https://repositorio.ufra.edu.br/jspui/handle/123456789/60 Tue, 30 Jun 2026 22:28:59 GMT 2026-06-30T22:28:59Z 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 https://repositorio.ufra.edu.br/jspui/handle/riufra/2865 Título: Fogo e a organização funcional da comunidade de árvores: implicações para a resiliência da floresta na Resex Tapajós-Arapiuns Autor(es): SILVA, Danilo Souza da Abstract: Tropical forests play a fundamental role in global sustainability. In this context, fire emerges as a threat because it affects not only the species vulnerable to fire, but also the taxonomic and functional compositions of communities, limiting the maintenance of biodiversity and provision of essential ecosystem services. This study aimed to understand how tree vegetation responds to fire, through functional attributes, and what are the implications for Amazonian forest resilience. The study compared the tree component of unburned forest areas and forests that burned in 2015 and in 2017, in the Tapajós-Arapiuns Extractive Reserve, located in western Pará State, Brazil. The most abundant species (above 50% of total abundance), which constitute the canopy and understory of the tree component, had 12 functional attributes evaluated (e.g., bark thickness, regrowth capacity, wood density). The results showed that species richness differs between the two forest types and suggest that the understory of burned forests responds to fire events through a change in species composition, which highlights species simplification for this stratum. We also observed that functional changes in burned forest arise mainly from attributes of indirect effect to fire, such as dispersal and pollination syndromes, and that there are changes in the functional composition of communities when analyzed at the individual level for both the canopy and the understory. Our study indicates that fire events have caused a negative effect on the tree component of Amazonian humid tropical forests, and that their action has caused functional changes in species in burned forest areas. Furthermore, the effects of fire can vary according to forest stratum. The changes observed as effects of fire may have important consequences for forest dynamics and intensifying studies in this area is essential in the Amazon. Thu, 16 Apr 2026 00:00:00 GMT https://repositorio.ufra.edu.br/jspui/handle/riufra/2865 2026-04-16T00:00:00Z https://repositorio.ufra.edu.br/jspui/handle/riufra/2864 Título: Sistemática de Hydrochorea Barneby & J.W.Grimes ( Leguminose, Mimosoideae) Autor(es): SOARES, Marcos Vinicius Batista Abstract: Hydrochorea is a Neotropical genus distributed in northern South America, occurring only in the Amazon and Cerrado domains. Belong the tribe Ingeae, its species have suffered several generic replacements throughout its history. Hydrochorea belongs to the "Alliance-Abarema" informal clade that also has the Abarema and Balizia genus, mainly differentiated by the type of fruit. The genus Hydrochorea is characterized by drupaceous loment fruit characteristic within the tribe, and rare in Mimosoideae. There are still many problems regarding the constituency of taxa currently subordinate to Hydrochorea. In this context, this paper aims to conduct the taxonomic study and the first attempt of the phylogenetic of Hydrochorea in order to show their infrageneric limits and the circumscription of their species as well as the relationships within the "Alliance-Abarema". In this work the "Alliance-Abarema" is strongly supported for two markers with Hydrochorea and Balizia in a polytomy, which together form the sister group of Abarema. Although Hydrochorea group is not resolved as monophyletic, length and support of the branches of this group is not high and the paraphyly of Hydrochorea regarding Balizia is not conclusive. New markers and population approaches should be tested to improve the resolution of this clade and clarify the relationship between these two genus. Hydrochorea is here circumscribed with five species and three varieties. Describes two new species and two lectotipifications are presented. Number of leaf jugae, prominent secondary veins, type and shape of the rachis extrafloral nectaries, flower bud, the shape of calyx in central flower and the presence or absence of this trichomes, were the character used in the separation of species. Taха grow predominantly in margin of rivers, floodplain forests and flooded forest, and areas where the seed can reach by dispersing the rivers. Further studies should be directed to countries like Venezuela, Bolivia, Guyana and Suriname and Brazil, in order to understand the ecology of these species in their natural habitat. Mon, 13 Apr 2026 00:00:00 GMT https://repositorio.ufra.edu.br/jspui/handle/riufra/2864 2026-04-13T00:00:00Z