11 research outputs found

    NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

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    Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset

    Processos de democracia direta: sim ou não? Os argumentos clássicos à luz da teoria e da prática

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    Regularmente surgem controvérsias sobre os processos de democracia direta, dos quais os mecanismos mais frequentes são a iniciativa popular, o plebiscito e o referendo. Por um lado, há autores que defendem a posição de que essas instituições tornam o jogo político mais lento, caro, confuso e ilegítimo; outros defendem a posição contrária e argumentam que processos de democracia direta são fundamentais para os cidadãos e a qualidade da democracia. O presente estudo analisa esse tema em torno de sete questões, baseadas em considerações teóricas e pesquisas empíricas: 1. A questão entre o minimalismo e o maximalismo democrático; 2. A concorrência entre maioria e minoria; 3. A concorrência entre as instituições representativas e os processos de democracia direta; 4. A questão da competência dos cidadãos; 5. A questão dos efeitos colaterais dos processos de democracia direta; 6. A questão do tamanho do eleitorado; 7. A questão dos custos dos processos de democracia direta. As sete questões são analisadas a partir de uma revisão bibliográfica que considera tanto fontes nacionais como internacionais. O estudo mostra que os processos de democracia direta podem ser um complemento para as instituições representativas em um sistema democrático. O bom desempenho dos plebiscitos, referendos e iniciativas populares depende tanto da regulamentação destes como também do desempenho das outras instituições políticas e da situação socioeconômica de um país. O estudo permite ampliar e aprofundar o debate sobre processos de democracia direta no Brasil

    Author Correction: One sixth of Amazonian tree diversity is dependent on river floodplains

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    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications 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, 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

    Produção de mudas de dois genótipos de alecrim-de-tabuleiro (Lippia gracilis Schauer) em função de fertilizante mineral, calcário, substratos e recipientes Seedling production of two "alecrim-de-tabuleiro" (Lippia gracilis Schauer) genotypes under mineral fertilizer, limestone, substrates and containers

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    Lippia gracilis Schauer popularmente conhecida como alecrim-de-tabuleiro possui moderada atividade antibacteriana, antimicrobiana e antiséptica. Objetivando avaliar o efeito de doses de fertilizante mineral, calcário, substratos e recipientes na produção de mudas de dois genótipos de alecrim-de-tabuleiro realizou-se experimentos com estacas de dois genótipos de L. gracilis. No experimento 1, foram utilizadas estacas apicais distribuídas em bandejas de poliestireno expandido de 128 células com o substrato pó-de-coco + areia (1:1), três repetições e oito estacas por repetição. O delineamento experimental foi em blocos ao acaso, em esquema fatorial 4x2x2, sendo quatro doses do fertilizante (6-24-12+micronutrientes) (1, 2, 3 e 4 g L-1), duas doses de calcário (0 e 1 g L-1) e dois genótipos (LGRA106 e LGRA201). Aos 35 após plantio, foram avaliadas a sobrevivência (%), enraizamento (%), comprimento de raiz (cm) e massa seca de raiz (mg). No experimento 2, foram utilizadas três repetições com oito estacas por repetição. O delineamento experimental foi em blocos ao acaso, em esquema de parcelas subdivididas onde foram testados nas parcelas dois recipientes (bandeja de poliestireno expandido de 128 alvéolos e tubetes de 110 cm³, na sub parcela foram testadas as combinações de quatro substratos (PC - pó de coco; PCA (1:1) - pó de coco + areia (1:1); PCA (2:1) - pó de coco + areia (2:1) e PCA (3:1) - pó de coco + areia (3:1) e dois genótipos (LGRA106 e LGRA201). Aos 35 dias após o plantio foram analisadas as mesmas variáveis do experimento 1, além de altura de parte aérea (cm) e massa seca de parte aérea (mg). A utilização de 1 g L-1 do fertilizante na ausência de calcário foi efetivo para sobrevivência de plantas e enraizamento de estacas de alecrim-de-tabuleiro. Com base nesses experimentos, concluiu-se que o genótipo LGRA106 é superior ao LGRA201 nas variáveis analisadas e recomenda-se a bandeja de poliestireno expandido para produção de mudas de L. gracilis via estaquia.<br>Commonly known as "alecrim-de-tabuleiro", Lippia gracilis Schauer (Verbenaceae) has moderate antibacterial, antimicrobial and antiseptic activity. This study aimed to evaluate the effect of doses of mineral fertilizer, limestone, substrates and containers on seedling production of two "alecrim-de-tabuleiro" genotypes, using cuttings. In experiment 1, apical cuttings were distributed on expanded polystyrene trays of 128 cells containing coir + sand (1:1), using three replicates of eight cuttings each. Experimental design was in randomized blocks, in a 4x2x2 factorial arrangement, i.e. four doses of fertilizer (6-24-12 + micronutrients) (1, 2, 3 and 4 g L-1), two doses of limestone (0 and 1 g L-1) and two genotypes (LGRA106 and LGRA201). At 35 days after planting, we evaluated survival (%), rooting (%), root length (cm) and root dry matter (mg). In experiment 2, three replicates of eight cuttings each were used. Experimental design was in randomized blocks, in a split-plot scheme. In the plots, we tested two containers (expanded polystyrene tray of 128 cells and 110 cm³ tubets). In the subplots, we tested four substrate combinations [coir, coir + sand (1:1), coir + sand (2:1) and coir + sand (3:1)] and two genotypes (LGRA106 and LGRA201). At 35 days after planting, the same variables of experiment 1 were evaluated, besides shoot length (cm) and shoot dry matter (mg). The use of 1 g L-1 fertilizer without limestone was effective for plant survival and cutting rooting. Based on these experiments, the genotype LGRA106 is superior to LGRA201 as to the evaluated variables and the expanded polystyrene tray is recommended for the production of L. gracilis seedlings through cuttings
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