Dissertações em Ciências Ambientais (Mestrado) - PPGCA/IG
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2855
O Mestrado Acadêmico em Ciências Ambientais teve início em 2005 e funciona no Programa de Pós-Graduação em Ciências Ambientais (PPGCA) do Instituto de Geociências (IG) da Universidade Federal do Pará (UFPA) em parceria com o Museu Paraense Emílio Goeldi (MPEG) e a Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA/Amazônia Oriental).
Navegar
Navegando Dissertações em Ciências Ambientais (Mestrado) - PPGCA/IG por Orientadores "CARVALHO, Cláudio José Reis de"
Agora exibindo 1 - 2 de 2
- Resultados por página
- Opções de Ordenação
Item Acesso aberto (Open Access) Avaliação da exploração florestal de impacto reduzido em atributos físicos e químicos do solo e na regeneração natural em Paragominas, PA(Universidade Federal do Pará, 2008) HIRAI, Eliana Harumi; SILVA, José Natalino Macedo; http://lattes.cnpq.br/0479038232182214; CARVALHO, Cláudio José Reis de; http://lattes.cnpq.br/5976057799163293This work was carried out at Fazenda Rio Capim, property of the Cikel Brasil Verde Madeiras Ltda., in the municipality of Paragominas, State of Pará, Brazil. The main objective was to study the effect of logging on the physical and chemical properties of the soil and on natural regeneration in three Working Units logged in 2000, 2003 and 2006., The treatments were gap center, primary and secondary skid trails, logging landing and one control plot. The diameter of each individual was measured at approximately 1,30 m of the ground; all species were identified and calculated the species richness, abundance, diversity Index, evenness and floristic similarity. Samples of litterfall were collected in same the locations of soil plots. For physical analysis (granulometry, texture, soil bulk density, resistance to the penetration, porosity and volumetric humidity) soil samples were collected at 0-5, 5-10, 10-20, 20-30 cm depth, and for the chemical analysis (pH, carbon stock and nitrogen, C/N) the samples were at 0-10 cm depth. In the primary skid trails it was considered its beginning, middle and end of the extension, and both for primary and secondary skid trails, the marks of the wheels of the machinery (RM), the place between the wheels (ER), and the edges of the trail (BT). Felling gaps were randomly measured and classified with areas <600m2 and> 600m2. The soil of the study areas is Yellow Latosol with very clay texture. The soil bulk density and porosity varied significantly among years and between treatments (p <0,001); no significant differences were found at 20-30 cm depth. Main and secondary skid trails and logging landings were the most affected treatments. Gaps had no influence on bulk density. It was verified that ER and BT did not differ statistically. The comparison among beginning, middle and end of the skid trails showed ere no significant differences for any of the comparisons. Results for to resistance to penetration were very similar to the bulk density and porosity. Volumetric humidity varied according to the combination year x treatment (p <0,001). Average pH values varied between 4,72 to 5,92. Litterfall decreased as time elapsed since logging. Average contents of C varied between 25,94 to 42,59 g.kg-1 and the contents of N between 2,23 to 3,35 g.kg-1, both considered as high values. For carbon stock of (Mg.ha-1) it was not found significant difference for any of the interactions (year, season and treatment). The relationship C/N for logged forest showed values between 10,37 and 15,42, indicating mineralization of the soil inorganic nitrogen. The three studied WUs presented high diversity and evenness. WUs logged in 2000 and 2003 showed the highest similarity (35,93%), followed by the WUs logged in in 2003 and 2006 (33,46%), and WUs logged in 2000 and 2006 (26,93%). It has been concluded that it is necessary a long observation period for evaluation of the effects of soil compaction on the growth of the regeneration. Indicators for good forest management practices should consider soil attributes (physical, chemical and biological) for a better understanding of the system and choice of other indicators that can give answers on the equilibrium of the forest ecosystem. The studied parameters can be used as indicators of environmental quality.Item Acesso aberto (Open Access) Dinâmica do amônio e nitrato em solos consorciados com plantios de Paricá (Schizolobium Amazonicum) em Aurora do Pará, Pará(Universidade Federal do Pará, 2008) DIAS, Joelma Dezincourt; CARVALHO, Cláudio José Reis de; http://lattes.cnpq.br/5976057799163293To obtain knowledge of the dynamics of nitrogen in soil in the forms of mineral-N: ammonium and nitrate from 3 different areas cultivated with paricá, paricá x freijó (PF), mahogany x paricá (PM), paricá x curauá x freijó (PCF) and secondary forest, was estimated rates of net mineralization and nitrification, stocks of carbon and nitrogen, pH, urease, basal respiration and physical parameters (density and total porosity). The study was conducted in northeastern Para in the city of Aurora do Para, in the farm business Tramontina SA, in October and November of 2007, representing the dry season, while January and march representing the rainy season. In all areas of the farm cultivated samples for chemical and physical analysis were taken at depths of 0-10, 10-20 and 20-30 cm. For net mineralization of the highest values occurred in the dry season, this result was observed for all areas of cultive. For net nitrification of the highest values occurred in October 2007 in the areas of secondary forest and paricá x curauá x freijó and the month of March in the areas of mahogany x paricá (PM) and paricá x freijó (PF). The values for the rates of net nitrification showed that there was significant interaction between treatment and season. The values of carbon stocks for all areas in the dry season varied from 11-17 Mg/ha and in the rainy season of 15-25 Mg/ha. The values for the storage of nitrogen varied from 0,78-1,80 Mg/ha in the dry season and 0,76-1,47 Mg/ha in the rainy season. The relation C/N for all systems was around 15/1 indicating a rapid process of decomposition of organic matter in soils.