Resumo: O Cerrado ocupa aproximadamente 23 % do território brasileiro e 70% do bioma correspondem ao cerrado Stricto Sensu (s. s.), sendo relevantes os estudos que buscam o entendimento da estrutura da vegetação nessas áreas. Com esse objetivo, foram estudadas 25 parcelas 20x10 m (200 m²). Foram incluídos na amostragem todos os troncos com diâmetro maior ou igual a 10 cm, obtidos a 30 cm do solo. Foram amostrados 662 indivíduos distribuídos em 69 espécies, pertencentes a 31 famílias. A densidade total absoluta foi de 1324 ind.ha-1 e a área basal total 6.351 m²/ha. Leguminosae foi a família com maior número de espécies (12). As espécies que apresentaram os maiores valores de Índice do Valor de Importância (IVI) foram Caryocar brasilienses Cambess., Anacardium occidentale L., Curatella americana L., Pouteria ramiflora (Mart.) Radlk., Qualea multiflora Mart. O índice de Shannon encontrado foi de (H' = 3.687). Não há distribuição homogênea das espécies na área, já que 19 espécies são de ocorrência rara (apenas um indivíduo), e apenas 21 têm mais de 10 indivíduos. Assim, a maior abundância registrada foi da família Vochysiaceae, de forma que Qualea multiflora apresentou o maior IVI.
The Tocantins-Araguaia Basin is one of the largest river systems in South America, located entirely within Brazilian territory. In the last decades, capital-concentrating activities such as agribusiness, mining, and hydropower promoted extensive changes in land cover, hydrology, and environmental conditions. These changes are jeopardizing the basin's biodiversity and ecosystem services. Threats are escalating as poor environmental policies continue to be formulated, such as environmentally unsustainable hydropower plants, large-scale agriculture for commodity production, and aquaculture with non-native fish. If the current model persists, it will deepen the environmental crisis in the basin, compromising broad conservation goals and social development in the long term. Better policies will require thought and planning to minimize growing threats and ensure the basin's sustainability for future generations.
ABSTRACT. In the State of Tocantins, there is an abundance of water bodies, and consequently a large range of gallery forests. Despite growing awareness of the importance of these forest resources and the need to conserve them, little is known about the composition and floristic diversity of existing remnants, which still represent part of the original vegetation. The aim of this study was to review and compare the floristic composition and structure of the tree layer of the gallery forest in two microbasins of Taquaruçu Grande Sub-basin, Palmas County, Tocantins State. For phytosociological sampling, contiguous 50 plots of 10 x 10 m were set in each area, where all the individuals with trunk circumference greater than or equal to 15, at 130 cm from the ground were sampled. To calculate the phytosociological parameters, was used Fitopac 1 software, and for the similarity calculation, was used Similarity Score of Sörensen. 928 individuals were recorded, totaling 139 tree species belonging to 45 botanical families for Area 1 and 2. Species richness for the two areas studied showed no differences, and the Shannon diversity index (H') that 3.751 and 3.671, showing that the species distribution was uniform A1 (J = 0.83) and A2 (P = 0.822). The similarity index between areas was 42%, a result considered low.Keywords: tree layer, watershed, similarity.Composição florística e estrutura fitossociológica de dois trechos de Mata de Galeria na Sub-Bacia do Taquaruçu Grande, Município de Palmas, Estado de Tocantins RESUMO. Apesar da importância desses recursos florestais e da necessidade de conservá-los, pouco se sabe sobre a composição e diversidade florística dos remanescentes existentes. O objetivo desse estudo foi analisar e comparar a composição florística e estrutural do estrato arbóreo da mata galeria em duas microbacias da sub-bacia do ribeirão Taquaruçu Grande, município de Palmas, Tocantins. Para o levantamento fitossociológico, foram alocadas 50 parcelas contíguas de 10 x 10 m em cada área, na qual todos os indivíduos com circunferência de tronco maior ou igual a 15 a 130 cm do solo foram amostrados. Para o cálculo dos parâmetros fitossociológicos foi utilizado o programa Fitopac 1, e para o cálculo da similaridade foi usado o Índice de Similaridade de Sörensen. Foram registrados 928 indivíduos, totalizando 139 espécies arbóreas pertencentes a 45 famílias botânicas para as áreas 1 e 2. A riqueza de espécies para as duas áreas não mostrou diferenças expressivas, assim como o índice de diversidade de Shannon (H') com 3,751 e 3,671, mostrando também que a distribuição das espécies foi uniforme A1 (J = 0,83) e A2 (J = 0,822). O índice de similaridade entre as áreas foi 42%, resultado considerado baixo.Palavras-chave: estrato arbóreo, microbacia, similaridade.
The objective of this work was to perform a temporal quantitative analysis, using the scientometric technique, considering the number of citations that the terms Primary Production of Aquatic Macrophytes and Energetic Ecology received in a 50-year period (1956 to 2006). The study related 189 papers published in 26 magazines. It was verified that researchers of several nationalities are working on the proposed themes, with a predominance of those from developed countries (USA and Germany). In Brazil, production on these themes, although small, coincides with the results obtained for other themes analyzed using the same research technique. This fact indicates that greater efforts should be made in the search for more intense scientific production in the country, in the different areas of knowledge, especially in the object of this study.
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