes of deforestation for the period evaluated were agricultural and livestock activities (47.9%), particularly family subsistence farming and extensive farming which were carried out in 94% of the identified areas.
22 citations
TL;DR: In this paper, the authors investigated the hooking mortality of Cichla spp., including speckled peacock bass (C. temensis Humbolt), butterfly peacock fish, and popoca fish, in the basin of the Negro River, the largest tributary of the Amazon River.
Abstract: Sport fishing for peacock bass Cichla spp. in the Brazilian Amazon has increased in popularity and attracts anglers who generate significant economic benefits in rural regions. The sustainability of this fishery is partly dependent on the survival of fish caught through catch-and-release fishing. The objective of this work was to investigate, hooking mortality of Cichla spp., including speckled peacock bass (C. temensis Humbolt), butterfly peacock bass (C. orinocensis Humbolt), and popoca peacock bass (C. monoculus Agassiz) in the basin of the Negro River, the largest tributary of the Amazon River. Fish were caught at two different sites using artificial lures, transported to pens anchored in the river and monitored for 72 hours. A total of 162 individual peacock bass were captured and hooking mortality (mean % ± 95% confidence intervals) was calculated. Mean mortality was 3.5% (± 5.0), 2.3% (± 3.5) and 5.2% (± 10.2) for speckled peacock bass, butterfly peacock bass, and popoca peacock bass, respectively. Lengths of captured fish ranged from 26 to 79 cm (standard length), however, only fish under 42 cm died. This research suggests that catch-and-release sport fishing of peacock bass does not result in substantial mortality in the Negro River basin.
21 citations
TL;DR: The aim of this study was to assess the persistence time, half-life time, macronutrient content and accumulation, and C:N ratio of straw coverage in a Ultisol in northeastern Para.
Abstract: Studies to select one or more species of coverage plants adapted to Amazonian soil and climate conditions of the Amazon are a promising strategy for the improvement of environmental quality, establishing no-till agricultural systems, and thereby reducing the impacts of monoculture farming. The aim of this study was to assess the persistence time, half-life time, macronutrient content and accumulation, and C:N ratio of straw coverage in a Ultisol in northeastern Para. Experimental design was randomized blocks with five treatments and five replicates. Plants were harvested after 105 days, growth and biomass production was quantified. After 84 days, soil coverage was 97, 85, 52, 50, and 15% for signalgrass ( Brachiaria brizantha ) (syn. Urochloa ), dense crowngrass ( Panicum purpurascens ), jack bean ( Canavalia ensiformes ), pearl millet ( Pennisetum americanum ) and sunn hemp ( Crotalaria juncea, ), respectively. Signalgrass yielded the greatest dry matter production (9,696 kg ha
19 citations
TL;DR: In this article, a study was conducted in Puruzinho lake (Humaita, AM) considering seasonal periods of rainy and dry in way to elucidate the flood pulse importance in the deposition, remobilization and distributions of mercury and organic matter in bottom sediments in the Madeira River Basin (Brazilian Amazon).
Abstract: The study was conducted in Puruzinho lake (Humaita, AM) considering seasonal periods of rainy and dry in way to elucidate the flood pulse importance in the deposition, remobilization and distributions of mercury and organic matter in bottom sediments in the Madeira River Basin (Brazilian Amazon). Bottom sediments and soils samples were analyzed for total mercury and organic matter. Mercury concentrations obtained in bottom sediment were 32.20-146.40 ng g-1 and organic matter values were 3.5 - 18.0%. The main region for accumulation of mercury and organic matter was in the central and deepest lake area In the rainy season there was a greater distribution of Hg and organic matter, mainly controlled by means of income of the Madeira river water during flooding, while the predominant process in the dry season was the remobilization of total Hg due to the resuspension of bottom sediments.
TL;DR: In this paper, a biota do solo dos remanescentes florestais and de areas em regeneracao (capoeiras) do CEB was studied.
Abstract: O Centro de Endemismo Belem (CEB) -regiao biogeografica localizada entre os rios Tocantins e Pindare- e a area mais desmatada da Amazonia. Estudar a biota do solo dos remanescentes florestais e de areas em regeneracao (capoeiras) do CEB e fundamental para promover praticas agricolas mais sustentaveis e orientar acoes de restauracao de areas degradadas. Dessa forma, o objetivo desse estudo foi identificar os principais determinantes da composicao e da diversidade dos grandes taxons de macrofauna do solo (uso atual do solo, nucleos geograficos, historico de uso, frequencia de fogo) em uma cronosequencia de capoeiras e florestas no CEB. A macrofauna foi amostrada em oito areas de capoeiras baixas (4-7 anos), seis areas de capoeiras medias (11-15 anos), sete areas de capoeiras altas (20-40 anos), oito areas de remanescentes de florestas e tres areas de pastagem. Sua composicao e diversidade foi estudada atraves de Analises de Componentes Principais e Entre-classes. Um total de 9.225 individuos pertencentes a 29 grandes taxons (ordens ou familias) foram coletados nas 32 parcelas amostradas. A composicao da macrofauna se mostrou sensivel ao efeito do historico de uso do solo e identificou comunidades significativamente distintas entre as micro-regioes, havendo nessa escala efeito da cronosequencia de capoeiras e florestas. A intensidade do uso do solo levou a reducao da abundância e da riqueza de predadores, indicando alteracoes significativas no funcionamento do solo. Esses resultados mostram um efeito duradouro da degradacao sobre a macrofauna do solo e consequentemente sobre suas funcoes ecologicas.
TL;DR: In this article, the anatomical characteristics, calorific power and volatiles and ash content of carbonized wood from Byrsonima spicata, Calophyllum brasiliense, Cecropia sciadophylla, Cochlospermum orinocense and Schefflera morotoni were evaluated.
Abstract: Charcoal is an important energy raw material and its properties are influenced by the wood’s anatomical and chemical composition and the production process. The aim of this study was to evaluate the anatomical characteristics, calorific power and volatiles and ash content of carbonized wood from Byrsonima spicata, Calophyllum brasiliense, Cecropia sciadophylla, Cochlospermum orinocense and Schefflera morototoni. The calorific power varied from 26,878 to 31,117 kJ kg -1 ; the content of volatile materials ranged from 20.9 to 31.7%; ash content ranged from 0.1 to 3.8%; and carbon content varied from 68.2 to 75.3%. Anatomical structures of charcoal can be used for species identification. The studied species are not indicated for charcoal production because the levels of ash and volatile compounds are higher than those recommended for charcoal produced for household use. In addition, the calorific power and level of carbon content are insufficient for use in the steel industry.
TL;DR: The mangrove crab (Ucides cordatus) is a valuable fishery resource, overfished along the Brazilian coast, and showed sexual dimorphism, with linear measurements significantly higher in males than in females, compared to other Brazilian states.
Abstract: The mangrove crab (Ucides cordatus) is a valuable fishery resource, overfished along the Brazilian coast. This study aimed to obtain bioecological data on this crab along the coast of the State of Amapa. Six bimonthly samplings were conducted between December 2008 and January 2010. Transects were used to estimate the density (burrows m-2) and population abundance (individuals m-2). All the animals were subjected to biometrics, with females being classified according to their stage of gonadal maturation. The mean density (1.09 burrows m-2) and abundance (0.31 individuals m-2) were influenced by the climate with the highest values in summer (1.17 burrows m-2 and 0.34 individuals m-2). The male to female ratio was 1.38:1 showing significant difference in the proportion of sexes. The individuals showed sexual dimorphism, with linear measurements significantly higher in males. The sampled animals also had larger carapace length and width (CL and CW) compared to crabs studied in other Brazilian states. There was a positive relationship between CW and CL and individual weight (IW) and CW for males (R2 = 0.83 and 0.90) and females (R2 = 0.79 and 0.84). The growth was negative allometric (CL increases to a lesser extent than CW) for both sexes. The highest frequency of ovigerous females (78%) and in maturation stage IV (38%) occurred in the CW size class between 59.8 and 67.5 mm. The peak of mature females occurred in May and August, showing a reproductive period different from those in other Brazilian states.
TL;DR: In this article, a composicao quimica elementar do fitoplancton and composta por elevadas concentracoes of Ca, P, Mn, Fe, Zn, Al, Ba and Pb.
Abstract: O fitoplancton e de grande importância para os estudos das interacoes solo-agua, como indicadores de modificacoes quimicas e biologicas nos ecossistemas naturais. O objetivo desse estudo foi determinar a composicao quimica total do fitoplâncton nos estuarios do rio Para e Mocajuba (Para, Brasil). As analises quimicas foram realizadas na agua superficial, sedimento de fundo (amostra total e fracao biodisponivel) e no fitoplancton, por espectrometria optica e de massa com plasma indutivamente acoplado. A composicao quimica elementar do fitoplancton e composta por elevadas concentracoes de Ca, P, Mn, Fe, Zn, Al, Ba e Pb. O fitoplancton do estuario do rio Mocajuba e rico em Fe (2.967 a 84.750 µg g-1) e do rio Para rico em Al (1.216 a 15.389 µg g-1), provavelmente com contribuicao antropogenica. O material fitoplanctonico apresentou elevado fator de bioconcentracao proveniente tanto da agua quanto da fracao biodisponivel, e reflete a eficiencia desses organismos em concentrar metais.
TL;DR: If the increases in the frequency of dry periods predicted by climate models for this region are confirmed, future changes in extension and directions of forest limits will be affected, disrupting ecological services as carbon storage and the maintenance of local biodiversity.
Abstract: Coupled carbon/climate models are predicting changes in Amazon carbon and water cycles for the near future, with conversion of forest into savanna-like vegetation. However, empirical data to support these models are still scarce for Amazon. Facing this scenario, we investigated whether conservation status and changes in rainfall regime have influenced the forest-savanna mosaic over 20 years, from 1986 to 2006, in a transitional area in Northern Amazonia. By applying a spectral linear mixture model to a Landsat-5-TM time series, we identified protected savanna enclaves within a strictly protected nature reserve (Maraca Ecological Station - MES) and non-protected forest islands at its outskirts and compared their areas among 1986/1994/2006. The protected savanna enclaves decreased 26% in the 20-years period at an average rate of 0.131 ha year-1, with a greater reduction rate observed during times of higher precipitation, whereas the non-protected forest islands remained stable throughout the period of study, balancing the encroachment of forests into the savanna during humid periods and savannization during reduced rainfall periods. Thus, keeping favorable climate conditions, the MES conservation status would continue to favor the forest encroachment upon savanna, while the non-protected outskirt areas would remain resilient to disturbance regimes. However, if the increases in the frequency of dry periods predicted by climate models for this region are confirmed, future changes in extension and directions of forest limits will be affected, disrupting ecological services as carbon storage and the maintenance of local biodiversity.
TL;DR: The leaf venation was the main character for separating species and the secondary vegetation formation the ecosystem with the largest number of species, and Abuta obovata and A. velutina are new records for Para state.
Abstract: Abuta is a genus taxonomically complex due overlapping of morphological character variation. This study deals with the taxonomic treatment of the Abuta genus in the Para state. The study includes the analysis of botanical material originated from new collections and specimens from the herbaria Museum Goeldi (MG), Agronomic Institute of the North (IAN), National Institute for Research in the Amazon (INPA), Rio de Janeiro Botanic Garden (RB) and New York Botanical Garden (NY). Identification key, descriptions, geographical distribution, comments, and illustrations of species are provided. In Para the genus is represented by 11 species: A. barbata, A. brevifolia, A. candollei, A. grandifolia, A. grisebachii, A. imene, A. obovata, A. rufescens, A. sandwithiana, A. solimoesensis and A. velutina. Abuta obovata and A. velutina are new records for Para state. The leaf venation was the main character for separating species and the secondary vegetation formation the ecosystem with the largest number of species.
TL;DR: In this paper, the authors investigated the influence of using lakes and its distance from the river (near and far) in the structure of the fish assemblages associated with floating meadows bank in floodplain lakes, Central Amazonian.
Abstract: The co-management of fishery resources developed by Amazonian riverine people is concerned with the maintenance of suitable environments for fish stock conservation. This type of co-management strategy is based on rules of access and use for fishery resources. In this research we investigated the influence of using lakes (preserved and managed for subsistence) and its distance from the river (near and far) in the structure of the fish assemblages associated with floating meadows bank in floodplain lakes, Central Amazonian. Fish were caught during flood period using seine nets in six lakes in a distance ranging from 0.87 to 10.9 km from the river. In floating meadows bank were captured a total of 623 specimens of fish, over 56 species. The analysis of covariance (ANCOVA) indicates that the co-management of lakes and distance did not influence significantly the ecological attributes of fish assemblages (abundance, richness, total weight, Shannon-Weaver and Berger-Parker diversity, evenness and dominance). According to analysis of similarity (ANOSIM) there was no difference in species composition among the lakes. These results suggest other factors, such as: short time of effective management, the agriculture as the most important economic activity of subsistence, the lack of fisheries in large-scale which cause significant environmental changes and the existence of an ecological factor of great intensity, “the flood pulse”, overlapping others of less intensity.
TL;DR: O objetivo do presente trabalho foi relatar a distribuicao geografica e novas ocorrencias das principais especies de nematoides encontradas associadas a mandioca em diferentes municipios dos estados do Acre, Amapa, Para e Rondonia.
Abstract: A cultura da mandioca (Manihot esculenta) tem importância socioeconomica no Brasil, no entanto ha ainda uma escassez de informacoes sobre a associacao de nematoides fitoparasitas, bem como ao comportamento de cultivares de mandioca ao parasitismo desses agentes. O objetivo do presente trabalho foi relatar a distribuicao geografica e novas ocorrencias das principais especies de nematoides encontradas associadas a mandioca em diferentes municipios dos estados do Acre, Amapa, Para e Rondonia. Alem disso, estudou-se, em casa de vegetacao, a reacao de algumas cultivares de mandioca ao parasitismo de Meloidogyne incognita raca 3, Pratylenchus brachyurus e P. zeae. Nematoides foram extraidos de 10 g de raizes ou 250 cm3 de solo e identificados sob microscopio de luz. A especie mais prevalente foi P. brachyurus, presente em 37,1% das amostras analisadas (n=35), seguida de M. incognita, encontrada em de 14,2% das amostras. Constituiram novas ocorrencias para mandioca no Brasil: Helicotylenchus erythrinae, M. enterolobii e Xiphinema longicaudatum. As cultivares de mandioca provenientes do Amapa (Amazonas, Colonia Matapi, Manteiga, Pretinha e Po-da-China) e as cultivares de mandioca Colonial e Caipora, provenientes do Acre, comportaram-se como suscetiveis a M. incognita raca 3. Por outro lado, as cultivares Caipora e Colonial comportaram-se como resistentes a P. brachyurus (fator de reproducao = 0,5 e 0,9, respectivamente) e imunes a P. zeae. Informacoes geradas neste estudo podem ser uteis para o manejo de areas cultivadas com mandioca e infestadas pelos nematoides das lesoes, P. brachyurus e/ou P. zeae.
TL;DR: The Biotic Ligand Model was used to predict the LC50 values for these species and it can be considered a promising tool for these tropical species and water conditions.
Abstract: In the last years many populations of anurans have declined and extinctions have been recorded. They were related to environmental pollution, changes of land use and emerging diseases. The main objective of this study was to determine copper sensitivity of the anuran of the Amazon Rhinella granulosa and Scinax ruber tadpoles at stage 25 and Scinax ruber eggs exposed for 96 h to copper concentrations ranging from 15 µg Cu L-1 to 94 µg Cu L-1. LC50 at 96 h of Rhinella granulosa Gosner 25, Scinax ruber Gosner 25 and Scinax ruber eggs in black water of the Amazon were 23.48, 36.37 and 50.02 µg Cu L-1, respectively. The Biotic Ligand Model was used to predict the LC50 values for these species and it can be considered a promising tool for these tropical species and water conditions. Copper toxicity depends on water physical-chemical composition and on the larval stage of the tadpoles. The Gosner stage 19-21 (related to the appearance of external gills) is the most vulnerable and the egg stage is the most resistant. In case of contamination by copper, the natural streams must have special attention, since copper is more bioavailable.
TL;DR: The results indicated that S. amazonicum had a peeling yield similar or even higher than those usually obtained for species traditionally used for this purpose in Brazil, like those of Pinus and Eucalyptus.
Abstract: The tropical tree Schizolobium amazonicum is native from the Amazonian forest, naturally occurring in Brazil, Peru and Colombia. This work aimed to study the veneer yield made from this species. For this purpose, 50 logs from S. amazonicum were rotary peeled in a plywood industry installed in Brazilian Amazon region. The results indicated that S. amazonicum had a peeling yield similar or even higher than those usually obtained for species traditionally used for this purpose in Brazil, like those of Pinus and Eucalyptus. It was also observed that the dendrometric parameters of the log can be used to estimate the peeling yield in this species.
TL;DR: All examined honey had antimicrobial activity against the tested pathogens, thus serving as potential antimicrobial agents for several therapeutic approaches.
Abstract: Honeys are described possessing different properties including antimicrobial. Many studies have presented this activity of honeys produced by Apis mellifera bees, however studies including activities of stingless bees honeys are scarce. The aim of this study was to compare the antimicrobial activity of honeys collected in the Amazonas State from Melipona compressipes, Melipona seminigra and Apis mellifera against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Chromobacterium violaceum, and Candida albicans. Minimum inhibitory concentrations were determined using the agar dilution method with Muller-Hinton agar (for bacteria) or Saboraud agar (for yeast). Staphylococcus aureus and E. faecalis were inhibited by all honeys at concentrations below 12%, while E. coli and C. violaceum were inhibited by stingless bee honeys at concentrations between 10 and 20%. A. mellifera honey inhibited E. coli at a concentration of 7% and Candida violaceum at 0.7%. C. albicans were inhibited only with honey concentrations between 30 and 40%. All examined honey had antimicrobial activity against the tested pathogens, thus serving as potential antimicrobial agents for several therapeutic approaches.
TL;DR: Os macropadroes cristalinos caulinares e foliares observados sao constitutivos e uteis a separacao interespecifica das especies estudadas desempenham funcoes relevantes para a autoecologia dos taxa de Piper analisados.
Abstract: Piper L. (Piperaceae) e monofiletico, com especies de dificil distincao taxonomica, sendo necessarios ferramentas que auxiliem a identificacao interespecifica. Os objetivos do trabalho foram descrever os macropadroes e caracterizar in situ a composicao quimica dos cristais caulinares e foliares de Piper arboreum Aubl. var. arboreum, P. callosum Ruiz & Pav. e P. tuberculatum Jacq., visando avaliar o uso dos cristais para a separacao interespecifica. Para tanto, amostras foram submetidas a analise em microscopias de luz e eletronica de varredura, microanalises espectroscopicas de raios-X por dispersao de energia e testes histoquimicos. Foram observados cristais prismaticos cuneiformes, tabulares, cubicos e bipiramidais; rafides; estiloides; drusas de cristais em bloco; rosetas cristalinas de estiloides e concrescencias cristalinas. Foram descritos 15 macropadroes cristalinos reunidos em tres categorias. Os cristais foram classificados quimicamente como: puros de oxalato de calcio e misturas entre oxalatos e sulfatos e entre oxalatos, sulfatos e silica. Rosetas cristalinas, concrescencias cristalinas silicificadas e 14 dos 15 macropadroes cristalinos descritos sao registros ineditos para inclusoes biominerais de Piper e Piperaceae. Os macropadroes cristalinos caulinares e foliares observados sao constitutivos e uteis a separacao interespecifica das especies estudadas. Ademais, os cristais desempenham funcoes relevantes para a autoecologia dos taxa de Piper analisados.
TL;DR: The anatomical description of the leaf organs of three representative Brazilian species of Mapania was aimed and thin-walled epidermal cells, stomata level and aerenchyma were considered to be adaptive to the humid environment in which the species occur.
Abstract: Mapania belongs to Mapanioideae, a quite controversial subfamily in Cyperaceae due to the existence of unusual characters in both reproductive and vegetative organs. The genus is represented by seven species in Northern Brazil but taxonomic valuable information related to the leaf organs is still unknown. The present study aimed the anatomical description of the leaf organs (either basal leaves or cataphylls and involucral bracts) of three representative Brazilian species of Mapania. Samples of cataphylls, basal leaves and involucral bracts were sectioned and stained for observations under light microscopy. The involucral bracts provide the most elucidative characters (ten) to distinguish the three species The basal leaves provides six distinguishing characters and are useful to M. macrophylla and M. pycnostachya, as they are absent in M. sylvatica. Mesophyll arrangement in the involucral bracts supports the circumscription of M. macrophylla and M. pycnostachya in M. sect. Pycnocephala and of M. sylvatica in M. sect. Mapania. Some features as thin-walled epidermal cells, stomata level and aerenchyma were considered to be adaptive to the humid environment in which the species occur. The translucent cells are here considered as aerenchyma precursors and a supportive function is assumed for the bulliform cells on the basal leaves and involucral bracts. No silica bodies were found which confirm it as a diagnostic character of Mapania among Hypolytreae genera.
TL;DR: O presente estudo teve por objetivo descrever as caracteristicas anatomicas de Theobroma grandiflorum, T. speciosum e T. subincanum, como contribuicao ao conhecimento biologico dessas especies, bem como fornecer subsidios aos estudos biotecnologicos de fruteiras nativas da Amazonia.
Abstract: As especies de Theobroma tem importância economica devido a sua utilizacao nas industrias cosmetica e alimenticia, principalmente na producao de chocolate. Entretanto, a anatomia de suas estruturas vegetativas permanece pouco conhecida. O presente estudo teve por objetivo descrever as caracteristicas anatomicas de Theobroma grandiflorum, T. speciosum e T. subincanum, como contribuicao ao conhecimento biologico dessas especies, bem como, fornecer subsidios aos estudos biotecnologicos de fruteiras nativas da Amazonia. Folhas em diferentes estagios de desenvolvimento foram coletadas e analisadas sob microscopia de luz e eletronica de varredura. Nas folhas expandidas de T. grandiflorum e T. subincanum foram observados tricomas dos tipos estrelado sessil, pedunculado e glandular digitiforme. Estas especies tambem foram similares quanto a morfologia da nervura central, a organizacao do mesofilo e a presenca de graos de amido no parenquima medular da nervura central. Tricomas glandulares claviformes e celulas mucilaginosas na epiderme do limbo foliar ocorreram somente em T. speciosum. A presenca de tricomas secretores de mucilagem nos apices vegetativos (coleteres) de todas as especies estudadas e um novo registro para o genero Theobroma.
TL;DR: The results show that there was variation in moisture content of P. angulata seed for varying periods and storage conditions, and the germination rate and germination rates remained high in ambient conditions when primed up to 24 months.
Abstract: The important chemical and food properties conferred to P. angulata make it necessary to conduct studies in seed conservation. This study evaluated the effect of priming of P. angulata seed for varying periods and storage conditions. Lots of seeds were stored in a refrigerator and in ambient conditions for up to 24 months. Some of these seeds were primed before or after storage. The results show that there was variation in moisture content. The germination rate and germination rate index remained high in ambient conditions when primed up to 24 months.
TL;DR: Evaluated in vitro activity of aqueous and hydroalcoholic extracts from Pycnoporus sanguineus and Lentinus crinitus against Fusarium sp.
Abstract: The alternative control of plant diseases aims to minimize environmental impacts through the use of natural products. The objective of this work was to evaluate the in vitro activity of aqueous and hydroalcoholic extracts from Pycnoporus sanguineus and Lentinus crinitus against Fusarium sp. A fungus known to cause disease in plants. Fungis amples were collected in the urban and rural areas of Parintins-AM, and tested against different extracts concentrations. Inhibition of mycelia growth, inhibition of conidial germination and inhibition of germination of sclerotia were assessed. Mycelial growth inhibition was highest with hydroalcoholic cold extracts. Hydroalcoholic and aqueous extracts from P. sanguineus obtained by ultrasonic ation and hydroalcoholic cold extract from L. crinitus caused 92% of conidia sporulation. Aqueous hot extracts inhibited sclerotia germination in both fungi samples as well as hydroalcoholic cold extract from L. crinitus . Fungi consortium inhibited sclerotia germination at 1000 μg mL
TL;DR: Evaluated differences in predation rates between two experimental manipulations of artificial ground nests in an undisturbed area of Amazonian forest in eastern Brazil showed that manipulation type was the only variable that significantly affected nestpredation rates.
Abstract: Observational and experimental studies have shown that increased concealment of bird nests reduces nest predation rates. The objective of the present study was to evaluate differences in predation rates between two experimental manipulations of artificial ground nests (i.e., clearing an area around the artificial nest or leaving it as natural as possible), and test whether environmental variables also affected nest predation in an undisturbed area of Amazonian forest in eastern Brazil. A generalized linear model was used to examine the influence of five variables (manipulation type, perpendicular distance from the main trail, total basal area of trees surrounding the nest site, understorey density, and liana quantity) on nest predation rates. Model results, showed that manipulation type was the only variable that significantly affected nest predation rates. Thus, to avoid systematic biases, the influence of nest site manipulation must be taken into consideration when conducting experiments with artificial nests.
TL;DR: The aim of this study was to investigate variation in WD in eight tree species that occur in the open savannas of Roraima, the largest savanna area in the northern Brazilian Amazon, and found that there is a discrepancy between the WD of stem and the woody parts of the crown.
Abstract: Densidade da madeira (DM) e uma variavel importante para estimativas de estoques de carbono arboreo em ecossistemas terrestres. Este tema e pobremente investigado em areas de savana da Amazonia brasileira. O objetivo deste estudo foi investigar a DM das oito principais especies arboreas que ocorrem na savana aberta de Roraima, a maior area de savana do norte do bioma Amazonia. Foram verificadas as variacoes na DM em funcao da especie e dos diferentes diâmetros observados ao longo da dimensao vertical de 75 individuos amostrados em seis sitios de coleta. Foi utilizado o metodo direto para obtencao de pecas de madeira do fuste e da copa. Os resultados indicaram discrepância significativa interespecifica, sendo Roupala montana Aubl. a especie de maior DM media (0,674 g cm-3). Foi detectado que existe variacao significativa da DM entre as pecas do fuste e da copa, independente da especie e do sitio de coleta. A densidade da madeira de pecas da copa com diâmetro entre 5 e 10 cm pode ser utilizada como preditora da DM media do individuo arboreo. Nos concluimos que a DM das oito especies arboreas investigadas possui variabilidade interespecifica, com discrepâncias entre a DM do fuste e das partes lenhosas da copa. As distincoes aqui detectadas devem ser considerados como uma importante ferramenta para melhorar as estimativas de estoque de carbono em areas de savanas na Amazonia.
TL;DR: Results show consistent quantitative and qualitative differences between these species regarding their seeds and seedlings, supporting a recent treatment of the latter taxon as a distinct species, endemic to Roraima State, northern Amazonia, Brazil.
Abstract: We carried out a comparative morphological study to evaluate the taxonomic value of seed and seedling traits of Entada polystachya and E. simplicata (Leguminosae, Mimosoideae, Mimoseae). Seeds of both species were collected from wild populations in Roraima State, Brazil. Our results show consistent quantitative and qualitative differences between these species regarding their seeds and seedlings. Testa fracture lines, funiculus impression, lens characters, radicle shape and length, and cotyledon lobes length, seedling morphology group, number of pinnae at first node, and hypocotyl length permit a straightforward distinction of E. polystachya from E. simplicata, supporting a recent treatment of the latter taxon as a distinct species, endemic to Roraima State, northern Amazonia, Brazil.