Dados sobre as mudanças do clima e da vegetação da Amazônia durante o Quaternário

The palynological investigation is discussed for Holocene sediment cores from five different sites in the Amazon basin. It is interpreted that the changes In the vegetation registered in the diagrams were due mainly to local processes of sedimentation and changes of water level. The pollen diagrams show successions in Alchornea, Symmeria, Myrtaceae, and Miconia play an important role. This reflects changes in the várzea and igapó forests. Other successions seem to be from open water via floating meadows (mainly of arasses) and Cecropia stands to várzea forest (Terra Nova diagram). Apparently lower effective precipitation in the Amazon basin was dated around and shortly after 4000 B.P. and 2100 B.P. (apparently the culmination of a relatively dry period between c. 2700 and 2000 B.P.), and around 700 B.P. (A.D. 1200). In other parts of tropical South America evidences of these "drier" intervals have been found (and dated) and seem to be regional phenomena

Pólen estocado nos ninhos de abelhas dos gêneros Partamona, Scaura e Trigona (Hymenoptera, Apidae)

Bees and angiosperms established a mutualistic relationship along the evolutionary time. The aim of this study is to contribute for the understanding of this relation analyzing pollen stored by stingless bees colonies distributed along the Rio Negro. Fourteen species of Meliponini from the genera Partamona, Scaura, and Trigona were studied with regard to the content of pollen pots. The pollen material was removed from the pollen pots, homogenized, and prepared according to the usual acetolysis technique. The overlap of the trophic niche and the grouping of species by similarity of niches was calculated. The identification revealed 78 pollen types belonging to 36 families, being 37 types attractive and 16 considered as promoters of a temporary specialization event. With the results, it was possible to indicate a list of important plants for meliponiculture in the Amazon.Abelhas e plantas estabeleceram ao longo do tempo evolutivo uma relação mutualística. Buscando contribuir para o entendimento dessa relação, foi analisado o pólen estocado por colônias de abelhas-sem-ferrão distribuídas ao longo do rio Negro. Foram estudados potes de pólen de 14 espécies de Meliponini dos gêneros Partamona, Scaura e Trigona. O material polínico foi retirado dos potes de pólen, homogeneizado e preparado segundo técnica usual de acetólise. Foram calculados a sobreposição de nicho trófico e o agrupamento das espécies pela similaridade de nichos. Foi identificado o total de 78 tipos polínicos, pertencentes a 36 famílias, sendo 37 destes, considerados atrativos, enquanto 16 foram promotores de eventos de especialização temporária. Com os resultados obtidos foi possível indicar uma lista de plantas de importância para a meliponicultura na Amazônia.361372Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Sobre a morfologia e anatomia da Casearia sylvestris Swartz

O presente trabalho visou um melhor conhecimento botânico, particularmente anatômico, da Casearia sylvestris Swartz, fornecendo ainda algumas informações fitoquímicas sobre essa espécie medicinal, nativa da flora brasileira

Revues reçues

O recurso polínico coletado por operárias de Melipona seminigra merrillae Cockerell, Melipona fulva Lepeletier, Trigona fulviventris (Smith) e CephaloTrigona femorata Guérin, no Campus da UFAM, Manaus (AM) foi estudado no período de março a outubro de 2001. Noventa tipos polínicos foram coletados pelas abelhas, distribuídos em 31 famílias, 67 gêneros e 10 formas Tipo. Trigona fulviventris diversificou mais suas coletas, utilizando 58 fontes no período. O tamanho do nicho polínico utilizado pelas abelhas ficou assim distribuído: T. fulviventris (58), M.s. merrillae (41), C. femorata (34) e M. fulva (25). Dos tipos determinados, os que mais contribuíram para a dieta das abelhas, apresentando as maiores freqüências nas amostras de pólen, foram Miconia myriantha (12,91%), Leucaena leucocephala (9,52%), Tapirira guianensis (6,53%), Eugenia stipitata (6,22%), Protium heptaphyllum (6,17%) e Vismia guianensis (5,93%). As abelhas de modo geral concentraram suas coletas em um número reduzido de espécies vegetais e com um grau diferenciado de uso para cada uma das fontes. Tipos polínicos com freqüência acima de 10% ocorreram em pequena proporção na maioria dos meses, sendo responsáveis por mais de 50% do total do pólen coletado em cada mês. A utilização das fontes de pólen variou conforme a espécie. T. fulviventris teve uma dieta mais ampla e diversificada, enquanto M. fulva foi a que menos diversificou suas coletas. T. fulviventris apresentou maior uniformidade no uso das fontes polínicas e a sobreposição de nichos polínicos foi maior entre M.s. merrillae e M. fulva e menor entre T. fulviventris e C. femorata.The objective of this study was to characterize the resources used by Amazonian bees Melipona seminigra merrillae, Melipona fulva, Trigona fulviventris and CephaloTrigona femorata, in an urban Forest patch at Manaus city from March to October 2001. The pollen analysis determined 90 pollen types, distributed in 31 families, 67 genera and 10 palynologycal types unidentified. Trigona fulviventris was the bee species that presented the most diversified pollen types, using 58 sources in that period. The size of pollen types used were distributed as follows: T. fulviventris (58), M.s. merrilae (41), C. femorata (34) and M. fulva (25). Plant species contributing the most for the diet of the bees and presenting the highest frequencies on the pollen samples were Miconia myriantha (12,91%), Leucaena leucocephalla (9,52%), Tapirira guianensis (6,53%), Eugenia stipitata (6,22%), Protium heptaphyllum (6,17%) and Vismia guianensis (5,93%). Generally the bees concentrated their collections on a reduced number of plant species and with a differentiated degree of use for each source. Pollen types with frequency above 10% occurred in a small proportion for most months, being responsible for more than 50% of all the pollen collected every month. Pollen source used varied according to the species, T. fulviventris had a more broad and diversified diet, whereas M. fulva was the bees species that least diversified its diet. T. fulviventris presented higher uniformity on the use of pollen sources and the pollen niches overlap was higher between M.s. merrillae and M. fulva and lower between T. fulviventris and C. femorata

Pollen storages in nests of bees of the genera Partamona, Scaura and Trigona (Hymenoptera, Apidae)

Bees and angiosperms established a mutualistic relationship along the evolutionary time. The aim of this study is to contribute for the understanding of this relation analyzing pollen stored by stingless bees colonies distributed along the Rio Negro. Fourteen species of Meliponini from the genera Partamona, Scaura, and Trigona were studied with regard to the content of pollen pots. The pollen material was removed from the pollen pots, homogenized, and prepared according to the usual acetolysis technique. The overlap of the trophic niche and the grouping of species by similarity of niches was calculated. The identification revealed 78 pollen types belonging to 36 families, being 37 types attractive and 16 considered as promoters of a temporary specialization event. With the results, it was possible to indicate a list of important plants for meliponiculture in the Amazon

Amazonian pollen database of species from the reserva ducke, manaus, amazonas, Brazil

The Amazonian Pollen Database (APD) was implemented in 2007, becoming a very dynamic and practical tool for consulting, allowing a fast and effective resulting research in Palynology. Most of the pollen grains described morphologically and inserted into the Amazonian Pollen Database are from plants collected in the Reserva Ducke, identified and deposited in the Herbarium of the National Institute of Amazonian Research (INPA). So far the following families were studied: Apocynaceae (25 species), Asteraceae (11 species), Gentianaceae (7 species), Hernandiaceae (1 species), Lecythidaceae (5 species), Monimiaceae (1 species), Siparunaceae (5 species) and Solanaceae (1 species). Besides, the pollen grains of 10 plant species from the várzea and igapó were described. The pollen grains taken from the anthers of the INPÁs Herbarium specimens were prepared according to the method of acetolysis and the resulting slide collection was deposited in the pollen collection of the Laboratory of Palynology at INPA. The Amazonian Pollen Database (APD) contains a database of images and data on the structure of pollen grains, with detailed morphological descriptions, such as size and shape of the pollen grain, measurements of the polar and equatorial axis or the diameter, number and type of apertures, type of ornamentation of the sexine, as well as ecological data of the plant and records of the origin of the material. The palynological data and ecological plants were inserted in the program in the English language and the images are in black and white and color. By consulting the pollen morphological data inserted in the database, it is possible to make the comparative analysis of pollen samples from different research areas that include the palynology

Algumas plantas visitadas para obtenção de pólen por operárias de Melipona seminigra merrillae em Manaus

During one year, in Manaus, the loads in the corbicula of 267 bees Melipona seminigra (from 13 to 27 per month) were studied. Of these, 104 (39%) had latex, resin or mud that the workers mix with wax in order to save energy; one corbicula load of mud or resin substitutes for 12 to 15 loads of nectar if this nectar is to be transformed into wax. Ninety-nine bees (60.7%) brought pollen of a single species of plant, 38 (23.3%) of two species of plants and 26 (15.9%) of three or more types of pollen. Among pollen types 19 families and 25 genera were represented. Only 13 types of pollen were identifyed to species: Bellucia imperialis, Bixa orellana, Cordia lanata, Croton lanjouwensis, Eschweilera fracta, Inga edulis, Mauritia flexuosa, Mimosa pudica, Protium heptaphyllum, Stachytarpheta cayennensis, Tapirira guianensis, Vernonia scabra, Warszewiczia coccinea.Estuda-se a carga transportada nas patas por 267 abelhas de Melipona seminigra durante um ano, em Manaus. Dessas, 104 (39%) não transportavam pólen, mas sim látex (no nosso caso do fruto de Vismia, inclusive com sementes), resinas e barro. Das 163 restantes (61%), 99 transportavam pólen de uma só espécie, 38 (23%) transportavam de duas espécies e 26 (16%) de três ou mais. As abelhas colheram pólen de 19 famílias e 25 gêneros diferentes. Apenas 13 tipos de pólen foram identificados até o nível de espécie

Some palaeoecological data from Rondonia, southern part of the Amazon Basin. ()

Palynological investigations on sediment cores from three localities in Rondonia in the southern part of the Amazon Basin, indicate that marked vegetational changes have ocurred there. The series of samples from Katira represents the late Cenozoic, probably Quaternary. The sediments from Capoeira might be partly of Holocene age (and possibly Upper Pleistocene as well). Apparently the climatic changes during several intervals of the Late Cenozoic (Quaternary) caused the development of savannas in this region which is now covered in tropical forest.O conceito de que houve períodos de clima seco durante o Pleistoceno na Amazônia, vem sendo debatido por inúmeros pesquisadores nos últimos anos. A teoria dos refúgios, proposta por Haffer, deu início a uma série de estudos para a explicação das mudanças climáticas da área amazônica. A maioria desses estudos foram baseados na distribuição atual de certas espécies de plantas e animais. Entretanto, o uso de dados para interpretação das flutuações climáticas no Pleistoceno exige uma extrapolação. Evidências palinológicas de Rondônia mostraram que savanas de gramíneas substituíram a floresta tropical durante certos períodos do Pleistoceno. Neste trabalho são discutidos os resultados da análise de pólen de amostras de sedimentos de Rondônia. Os diagramas polínicos mostraram mudanças na vegetação de floresta para savana o vice-versa. Os sedimentos de Katira devem ser de idade Cenozóica Superior, provavelmente Quaternária. Os sedimentos de Capoeira representam em parte uma idade do Holoceno (e, possivelmente, do Pleistoceno Superior). As condições climáticas ocorridas durante certos intervalos do Cenozóico Superior (Quaternário) parecem ter favorecido ao desenvolvimento de savanas na área em discussão, que é atualmente coberta pela floresta tropical

Polinizadores de bertholletia excelsa (Lecythidales: Lecythidaceae): interações com abelhas sem ferrão (Apidae: Meliponini) e nicho trófico

This paper presents an analysis of the foraging behavior and interactions of Xylocopa frontalis Olivier (Apidae: Xylocopini) and Eulaema mocsaryi (Friese) (Apidae: Euglossini) in the presence of stingless bees (Apidae: Meliponini) in flowers of Bertholletia excelsa, the Brazilian nut. The palynological load carried by both species was also examined. This study was conducted in the farm Aruanã, Itacoatiara/ Amazonas state, Brazil, during the flowering peak of B. excelsa. The visitation by the main pollinators X. frontalis and E. mocsaryi were influenced by the presence and activities of stingless bees in the flowers of B. excelsa. Meliponini bees did not have any effect on the visits and collection of fl oral resources by X. frontalis, while negatively affecting the number of visits by E. mocsaryi. The stingless bees presented a variety of strategies to get access to pollen grains of B. excelsa, grouped into two categories: opportunism - Frieseomelitta trichocerata Moure, Tetragona goettei (Friese), and Tetragona kaieteurensis (Schwarz), and stealing - Trigona branneri Cockerell, Trigona fuscipennis Friese, and Trigona guianae Cockerell. The palynological analysis from X. frontalis showed that the bee collected pollen in a few species of plants, but mainly on B. excelsa. The pollen grains of B. excelsa were poorly represented in the pollen shipments of E. mocsaryi, due to its large trophic niche in the locality

Biologia reprodutiva de Davilla kunthii A. St-Hil. (Dilleniaceae) na Amazônia Central

This survey aimed at describing the interactions of floral visitors and Davilla kunthii A. St.-Hil. as well as characteristics of its reproductive biology in Itacoatiara, state of Amazonas, Brazil. Tests of the breeding system were performed. The guild of visitors was described according to richness, abundance, relative frequency and constancy. The breeding system tests indicated that D. kunthii is self-compatible. The pollination system was characterized as generalist, with 39 visitor species, from three different orders. Bees were the main group of pollinators, thus some behavioural aspects were described. Th e period of highest foraging activity was between 7 and 10 am. Some species presented agonistic and monopolistic behaviour. Given the behaviour and destructive potential, the Curculionidae seem to have a greater impact as seed predators than pollinators.Este trabalho descreve as relações entre visitantes florais e Davilla kunthii A. St.-Hil., bem como características de sua biologia reprodutiva em Itacoatiara (Amazonas). Foram realizados os testes referentes ao estudo do sistema reprodutivo. A guilda de visitantes foi caracterizada quanto à riqueza, abundância, frequência relativa e constância. Os testes para sistema reprodutivo indicaram que D. kunthii possui auto-compatibilidade. O mecanismo de polinização configurou-se como generalista com 39 espécies de visitantes florais, provenientes de três diferentes ordens. Abelhas corresponderam ao principal grupo de polinizadores, desta forma, alguns aspectos comportamentais foram descritos. O horário de maior forrageamento ocorreu entre 7 e 10 horas. Algumas espécies apresentaram interações agonísticas e comportamento monopolizador da fonte de alimento. Dado o comportamento e o potencial destrutivo, embora possa ocasionalmente atuar como polinizadores, Curculionidae parecem possuir maior impacto como predadores de sementes.487496Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq