RESUMO -A análise do padrão de deposição de serapilheira foi empregada como bioindicador para comparar diferentes estádios de regeneração de floresta secundária, capoeira e pasto e um modelo de plantio adensado de revegetação. LITTER DEPOSITION AS BIOINDICATOR OF RESTORATION IN A DENSE REVEGETATION SYSTEM
ABSTRACT. Forest plantations may minimize the effects of deforestation in the Amazon. However, there are differences among species in terms of their influences on soil recovery. The effects of monospecific plantations of Acacia mangium, Dipteryx odorata, Jacaranda copaia, Parkia decussata,and Swietenia macrophylla, and areas of pasture and native forest on the chemical soil attributes of the Brazilian Amazon were evaluated. One bulked soil sample was collected per plot (0.00-0.05, 0.05-0.10, and 0.10-0.30 m; three plots of 128 m 2 ) in each area. No significant differences in most of the soil attributes were observed among the forest plantations. However, soil K + and P were higher in the Swietenia macrophylla plantations, while higher values of Ca 2+ , sum of bases, and pH occurred in Jacaranda copaia plantations. In the native forest, the pH, and P content were lower, whereas the soil organic matter (SOM) content, soil organic carbon (SOC) content, cation exchange capacity (CEC), N content, H+Al content, and Al 3+ content were higher than in the plantations. The lowest values of SOM, SOC, CEC, K
ABSTRACT.Internal retranslocation is an important mechanism for nutrient conservation in plants, which depends on different factors. However, there are little data about this subject, especially on tropical forest species. This study aimed to evaluate the macronutrient retranslocation dynamic and the influence of ecological (P: pioneer x NP: non-pioneer) and phenological (ND: non-deciduous x D: semideciduous / deciduous) characteristics on the macronutrient content of leaves of five tree species on monospecific plantations in the Brazilian Amazon: Acacia mangium Willd., Parkia decussata Ducke, Dipteryx odorata (Aublet) Willd., Jacaranda copaia (Aubl.) D. Don and Swietenia macrophylla King. Photosynthetically active green leaves and senescent leaves (leaf litter) were collected. Retranslocation was estimated through an equation proposed by Attiwill, Guthrie and Leuning (1978). The pioneer species presented higher foliar contents of N; the non-pioneer species presented higher contents of K, Ca and S; and the results were inconclusive for P and Mg. The deciduous species presented higher foliar contents of K and of P, whereas the foliar contents of N, Ca, Mg and S were virtually identical between the phenological groups. The internal retranslocation of foliar nutrients in pioneer and non-deciduous species was higher than that of nonpioneer and deciduous species.Keywords: ecological groups, litterfall, nutrient cycling, phenological groups, plant nutrition. Retranslocação de nutrientes em espécies florestais na Amazônia Brasileira RESUMO.A retranslocação interna é um importante mecanismo de conservação de nutrientes nas plantas, que depende de diferentes fatores. Contudo, ainda são incipientes os dados desta natureza, principalmente para espécies florestais tropicais. O presente trabalho objetivou avaliar a dinâmica de retranslocação de macronutrientes e a influência dos grupos ecológico (P: pioneiras x NP: não-pioneiras) e fenológico (ND: não-decíduas x D: semidecíduas / decíduas) nas concentrações foliares de macronutrientes em cinco espécies arbóreas em monocultivo na Amazônia brasileira: Acacia mangium Willd., Parkia decussata Ducke, Dipteryx odorata (Aublet) Willd., Jacaranda copaia (Aubl.) D. Don e Swietenia macrophylla King. Para tanto, foram coletadas folhas verdes fotossinteticamente ativas e folhas da serapilheira. A retranslocação foi estimada segundo a equação de Attiwill, Guthrie e Leuning (1978). As espécies pioneiras apresentaram maiores concentrações foliares de N; as não-pioneiras apresentaram maiores concentrações de K, Ca e S; e os resultados foram inconclusivos para P e Mg. As concentrações foliares de K e de P foram maiores nas espécies decíduas, enquanto que as de N, Ca, Mg e S foram praticamente idênticas entre os grupos fenológicos. No geral, as espécies pioneiras e as não-decíduas foram mais eficientes na retranslocação de nutrientes.Palavras-chave: grupos ecológicos, serapilheira, ciclagem de nutrientes, grupos fenológicos, nutrição de plantas.
Planting of forest species of timber interest helps to reduce the deforestation pressure on the Amazon forest, promotes sustainable development of the producing region and generates ecological benefits. The objective of this work was to evaluate the survival rate and growth of four native (Swietenia macrophylla, Parkia decussata, Dipteryx odorata and Jacaranda copaia) and one exotic (Acacia mangium) species in monospecific plantations (spacing of 2 x 2 m) established on areas previously used for grazing, in Itacoatiara, State of Amazonas, Brazil. When the trees were four years old, we collected biometric data )], e dados qualitativos obtidos por diagnose visual [taxa de sobrevivência (S; %), estado nutricional (NS, G: bom; D: deficiente; %) e estado fitossanitário (PS, S: satisfatório; NS: não-satisfatório; %). Para cada espécie considerouse três parcelas de 128 m 2 , cada uma com 32 plantas. Jacaranda copaia, seguida de Dipteryx odorata e Parkia decussata, foram as espécies mais recomendadas para o plantio em áreas com condições edafoclimáticas semelhantes às do presente trabalho, devido ao seu melhor desempenho para a maioria das variáveis.
This study aimed to evaluate the use of litterfall as an indicator of fragmentation in a Semi-deciduous Seasonal Forest in Além Paraíba, MG, Brazil. Litterfall was collected monthly for one year in conical collectors (0.25 m 2 of surface), located at seven distances from the forest edge: 10, 30, 60, 100, 160, 250 and 350 m. The litterfall was dried in an oven and separated (leaves, branches, reproductive structures, miscellaneous). Litterfall was greater near the forest edge, probably due to a predominance of species with high leaf deposition (pioneers and deciduous). Litterfall had peaks at the beginning of the rainy season for the average obtained from the seven distances from the forest edge. The edge effect did not clearly influence the contribution of the fractions or the seasonality of total litterfall.
Este artículo tiene como objetivo principal estudiar aspectos del sistema agrícola de la comunidad rural Gatos, localizado en el municipio de Ibirapitanga, Bahia, Brasil, presentando un breve panorama socioambiental del sistema agrícola de esta comunidad. Como metodología, se hizo el levantamiento de datos secundarios de naturaleza socioeconómica y ambiental del municipio de Ibirapitanga, datos e informaciones sobre los municipios cubiertos por la APA del Pratigi, levantamientos de datos y observaciones in loco en la comunidad Gatos, además de interpretación de imágenes de sensores orbitales. Entre los resultados obtenidos, se señala que, aunque insertado dentro de un Área de Protección Ambiental, el referido sistema agrario presenta significativas fragilidades que envuelven desde cuestiones ambientales, hasta cuestiones de orden económico-productivo y social.
Anamnese: Apreendida pela reserva ambiental do Rio Vermelho; encontrava-se bastante debilitada; porém mansa. O estresse gerado , pode ter sido a causa morte.
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