21 research outputs found

    Biased-corrected richness estimates for the Amazonian tree flora

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    Amazonian forests are extraordinarily diverse, but the estimated species richness is very much debated. Here, we apply an ensemble of parametric estimators and a novel technique that includes conspecific spatial aggregation to an extended database of forest plots with up-to-date taxonomy. We show that the species abundance distribution of Amazonia is best approximated by a logseries with aggregated individuals, where aggregation increases with rarity. By averaging several methods to estimate total richness, we confirm that over 15,000 tree species are expected to occur in Amazonia. We also show that using ten times the number of plots would result in an increase to just ~50% of those 15,000 estimated species. To get a more complete sample of all tree species, rigorous field campaigns may be needed but the number of trees in Amazonia will remain an estimate for years to come

    Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

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    This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The percentages of dispersal modes per plot are included as Supporting Information (Table S7, based on 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests in Amazonia). The dispersal modes assigned to these 5433 species and morphospecies are also included as Supporting Information (Table S8).Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types.Colombian institution Departamento Administrativo de Ciencia, Tecnología e Innovación COLCIENCIASFaculty of Sciences, Universidad de los Ande

    Consistent patterns of common species across tropical tree communities

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    Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

    Consistent patterns of common species across tropical tree communities

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    Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1-6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth's 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world's most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

    Influenza A H1N1: Five Years of Diagnostics in Brazil

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    O ser que envelhece: técnica, ciência e saber The being that ages: technique, science and knowledge

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    Abordamos a Gerontologia, que se pretende ciência do envelhecimento. A partir de Bachelard e Canguilhem, discutimos as perspectivas da Gerontologia como ciência naquilo que se refere à Fisiologia do Envelhecimento, da Genética do Envelhecimento ou da Biogerontologia e como um conjunto de técnicas de cura, de alívio da dor, de ação sobre a vida do ser que envelhece através da Geriatria, da Psicogeriatria, da Enfermagem Geriátrica, do Serviço Social, por exemplo. A partir do pensamento de Foucault, consideramos que a Gerontologia inclui os saberes sobre este ser único que pensa sobre si mesmo e sobre suas próprias representações por meio da Antropologia, da Psicanálise, entre outras. Quanto a ter por objeto o envelhecimento, entendemos que se trata de um projeto absolutamente ambicioso, que praticamente coincide com as Ciências Humanas e da Vida quando tematizam a juventude e o envelhecer. Hoje, parece-nos, a Gerontologia corresponde a um conjunto de ciências, técnicas e saberes voltados, principalmente, para esse ainda nebuloso domínio que é a velhice.<br>We address Gerontology in its perception as the science of aging. Based on Bachelard and Canguilhem, we discuss the perspectives of Gerontology as science in terms of Aging Philosophy, Aging Genetics or Bio-Gerontology, and as a set of techniques for cure such as pain relief, action on life of the being that ages through Geriatrics, Psycho-geriatrics, Geriatric Nursing and Social Service. Based on Foucault, we consider that Gerontology comprises all knowledge on that unique being who thinks about himself and about his own representations, through Anthropology, Psychoanalysis, and so on. As to the fact that aging is the object , we see this as an ambitious project, which almost coincides with Human Sciences and Life when these deal with youth and old age. Gerontology is today a set of sciences, techniques and knowledge, mainly concerned with the still indefinite domain of old age

    A gerontologia e a interdisciplinaridade: aspectos relevantes para a enfermagem La gerontología e interdisciplinaridade: los aspectos relevantes para la enfermería Gerontology and interdisciplinarity: relevant aspects to nursing

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    Este artigo retrata a Gerontologia como área rica e cheia de lacunas a serem preenchidas pelas disciplinas que a compõem, indo além das abordagens convencionais à clientela idosa, visando a caminhos renovados para a Enfermagem, que, dentre tantas disciplinas, também está no processo construtivo de conhecimento. Tem como objetivo destacar a importância da Gerontologia para a atuação interdisciplinar, principalmente para Enfermagem, ressaltando o cliente idoso no contexto social. A interdisciplinaridade é instrumento condutor para Gerontologia em busca de mudanças que venham a somar conhecimentos e redundar em esforços no processo de desenvolvimento da área da saúde em relação ao cliente idoso e às diversas disciplinas que contemplam uma atuação relevante que, sem dúvida, permitem avanços para a Enfermagem.<br>Este artículo retrata la Gerontología como área rica y llena de lagunas para ser resueltas por las disciplinas que la componen, yendo más allá de los abordajes convencionales a la población anciana, buscando caminos renovados para enfermería, que dentro de tantas disciplinas, también está en el proceso constructivo del conocimiento. Tiene como objetivo destacar la importancia de la gerontología para la actuación interdisciplinaria, principalmente para enfermería, resaltando al paciente anciano en el contexto social. La interdisciplinariedad La interdisciplinariedad es instrumento conductor para la Gerontología en busca de cambios que vengan a agregar conocimientos que redunden en esfuerzos para el proceso de desarrollo del área de la salud en relación con el cliente anciano, y las diversas disciplinas que contemplan una actuación relevante que, sin duda, permitan avances para enfermería.<br>This article shows Gerontology as a rich area and full of gaps to be filled by the disciplines that form it, going beyond the conventional approaches to the elderly client and aiming at finding new Nursing paths as, among other sciences, it is in the process of knowledge building. The study aims at emphasizing the importance of Gerontology in an interdisciplinary context, specially for Nursing, as well as the relevance of the elderly client in the social context. The interdisciplinarity is the Gerontology guiding tool in the search for changes that may sum-up knowledge and efforts in the process of health development regarding the elderly clients and other disciplines, enabling Nursing advancement

    Enfermagem gerontológica: a produção do conhecimento na profissão (1970-1996)

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    Este estudo objetiva descrever a construção do conhecimento como constituinte de poder profissional na Enfermagem Gerontológica no Brasil, no período de 1970 a 1996. É um estudo descritivo, qualitativo, com abordagem sócio-histórica, que utiliza a história oral temática e se realiza com 14 enfermeiras pioneiras na área. As categorias encontradas são: 1. Os primórdios das pesquisas; 2. A inserção da gerontologia na formação profissional; 3. Relevância do conhecimento para a especialidade. A compreensão histórica permitiu conhecer os esforços para o desenvolvimento da produção científica na área, ao detalhar a criação dos grupos de pesquisa e as dificuldades encontradas na formação profissional. A relação entre o conhecimento e poder profissional é discurso unânime entre as enfermeiras pioneiras, confirmada nos esforços empreendidos por estas para o desenvolvimento do conhecimento especializado na área
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