8 research outputs found

    Veredas da região sudeste: peculiaridades florísticas e estruturais e situação de conservação

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    The Mauritia flexuosa L. f. (Arecaceae) palm swamps (known as veredas in Brazil) are hygrophilous communities associated with hydromorphic soils in areas of headwaters, and feature special importance for water and biodiversity maintenance in the Cerrado biome. In northern Minas Gerais, the veredas have more complex structure and floristic composition in comparison with the veredas located in other parts of central Brazil, in the same biome. However, these areas are less studied and suffering various environmental impacts, which can uncharacterize them even before they are properly known. In the present work, a literature review was carried out, in which the age and the development of vegetation in the veredas of central Brazil and north of Minas Gerais were addressed. The conservation status and the importance of these areas for the biome were also discussed. Hence it was concluded that the veredas of the north of Minas Gerais are older than the veredas of central Brazil, suggesting that they are in a more advanced stage of ecological succession. However, many factors can influence the floristic composition and structure of these plant communities, requiring further studies involving ecological processes in veredas in order to elucidate those matters. Keywords: vegetational structure, ecological succession, palynological analysis.As veredas são comunidades higrófilas associadas a solos hidromórficos em áreas de nascentes, e apresentam importância singular para a manutenção hídrica e da diversidade biológica no bioma Cerrado. No norte de Minas Gerais, as veredas possuem estrutura e composição florística consideravelmente mais complexa do que as veredas localizadas em outras partes do Brasil central, dentro do mesmo domínio fitoecológico. Porém, são áreas pouco estudadas e que sofrem diversos impactos ambientais, que podem descaracterizá- las, antes mesmo que elas sejam conhecidas. No presente trabalho foi realizada uma revisão bibliográfica, na qual foram abordados a idade e o desenvolvimento da vegetação das veredas do Brasil central e do norte de Minas Gerais. São discutidos, ainda, a situação de conservação e a importância dessas áreas para o bioma. Assim, concluiu-se que as veredas norte mineiras são mais antigas do que as veredas do Brasil central, podendo estar em um estágio mais avançado de sucessão ecológica. No entanto, muitos fatores podem influenciar a composição florística e a estrutura dessas comunidades vegetais, sendo necessários mais estudos envolvendo os processos ecológicos em veredas para que essa questão seja elucidada.Palavras-chave: análise palinológica, estrutura da vegetação, sucessão ecológic

    SOBREVIVÊNCIA E CRESCIMENTO DE SETE ESPÉCIES ARBÓREAS NATIVAS EM UMA ÁREA DEGRADADA DE FLORESTA ESTACIONAL DECIDUAL, NORTE DE MINAS GERAIS1

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    RESUMO Este trabalho objetivou avaliar o crescimento e sobrevivência de sete espécies arbóreas nativas em diferentes tratamentos, em uma área degradada na Reserva da COPASA (Juramento, MG). Para tal, foram utilizados aproximadamente 1,2 ha da área, onde foram plantadas 899 mudas, de sete espécies nativas (Anadenanthera colubrina, Copaifera langsdorffii, Dilodendron bipinatum, Myracrodruon urundeuva, Pterogyne nitens, Schinopsis brasiliensis e Senegalia polyphylla), acompanhadas durante 24 meses. A área foi dividida em cinco parcelas de 0,24 ha, que representaram os seguintes tratamentos: (T1) parcela semeada com capim (Brachiaria sp.); (T2) parcela onde as covas foram tratadas com condicionador de solo; (T3) parcela semeada com capim consorciado com leguminosa (Cajanus cajan); (T4) parcela semeada com leguminosa; e (T5) controle. A porcentagem de mortalidade foi maior no T2 e menor no T3, sendo as espécies C. langsdorffii (43,66%) e S. brasiliensis (11,64%) aquelas com maior e menor porcentagem de mortalidade, respectivamente. O crescimento (altura e diâmetro) das mudas foi maior no T2 (24,32 ± 26,05 cm e 0,51 ± 0,37 mm, respectivamente) e menor no T1 (10,82 ± 22,57 cm e 0,26 ± 0,27 mm; respectivamente). As espécies com maior crescimento em altura foram A. colubrina e S. polyphylla, já D. bipinatum e S. brasiliensis apresentaram maior crescimento em diâmetro. Pterogyne nitens apresentou o menor crescimento, além de alta mortalidade, mostrando baixa capacidade de estabelecimento em ambientes degradados

    Riparian vegetation structure and soil variables in Pandeiros river, Brazil

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    Abstract This study analyzed the floristic, structural variations and their relationships with soil variables in two stretches of riparian vegetation in an ecotonal region between savanna and semiarid zones. We following the hypothesis of despite the proximity between the sampled areas, soil conditions are distinct and lead to changes in structure and composition of the vegetation. This study was development at EPA of Pandeiros River, Minas Gerais, where we allocated 140 plots of 10 × 10 m (100 m2), with 10 m distance between plots, in two areas of riparian vegetation, named Larga and São Domingos (70 plots in each area), where we conducted the phytosociological survey and collected soil samples. In total, 751 arboreal individuals were sampled, distributed in 89 species and 35 botanical families. The areas differed strongly in structure and species composition, and showed floristic peculiarities and influence of surrounding vegetation. Despite of low distance between the sampled areas, these are singular environments influenced by different soils, by the mixed composition of the ecotonal area and the anthropogenic impacts to which they are exposed

    Survival of Saplings in Recovery of Riparian Vegetation of Pandeiros River (MG)

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    <div><p>ABSTRACT This study monitored the survival of saplings planted according to different recovery models in a riparian forest of the Pandeiros river (Januária, MG). The models consisted of planting the saplings in lines of 2 or 4 m with presence (T2S and T4S, respectively) or absence of direct seeding (T2 and T4, respectively). We planted 16,259 saplings of 17 botanical families, 32 genera and 33 species. The saplings, in general, presented a survival rate after one year of 34.4% (±1.8). The species with highest survival rates were Jacaranda brasiliana, with 85.0% (±13.5) of survival, Anadenanthera colubrina, with 70.1% (±7.0), and Triplaris gardneriana, with 69.3% (±9.1). Survival did not vary between the models tested, probably due to the short evaluation period (12 months).</p></div

    Sensitivity of South American tropical forests to an extreme climate anomaly

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    NERC Knowledge Exchange Fellowship (NE/V018760/1) to E.N.H.C.The tropical forest carbon sink is known to be drought sensitive, but it is unclear which forests are the most vulnerable to extreme events. Forests with hotter and drier baseline conditions may be protected by prior adaptation, or more vulnerable because they operate closer to physiological limits. Here we report that forests in drier South American climates experienced the greatest impacts of the 2015–2016 El Niño, indicating greater vulnerability to extreme temperatures and drought. The long-term, ground-measured tree-by-tree responses of 123 forest plots across tropical South America show that the biomass carbon sink ceased during the event with carbon balance becoming indistinguishable from zero (−0.02 ± 0.37 Mg C ha−1 per year). However, intact tropical South American forests overall were no more sensitive to the extreme 2015–2016 El Niño than to previous less intense events, remaining a key defence against climate change as long as they are protected.Publisher PDFPeer reviewe
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