https://tedebc.ufma.br/jspui/handle/tede/3333 2026-05-02T11:31:55Z https://tedebc.ufma.br/jspui/handle/tede/6922 Título: Estrutura de redes de interações ecológicas entre dieta, parasitos e lagartos da região do Parque Nacional da Chapada das Mesas Autor: SANTOS, Maciel Garreto dos Primeiro orientador: BRITO, Samuel Vieira Abstract: The complex web of interactions that structures biotic communities is the focus of study of ecological networks, a science that aims to describe and evaluate patterns of interactions between species and their effects on ecological processes. These processes are determined by the food resources between a small group, populations or communities of organisms co-occurring in space-time, and network analysis stands out as a valuable tool for demonstrating the path of energy circulating within ecosystems. On average, about 35% of the energy that flows between these networks occurs via parasitism. Thus, lizards, which are essential organisms for the ecological dynamics of natural processes and occupy a key position in the trophic chain, where they act as primary and secondary predators and/or as prey, are an important taxon to investigate in terms of their diet and that of their associated endoparasites, since these organisms use various reproductive strategies and strategies for obtaining food. The present study is the first research for the Cerrado biome with ecological network approaches using lizards as models, which aimed to evaluate and understand how the networks of host-parasite interactions and diet of lizards from the Chapada das Mesas National Park region are structured. Bipartite nets (host-parasite net and predator-prey net) were constructed, in addition to the lizard species, the nets were set up with eight species of endoparasites and 29 categories of food items. The networks did not present a well-defined nesting pattern or modularity, with a diffuse pattern with low values of modularity and more pronounced nesting, although not very expressive, indicating that there are species that are specialists, following the same path in the network as the generalist species and few specialist species interacting with other specialists. We identified the lizard species that played a functional role in structuring the topology of the networks and network modules. We also found that the habits related to the lizards' foraging strategies and seasonality influenced the structuring of the nets. This is because the opportunistic and generalist lizard species occupied a central position in the parasite-host networks and in the predator-prey networks, in both seasons. The differences in the foraging behavior of the lizards, combined with the breadth of niches may explain why lizards such as T. hispidus, A. ameiva and A. ocellifera had a greater diversity of parasites and the highest consumption of prey, especially during the dry season. Thus, we found evidence that the habits related to the lizards' foraging strategies and seasonality are related to their positions, both in the networks between parasite and hosts and between lizard predators and their prey, determining all the metrics of centrality of the networks. Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação; Documento sob sigilo. Prazo provável para disponibilização total: não informado. Motivo do sigilo: não informado. 2024-05-24T00:00:00Z https://tedebc.ufma.br/jspui/handle/tede/6907 Título: MONITORAMENTO DA VARIABILIDADE ESPAÇO-TEMPORAL DA CONCENTRAÇÃO ATMOSFÉRICA DE DIÓXIDO DE CARBONO SOBRE ÁREAS AGRÍCOLAS NA ROTA DE EXPORTAÇÃO DE GRÃOS DO PORTO DE ITAQUI Autor: RODRIGUES, Alayne Araújo Primeiro orientador: SANTOS, Gustavo André de Araújo Abstract: The monitoring of atmospheric carbon dioxide (CO₂) concentration is essential for understanding the impacts of land use and land cover on the carbon balance. In this context, remote sensing emerges as a strategic tool, enabling the acquisition of key data to promote the sustainability of agricultural production, including a better understanding of CO₂ emissions in agroecosystems. Therefore, the objective of this study was to analyze, characterize, and quantify the spatiotemporal dynamics of carbon stock in agricultural areas along the grain export corridor of the Port of Itaqui, using data from the Orbiting Carbon Observatory-2 (OCO2) over the past decade. Time series from 2016 to 2023 of XCO₂ information for pasture and soybean areas were obtained from the platform managed by NASA’s GES DISC and compared with meteorological elements (precipitation, temperature, and relative humidity) extracted from NASA POWER, as well as vegetation indices (NDVI, EVI, and LAI) derived from the MODISTerra sensor. Statistical analyses included annual and monthly boxplots, temporal trend graphs of XCO₂ using the non-parametric Mann-Kendall test, and the Shapiro-Wilk normality test with a 5% significance level, all performed using Python programming language. Thematic maps were created using QGIS® and ArcGIS® software to investigate the influence of environmental factors on carbon dynamics. In addition, the “hot spot analysis” technique was applied to identify spatial clusters of high and low CO₂ concentrations in soybean and pasture areas, along with the analysis of XCO₂ anomalies for both land-use types. The temporal variation for pasture and soybean areas did not show a significant trend, presenting stable behavior with few oscillations over the years. The Shapiro-Wilk test indicated that the data do not follow a normal distribution, although they approximate a normal curve. Spatial analysis revealed patterns of CO₂ concentration hot-spots in degraded pasture areas, whereas regions dominated by soybean cultivation showed a higher occurrence of cold-spots. The years with the greatest hot spot intensity in pasture and soybean areas were 2020 and 2022, while the years with the most prominent cold-spots in pasture areas were 2019, 2021, and 2023, and for soybean areas, 2019 and 2021. In soybean areas, a negative correlation was observed between XCO₂ and the vegetation indices NDVI and EVI. The influence of meteorological variables was significant: precipitation and relative humidity showed a positive association with XCO₂ reduction, especially during drought periods, while temperature exhibited an inverse correlation. These findings indicate that the region’s agroecosystems respond differently to climatic conditions and soil management, with direct implications for agricultural sustainability and greenhouse gas mitigation. Furthermore, socioeconomic connections are feasible to link XCO₂ patterns to agricultural expansion, global commodity demand, and public policies aimed at carbon neutrality. These perspectives reinforce the importance of using remote sensing combined with climate data to monitor emissions and carbon sequestration. Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação 2025-09-26T00:00:00Z https://tedebc.ufma.br/jspui/handle/tede/6857 Título: Produção, decomposição de palhada e liberação de nutrientes por plantas de cobertura em sistemas integrados na região Meio-Norte Autor: PINTO JÚNIOR, Fernando Freitas Primeiro orientador: MARQUES, Jordânio Inácio Abstract: Piauí and Maranhão make up the northern portion of MATOPIBA, contributing significantly to increased production in this region due to the existence of arable land still available for expansion. Agricultural areas exhibit high variability in soil types, climate, and vegetation, which directly affects soil fertility and organic matter content and stocks. In addition, the different possibilities for land use and occupation make soil and organic matter management a complex and relevant factor for the sustainability of agriculture in this part of the Northeast. Integrated systems are an important alternative for optimizing the use of natural resources with synergies between agricultural production, in the economic and environmental spheres. Although integrated systems are recognized as relevant to the sustainability of agroecosystems, research is still needed to identify promising cover crops in the challenging soil and climate conditions of the Mid-North region. The objective was to evaluate biomass production, decomposition dynamics, and nutrient release of forage grass species in consortium with corn, used as ground cover crops in integrated production systems in the Mid-North Cerrado of Brazil. The experiments were conducted in an Agroforestry System (ILF) at Fazenda Vó Desidério, in Bom Jesus-PI, in the Cerrado of Southwest Piauí, and in an Agro-Livestock System (ILP) at Fazenda Barbosa, in Brejo-MA, in Eastern Maranhão. The experimental design was randomized blocks with five treatments and four replicates. The treatments were: forage grasses of the genus Megathyrsus and Urochloa in consortium with corn and corn alone, as a control. Plant residue decomposition, grain yield and dry forage mass, and soil fertility were evaluated. The data were submitted and verified for normality and homogeneity of variances and subjected to analysis of variance. When significant, productivity data (grass biomass and corn and soybean grains) and nutrient contents were compared using Tukey's test (P<0.05). There was no significant effect on residual biomass production in Brejo-MA. In Bom Jesus-PI, M+Massai differed from the other treatments. For soil fertility after intercropping, only the chemical attributes K+ , Fe3+ and Mn in Bom Jesus and Zn in Brejo showed a difference. There was a significant effect on soybean productivity in Bom Jesus. The M+Ruziziensis intercrops in Bom Jesus provide greater availability of K+ , Fe3+ and Mn in the soil. In Brejo M+Marandu, it provides an increase in Zn. The intercropping of forage grasses of the genus Megathyrsus and Urochloa does not reduce corn productivity when intercropped. The cultivation of M+Ruziziensis in Bom Jesus and M+Tamani in Brejo, although not resulting in increased soybean productivity, shows potential as cover crops in the Cerrado of the Mid-North region of Brazil. Further studies are needed to assess the long-term effects of the interaction between the corn and forage grass intercropping system on soil fertility, nutrient cycling, and intercropping system productivity under other experimental or seasonal conditions. Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação 2025-08-23T00:00:00Z https://tedebc.ufma.br/jspui/handle/tede/6848 Título: Lógica fuzzy aplicada à modelagem do risco de incêndios florestais no bioma Cerrado, Brasil Autor: SOUSA, Andreza Maciel de Primeiro orientador: MACHADO, Nítalo André Farias Abstract: Wildfires cause environmental and socioeconomic impacts by compromising soil quality, vegetation, and natural resources. In the Cerrado biome, despite the recurrence of fire, the factors associated with large-scale wildfires are still poorly understood. The objective of this study was to develop and validate a wildfire risk (WR) model for the Cerrado biome using fuzzy logic. In Chapter 1, a literature review is presented that aims to introduce key concepts and contextualize the Cerrado in light of current environmental and socioeconomic challenges. In Chapter 2, the study on WR modeling using fuzzy logic and GIS is presented, integrating biotic, abiotic, and anthropogenic factors for the Brazilian Cerrado. The WR model was developed using the fuzzy gamma overlay method. The validation was performed through cluster analysis and the construction of a dendrogram between the WR classes and wildfire hotspot data from the Brazilian National Institute for Space Research (INPE), complemented by Kernel density analysis. The “moderate” and “high” wildfire risk classes represented 68.35% and 28.43% of the biome, respectively. There was a greater concentration of these classes in the centralsouthern and southeastern regions of the Cerrado. The variables land use and land cover, roads, population density, precipitation, mean temperature, and water deficit were identified as the most influential variables in the modeling. Kernel density analysis of fire hotspots recorded by the Brazilian National Institute for Space Research (INPE) revealed critical areas along the agricultural frontier of MATOPIBA, which was also identified as a critical area in the WR model. The dendrogram revealed two main groups: (1) “high” risk, associated with fire risk, and (2) “moderate” risk, associated with wildfire frequency, both derived from data provided by the Brazilian National Institute for Space Research (INPE). Meanwhile, the “low” and “very high” risk classes remained isolated at the adopted cut level, validating the quality of the developed model. In conclusion, the developed model proved effective in predicting and identifying wildfire risk areas in the Cerrado. In addition, it demonstrated potential for application in other regions due to its low processing cost, thereby contributing to the development of wildfire prevention and suppression strategies. Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação 2026-02-23T00:00:00Z