The Experts below are selected from a list of 1962 Experts worldwide ranked by ideXlab platform
Rodolfo Salm - One of the best experts on this subject based on the ideXlab platform.
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Palm community transitions along a topographic gradient from floodplain to terra firme in the eastern Amazon
Acta Amazonica, 2015Co-Authors: Rodolfo Salm, Anderson Prates, Nadson Ressyé Simões, Lisa FederAbstract:Palms show clear niche segregation patterns along topographic gradients in tropical forests, with some species associated to terra firme and others to seasonally flooded areas. The aim of this study was to quantitatively describe the fine-scale spatial variation within a palm community, tracking the changes in species' abundance along environmental gradients associated with a perennial stream the eastern Amazon. The study of palm communities was based on 60 forest plots in which all adult palms were counted. We found a total of 566 palms in a community containing 11 species. Furthermore, we found a significant separation in the palm community between seasonally-flooded and terra firme forests. We found a gradient with various densities of the three most abundant palm species within the first 100 m away from the flooded area. Other species were located exclusively in the terra firme forest. The abundance of the six most common species were distributed in relation to humidity gradients from floodplains to terra firme, with palm distribution from the most flood-tolerant to the least flood-tolerant palm species as follows: Euterpe oleracea, Attalea phalerata and Socratea exorrhiza (species with floodplain affinity), Astrocaryum gynacanthum, Astrocaryum aculeatum, Attalea maripa (species with terra firme affinity)
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Invertebrate and Vertebrate Seed Predation in the Amazonian Palm Attalea maripa1
Biotropica, 2006Co-Authors: Rodolfo SalmAbstract:Spatial-scale-dependent patterns of Attalea maripa seed predation and removal by the beetle Pachymerus cardo and vertebrates were examined in a palm patch and its adjacent forest in southeastern Amazon. Seed survivorship depended on the distance from the palm patch, but was unrelated to distance from individual fruiting palms.
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THE IMPORTANCE OF FOREST DISTURBANCE FOR THE RECRUITMENT OF THE LARGE ARBORESCENT PALM Attalea MARIPA IN A SEASONALLY-DRY AMAZONIAN FOREST
Biota Neotropica, 2005Co-Authors: Rodolfo SalmAbstract:The hypothesis that forest disturbance is important for the recruitment of the large arborescent palms Attalea maripa was tested with a natural experiment in the Pinkaiti site (7o 46'S; 51o 57'W), a seasonally-dry Amazonian forest. A 8,000 m long trail, that crosses, in its lower half, an open forest along the Pinkaiti stream bottomlands and, on its upper half, a dense forest on a hill, was divided in 160 0.15 ha (50x30 m) sampling units. At each unit, adult palms were counted and percentage of canopy openness was measured with a concave spherical densiometer. The palms were nearly five times more abundant at the bottomlands, whose forest had a canopy 14.8% more open than that of the hill; supporting the hypothesis that disturbance is important for their recruitment.
Iris Hordijk - One of the best experts on this subject based on the ideXlab platform.
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Cattle affect regeneration of the palm species Attalea princeps in a Bolivian forest–savanna mosaic
Biotropica, 2019Co-Authors: Iris Hordijk, Fabian Meijer, Esther Nissen, Tjaelle Boorsma, Lourens PoorterAbstract:Attalea princeps is an important palm species that shapes the forest–savanna mosaic in Beni, Bolivia, as it dominates the two principal forest landscape elements (forest islands and gallery forest), and provides a vital microhabitat, food, and nesting source for numerous plant and animal species. The forest–savanna mosaic is used for extensive grazing, and the palm population is declining on the forest islands due to a low regeneration rate, which threatens the maintenance of this landscape. We therefore examined the (a)biotic factors that influence the population structure of Attalea in the centers and edges of forest islands and gallery forests. Ninety-one 0.1-ha plots were established, and 500 palm adults and 3,700 juveniles were measured for their size, health condition, and fire damage. For each plot, habitat characteristics, such as landscape position, grazing pressure, and soil conditions, were measured. Attalea population density was significantly lower on the forest islands than in the gallery forests, especially in the juvenile life stage. A structural equation model showed that juvenile density is positively related to the health condition of juveniles and amount of fruits present, where the amount of fruits is positively affected by the condition of adults. Juvenile density is negatively influenced by grazing, affecting the health condition of the juvenile, as well as organic matter and phosphate availability in the soil. Therefore, it is recommended to decrease the grazing pressure by decreasing livestock densities, fencing off vulnerable forest islands, or by rotating cattle.Abstract in Spanish is available with online material.
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cattle affect regeneration of the palm species Attalea princeps in a bolivian forest savanna mosaic
Biotropica, 2019Co-Authors: Iris Hordijk, Fabian Meijer, Esther Nissen, Tjaelle Boorsma, Lourens PoorterAbstract:Attalea princeps is an important palm species that shapes the forest–savanna mosaic in Beni, Bolivia, as it dominates the two principal forest landscape elements (forest islands and gallery forest), and provides a vital microhabitat, food, and nesting source for numerous plant and animal species. The forest–savanna mosaic is used for extensive grazing, and the palm population is declining on the forest islands due to a low regeneration rate, which threatens the maintenance of this landscape. We therefore examined the (a)biotic factors that influence the population structure of Attalea in the centers and edges of forest islands and gallery forests. Ninety-one 0.1-ha plots were established, and 500 palm adults and 3,700 juveniles were measured for their size, health condition, and fire damage. For each plot, habitat characteristics, such as landscape position, grazing pressure, and soil conditions, were measured. Attalea population density was significantly lower on the forest islands than in the gallery forests, especially in the juvenile life stage. A structural equation model showed that juvenile density is positively related to the health condition of juveniles and amount of fruits present, where the amount of fruits is positively affected by the condition of adults. Juvenile density is negatively influenced by grazing, affecting the health condition of the juvenile, as well as organic matter and phosphate availability in the soil. Therefore, it is recommended to decrease the grazing pressure by decreasing livestock densities, fencing off vulnerable forest islands, or by rotating cattle.Abstract in Spanish is available with online material.
Lourens Poorter - One of the best experts on this subject based on the ideXlab platform.
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Cattle affect regeneration of the palm species Attalea princeps in a Bolivian forest–savanna mosaic
Biotropica, 2019Co-Authors: Iris Hordijk, Fabian Meijer, Esther Nissen, Tjaelle Boorsma, Lourens PoorterAbstract:Attalea princeps is an important palm species that shapes the forest–savanna mosaic in Beni, Bolivia, as it dominates the two principal forest landscape elements (forest islands and gallery forest), and provides a vital microhabitat, food, and nesting source for numerous plant and animal species. The forest–savanna mosaic is used for extensive grazing, and the palm population is declining on the forest islands due to a low regeneration rate, which threatens the maintenance of this landscape. We therefore examined the (a)biotic factors that influence the population structure of Attalea in the centers and edges of forest islands and gallery forests. Ninety-one 0.1-ha plots were established, and 500 palm adults and 3,700 juveniles were measured for their size, health condition, and fire damage. For each plot, habitat characteristics, such as landscape position, grazing pressure, and soil conditions, were measured. Attalea population density was significantly lower on the forest islands than in the gallery forests, especially in the juvenile life stage. A structural equation model showed that juvenile density is positively related to the health condition of juveniles and amount of fruits present, where the amount of fruits is positively affected by the condition of adults. Juvenile density is negatively influenced by grazing, affecting the health condition of the juvenile, as well as organic matter and phosphate availability in the soil. Therefore, it is recommended to decrease the grazing pressure by decreasing livestock densities, fencing off vulnerable forest islands, or by rotating cattle.Abstract in Spanish is available with online material.
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cattle affect regeneration of the palm species Attalea princeps in a bolivian forest savanna mosaic
Biotropica, 2019Co-Authors: Iris Hordijk, Fabian Meijer, Esther Nissen, Tjaelle Boorsma, Lourens PoorterAbstract:Attalea princeps is an important palm species that shapes the forest–savanna mosaic in Beni, Bolivia, as it dominates the two principal forest landscape elements (forest islands and gallery forest), and provides a vital microhabitat, food, and nesting source for numerous plant and animal species. The forest–savanna mosaic is used for extensive grazing, and the palm population is declining on the forest islands due to a low regeneration rate, which threatens the maintenance of this landscape. We therefore examined the (a)biotic factors that influence the population structure of Attalea in the centers and edges of forest islands and gallery forests. Ninety-one 0.1-ha plots were established, and 500 palm adults and 3,700 juveniles were measured for their size, health condition, and fire damage. For each plot, habitat characteristics, such as landscape position, grazing pressure, and soil conditions, were measured. Attalea population density was significantly lower on the forest islands than in the gallery forests, especially in the juvenile life stage. A structural equation model showed that juvenile density is positively related to the health condition of juveniles and amount of fruits present, where the amount of fruits is positively affected by the condition of adults. Juvenile density is negatively influenced by grazing, affecting the health condition of the juvenile, as well as organic matter and phosphate availability in the soil. Therefore, it is recommended to decrease the grazing pressure by decreasing livestock densities, fencing off vulnerable forest islands, or by rotating cattle.Abstract in Spanish is available with online material.
Fernando Abadfranch - One of the best experts on this subject based on the ideXlab platform.
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deforestation effects on Attalea palms and their resident rhodnius vectors of chagas disease in eastern amazonia
PLOS ONE, 2021Co-Authors: Walter Souza Santos, Rodrigo Gurgelgoncalves, Lourdes Maria Garcez, Fernando AbadfranchAbstract:Attalea palms provide primary habitat to Rhodnius spp., vectors of Trypanosoma cruzi. Flying from palms, these blood-sucking bugs often invade houses and can infect people directly or via food contamination. Chagas disease (CD) risk may therefore increase when Attalea palms thrive near houses. For example, Attalea dominate many deforested landscapes of eastern Amazonia, where acute-CD outbreaks are disturbingly frequent. Despite this possible link between deforestation and CD risk, the population-level responses of Amazonian Attalea and their resident Rhodnius to anthropogenic landscape disturbance remain largely uncharted. We studied adult Attalea palms in old-growth forest (OGF), young secondary forest (YSF), and cattle pasture (CP) in two localities of eastern Amazonia. We recorded 1856 Attalea along 10 transects (153.6 ha), and detected infestation by Rhodnius spp. in 18 of 280 systematically-sampled palms (33 bugs caught). Distance-sampling models suggest that, relative to OGF, adult Attalea density declined by 70-80% in CP and then recovered in YSF. Site-occupancy models estimate a strong positive effect of deforestation on palm-infestation odds (βCP-infestation = 4.82±1.14 SE), with a moderate decline in recovering YSF (βYSF-infestation = 2.66±1.10 SE). Similarly, N-mixture models suggest that, relative to OGF, mean vector density sharply increased in CP palms (βCP-density = 3.20±0.62 SE) and then tapered in YSF (βYSF-density = 1.61±0.76 SE). Together, these results indicate that disturbed landscapes may support between ~2.5 (YSF) and ~5.1 (CP) times more Attalea-dwelling Rhodnius spp. per unit area than OGF. We provide evidence that deforestation may favor palm-dwelling CD vectors in eastern Amazonia. Importantly, our landscape-disturbance effect estimates explicitly take account of (i) imperfect palm and bug detection and (ii) the uncertainties about infestation and vector density arising from sparse bug data. These results suggest that incorporating landscape-disturbance metrics into the spatial stratification of transmission risk could help enhance CD surveillance and prevention in Amazonia.
Silvia Aparecida Oesterreich - One of the best experts on this subject based on the ideXlab platform.
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acute and subacute oral toxicity assessment of the oil extracted from Attalea phalerata mart ex spreng pulp fruit in rats
Food Research International, 2017Co-Authors: Fernando Freitas De Lima, Giseli Karenina Traesel, Sara Emilia Lima Tolouei Menegati, Ariany Carvalho Dos Santos, Roosevelt Isaias Carvalho Souza, Vinicius Soares De Oliveira, Eliana Janet Sanjinezargandona, Claudia Andrea Lima Cardoso, Silvia Aparecida Oesterreich, Maria Do Carmo VieiraAbstract:Abstract Attalea phalerata Mart. ex Spreng., popularly known as “bacuri”, is a native plant from the brazilian Cerrado and used in folk medicine as a pulmonary decongestant, an anti-inflammatory for joints and antipyretic. There is an expectation about the use in chronic disease of the Attalea phalerata oil since its composition is high in carotenoids and beneficial fatty acids. The aim of the study was to evaluate the toxicological profile of the oil extracted from Attalea phalerata Mart. ex Spreng. pulp (APO). Acute and subacute toxicity studies were performed in male and female Wistar rats according to the OECD - Guidelines 425 and 407. For the acute toxicity, one single dose of the APO (2000 mg/kg) was administered by gavage to five female rats. In the subacute toxicity, four different doses (125, 250, 500 and 1000 mg/kg) of the APO were administered to male and female rats for 28 consecutive days. No deaths or behavioral changes were observed during both experiments as well as no changes in organ weights, hematological, histopathological parameters. The biochemical parameters showed changes in phosphatase alkaline and albumin levels, however these values are within the normal range for the species. A significant reduction in cholesterol and triglycerides was also observed in some of the animals treated with the APO. Therefore, the LD50 is higher than 2000 mg/kg and the APO oil can be considered safe at the doses tested in rats. However, further assessments are required in order to proceed to clinical studies in humans.
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study on the cytotoxic genotoxic and clastogenic potential of Attalea phalerata mart ex spreng oil pulp in vitro and in vivo experimental models
PLOS ONE, 2016Co-Authors: Fernando Freitas De Lima, Giseli Karenina Traesel, Sara Emilia Lima Tolouei Menegati, Maria Do Carmo Vieira, Flavio Henrique Souza De Araujo, Caroline Honaiser Lescano, Sara Moraes Peixoto, Felipe Ariel Mao Silva, Silvia Cristina Vieira, Silvia Aparecida OesterreichAbstract:Attalea phalerata Mart. ex Spreng. (Arecaceae), popularly known as "bacuri", is used in Brazilian folk medicine. Its oil is used orally to relieve pulmonary congestion and joint pain. In topical applications, it is applied as an effective hair tonic and anti-dandruff. The in natura pulp and its nuts are used as food because of its nutritional value. Despite its use in folk medicine, there is a lack of data regarding its in vivo/in vitro cytotoxic/genotoxic and clastogenic effects. Therefore, in this study, we evaluated the cytotoxic, genotoxic and clastogenic effects of Attalea phalerata Mart. ex Spreng. oil (APMO) in vitro and in vivo. For the analysis of cytotoxic potential, the Artemia salina and MTT (3-(4,5-dimethizzol-zyl)-2,5-diphenyltetrazolium bromide) assays were performed. Possible cytotoxic, genotoxic and clastogenic effects of APMO intake were determined by performing the comet and micronucleus assays. Male and female Wistar rats were orally treated with doses of 125, 250, 500 or 1000 mg.kg-1 of the APMO daily for 28 consecutive days (four weeks). The results showed that the APMO did not induce cell death in the experiments of Artemia salina and MTT, indicating that it has no cytotoxicity. The APMO did not cause significant damage to the DNA of the rats in the four doses used when compared to the negative control group (saline + Tween® 80). The APMO did not present any significant increase in micronucleated polychromatic erythrocytes (MNPCEs) for the four tested doses. When compared to the positive control group, all groups (comet and micronucleus tests) were statistically different. These data suggest that the administration of Attalea phalerata Mart oil. ex Spreng does not cause cytotoxicity, genotoxicity and clastogenicity in experimental models in vitro and in vivo following oral administration in this study.