Siltation rate and main anthropic impacts on sedimentation of the São Luís tidal inlet - State of Maranhão, Brazil

Abstract In recent decades, intense human intervention in the coastal zone has given rise to severe siltation and erosion problems. This scenario is located the São Luís tidal inlet, formed by the mouths of the Anil and Bacanga rivers which due to various kinds of interference have been changing their sediment transport and deposition processes. With these changes in mind, this study sought to evaluate the evolution of the siltation and sedimentation rates in this area, as well as the main anthropogenic influences associated with this process. The methodology consisted in verifying the morphological evolution on the basis of the scanning and vectorization of nautical charts of 1947 and 1966, bathymetric surveys conducted in 2006, and aerial photos dating from 2011. The results show a silting up process coincident with interventions that occurred in the Anil and Bacanga river basins, with a volume of silt estimated at 8.5x106 m3, over the period from 1944 to 2011 (64 years), at a rate of 1.6 cm.yr-1. These processes are associated mainly with the construction of the Bacanga dam and land reclamation projects undertaken for the purpose of providing new areas for urban expansion. The evaluation of the results showed intense and advanced silting up of the São Luís tidal inlet, at rates proportionally greater than those of other estuaries, calling for corrective actions and the implementation of coastal management policies for this area.Resumo As intensas intervenções antrópicas na zona costeira fizeram surgir, nas últimas décadas, graves problemas de assoreamento e erosão nessas áreas. Neste cenário, enquadra-se a embocadura estuarina de São Luís, formada pela foz dos rios Anil e Bacanga, que devido a diversas interferências, vem sofrendo alterações nos processos de transporte e deposição. Em função de tais alterações, realizou-se o presente estudo que objetivou avaliar a evolução e estimar as taxas de assoreamento na referida área, assim como verificar as principais influências antrópicas associadas ao processo. Analisou-se a evolução morfológica a partir da digitalização e vetorização das cartas náuticas de 1947 e 1966, levantamentos batimétricos realizados em 2006, e fotos aéreas datadas de 2011. Os resultados evidenciaram um processo de preenchimento sedimentar que coincide com as intervenções que ocorreram na bacia dos rios Anil e Bacanga, com estimativas de volume assoreado na ordem de 8,5x106 m3, no período de 1944 a 2011 (64 anos), com taxa de 1,6 cm ano-1. Esses processos estiveram associados principalmente à construção da barragem do Bacanga e atividades de aterramento para construção de avenidas e expansão de bairros. A avaliação dos resultados demonstra intenso e avançado processo de preenchimento sedimentar na região da Embocadura Estuarina de São Luís, inclusive com taxas proporcionais superiores às registradas em outros estuários semelhantes do planeta, impondo a necessidade de ações corretivas e aplicação de políticas de gestão costeira para a área

Pervasive gaps in Amazonian ecological research

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

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

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

Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others

HYPERSALINE INTERTIDAL HABITATS ON THE COAST OF MARANHÃO, NORTHERN BRAZIL: AN INTRODUCTION

O litoral maranhense caracteriza-se por seus extensos manguezais, que cobrem mais da metade dos seus 640 km de linha de costa. A região costeira maranhense encontra-se exposta a um clima sazonalmente seco, com uma precipitação anual média de 1952 mm, concentrados no período de dezembro a julho. Esta combinação de clima sazonalmente seco e extensos terrenos intertidais é propícia ao desenvolvimento de água e solos hipersalinos.Em concentrações elevadas, geralmente acima de 100 ppt, a salinidade pode levar à total eliminação da cobertura vegetal da zona intertidal gerando os “apicuns”.Não há duvida que os apicuns sejam os principais ambientes hipersalinos da zona intertidal maranhense, contudo ainda não sabemos se eles são os únicos, abrindo assim a possibilidade de que outros sistemas hipersalinos, tais como “ salt pans” e “sabkhas”, também ocorram no nosso litoral. Dessa maneira, o objetivo principal do presente trabalho é propiciar uma base teórica sobre as características e peculiaridades dos principais sistemas hipersalinos da região intertidal, constituindo assim um primeiro passo na direção do estudo da diversidade de ambientes hipersalinos do litoral maranhense.ABSTRACTMaranhão state, Northern Brazil, has extensive mangrove forests fringing more than half of its 640 km coastline. The coast has a seasonally dry climate with average annual rainfall of 1952 mm, falling mostly between December and July. The combination of climate and extensive intertidal zones has led to porewater and soil hypersalinity, which in turn play an important role in the development of mangrove zonation patterns. Extreme salinity levels, (usually over 100 ppt) can lead to the elimination of intertidal plant cover, forming salt barrens, known locally as “apicuns”. There is no doubt that the apicum is the main hypersaline intertidal environment in Maranhão state. We still do not know, however, whether other hypersaline environments, such as salt pans and sabkhas, do occur along this coast. The characteristics abd peculiarities of several intertidal hypersaline environments are discussed here to provide a basis for future studies of the diversity of Maranhão’s coastal hypersaline environments.

HYPERSALINE INTERTIDAL HABITATS ON THE COAST OF MARANHÃO, NORTHERN BRAZIL: AN INTRODUCTION

O litoral maranhense caracteriza-se por seus extensos manguezais, que cobrem mais da metade dos seus 640 km de linha de costa. A região costeira maranhense encontra-se exposta a um clima sazonalmente seco, com uma precipitação anual média de 1952 mm, concentrados no período de dezembro a julho. Esta combinação de clima sazonalmente seco e extensos terrenos intertidais é propícia ao desenvolvimento de água e solos hipersalinos.Em concentrações elevadas, geralmente acima de 100 ppt, a salinidade pode levar à total eliminação da cobertura vegetal da zona intertidal gerando os “apicuns”.Não há duvida que os apicuns sejam os principais ambientes hipersalinos da zona intertidal maranhense, contudo ainda não sabemos se eles são os únicos, abrindo assim a possibilidade de que outros sistemas hipersalinos, tais como “ salt pans” e “sabkhas”, também ocorram no nosso litoral. Dessa maneira, o objetivo principal do presente trabalho é propiciar uma base teórica sobre as características e peculiaridades dos principais sistemas hipersalinos da região intertidal, constituindo assim um primeiro passo na direção do estudo da diversidade de ambientes hipersalinos do litoral maranhense.ABSTRACTMaranhão state, Northern Brazil, has extensive mangrove forests fringing more than half of its 640 km coastline. The coast has a seasonally dry climate with average annual rainfall of 1952 mm, falling mostly between December and July. The combination of climate and extensive intertidal zones has led to porewater and soil hypersalinity, which in turn play an important role in the development of mangrove zonation patterns. Extreme salinity levels, (usually over 100 ppt) can lead to the elimination of intertidal plant cover, forming salt barrens, known locally as “apicuns”. There is no doubt that the apicum is the main hypersaline intertidal environment in Maranhão state. We still do not know, however, whether other hypersaline environments, such as salt pans and sabkhas, do occur along this coast. The characteristics abd peculiarities of several intertidal hypersaline environments are discussed here to provide a basis for future studies of the diversity of Maranhão’s coastal hypersaline environments.

Siltation rate and main anthropic impacts on sedimentation of the São Luís tidal inlet - State of Maranhão, Brazil

Abstract In recent decades, intense human intervention in the coastal zone has given rise to severe siltation and erosion problems. This scenario is located the São Luís tidal inlet, formed by the mouths of the Anil and Bacanga rivers which due to various kinds of interference have been changing their sediment transport and deposition processes. With these changes in mind, this study sought to evaluate the evolution of the siltation and sedimentation rates in this area, as well as the main anthropogenic influences associated with this process. The methodology consisted in verifying the morphological evolution on the basis of the scanning and vectorization of nautical charts of 1947 and 1966, bathymetric surveys conducted in 2006, and aerial photos dating from 2011. The results show a silting up process coincident with interventions that occurred in the Anil and Bacanga river basins, with a volume of silt estimated at 8.5x106 m3, over the period from 1944 to 2011 (64 years), at a rate of 1.6 cm.yr-1. These processes are associated mainly with the construction of the Bacanga dam and land reclamation projects undertaken for the purpose of providing new areas for urban expansion. The evaluation of the results showed intense and advanced silting up of the São Luís tidal inlet, at rates proportionally greater than those of other estuaries, calling for corrective actions and the implementation of coastal management policies for this area

ATLANTIC ANTS: a data set of ants in Atlantic Forests of South America

International audienc