https://repositorio.ufra.edu.br/jspui/handle/123456789/19 Programa de Pós-Graduação em Ciências Biológicas/Botânica Tropical Mon, 28 Sep 2026 21:22:32 GMT 2026-09-28T21:22:32Z http://repositorio.ufra.edu.br:443/jspui/retrieve/d870b658-48d3-4ebe-8902-e4cc7fa4eb25/PPGCBOT.jfif https://repositorio.ufra.edu.br/jspui/handle/123456789/19 https://repositorio.ufra.edu.br/jspui/handle/riufra/2909 Título: Ajustes anatômicos e fisiológicos revelam mecanismos de sobrevivência em mudas sob déficit hídrico Autor(es): FIGUEIREDO, Stefany Priscila Reis Abstract: Some tropical forests experience prolonged droughts, making it essential to understand species' drought resistance mechanisms. Anatomical traits related to hydraulic architecture explain how water transport occurs in plants and how species cope with water scarcity. However, the ability of species to adjust their hydraulic architecture to water availability remains unclear. We assessed variations in hydraulic architecture and physiological responses to drought, focusing on the coordination between anatomical and physiological traits. This study was conducted in a greenhouse with seedlings of three tropical species: Clitoria fairchildiana, Manilkara elata, and Bertholletia excelsa. We applied three water availability treatments (15%, 50%, and 100% of field capacity) for four months. We measured branch anatomical traits: Vessel area (VA), Hydraulic diameter (Dh), Vessel density (VD), Vessel grouping index (VG), Vessel lumen fraction (F), and Xylem theoretical conductivity (Ks); physiological traits: Leaf predawn (ψPD) and midday (ψMD) water potential, and pressure-volume curve traits. All species adjusted their traits in response to water availability. Manilkara elata, the species with the highest wood density, exhibited smaller anatomical and hydraulic trait variations, with only a decrease in turgor loss point through osmotic adjustment under water limitation. The two species with lower wood density showed contrasting responses. Bertholletia excelsa enhanced hydraulic efficiency by increasing specific hydraulic conductivity, vessel area, and hydraulic diameter, while C. fairchildiana increased drought resistance by adjusting turgor loss point and osmotic potential. Our results highlight a trade-off between water transport efficiency and drought resistance, indicating distinct responses that contribute to species survival under water limitation. Mon, 07 Jul 2025 00:00:00 GMT https://repositorio.ufra.edu.br/jspui/handle/riufra/2909 2025-07-07T00:00:00Z https://repositorio.ufra.edu.br/jspui/handle/riufra/2904 Título: A tribo Ingeae Bentham (leguminosae - mimosoideae) na Floresta Nacional de Caxiuanā, Pará, Brasil Autor(es): SILVA, Francismeire Bonadeu da Abstract: (Genera Abarema Pittier, Calliandra Benth. Enterolobium Mart., Hydrochorea Barneby & J. W. Grimes, Macrosamanea Britton & Rose ex Britton & Killip and Zygia P. Brawne (Leguminosae-Mimosoideae) in Caxiuană National Forest, Pará) This study presents a taxonomic treatment of the species of the genera Abarema Pittier, Calliandra Benth., Enterolobium Mart., Hydrochorea Barneby & J. W. Grimes, Macrosamanea Britton & Rose ex Britton & Killip and Zygia P. Brawne occurring in Caxiuană National Forest, along with taxonomic key, descriptions, illustrations and comments morphological and taxonomic data as well as geographical distribution and phenology of species. Abarema was the most representative genus (3 spp.), followed by Calliandra and Zygia (2 spp. cada) and the other genera are represented by one species each. Thu, 17 Sep 2026 00:00:00 GMT https://repositorio.ufra.edu.br/jspui/handle/riufra/2904 2026-09-17T00:00:00Z https://repositorio.ufra.edu.br/jspui/handle/riufra/2884 Título: Respostas ecofisiológicas e bioquímicas de plantas jovens de Hymenaea courbaril L. e H. stigonocarpa Mart. submetidas à deficiência hídrica e reidratação Autor(es): LUZ, Luana Moraes da / Abstract: The water supply for a species is the result of interactions that take place over the soil-plant-atmosphere.When the amount of water absorbed is greater than the amount transpired the plant suffers from water stress which may lead to increasing tensions negative xylem vessel, resulting in changes in water relations reflected in photosynthetic capacity associated with changes in the metabolism of carbon and nitrogen. The objective of this study was to investigate the effects of water stress and rehydration in physiological and biochemical aspects in young plants of H. courbail and H. stigonocarpa. The experiment was conducted in a greenhouse belonging to the Institute of Agricultural Sciences (ICA) of the Federal Rural University of Amazonia (UFRA) in Belém / PA. Fifty changes of each species under study were transplanted to pots containing 18 kg of polyethylene Yellow Latosol of medium texture. After five months of acclimatization, measurements of physiological and biochemical parameters were performed, one at the beginning of the experiment, 13 and 26 days after the suspension fluid. In the latter when the plants were rehydrated by two and four days. The species H. courbaril reduced their transpiration, photosynthesis, stomatal conductance, water potential and relative water content after 26 days 93.8, 93.5, 87.0, 525 and 52.8%, respectively compared to the initial water status. While in the same period H. stigonocarpa decreased transpiration, photosynthesis, stomatal conductance, water potential and relative content of up to 60.9, 31.3, 60.2, 135 and 25% respectively. Both species after four days of rehydration were able to recover most of their physiological characteristics, except for the relative water content for both and photosynthesis of H. courbaril. Similar to changes in physiological, biochemical aspects were also affected, for example, nitrate reductase activity was reduced by 56% for H. courbaril and 30% in H. stigonocarpa, after 26 days of stress. At the same time, both species to increase the concentration of sucrose in 18% with a decrease of 52 to 29% of the content of starch and soluble proteins, respectively. The rates of total soluble carbohydrates, free amino acids, proline and glycine betaine had a significant increase from the thirteenth day in both species reaching values, respective, 1.8, 1.7, 2.6 and 2.0, 2.6, 1.5, 2.6 and 1.5 times greater than the initial water status. Only the concentrations of carbohydrates and proline were repurchased for H. courbaril. However, H. stigonocarpa except nitrate reductase, was able to recover biochemical variables after four days of rehydration. Therefore, H. stigonocarpa due to the recovery of most of their biochemical and physiological characteristics, exerts greater adaptability in relation to water stress, which makes it potentially recommended for environments with water restrictions, despite H. courbaril show high plasticity in this environment. Tue, 28 Apr 2026 00:00:00 GMT https://repositorio.ufra.edu.br/jspui/handle/riufra/2884 2026-04-28T00:00:00Z https://repositorio.ufra.edu.br/jspui/handle/riufra/2881 Título: Briófitas do Parque Nacional das Nascentes do rio Parnaíba, cerrado brasileiro. Autor(es): SILVA, Jainara Pereira Abstract: The Nascentes do Rio Parnaíba National Park (NRPNP) is the largest conservation unit in the Brazilian Cerrado (729,800 hectares), encompassing the second largest hydrographic basin in the Northeastern region (Parnaíba River) and has a diverse vegetation cover, including fields, savannas, savannas or swamps or buritizais, gallery forests and riparian forests. The vascular flora of the park is poorly known, while the avascular flora (bryophytes) remains unknown. The general objective of this dissertation was to understand the bryophyte flora in different types of environments in the NRPNP, and the landscape aspects that determine the structuring of bryophyte communities in riparian forests. The first objective was to investigate the richness and composition of the bryophytes from the NRPNP in different environments, as well as the preferred substrates, reproductive aspects and the geographic distribution of the species (Chapter I). Four new occurrences were found for the Cerrado and Frullania eboracensis, a new record for Brazil. The gallery forest had the highest species richness (72 spp.), followed by vereda (17 spp.) and cerrado sensu stricto (11 spp.). The most colonized substrate was rocks (56 spp.). Monoecious species predominated over dioecious species. The second objective was to investigate how landscape aspects shape bryophyte communities in riparian forests in the Brazilian Cerrado, to answer the following question: How do landscape characteristics of riparian forests influence the richness, abundance and composition of bryophyte species? (Chapter II). It was found that heterogeneity between environments is an important factor in determining the diversity of bryophytes in riparian forest ecosystems, and that altitude significantly influenced the richness, abundance and composition of bryophytes in these forests, even at altitudinal gradients of approximately 100 meters. Variables related to humidity on a landscape scale had little importance in models of species richness and abundance, while distance from the waterfall influenced negatively the composition of bryophytes in the riparian forests of the NRPNP. The results of this dissertation indicated that the NRPNP environments present a high diversity of bryophytes, especially gallery forests, and that the structure of bryophyte communities in riparian forests in the Cerrado is shaped by environmental heterogeneity and forest topography, with subtle variations at altitude an important predictor of bryophyte distribution. Mon, 27 Apr 2026 00:00:00 GMT https://repositorio.ufra.edu.br/jspui/handle/riufra/2881 2026-04-27T00:00:00Z