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

Características morfogênicas e perfolhamento do Panicum maximum Jacq. cv. Tanzânia irrigado

Avaliou-se o efeito de diferentes turnos de rega e níveis de irrigação sobre as características morfogênicas e o perfilhamento de Panicum maximum Jacq. cv. Tanzânia. Uma bancada experimental foi montada sob ambiente protegido, onde foram colocados recipientes cultivados com o capim. As irrigações foram realizadas com turnos de rega de 1, 4 e 7 dias, e lâminas de irrigação para restabelecer 50, 75 e 100% da disponibilidade total de água no solo. A densidade populacional de perfilhos foi obtida por meio de contagem de perfilhos vivos após cada corte. As características morfogênicas foram estudadas por meio da taxa de aparecimento de folhas (TApF), taxa de alongamento de folhas (TAlF) e colmos (TAlC), número de folhas emergentes (NFEm), expandidas (NFEx) e vivas (NFV). O perfilhamento foi maior para maior nível de irrigação. O clima proporcionou maior efeito nas características morfogênicas que os tratamentos. Os fatores estudados não proporcionaram efeito expressivo na TAlC, NFEm, NFEx e NFV.The aim of this work was to study the effect of different irrigation interval and irrigation depth on morphogenetic characteristics and tillering of the Panicum maximum Jacq. cv. Tanzania. The grass was cultivated in recipients in a greenhouse. The irrigations were performed with intervals of 1, 4 and 7 days, in order to reestablish soil water content to 50, 75 and 100% of the total available water in the soil. The tillering was obtained through counting of living tiller after each cut. The morphogenetic characteristics were studied through the leaf appearance rate (LAR), leaf elongation rate (LER) and stem elongation rate (SER), emerging leaf numbers (EmLN), expanded leaf numbers (ExLN) and living leaf numbers (LLN). The tillering was larger for larger irrigation depth. The climate provided greater effect in the morphogenetic characteristics than the treatments. The studied factors were not significant for SER, EmLN, ExLN and LLN

Produtividade do capim tanzânia em diferentes níveis e freqüências de irrigação

Objetivou-se estudar o efeito de diferentes freqüências e níveis de irrigação sobre a produtividade de massa seca (MS) do Panicum maximum Jacq. cv. Tanzânia. Uma bancada experimental foi montada em ambiente protegido, onde foram colocados recipientes cultivados com o capim tanzânia. As irrigações foram realizadas com freqüências de um, quatro e sete dias, e lâminas de irrigação para restabelecer 50, 75 e 100% da disponibilidade total de água no solo. A evapotranspiração da cultura foi obtida por meio de quatro lisímetros de drenagem. A produtividade de MS foi obtida por meio do material pré-seco, em estufa ventilada, a 65ºC, por 72 horas, e seco definitivamente em estufa a 105ºC, por 24 horas. A menor produtividade de MS (73,1 g recipiente-1) foi encontrada no tratamento de nível de irrigação de 50% e freqüência de sete dias. A maior produtividade de MS (129,5 g recipiente-1) foi encontrada no tratamento de nível de irrigação de 100% e freqüência de um dia. Conclui-se que a produtividade de MS aumentou à medida que aumentou o nível de irrigação e diminuiu a freqüência de irrigação.The aim of this work was to study the effect of different irrigation frequencies and levels on dry matter (DM) yield of Panicum maximum Jacq. cv. Tanzania. The experiment was carried out under greenhouse conditions, where drums were filled out with soil and cultivated with tanzania grass. The irrigations were performed with a frequency of 1, 4 and 7 days, in order to re-establish soil water content to 50, 75 and 100% of the total available water in the soil. The crop evapotranspiration (ETc) was obtained by means of four drainage lysimeters. The yield of DM was obtained by means of the material pre-dried in ventilated stoves at 65ºC, for 72 h, and dried definitively in stoves at 105ºC, for 24 h. The smallest DM yield (73.1 g vessel-1) was obtained for total available water in the soil of 50% and 7-day irrigation frequency. The highest DM yield (129.5 g vessel-1) was obtained for total available water of 100% and 1-day irrigation frequency. The authors concluded that the DM yield increases with the increasing of percentage of total available water and decreasing of irrigation frequency

Exigência nutricional de lisina para codornas européias machos de 21 a 49 dias de idade

O experimento foi conduzido como objetivo de estimar a exigência de lisina total para codornas européias (Coturnix coturnix coturnix) machos de 21 a 49 dias de idade. Foram utilizadas 315 codornas (peso vivo médio de 80 g) alimentadas com rações à base de milho, farelo de soja e farelo de glúten de milho. A ração basal, formulada sem suplementação de lisina sintética, continha 20% de PB, 2.900 kcal de energia metabolizável (EM)/kg e 0,9% de lisina total e foi suplementada com 0,125; 0,231; 0,357 e 0,483 de L-lisina-HCl (79%), resultando em rações com 1,0; 1,1; 1,2 e 1,3% de lisina total, respectivamente. Utilizou-se delineamento inteiramente casualizado, com cinco tratamentos, sete repetições e nove aves por unidade experimental. Foram avaliados o consumo de ração, o peso final, o ganho de peso, a conversão alimentar, o índice de eficiência produtiva e os rendimentos de peito e de carcaça. Observou-se efeito não-significativo para todas as variáveis avaliadas. A exigência dietética de lisina total para codornas européias machos de 21 a 49 dias de idade é de 0,9%, que corresponde a um consumo diário de 207 mg de lisina por ave

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora