94 research outputs found

    Dieta de morcegos filostomídeos (Mammalia, Chiroptera, Phyllostomidae) em fragmento urbano do Instituto São Vicente, Campo Grande, Mato Grosso do Sul

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    Os morcegos (Chiroptera), devido à sua diversidade e abundância exercem um importante papel ecológico para o ecossistema. O objetivo deste trabalho foi reportar a dieta das espécies de morcegos frugívoros capturados nos fragmentos do Instituto São Vicente, zona urbana do município de Campo Grande, MS. As coletas ocorreram entre setembro de 2011 e Junho de 2012, sendo realizadas com o auxílio de redes-de-neblina. Foram realizadas 154 capturas, com ocorrência de 10 espécies representantes de três famílias, sendo predominantes as espécies frugívoras. Dentre as capturas foram obtidas 41 amostras fecais, onde se verificou a presença de polpa, vestígios de artrópodes e sementes. O recurso mais utilizado por quirópteros foram plantas pioneiras, constatado através do predomínio de sementes da espécie Cecropia pachystachya, consumida em maior intensidade por Artibeus lituratus. Os resultados ressaltam a importância destes animais no ambiente, em especial no processo de regeneração dessas áreas através da dispersão de sementes.Due to their abundance and diversity, bats (Chiroptera) play an important ecological role in the ecosystem. The objective of this study was to report the diet of fruit bat species captured in fragments of the Instituto São Vicente, Campo Grande, MS. The study was carried out September 2011 and June. We captured 154 individuals belonging to 10 species, and the frugivorous were predominant. 41 fecal samples were collected, demonstrating the presence of pulp, seeds and traces of arthropods. The resources most used by bats were pioneer plants, evidenced by the predominance of seeds of Cecropia pachystachya, consumed by Artibeus lituratus. The results shows the importance of these animals for seed dispersal

    The biogeography of the Amazonian tree flora

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    We describe the geographical variation in tree species composition across Amazonian forests and show how environmental conditions are associated with species turnover. Our analyses are based on 2023 forest inventory plots (1 ha) that provide abundance data for a total of 5188 tree species. Within-plot species composition reflected both local environmental conditions (especially soil nutrients and hydrology) and geographical regions. A broader-scale view of species turnover was obtained by interpolating the relative tree species abundances over Amazonia into 47,441 0.1-degree grid cells. Two main dimensions of spatial change in tree species composition were identified. The first was a gradient between western Amazonia at the Andean forelands (with young geology and relatively nutrient-rich soils) and central–eastern Amazonia associated with the Guiana and Brazilian Shields (with more ancient geology and poor soils). The second gradient was between the wet forests of the northwest and the drier forests in southern Amazonia. Isolines linking cells of similar composition crossed major Amazonian rivers, suggesting that tree species distributions are not limited by rivers. Even though some areas of relatively sharp species turnover were identified, mostly the tree species composition changed gradually over large extents, which does not support delimiting clear discrete biogeographic regions within Amazonia

    Unraveling Amazon tree community assembly using Maximum Information Entropy: a quantitative analysis of tropical forest ecology

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    In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain eight times more of local relative abundances than constraints based on directional selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary methods, furthering our understanding of ecological dynamics

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

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    Unidad de excelencia María de Maeztu CEX2019-000940-MAim: 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

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

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    Para investigar los patrones geográficos y las correlaciones ecológicas en la distribución geográfica de los modos de dispersión arbórea más comunes en la Amazonia (endozoocoria, sinzoocoria, anemoocoria e hidrocoria). Se examina si la abundancia proporcional de estos modos de dispersión podría explicarse por la disponibilidad de agentes dispersores (hipótesis de disponibilidad de dispersores) y/o la disponibilidad de recursos para la producción de frutos zoocoros (hipótesis de disponibilidad de recursos). Se utilizaron parcelas de inventario de árboles establecidas entre 1934 y 2019. Los principales taxones estudiados fueron árboles con un diámetro a la altura del pecho (DAP) ≥ 9,55 cm. Se asignaron modos de dispersión a un total de 5433 especies y morfoespecies en 1877 parcelas de inventario de árboles en bosques de abeto, inundados estacionalmente y permanentemente inundados. Se investigaron los patrones geográficos en la abundancia proporcional de los modos de dispersión. Se realizó una prueba de distancia media entre pares ponderada por abundancia (MPD) y ajustamos modelos lineales generalizados (GLM) para explicar la distribución geográfica de los modos de dispersión. La anemocoria se asoció significativa y positivamente con la velocidad media anual del viento, y la hidrocoria fue significativamente mayor en los bosques inundados. Los modos de dispersión no mostraron consistentemente asociaciones significativas con la disponibilidad de recursos para la construcción de frutos zoocoros. Una menor disimilitud en los modos de dispersión, resultante de una mayor dominancia de la endozoocoria, se produjo en los bosques de abeto (excluyendo los podzoles) en comparación con los bosques inundados. La hipótesis dispersor-disponibilidad fue bien apoyada para los modos de dispersión abióticos (anemochoria e hidrochoria). La disponibilidad de recursos para la construcción de frutos zoochorios parece una explicación poco probable para la distribución de los modos de dispersión en la Amazonia. La asociación entre los frugívoros y la abundancia proporcional de zoocoría requiere más investigación, ya que el crecimiento de árboles no sólo depende de los vectores de dispersión, sino también de las condiciones que favorecen o limitan el crecimiento de plántulas en los distintos tipos de bosque.Revisión por pares

    Estimating the global conservation status of more than 15,000 Amazonian tree species

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    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century

    Estimating the global conservation status of more than 15,000 Amazonian tree species

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

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    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

    Geography and ecology shape the phylogenetic composition of Amazonian tree communities

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    Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2^{2} = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2^{2} = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions
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