12 research outputs found

    Phylogenetic regionalization of tree assemblages reveals novel patterns of evolutionary affinities in the Atlantic Forest

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    peer reviewedAim: We used a phylogenetic approach to group assemblages of woody plant into major vegetation units in the Atlantic Forest, thus for the first time incorporating information on species evolutionary relationships into a bioregionalization of this critical hotspot. A phylogenetic regionalization will provide a spatially explicit framework for answering many basic and applied questions in biogeography, ecology and conservation. Location: Atlantic Forest. Taxon: Angiosperms. Methods: Our data set comprises 614 genera and 116 families, spread over 1,755 assemblages. To place assemblages in a multivariate evolutionary composition space, we used a phylogenetically informed ordination analysis, and to determine what the main phylogenetic groups of assemblages were, we used K-means clustering based on phylogenetic dissimilarity of assemblages. To quantify how well environmental variables distinguish the phylogenetic groups found, we implemented classification tree approaches. Then, to explore the evolutionary turnover between the phylogenetic groups, we calculated phylogenetic beta diversity. Finally, we determined the lineages that are most strongly associated with individual phylogenetic groups using an indicator analysis for lineages. Results: Our analyses suggest that there are seven principal groups, in terms of evolutionary lineage composition, in the Atlantic Forest. The greatest turnover of phylogenetic lineage composition separates tropical evergreen rain forest and semideciduous assemblages from subtropical and highland assemblages. The mixed subtropical forest showed the lowest phylogenetic compositional similarity values with other groups. Tropical rain forest had the highest number of significant indicator lineages, and the highest values of the indicator statistic for lineages. Main conclusions: We found that the most pronounced evolutionary division separates southern and highland tree assemblages from those occurring under more tropical climates and at lower elevations. Our phylogenetic analyses point to an environmentally driven compositional division, likely based on the regular occurrence of freezing versus non-freezing temperatures. Precipitation and edaphic regimes that assemblages experience had less definitive effects on their evolutionary lineage composition

    Capacitação de catadores em Mundo Novo - MS

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    A partir de uma parceria entre a Unidade Universitária de Mundo Novo, da Universidade Estadual de Mato Grosso do Sul (UEMS/MN), e a Secretaria de Assistência Social do município foi realizada a capacitação dos catadores da Associação dos Recicladores Ambientais de Mundo Novo com o objetivo de incrementar a renda, buscando o resgate da cidadania dos associados. Foram planejadas atividades que salientaram a importância ambiental e socioeconômica da atividade profissional utilizando vídeos e palestras ministradas pelos alunos do curso de Ciências Biológicas da UEMS/MN, abordando conteúdos de ecologia, recursos naturais, desenvolvimento sustentável e coleta seletiva. Esses conceitos foram trabalhados utilizando recursos audiovisuais, tendo em vista a singularidade do público alvo, composto, em sua maioria, por semiletrados. Por meio de uma oficina conduzida por uma artista plástica, os catadores foram incentivados a fabricar produtos de cunho artesanal a partir de materiais descartáveis como forma de incrementar a renda familiar. Os associados compreenderam a importância do trabalho realizado na busca de um meio ambiente mais equilibrado e o seu papel na sociedade; consequentemente, acredita-se que a autoestima do grupo foi elevada de forma significativa. Espera-se que eventos dessa natureza possam se tornar mais frequentes; entretanto, é necessário que a comunidade universitária esteja preparada para lidar com realidades tão diferenciadas, o que consolida a importância de projetos de extensão universitária.

    Flooding avoidance Triplaris gardneriana Wedd. (Polygonaceae): growth and morpho-anatomical aspects

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    The aim of this study was to analyze the effect of flooding in Triplaris gardneriana Wedd, cultivated in drained soil (control) and in flooded condition. The experiment was developed in a greenhouse, using plants with 90 days after the emergency. The response to treatment was evaluated at 0, 30, 60 and 90 days. Growth measurements were made, such as biomass allocation, relative growth rate (RGR). Adventitious roots were not measured only observed, as well as the development of hypertrophied lenticels. The RGR was continuously reduced along the 90 days in flooding conditions for the roots, stem and leaves, compared to control. The flooding of the substrate caused alterations such as: increasing of the cortex width and diameter of the central cylinder of root and increasing the diameter of the vessel element of the root and stem. Results show that T. gardneriana remains under stress when submitted to flooding. Therefore, the production of structures as lenticels, aerenchyma and adventitious roots, structures related to the avoidance of this type of stress, were key factors for the maintenance and survival of T. gardneriana.

    Floristic distributional patterns in a diverse ecotonal area in South America

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    The Paraguayan territory and region, in the centre of South America, is a huge transition area with a succession of various vegetation types. However, this area has received little attention from researchers, with few works published on its flora and its delimitations. We aimed to identify the most important environmental driving forces and delimit floristic patterns in this region, since understanding the forces that drive floristic variations in this ecotonal region could help comprehend the distribution of vegetation not only in this region but throughout South America. We obtained 1234 tree species occurrence records, 205 geographic coordinates and 23 environmental variables and altitude from the ‘NeoTropTree’ database and verified the influence and contribution of environmental factors through variance partition. We tested the floristic consistency of the different vegetation types using dendrogram, indicator species and ordination analyses. We also constructed multiple linear models to check the correlation between species distribution and environmental variables. We found eight consistent vegetation types. The spatial variables coupled with environmental variables were more important than individual environmental or spatial variables. Among the environmental variables, the aridity index was the most important. Despite the importance of spatial factors, due to environmental heterogeneity, we found a gradient related to climate and edaphic variables related to tree flora. The results confirm that the Paraguayan territory and region can be considered to be a diversified and important ecotone area in South America with respect to tree flora

    Evolutionary history of campo rupestre: an approach for conservation of woody plant communities

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    The campo rupestre sensu lato is among the most species-rich vegetation in the world, harbouring a high proportion of endemic species. We aimed to identify the processes that could generate a high level of phylogenetic diversity (PD) in campo rupestre for woody species and point out biodiversity hotspot areas which may provide additional information for conservation planning. We compiled a database of 2049 woody species from 185 community inventories. We calculated the evolutionary history using species richness (SR), PD, mean pairwise phylogenetic distance between species (MPD), the mean nearest taxon distance (MNTD) and their equivalents standardised (ses.PDss, ses.MPD, ses.MNTD), evolutionary distinctiveness (ED), and biogeographically weighted evolutionary distinctiveness (BED). Cloud dwarf-forests had the highest SR, PD, MPD and ses.MPD and lowest MNTD, while rupestrian cerrado presented the highest ses.PD and ses.MNTD. All areas are important for conservation, but the intersections between the hotspots should receive special attention in future conservation actions. The grids identified as hotspots by three or more metrics were localized mainly in Espinhaço Range in Minas Gerais State and a further expansion of protected areas is required. Moreover, the intersections between the hotspots obtained by mean ED and ses.PD are concentrated in the rocky dwarf forest and rupestrian cerrado, with considerable conservation gaps. The degree of protection of campo rupestre was low with unprotected areas comprising 56% of the species. Our results show an urgent need for increasing protected areas of campo rupestre in order to avoid the loss of valuable, endemic species with unique evolutionary history

    Influence of edaphic factors on the floristic composition of an area of cerrad\ue3o in the Brazilian central-west

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    This study describes the influence of edaphic factors on the floristic composition of an area of cerradão (woodland savanna) in the city of Campo Grande, located in the Brazilian central-west. In 10 plots (5 × 20 m each), we evaluated all trees with a diameter at breast height > 4.77 cm. Soil samples were analyzed for each plot in order to determine edaphic variables correlated with species composition. We sampled 1180 individuals of 61 species. The evenness index was 0.74, which indicates uneven distribution of species, which was explained by a high abundance of Qualea parviflora, Curatella americana, Qualea grandiflora, Terminalia argentea and Astronium fraxinifolium. We registered more trees in the smallest diameter class and in the middle layer of the vertical structure. The soil was dystrophic with a clay texture, which explains the higher abundance of species related to dystrophic cerradão. However, we also found some trees typical of mesotrophic cerradão and deciduous forests, which could be attributable to the presence of patches of fertile soil within the dystrophic cerradão or could indicate that those mesotrophic species are tolerant of lower levels of soil nutrients
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