Programa de Pós-Graduação em Ciências Florestais https://repositorio.ufra.edu.br/jspui/handle/123456789/17 2026-07-07T19:47:02Z 2026-07-07T19:47:02Z CARDOSO, Kerolém Prícila Sousa https://repositorio.ufra.edu.br/jspui/handle/riufra/2883 2026-05-29T14:54:08Z 2026-04-28T00:00:00Z

Título: Comportamento bioquímico em mudas de castanheira-do-brasil (Berthollethia excelsa Bonpl.) Submetidas a diferentes concentrações de alumínio Autor(es): CARDOSO, Kerolém Prícila Sousa Abstract: Most Brazilian soils have acidic characteristics, and one of the elements present in this soil is aluminum, which is toxic to plants, affecting the metabolism of several species. Faced with the problems limiting the phytotoxicity of aluminum to vegetables, this study aimed to investigate the biochemical behavior in seedlings of Berthollethia excelsa Bonpl. subjected to different concentrations of aluminum. The experiment was conducted in a greenhouse using a completely randomized design with five treatments (0 mg L-1, 20 mg L-1, 40 mg L-¹, 60 mg L-1 and 80 mg L-¹ of Alt3+) and seven replicates. The analyzed variables were photosynthetic pigments, nitrate reductase, electrolyte leakage, nitrate, free ammonium, N-aminosoluble, soluble proteins, total soluble sugars, reducing and non-reducing sugars, sucrose, proline and glycine betaine. According to the results, photosynthetic pigments, nitrate, nitrate reductase, ammonium, N-aminosoluble, total soluble sugars, reducing and non-reducing sugars and sucrose reduced with the highest concentration of aluminum in the medium. Electrolyte leakage showed increase as well as soluble proteins, and the osmoregulators, proline and glycine betaine, showed increases suggesting the attenuation of the stress caused by the toxicity of this metal. Despite the negative influence on the biochemical processes, brazilian chestnut, presented mechanisms of tolerance to aluminum toxicity, maintaining the biochemical activities for the vegetative development.

2026-04-28T00:00:00Z Lemos, Jonathan Chaves de https://repositorio.ufra.edu.br/jspui/handle/riufra/2882 2026-06-03T18:38:48Z 2026-01-01T00:00:00Z

Título: Caracterização energética da madeira e do carvão vegetal de Schizolobium parahyba var. amazonicum cultivado em sistema silvipastoril e indicações de uso Autor(es): Lemos, Jonathan Chaves de Abstract: Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby, known as paricá, is a forest species native to the Amazon, widely cultivated in agroforestry systems due to its rapid growth and biomass production potential. To evaluate the energetic quality of the wood and charcoal of Schizolobium parahyba var. amazonicum cultivated in different silvicultural strata, as well as the suitable diameter for energetic use of residues, aiming at their utilization in combustion and carbonization processes. Analyses of basic density, chemical composition (molecular and proximate), calorific value, energy density, and thermogravimetric analysis of the wood were performed, in addition to controlled carbonization of samples with diameters greater than 10 cm to determine gravimetric yields and characterize the charcoal. The average basic density of the wood was 314.50 kg m⁻³, showing no statistically significant difference among the strata. The average total extractives content was 3.82%, with statistically significant difference between strata 1 and 3. The average total lignin and holocellulose contents were 27.94% and 67.84%, respectively. The remaining parameters showed no significant differences among the strata for the respective analyses. The proximate chemical composition of the wood presented average values of 83.26% volatile materials, 16.33% fixed carbon, and 0.40% ash. The average higher heating value of the wood was 4600.95 kcal kg⁻¹ and the average energy density was 1447.04 Mcal m⁻³. Carbonization resulted in an average gravimetric yield of 30.50% and charcoal with an average apparent density of 142 kg m⁻³. The proximate chemical composition of the charcoal presented average values of 20.79% volatile materials, 76.57% fixed carbon, and 2.64% ash, while the average higher heating value was 7240.66 kcal kg⁻¹ and the average energy density of the charcoal was 1021.01 Mcal m⁻³. Paricá wood indicates potential for use in direct combustion, due to the higher energy density in relation to charcoal, and may also be destined for heat generation in boilers and for the production of densified fuels, such as pellets and briquettes. On the other hand, although charcoal presents lower energy density, its chemical characteristics indicate potential for specific applications, such as biochar or activated carbon. Thus, paricá demonstrates versatility for multiple energy uses, allowing differentiated biomass utilization according to the diameter of the fractions and the intended energetic purpose in agroforestry systems.

2026-01-01T00:00:00Z CRUZ FILHO, Deusdedith https://repositorio.ufra.edu.br/jspui/handle/riufra/2868 2026-04-23T18:59:05Z 2005-08-30T00:00:00Z

Título: Avaliação da quantidade de resíduos lenhosos em área de floresta explorada e não explorada, utilizando amostragem por linha interceptadora, no médio Rio Moju, Pará, Brasil Autor(es): CRUZ FILHO, Deusdedith Abstract: This dissertation compares the volumes of coarse woody debris produced in an area of primary forest with another area of forest logged using reduced impact methods called Farm Saint Marta (3º04'S, 49º14'W). This area is located in the hidrografic basin of the medium river Moju, near the city of Homonym, Northeast of the State of Pará, Eastern Amazônia. The studies were carried out in a total area of 426Ha, incorporating the 4 Work Units of forest management areas. Two of these units have been explored by reduced impact logging, totaling 217Ha, and the other two units are primary forest totaling 209Ha. Line intercept sampling was the method used to quantify the coarse woody debris in 6,000 m of lines for each unit, totaling 12,000 m of sampling lines. The fallen woody debris was measured on the forest floor, with diameter over 10 cm, considering the diameter and the state of decomposition of the measured parts, for the calculation of the volume and necromassa, as related to the indices of density of the specific wood for each decay class. Statistical tests demonstrated a significant difference in the volume and necromassa estimates, and a highly significant difference in the carbon supply, between the study sites. Studies were conducted to test the correlation between the classes and the diameters, which were adjusted to the linear regression equation, in this way demonstrating that there was a correlation between these indicators in the study sites. The correlation between diameter classes and their respective volumes was also tested, and the adjustment of this result to the linear regression equation demonstrated a correlation between these instances. This generated specific equations for the case study, for the quantification of the volume of woody debris through the diameter of these materials, measured in the forest, with the objective of generating of indicators for utilization on an industrial scale. The estimates of necromassa and carbon will contribute towards the monitoring of emissions of greenhouse gasses emitted by the coarse woody debris as well as for calculations for the commercialization of carbon credits.

2005-08-30T00:00:00Z FEIO, Paulo Humberto Benigno https://repositorio.ufra.edu.br/jspui/handle/riufra/2867 2026-04-23T13:52:25Z 2026-04-22T00:00:00Z

Título: Estrutura e diversidade florística da savana amapaense são influenciadas pelo gradiente ambiental Autor(es): FEIO, Paulo Humberto Benigno Abstract: The Brazilian savanna, consisting of a heterogeneous mosaic of plant formations, occupies approximately 23% of Brazilian territory. Its vegetation encompasses a wide variety of physiognomic features, alternating between savanna, grassland, and forest formations. In the Amazon, the savanna zones, also known as Amazonian savannas, are distributed across the states of Amapá, Amazonas, Pará, and Roraima, and despite being considered one of the 25 critical areas for biodiversity conservation in the world, the savanna has been the target of few concrete actions and few studies aimed at its conservation. The savannah area of the state of Amapá is the second largest continuous area of savannah in the Amazon, second only to the areas of the state of Roraima. Studies focused on the structural composition and floristic diversity of its vegetation are important to guide the definition of priority areas for their conservation, and to support the planning of actions in the restoration of degraded environments. The present study, mostly conducted in permanent plots, was grouped according to site characteristics into five groups: a) G1 plots 04, 07, 08 and 15; b) G2 plots 05, 09, 18 and 19; c) G3 plots 03, 16 and 20; d) G4 plots 01, 02, 11, 12 and 13; e) G5 plots 06, 10, 14 and 17 The objective was to evaluate the structure and floristic diversity of the tree and shrubby-arboreal in the Amapá savanna, seeking to answer the following question: The floristic composition and shrubby-arboreal structure of the Amapá savannas vary significantly among the different sample groups, reflecting the influence of a regional environmental gradient? As results we have, especially in group G1, the species Ouratea racemiformis Ule, Curatella americana L e Byrsonima crassifolia (L.) Kunth showed significant association with the floristic gradients revealed by NMDS in the dissimilarity of the floristic-structural pattern. On the other hand, group G4 stood out for being isolated in the ordination space, possibly related to more structured or conserved vegetation, while groups G2, G3 and G5 showed overlap and dispersion, indicating floristic transition or similarity between them. Rarefaction analysis (Hill, q = 0) revealed differences in species richness between the groups, in which G1 presented the highest observed richness (21 species), G3 and G4 intermediate richness (17 and 14 species), G2 and G5 presented the lowest observed richness (11 species). Overall, the result of this study aims to contribute with information on the structural composition and floristic diversity of the shrubby-arboreal vegetation in the savanna areas of Amapá.

2026-04-22T00:00:00Z