69 research outputs found

    Restoration and Management of Healthy Wetland Ecosystems

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    ECOLOGY OF AQUATIC MACROPHYTES IN BRAZIL: THE LEGACY OF FRANCISCO DE ASSIS ESTEVES

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    In this review, we evaluate the contribution of Brazilian limnologists to research outputs on aquatic macrophyte ecology. We found a strong “adviser effect” of Professor F.A. Esteves on the Brazilian scientific production focused on aquatic macrophytes. In general, articles focused on a variety of themes, including, inter alia, the role of aquatic macrophytes on the biodiversity of other groups, the interaction between macrophytes and the environment, the effects of environmental factors on aquatic macrophytes distribution and biodiversity, the effects of invasive species on aquatic biodiversity, aquatic macrophytes control and decomposition. Emerging topics (e.g., metacommunity ecology, biodiversity-ecosystem functioning, and patterns of diversity and their determinants) are being embraced by Brazilian limnologists that use aquatic macrophytes as organism models. Despite the fact there is much to study, we think that directly (e.g., via mentoring) or indirectly (via publications), our current knowledge about macrophytes ecology was inspired by Chico Esteves

    Potential implications to wheat establishment due to negative effects of Eragrostis plana in rhizospheric soil

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    Exotic plants, such as Eragrostis plana in southern Brazil, may cause significant problems in agriculture. This study aimed to elucidate the influence of E. plana rhizosphere soil on wheat germination and initial development. Bioassays with soil sampled from an infested agroecosystem were carried out using wheat as the target species. A factorial design was used, crossing soil from the horizontal and vertical distances from the E. plana tiller base and considering seasons as a blocking factor. The interaction between season and vertical and horizontal soil positions influenced normal wheat seed germination, with the lowest values (69%) observed in the winter bottom and intermediate soil positions. The highest abnormal seedling percentage (17.6%) was recorded in the summer middle vertical soil position. Dormant wheat seeds were higher (7%) in the spring bottom and distal soil positions. The season was the most important factor for germination, but hypocotyl, radicle, and total wheat seedling length also varied according to soil position. Shorter hypocotyls and seedlings were registered in the summer soil surface, while shorter radicles were observed in the proximal horizontal soil position in the same season. This variable response of wheat germination and seedling development to the infested soil demonstrated E. plana seasonality. The influence also varied according to the distance from the plant tiller base. These findings may be used to improve E. plana management in infested fields and to understand the mechanism of action of its allelochemicals in future research

    World distribution, diversity and endemism of aquatic macrophytes

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    To test the hitherto generally-accepted hypothesis that most aquatic macrophytes have broad world distributions, we investigated the global distribution, diversity and endemism patterns of 3457 macrophyte species that occur in permanent, temporary or ephemeral inland freshwater and brackish waterbodies worldwide. At a resolution of 10 × 10° latitude x longitude, most macrophyte species were found to have narrow global distributions: 78% have ranges (measured using an approach broadly following the IUCN-defined concept “extent of occurrence”) that individually occupy <10% of the world area present within the six global ecozones which primarily provide habitat for macrophytes. We found evidence of non-linear relationships between latitude and macrophyte α- and γ-diversity, with diversity highest in sub-tropical to low tropical latitudes, declining slightly towards the Equator, and also declining strongly towards higher latitudes. Landscape aridity and, to a lesser extent, altitude and land area present per gridcell also influence macrophyte diversity and species assemblage worldwide. The Neotropics and Orient have the richest ecozone species-pools for macrophytes, depending on γ-diversity metric used. The region around Brasilia/Goiás (Brazil: gridcell 10–20 °S; 40–50 °W) is the richest global hotspot for macrophyte α-diversity (total species α-diversity, ST: 625 species/gridcell, 350 of them Neotropical endemics). In contrast, the Sahara/Arabian Deserts, and some Arctic areas, have the lowest macrophyte α-diversity (ST <20 species/gridcell). At ecozone scale, macrophyte species endemism is pronounced, though with a>5-fold difference between the most species-rich (Neotropics) and species-poor (Palaearctic) ecozones. Our findings strongly support the assertion that small-ranged species constitute most of Earth’s species diversity

    Puntos de inflexión en los gradientes de composición de las comunidades de plantas acuáticas de diferentes continentes

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    Sección: SIBECOL-AIL Meeting in Aveiro-2022[EN] Unravelling patterns and mechanisms of biogeographical transitions is crucial if we are to understand compositional gradients at large spatial extents, but no studies have thus far examined breakpoints in community composition of freshwater plants across continents. Using a dataset of almost 500 observations of lake plant community composition from six continents, we examined, for the first time, if such breakpoints in geographical space exist for freshwater plants and how well a suite of ecological factors (including climatic and local environmental variables) can explain transitions in community composition from the subtropics to the poles. Our combination of multivariate regression tree (MRT) analysis and k-means partitioning suggests that the most abrupt breakpoint exists between temperate to boreal regions on the one hand and freshwater plant communities harbouring mainly subtropical or Mediterranean assemblages on the other. The spatially structured variation in current climatic conditions is the most likely candidate for controlling these latitudinal patterns, although one cannot rule out joint effects of eco-evolutionary constraints in the harsher high-latitude environments and post-glacial migration lags after Pleistocene Ice Ages. Overall, our study supports the foundations of global regionalisation for freshwater plants and anticipates further biogeographical research on freshwater plant communities once datasets have been harmonised for conducting large-scale spatial analyses[ES] Desentrañar los patrones y mecanismos que subyacen a las transiciones biogeográficas es un requisito fundamental a la hora de comprender los gradientes de composición de las comunidades ecológicas a grandes extensiones espaciales, si bien ningún estudio ha examinado explícitamente estos puntos de inflexión para comunidades de plantas acuáticas de diferentes continentes. Utilizando una completa base de datos que condensa un total de casi 500 observaciones individuales sobre las comunidades florísticas lacustres de seis continentes, este trabajo pretende delinear las transiciones biogeográficas en plantas acuáticas a escala global, así como valorar el papel que desempeñan diversos mecanismos ecológicos (a saber, las condiciones climáticas y las características locales del hábitat) sobre estos puntos de inflexión en el espacio geográfico comprendido entre las latitudes subtropicales y los polos. Nuestros resultados obtenidos mediante la ejecución simultánea de árboles de regresión multivariante (MRT) y algoritmos de agrupación por k-medias demuestran la existencia de un punto de inflexión entre las regiones templadas y boreales y los lagos localizados en las bandas subtropicales y en las inmediaciones del Mediterráneo. La estructura espacial que subyace a la distribución de los condicionantes climáticos en nuestro planeta parece ser el principal mecanismo de control de dichas transiciones biogeográficas, si bien estos patrones latitudinales también podrían explicarse en base a constricciones eco-evolutivas en las regiones más septentrionales y a la colonización diferencial de los territorios norteños antaño cubiertos por el hielo durante el Último Máximo Glacial. En síntesis, nuestro estudio proporciona una base teórica preliminar para futuras investigaciones encaminadas a delimitar las unidades geográficas de los principales componentes de la flora acuática contemporánea y también anticipa un creciente interés por los estudios de carácter fitogeográfico en las aguas continentales, si bien los análisis venideros deberán prestar especial atención a la armonización de datos biológicos potencialmente heterogéneos en naturaleza y con orígenes disparesSIJGG was funded by the European Union Next Generation EU/PRTR (grant no. AG325). Academy of Finland supported JH, JGG (grant no. 331957), and JA (grant no. 322652). CFL appreciates financial support from the Spanish Ministry of Science and Technology (grant no. CL2017- 84176R). BAL was supported by National Research, Development, and Innovation Office (grant no. NKFIH, OTKA FK127939) and by the Bolyai János Research Scholarship of the Hungarian Academy of Sciences. SK was supportedby NWO Vidi (grant no. 203098). LR was funded by MESRSI (Ministry of Higher Education, Scientific Research and Innovation of Morocco) as part of the BiodivRestore Program (RESPOND Project) and by the Tour du Valat Foundation. Sampling of the Brazilian coastal lakes was financed by NWO (grant no. W84-549), the National Geographic Society (grant no. 7864-5), and CNPq (grants no. 480122, 490409, 311427

    Protected areas: A focus on Brazilian freshwater biodiversity

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    Brazil has a variety of aquatic ecosystems and rich freshwater biodiversity, but these components have been constantly damaged by the expansion of unsustainable activities. An array of different conservation strategies is needed, especially the creation of protected areas (PAs, hereafter). However, Brazil's PAs are biased towards terrestrial ecosystems and we argue that current PAs have limited efficacy in the protection of freshwater biodiversity. New PAs should better consider aquatic environments, covering entire basins, rivers and other freshwater habitats. We recommend ways to implement these PAs and provide guidance to avoid social impacts. Freshwater systems in Brazil provide essential goods and services but these ecosystems are being rapidly degraded and will be lost if not adequately protected. © 2018 The Authors. Diversity and Distributions Published by John Wiley & Sons Lt

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
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