PPGE - Mestrado em Ecologia
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Master Thesis Fatores que influenciam a presença e detecção de aves limícolas residentes no sítio Western Hemisphere Shorebird Reserve Network (WHSRN) Banco dos Cajuais, Nordeste brasileiro(Universidade Federal do Rio Grande do Norte, 2024-03-26) Souza, Victoria Maria Reis de; Pichorim, Mauro; Mobley, Jason Alan; http://lattes.cnpq.br/4414896140171246; http://lattes.cnpq.br/5696697654544552; http://lattes.cnpq.br/0387100616590028; Faria, Fernando Azevedo; http://lattes.cnpq.br/3734809049467543; Guzzi, Anderson; http://lattes.cnpq.br/1540345567927880Providing accurate information on population status and habitat preferences is essential for developing conservation strategies for shorebirds. Using key species to understand patterns of habitat use can contribute and extend conservation benefits to other shorebird species that share the same habitat. The aim of this study was to analyze the habitat preferences of the endangered Wilson’s Plover (Charadrius wilsonia) and the American Oystercatcher (Haematopus palliatus), breeding shorebirds residing strictly along the coast. We analyzed the presence of the species with environmental and anthropic variables, to understand which variables influence the occupancy (Ѱ) and detectability (p) probabilities of the species in the Western Hemisphere Shorebird Reserve Network site Banco dos Cajuais, in the semi-arid central portion of the coastal zone of Brazil. Data were collected from July 2022 to June 2023. We found that H. palliatus was more present (Ѱ = 0.99) than C. wilsonia (Ѱ = 0.87), but both species had a high probability of occupancy. We found that the occupancy of C. wilsonia and H. palliatus is influenced by variation in the structure of the environment and by natural and anthropogenic disturbances. Among the most important explanatory variables for species occupancy, a negative influence stands out for C. wilsonia between occupancy and the distance from river channels and for H. palliatus a positive influence between occupancy and the availability of exposed sandy beach soil. The results of this work can contribute to the management of areas recognized as priorities for the conservation of C. wilsonia and H. palliatus, in addition to helping to identify new areas which have determining factors for the occurrence of the species.Master Thesis Fenologia reprodutiva no limite norte da Mata Atlântica: importância dos fatores ambientais e evolutivos(Universidade Federal do Rio Grande do Norte, 2025-09-12) Câmara, João Paulo Pereira da; Staggemeier, Vanessa Graziele; Calvente, Alice de Moraes; http://lattes.cnpq.br/7557922092763217; https://orcid.org/0000-0003-4911-9574; http://lattes.cnpq.br/4357034543526737; http://lattes.cnpq.br/6436577052641213; Gressler, Eliana; http://lattes.cnpq.br/8557254418282155; Soares, Natalia Costa; https://orcid.org/0000-0001-5408-7146; http://lattes.cnpq.br/4642385280748629Phenology studies the patterns of recurrent events in living organisms and their relationship with extrinsic and intrinsic factors. Phenological studies are crucial for the management and preservation of ecosystems, as they provide valuable information about the availability of resources over time and space. At higher latitudes, plant phenology is mainly driven by variations in day length. However, in less seasonal regions near the equator, phenology is expected to be more influenced by other environmental factors, such as precipitation, or by evolutionary factors, such as phylogeny. Due to the scarcity of phenological data on the northern limit of the Atlantic Forest in Brazil, this study aims to reduce the gap by testing the hypotheses that climate and evolutionary history structure the reproductive patterns of plant communities at low latitudes, close to the equatorial line. To this end, we monitored 1,092 individuals from 93 species every two weeks in two Conservation Units (CUs) in Rio Grande do Norte, Brazil. We collected qualitative and quantitative data for four reproductive phenophases (flower bud, anthesis, immature fruit, and mature fruit) and analyzed them in conjunction with climate and evolutionary history (phylogeny) data. Our study tested: (i) whether there is seasonality and synchrony of the plant species that make up the two observed communities, and (ii) whether the reproductive response of these species is influenced by climate or phylogeny. The results show that environmental factors were the main predictors of phenology. The community showed seasonality and synchrony in its flowering and fruit development phenophases. Longer day length and more intense precipitation were the most important environmental triggers for the occurrence of flower buds and anthesis, while warmer temperature and higher precipitation were important for fruit development. Fruiting was continuous, and the production of mature fruits was better explained when considering the evolutionary history of the lineages, environmental factors, and the shared influence between them. The present research provides unprecedented and crucial data on the phenology of species at the northern limit of the Atlantic Forest, in addition to providing insights into the influence of environmental and evolutionary factors in determining the phenophase of plant species.Master Thesis Efeito positivo da diversidade e facilitação na regeneração de uma área restaurada na maior floresta sazonal do Brasil(Universidade Federal do Rio Grande do Norte, 2025-02-27) Neves, Rainara da Silva; Ganade, Gislene Maria da Silva; Fagundes, Marina Vergara; http://lattes.cnpq.br/1774929049634678; Malvido, Julieta Benitez; Lopes, Milena Cordeiro de Amorim; http://lattes.cnpq.br/1459643441710337Natural plant regeneration is a fundamental ecological process for maintaining the dynamics of colonization and species replacement in plant communities in the long term. After the restoration process, natural regeneration can increase the speed of recovery of the structure, function, composition and plant biodiversity of the community. The diversity of cultivated tree species planted during restoration can enhance the natural regeneration of plants in restored communities through complementarity and facilitation mechanisms. However, the role of planted tree diversity on natural regeneration is still poorly understood. The present study aims to test how the diversity of planted trees and their facilitation potential in restored Caatinga communities affect the dynamics of natural regeneration of tree species. We conducted a survey of woody species that naturally colonized a Caatinga restoration experiment focused on biodiversity and ecosystem functioning (BEF) after 7 years of planting. The experiment had 6 diversity treatments (1, 2, 4, 8, 16 tree species and control plots without planting) and a gradient of facilitation potential of the tree species planted in the plots. A total of 4,017 regenerating individuals were counted, comprising 15 woody species representing 10 families, with Fabaceae being the most abundant with 5 species. The results demonstrate positive synergistic effects of diversity and facilitation on the abundance of regenerants. The high diversity and high facilitation potential of planted trees increased the abundance of regenerants in the restored communities. In the regenerating community, there was low equitability, with high dominance of Jatropha mollissima, a native, pioneer species with great attractiveness for a fauna of pollinators and seed-dispersing ants. The abundance of this species was also enhanced by the high diversity and high facilitation potential of planted trees. This study demonstrates that the structure of the restored plant community is a key factor in fostering natural forest regeneration. Thus, implementing communities planted with facilitating species and greater plant diversity can maximize the success of dryland restoration, contributing to the regeneration, maintenance and functioning of communities in the long term.Master Thesis Relação do habitat e região corporal na sinalização e camuflagem de lagartos de uma área de Mata Atlântica(Universidade Federal do Rio Grande do Norte, 2025-08-20) Queiroz, Vitoria Godeiro de; Garda, Adrian Antonio; Pessoa, Daniel Marques de Almeida; https://orcid.org/0000-0002-2516-6766; http://lattes.cnpq.br/8413512010176898; https://orcid.org/0000-0002-1178-1207; http://lattes.cnpq.br/2685356834735366; http://lattes.cnpq.br/8701639920268535; Mesquita, Daniel Oliveira; http://lattes.cnpq.br/4914661659187454; São Pedro, Vinícius de Avelar; http://lattes.cnpq.br/7404103190291423Master Thesis Origens natais de machos e diferenças no uso do habitat entre machos e fêmeas de tartarugas-oliva (Lepidochelys olivacea) da costa de Sergipe, Brasil(Universidade Federal do Rio Grande do Norte, 2025-08-22) Santos, Igor Peres Puertas dos; Garda, Adrian Antonio; Monteiro, Danielle da Silveira; http://lattes.cnpq.br/6778147001344996; https://orcid.org/0000-0002-1178-1207; http://lattes.cnpq.br/2685356834735366; https://orcid.org/0000-0001-5916-5369; http://lattes.cnpq.br/7474465591317300; Vargas, Sarah Maria; https://orcid.org/0000-0002-8042-7295; http://lattes.cnpq.br/1956218219090768; Stahelin, Gustavo David; https://orcid.org/0000-0001-5381-4786; http://lattes.cnpq.br/9287217385031165Understanding migratory patterns, natal origins, and habitat use by sea turtles is crucial to refining and delineating conservation strategies, particularly during non-reproductive phases. Moreover, knowledge about these characteristics in male sea turtles is scarce due to the difficulty of accessing these animals, which, unlike females, spend their entire lives at sea. The olive ridley sea turtle (Lepidochelys olivacea), classified as “vulnerable” both nationally and internationally, is the most abundant sea turtle species in the world, yet one of the least studied. Sergipe, in northeastern, hosts the main nesting area for this species along the Brazilian coast. Although nesting numbers have increased in recent years, the high number of stranded turtles is concerning for population stability, particularly due to the high mortality rate among males. This high number of male strandings is believed to be due to their presence along the Sergipe coast during the whole year. Additionally, there is a tendency toward female-biased hatchling sex ratios in the region due to high temperatures, suggesting that the male population feeding and reproducing along the Sergipe coast may represent a mixed stock. Based on this, the study aimed to assess the genetic diversity and natal origins of male olive ridleys stranded along the Sergipe coast using the mtDNA control region and to identify preferred habitat use areas for males by analyzing stable carbon and nitrogen isotopes in epidermal tissue. Results show that males have low genetic diversity, with natal origins mainly from Angola, Gabon/São Tomé and Príncipe/Equatorial Guinea; this pattern was already observed for olive ridley populations in adjacent areas, such as Alagoas and Ceará; with the same countries as source areas. Results also suggest that male olive ridleys feeding and reproducing along the Sergipe coast presents habitat use similar to those of females during the reproductive period, but show differences in the postreproductive period, in which females migrate to feeding areas while males remain in the region. Results of this study, although preliminary, provide important information for understanding the ecology, migration patterns, and connectivity of male olive ridley sea turtles in the species' main nesting ground in the Southwest Atlantic.Master Thesis Padrões de ocupação e uso de habitats costeiros por aves limícolas migratórias na porção semiárida do litoral brasileiro(Universidade Federal do Rio Grande do Norte, 2024-03-25) Monteiro, José Onofre Nascimento; Pichorim, Mauro; Mobley, Jason Alan; http://lattes.cnpq.br/4414896140171246; http://lattes.cnpq.br/5696697654544552; http://lattes.cnpq.br/7129531291770486; Oliveira, Carlos David da Silva; Las-Casas, Flor Maria Guedes; http://lattes.cnpq.br/1452162168205713Many shorebird species are associated with coastal ecosystems during their annual migratory movements between breeding and overwintering areas. The semi-arid coastal region of northeastern Brazil presents a vast landscape of suitable habitats for these birds. Investigating the use of these habitats by shorebirds as a function of landscape structure and anthropic disturbances is a useful approach to better understand their occupancy patterns in the semi-arid region. In 2022 and 2023 we conducted n=3 independent data sampling campaigns, representing n=111 individual 1km long transects, totaling 804 km, covering the entire coastline of Ceará and part of Rio Grande do Norte. Presence/absence data for the species (Calidris canutus, Calidris pusilla, Limnodromus griseus and Numenius hudsonicus) were collected by means of visual observation using binoculars and spotting scopes. Specific habitat characteristics and other variables, such as proximity to particular habitats, human occupations, and degree of disturbances related to tourism activities were recorded during each transect. In addition, information on landscape variables such as land cover in different classes was collected using satellite images. We analyzed the influence of environmental variables on the occupation of the species through static occupation models, using the MARK program. The three most influential variables in the distribution of the species were the distance from estuaries, urban area coverage and aquaculture. The response of species occurrence along the gradient of variables showed that C. canutus had the lowest occupancy among the species (ψ = 0.31), followed by L. griseus (ψ = 0.44), N. hudsonicus (ψ = 0.71), and C. pusilla (ψ = 0.72). These results indicate the influence of landscape structure and vulnerability of shorebirds to anthropogenic impacts, especially related to habitat loss during the wintering period on the semi-arid Brazilian coast. Our results will help to inform conservation strategies and better define the ecological requirements of this threatened species during the greater part of its non-breeding periods.Master Thesis Impactos do desastre de petróleo de 2019 sobre a biota marinha no Rio Grande do Norte(Universidade Federal do Rio Grande do Norte, 2025-05-15) Silva, Adrian Pereira da; Mendes, Liana de Figueiredo; http://lattes.cnpq.br/8630238560783274; http://lattes.cnpq.br/1926482145868299; Bauer, Arthur de Barros; http://lattes.cnpq.br/1260428303314421; Kikuchi, Ruy Kenji Papa de; https://orcid.org/0000-0002-6271-7491; http://lattes.cnpq.br/8391627429679768Marine biodiversity is subject to a variety of impacts from pollutants resulting from human activities and exhibits different ecophysiological responses depending on the species and its susceptibility to contamination. Oil and its derivatives are major sources of impact on marine biota, stemming from chronic pollution and, more notably, from acute events such as oil spills. The harmful effects on marine fauna include physiological irregularities, developmental issues, and long-term contamination-related effects. Thus, oil contamination in marine organisms is a cause for concern, as it compromises both population health and environmental integrity. However, beyond assessing overall contamination levels, it is essential to examine speciesspecific data and consider whether ecological traits influence variations in contamination. This study aims to investigate oil contamination in marine organisms from three different taxonomic groups—mollusks, crustaceans, and fish—collected from four beaches along the southern coast of Rio Grande do Norte, an area affected by the 2019 oil spill. The research applies ecological traits of different species to understand contamination levels and associated damage. In Chapter I, chemical analysis was conducted to detect polycyclic aromatic hydrocarbons (PAHs) in 12 species. Higher PAH concentrations were found in invertebrates compared to vertebrates, reinforcing the greater susceptibility of mollusks and crustaceans to PAH contamination, as reported in the literature. The contamination profile showed a predominance of light PAHs, a pattern commonly observed in past oil spill events. Chapter II focuses on gastrointestinal and histopathological analyses in fish. These analyses detected the presence of oil in the stomach and tissue damage in the gastrointestinal tract, particularly in demersal, invertebrate-feeding fish species. The study provides an overview of contamination and its effects on marine species following the 2019 disaster, and examines the relationship between ecological characteristics and vulnerability to PAH contamination.Master Thesis Comportamento e padrões de uso em praias por aves marinhas em uma ilha oceânica brasileira(Universidade Federal do Rio Grande do Norte, 2025-03-20) Silva, André Alves Reis; Mendes, Liana de Figueiredo; Paixão, Randson Modesto Coêlho da; https://orcid.org/0000-0003-3205-5316; http://lattes.cnpq.br/3674727933018888; http://lattes.cnpq.br/8630238560783274; http://lattes.cnpq.br/8977628150458138; Mobley, Jason Alan; http://lattes.cnpq.br/4414896140171246; Rodrigues, Marcelo CâmaraSeabirds, as top predators in the food chain, have a wide global distribution and behavioral flexibility, adjusting their foraging strategies according to abiotic factors and prey availability. In Brazil, oceanic islands such as the Fernando de Noronha Archipelago are important areas for breeding, resting, and feeding. Noronha stands out for its biodiversity, hosting species such as the magnificent frigatebird (Fregata magnificens), boobies (Sula spp.), and noddies (Anous spp.). In the first chapter, we evaluated the composition of the seabird community in flight on the main island, considering time of day (7h, 9h, 11h, 15h, and 17h), seasonality (rainy and dry seasons), and spatiality (inner sea and outer sea). We identified higher diversity during the dry season, especially in the outer sea in the morning and under conditions of no swell. The inner sea showed greater variability between morning and afternoon, highlighting seasonal differences. In the second chapter, we investigated the behavior of the brown booby (Sula leucogaster) in Fernando de Noronha, considering spatial, diurnal, and seasonal variations. Using focal animal sampling and scan sampling techniques, we recorded behaviors such as foraging, resting, interactions, and passing. We observed a higher frequency of active search behavior (BAT) during the dry season and resting on rocks (REP) during the rainy season. Feeding activity predominated in the dry month, in the morning, and in the outer sea region, while resting occurred in the inner sea during the rainy season, especially in the late afternoon. The results highlight the strong influence of seasonality and diurnal variation on the behavior of the brown booby and the composition of seabirds in Fernando de Noronha. The dry season favors greater feeding activity and diversity, especially in the outer sea, while the rainy season intensifies resting behaviors in the inner sea. These findings reinforce the importance of implementing long-term monitoring, gathering behavioral information on the seabird community in an oligotrophic environment.Master Thesis Atividade vocal, riqueza de espécies, e os coros e "nãocoros" das aves em dois pontos com condições ambientais diferentes no RN(Universidade Federal do Rio Grande do Norte, 2025-03-18) Pinheiro, Thiago Augusto Mendes; Lima, Renata Santoro de Sousa; Ferreira, Luane Maria Stamatto; https://orcid.org/0000-0002-2638-1695; http://lattes.cnpq.br/1514389007687960; http://lattes.cnpq.br/6008949452293667; Pichorim, Mauro; Almeida, Marina Scarpelli Drummond deBirds’ vocal activity is a defining feature of this group, and their vocal output is often used as a detection tool (in terms of presence/absence) in many ecological studies about these animals. Birds’ acoustic activity can be influenced by environmental factors that also affect species richness at a given spot. Using audio recordings acquired through Passive Acoustic Monitoring (PAM), this study aimed to i) investigate the influence of a set of environmental factors on birds’ vocal activity (measured as the number of vocalizations) and species richness in two sampling sites with distinct environmental conditions located at Rio Grande do Norte state, Brazil; and ii) compare the influence of the environmental variables on the vocal activity and species richness between the two sites. The study was conducted in the rural zone of the municipality of Currais Novos (Caatinga biome) and at the Parque das Dunas state park, in Natal, during twelve monthly 3-day sampling campaigns, covering two periods (04:00 – 10:00 and 14:00 – 20:00) recording for 1 minute at every 10-minute cycle. Generalized Additive Models (GAMs) were built to evaluate the relationship between six environmental variables, including hourly precipitation, NDVI vegetation index, cloud cover, thermal sensation, light condition and wind speed, and the response variables (vocal activity and species richness). Results suggest that the set of environmental factors play a collective and significant role in this system, with distinct effects of these factors on the response variables in both sampling sites. The factor representing light condition showed the highest estimate values in all models with consistent positive effects. As far as we know, this is the first study to evaluate how environmental factors may influence birds’ acoustic behavior in Brazil, conducted in traditionally understudied environments.Master Thesis Efeito das mudanças climáticas sobre a distribuição de cianobactérias no semiárido brasileiro(Universidade Federal do Rio Grande do Norte, 2024-08-23) Medeiros, Ludmille Espínola de; Dias, Juliana Déo; Mantovano, Tatiane; http://lattes.cnpq.br/8119278936427700; http://lattes.cnpq.br/7472960167899416; Moresco, Geovani Arnhold; Becker, VanessaClimate change causes universal challenges and intergenerational impacts. Global climate warming has been observed since the Industrial Revolution and has led to a shortage of natural resources, causing different effects such as changes in precipitation and temperature patterns. These variables are essential for the occurrence of aquatic species, as they affect resource availability and can alter the biogeochemical processes that regulate the life cycle. Empirical evidence indicates a sharp increase in the proliferation of cyanobacteria with climate-related changes. Cyanobacteria are photosynthetic organisms that occur in marine and freshwater environments, grouping around in colonies or filaments, and many species can produce potentially toxic blooms. In the semiarid region of Brazil, the occurrence of cyanobacteria is widely recorded in reservoirs for multiple uses, including public supply, and may affect biodiversity and human health. In this study we tried to understand the current and future distribution of environmental cyanobacteria (colonial and filamentous) that produce toxins in the Brazilian semiarid region using the niche modelling approach to estimate the areas suitable for the establishment of these populations, associating the already known occurrence points with the bioclimatic variables inherent to the ecology of the species and the climate scenarios (moderate and pessimistic) projected by the Intergovernmental Panel on Climate Change (IPCC) focusing on the time interval 2081-2100. Isothermality, annual temperature variation, precipitation volume of the wettest, coldest and driest quarters, plus the elevation were the variables most important for the potential distribution of the species. The projections showed that the Brazilian semiarid region has high climatic suitability for the occurrence of all scientific species, but the models indicated the expansion of habitat suitability in the future, both in the moderate and pessimistic scenarios, only for Microcystis aeruginosa (colonial) and Planktothrix agardhii (filamentous). Therefore, the results obtained suggest a link between temperature and precipitation variability effects on the distribution patterns and adaptive strategies of the species.Master Thesis Sequestro de carbono florestal para diferentes técnicas de restauração ecológica na Caatinga(Universidade Federal do Rio Grande do Norte, 2024-02-29) Medeiros, Úrsula Tathiana Oliveira de; Ganade, Gislene Maria da Silva; Villavicencio, Lourdes Milagros Mendoza; http://lattes.cnpq.br/3024078007563102; https://orcid.org/0000-0003-3607-2754; http://lattes.cnpq.br/8269534603338248; Monteiro, Felipe Ferreira; Franco, Jeanne Raquel de AndradeEcological restoration plays a crucial role in overcoming the urgent challenges related to ecosystem degradation, biodiversity loss and climate change. As a solution to the degraded environment of the Caatinga, ecological restoration seeks to recover ecosystem services, such as carbon capture from the atmosphere, and can also be an ally as a technique to promote carbon sequestration in degraded areas, strengthening the potential for climate change mitigation. This study seeks to identify effective restoration techniques and assess their impact on carbon accumulation, tree species development and seedling characteristics, with the aim of optimizing biomass production in semi-arid ecosystems. The research involved six tree species native to the Caatinga and implemented five planting treatments in 12m x 8m plots with 2m spacing, replicated five times. These treatments included the control (no manipulation), irrigation, litter transplanting, a combination of irrigation and litter transplanting, and agroforestry. The seedlings were categorized based on the dimensions of the roots (small or large) and the aerial part (small or large), and measurements of height, diameter at ground height, aerial biomass and water content of the plants were recorded three years after restoration, at the end of the experiment. Our results revealed that the addition of water had a significant impact on carbon accumulation. Jurema preta (Mimosa tenuiflora) proved to be the most promising species for greenhouse gas neutralization projects, accumulating approximately 0.09 kg of carbon per m2. The research also looked at the importance of the size of the seedlings, indicating that plants with larger roots and aerial parts accumulated more biomass and had a higher survival rate. In addition, the Catingueira species showed excellent survival in water-restricted treatments, especially when the seedlings had small roots. The total carbon accumulated at the end of the experiment was 0.1 kg per m2. These findings offer guidelines and strategies for management and restoration, highlighting the importance of taking into account not only the availability of water, but also the particularities of the species and the size of the seedlings in order to maximize the effectiveness of restoration projects in the Caatinga.Master Thesis Comunidades de insetos sendo afetadas pela sinergia entre diversidade de espécies e facilitação da comunidade vegetal(Universidade Federal do Rio Grande do Norte, 2025-02-27) Lima, Samuel Nascimento de; Ganade, Gislene Maria da Silva; http://lattes.cnpq.br/3024078007563102; http://lattes.cnpq.br/6161272569266100; Leal, Anderson Dantas; Gianuca, Andros TaroucoThe intensification of habitat loss has led to a decline in the world's entomofauna. The diversity of plant species and the facilitation between plants can be fundamental for the sustainability of this entomofauna, because they influence the base of the food chain of these organisms. This influence occurs through an increase in primary productivity due to increased niche complementarity between plants and improved soil and climate conditions. However, studies on how the processes of diversity and facilitation affect forest ecosystems are still incipient, especially in tropical forests in arid and semi-arid regions of the world. In the Brazilian semi-arid region, the process of habitat destruction is intensifying and causing desertification. The reconstruction of these degraded habitats through ecological restoration is a fundamental process in mitigating the loss of habitat and biodiversity by replenishing vegetation that is diverse in terms of the number of species and morpho-functional characteristics that provide for the colonization of other trophic levels. This study aims to investigate how species diversity and the functional diversity of vegetation as well as facilitation processes are influencing the abundance, richness and functional diversity of insects in a Caatinga restoration experiment focused on the relationship between plant biodiversity and ecosystem functioning (BEF-BrazilDry). Using Generalized Linear Mixed Models (GLMM), we observed that insect abundance was positively influenced by the interaction between the richness of planted trees and their facilitation capacity. The abundance, species richness and functional diversity of insects benefited from the height of the trees in the experimental communities studied, showing the importance of the availability of resources and nesting and foraging areas. Our results suggest that in addition to the species richness of the trees, the type of interactions they have is also important for the colonization of higher trophic levels. In order to encourage insect diversity, the restoration of dry forests should consider planting large saplings in addition to a high diversity of tree species with high facilitation potential.Master Thesis Padrões históricos e atuais do uso do solo em bacias de drenagem e sua relação com a proximidade de lagos e reservatórios(Universidade Federal do Rio Grande do Norte, 2025-02-20) Monte, Otávio de Sena; Silva, Adriano Caliman Ferreira da; https://orcid.org/0000-0003-1368-7051; http://lattes.cnpq.br/5732240601827737; Gripp, Anderson da Rocha; Carneiro, Luciana SilvaLand-use change is a major driver of terrestrial and aquatic ecosystem transformations, affecting carbon fluxes, biodiversity, and ecosystem services worldwide. Understanding catchment land-use dynamics is critical, as these areas are shaped by several socioenvironmental factors. However, whether and how the aquatic ecosystem type (natural lake or reservoir) and the distance from its shores influence the catchment land-use dynamics remains limited. This study investigates the spatiotemporal land-use dynamics in 98 tropical catchments, encompassing natural lakes and reservoirs in northeast Brazil. For this, we used the MapBiomas Land-Use/Land-Cover Collection (1985–2022). The land-use dynamics (LUd) were depicted by a composite variable derived from principal component analysis (PCA) scores, which incorporated the current relative extent of land use, the land-use change rate, and long-term land-use trends. We hypothesized that: i) LUd is greater in reservoir catchments, ii) LUd increases with greater distance from the shore in both lake and reservoir catchments, and iii) the distance-mediated increase in LUd is stronger in reservoir catchments. Using regression tree analysis (RTA), we explore how morphometric and geomorphological characteristics of aquatic environments and their catchments, as well as demographic and climatic characteristics, influence the spatiotemporal land-use index (SLUi), calculated as the effect sizes (Fisher’s z) of LUd as a function of distance from the shore. Our results reveal that LUd is more intense in lake catchments and differs significantly between lake and reservoir catchments: LUd increases with distance from lakes but decreases with distance from reservoirs. This suggests that areas closer to lakes are more effectively protected than those further away, whereas in reservoir catchments, headwater regions are less impacted than areas closer to the reservoir shores. Human population size, slope, longitude, waterbody area, and catchment area are the key landuse predictors in the studied catchments. These findings provide new insights into the mechanisms driving land-use dynamics in catchments of tropical ecosystems, highlighting the importance of considering ecosystem type as a predictor of catchment land-use dynamics.Master Thesis Impactos na qualidade da água causados pela antropização da zona ripária em reservatórios no semiárido tropical brasileiro(Universidade Federal do Rio Grande do Norte, 2024-07-26) Gomes, Augusto César Cavalcanti; Becker, Vanessa; Dias, Juliana Déo; http://lattes.cnpq.br/8119278936427700; http://lattes.cnpq.br/2999389235108507; https://orcid.org/0000-0002-7845-3873; http://lattes.cnpq.br/1395750032048311; Angelini, Ronaldo; Severiano, Juliana dos SantosThe anthropization of terrestrial ecosystems affects aquatic systems by introducing nutrients from the watershed through surface soil processes. The application of geoprocessing tools can support the sustainable management of these ecosystems, helping guide decisions regarding the protection of riparian zones and aquatic ecosystems. This study aimed to assess the relationship between water quality in stored reservoirs and different land use and occupation categories, and whether the response to anthropization varies with reservoir volume. The reservoirs were grouped into large (n = 6) and medium (n = 11) categories based on their maximum water volume (greater or less than 75 hm³). We hypothesized that larger reservoirs have more extensive anthropization areas due to the size of their riparian zones; however, the impact on water quality is delayed due to the dilution effect from their larger water volumes. The study was conducted in 17 reservoirs located in the semi-arid tropical region, within the watersheds of Apodi-Mossoró (RN), Piancó-Piranhas-Açu (RN/PB), and the Paraíba River (PB) in northeastern Brazil. Land use and occupation in the riparian zone were analyzed using geoprocessing, and the following categories were assessed: agriculture and livestock farming, dense caatinga, sparse caatinga, exposed soil, and urban areas. No significant differences were found regarding stored water volumes across the reservoirs. All reservoirs exhibited high nutrient concentrations and algal biomass. Few correlations were found between land use categories and the limnological conditions of the water, and where present, they were weak to moderate. The history of flooding since the reservoirs' operation may have contributed to nutrient feedback into the water. The tendency toward increased eutrophication was more pronounced in smaller reservoirs. The expansion of agriculture and livestock farming activities and exposed soils, especially during prolonged droughts, exacerbated diffuse pollution. The suppression of native vegetation may reduce the buffering effect of soils and vegetation in the riparian zone. Dense caatinga vegetation remains but may not be sufficient to protect reservoirs from nutrient influx. These reservoirs, located in drainage areas with sparse caatinga vegetation, promoted higher nutrient influx when flooded. Thus, no significant segregation was observed between reservoir volumes regarding trophic state.Master Thesis Salinização causa evolução rápida da tolerância e menor tamanho celular em uma cianobactéria formadora de florações(Universidade Federal do Rio Grande do Norte, 2024-02-28) Domingos, Ingrid Elaine Rodrigues; Ger, Kemal Ali; Panosso, Renata de Fátima; http://lattes.cnpq.br/2543467420133635; http://lattes.cnpq.br/0949406269847477; https://orcid.org/0009-0004-4300-7998; http://lattes.cnpq.br/3994802730022496; Becker, Vanessa; Azevedo, Sandra Maria Feliciano de Oliveira eGlobal changes act as selective forces responsible for inducing species evolution over a short period of time, events that have implications on the structure and functioning of ecosystems, but limited information exists about subsequent ecological effects. Salinization, as a stress factor to freshwater ecosystems, not only represents a threat to biodiversity and key ecosystem functions and services but also exerts selective pressure on species. However, the way species locally adapt to salinization through microevolutionary processes is poorly understood. Thus, we investigated the capacity for rapid evolution to increased salinity and its effects on functional characteristics, growth, and morphology of Brazilian strains of Microcystis aeruginosa (Kütz.). Furthermore, we believe that populations adapted to high salinities will exhibit higher growth rates and smaller cell sizes. To this end, we set up a Common Garden experiment with 4 strains of toxin-producing Microcystis. Prior to the Common Garden, all strains were divided into 3 populations (replicates) and exposed to 2 treatments: addition of NaCl (1.5 g/L) and control (0 g/L NaCl) for a period of 6 to 8 months, resulting in over 100 generations. After this period, each population was exposed to treatments of 0, 1.5, 3, and 5 g/L NaCl with 3 replicates each in a Common Garden design for an additional 7 generations to remove the effects of phenotypic and epigenetic plasticity in the populations. After this stage, morphological and growth characteristics were measured. To test how salinity concentrations and adaptation affect Microcystis growth and morphology, we used Generalized Linear Models (GLMs). Populations exposed to a concentration of 1.5 g/L in the selection stage (adapted) showed higher growth rates compared to those exposed to the control (non-adapted) and grew in all salinization treatments, indicating increased salt tolerance driven by selection on preexisting genetic variation. Two strains, originally growing as individual cells, produced colonies at higher salinities. Colony formation, as well as size, was greater in nonadapted populations, indicating that adapted populations likely do not need to invest in colony formation to survive. The results demonstrate that adaptation to relatively low concentrations (1.5 g/L) of salt also enables tolerance to higher salinities (>3 g/L). We show rapid evolutionary adaptation (microevolution) of a common aquatic primary producer to freshwater salinization over ecological time, with effects on key traits (phenotype) such as cell size. Such adaptation is likely to occur in other cyanobacteria and microalgae species in nature where salinization occurs, with consequences for ecosystem functions still unknown. Our results justify a broader view of the ecoevolutionary implications of salinization-driven selection in aquatic ecosystems.Master Thesis Resgate histórico como ferramenta para reconstruir a abundância passada de tubarões no litoral do nordeste brasileiro(Universidade Federal do Rio Grande do Norte, 2019-04-23) Carvalho, Fábio Henrique Dantas de; Lopes, Priscila Fabiana Macedo; Longo, Guilherme Ortigara; http://orcid.org/0000-0003-2033-7439; http://lattes.cnpq.br/3947302863354812; http://lattes.cnpq.br/0025274238475995; http://lattes.cnpq.br/9516428703964228; Angelini, Ronaldo; Leduc, Antoine; Bevilacqua, Ana Helena VarellaKnowing the situation of fish stocks is essential for the management and maintenance of fisheries. However, in Brazil little is known about most stocks, even those of interest to small-scale fisheries. In the absence of this information, historical surveys using interviews with fishers and other groups of people that directly observe fishing resources (e.g., researchers and divers) serve as a tool to evaluate the actual trends of these stocks. Nevertheless, there may be a common distortion associated with this methodology, known as the shifting baseline syndrome. In this syndrome, the informant tends to believe that the moment he or she began to observe the resource, the resource was at its peak of abundance, which disregards past exploitations and can lead to a false perception of the current state of the stocks. One way to alleviate this distortion is to include informants of different ages and experiences, seeking to retrieve the oldest information possible. The general objective of the present research was to do a historical survey of the sighting of some species of sharks by artisanal fishers on the northeastern Brazilian coast, evaluating possible changes in shark occurrences and their sizes along the last six decades, using for that information provided by artisanal fishers. The data were collected along part of the northeastern coast (states of Rio Grande do Norte, Paraíba, Pernambuco and Bahia). Out of the eight species analyzed, in three (Carcharhinus leucas, Ginglymostoma cirratum and Sphyrna lewini) the fishers perceived a decreased in their maximum size over the years. Coastal species were the most likely to suffer from these size variations. The different groups of fishers, classified into age groups, had different perceptions of the average sizes of the species Carcharhinus leucas and Isurus oxyrinchus. With the ever-increasing risk of extinction of large predators, we hope to contribute to the understanding of the patterns of abundance and size changes of fish and their stocks over the recent past through the knowledge accumulated by fishers.Master Thesis Frugivoria em Myrteae (Myrtaceae) nas Américas(Universidade Federal do Rio Grande do Norte, 2024-07-31) Moreira, Victor de Paiva; Staggemeier, Vanessa Graziele; https://orcid.org/0000-0003-4911-9574; http://lattes.cnpq.br/4357034543526737; https://orcid.org/0000-0002-9837-8380; http://lattes.cnpq.br/4501919971368014; Pinto, Miriam Plaza; Gressler, ElianaMyrtaceae is one of the most species-rich families among angiosperms and plays a crucial ecological role in tropical regions, particularly in the Americas, where it is represented by the tribe Myrteae. This group exhibits a wide diversity of fleshy fruits that serve as resources for fauna, relying on frugivores for seed dispersal. This plant-animal interaction impacts the evolutionary success of both lineages, and it is expected that fruit selection by frugivores may explain the high species diversity within this tribe. Based on this premise, we divided this dissertation into two chapters. The first chapter aimed to review the consumption of Neotropical Myrteae fruits by animals through a systematic literature search using the Web of Science, Scopus, and SciELO databases, as well as additional references cited in these studies. We found 324 sources of information. The research covered 18 countries from Mexico to southern South America, with a high concentration of studies in Brazil (188 out of 324; 58%). We recorded a total of 1,858 frugivory interactions, involving 200 Myrteae species and 292 frugivore species (152 bird species, 106 mammals, 17 fishes, 8 ants, 8 reptiles, and 1 crustacean). Of this total, 722 interactions were unique records between identified species (i.e., excluding duplicate records found in different studies and records where one or both species were unidentified at the species level). Approximately 40% of the studies recorded interactions involving Myrteae species with some level of taxonomic uncertainty (species or genus). The interactions occurred with at least 19 genera of Myrteae, with Eugenia being the most studied, appearing in 165 studies (51% of the total). This genus also had the most studied species, at least 65, and the most recorded interactions (541 in total, with 371 involving identified animal species). In the second chapter, we filtered the initial database for interactions where both plant and animal taxonomy were known at the species level and focused only on vertebrates (since interactions with ants and crustaceans are exceptions in the dispersal patterns of Myrteae). We then characterized the associations between fruit and seed traits and their frugivores, testing the hypothesis of seed dispersal syndromes and their impact on Myrteae speciation. From 225 studies, we found 1,019 interactions (697 unique) involving 254 vertebrate species and 163 Myrteae species. Primates consumed 79 Myrteae species (127 unique interactions), while birds consumed 42 species (221 unique interactions), with other vertebrates playing a lesser role in the group's dispersal. The majority of Myrteae species produced small, black fruits with a single seed, which were dispersed by all visiting groups, particularly birds. The second most important group of fruits included large, yellow, multi-seeded fruits, characteristic of the genera Psidium and Campomanesia, which were more frequently visited by primates. Other dispersal syndromes were unclear, with significant overlap in fruit and seed traits consumed by birds and mammals. Even when mammals were subdivided by order, dispersal syndromes were not evident in Myrteae. Additionally, we found a sampling bias in frugivory studies, with a high concentration of data from the Paraná domain region. To remove a potential biogeographic effect, network metrics were calculated only for this domain (105 Myrteae species, 139 animal species, 568 interactions, 422 unique interactions). The network exhibited modularity, but without an evident pattern associated with fruit functional traits or the animals consuming them. Few modules displayed notable characteristics, such as the absence of small fruits in module 1, exclusivity of mammals in module 5, and a predominance of birds and small fruits in modules 8 and 9. This lack of clear patterns was likely due to many interactions occurring with low frequency, obscuring the identification of more general patterns. Many important interactions occurred with primates, some of which acted as connector species and module hubs, including endangered species such as Brachyteles arachnoides, Leontopithecus caissara, and L. chrysopygus, highlighting their importance in maintaining natural forest regeneration in this province. In a scenario of high threats, these species would be the first to disappear, affecting the conservation of these environments. We also found a trend, although not significant, that lineages producing large and yellow fruits tend to have lower speciation rates. While lineages producing small, black fruits, consumed by all frugivore groups, exhibit more varied speciation rates, with only these lineages showing higher speciation rates within the Myrteae tribe. The database generated in this dissertation advances our knowledge of frugivory interactions in Myrteae in the Americas, identifies knowledge gaps, and suggests directions for future studies. Moreover, the analysis of the interaction network from a macroevolutionary perspective provided insights into how fruit selection by frugivores may have shaped the evolution and diversification patterns in plants.Master Thesis Diversidade de frutos em Myrtaceae: hipóteses ecológicas e evolutivas para o sucesso desta família neotrópico(Universidade Federal do Rio Grande do Norte, 2024-06-27) Cunha, Hercília Freitas da; Staggemeier, Vanessa Graziele; Vasconcelos, Thais Nogales da Costa; https://orcid.org/0000-0003-4911-9574; http://lattes.cnpq.br/4357034543526737; https://orcid.org/0000-0002-1152-5799; http://lattes.cnpq.br/3439479756280087; Vieira Filho, Edson Aparecido; Paterno, Gustavo Brant de CarvalhoFleshy fruits are the link between fauna and flora. They serve as a resource for fauna, while at the same time favouring the colonisation of plant species. Selective pressures in plant-animal interactions can shape fruit and seed characters and have the potential to explain current species diversity. In this dissertation, I used Myrtaceae, one of the most species-rich families in the tropics, as a model to test the effect of plant and fruit characters on the family's speciation rates. Thus, in chapter one I expanded the morphological database of Myrtaceae fruits and seeds, resulting in data for 956 species and adding new variables on display, plant height and life habit. Myrtaceae showed wide morphological variation, with large fruits with several small seeds or small fruits with few small seeds. Black colouring is present in half of the species in the database, occurring in 56.8%, followed by yellow (17.4%) and red (17.4%). Orange, green, brown and grey are less common in the fruits of the Myrteae tribe (8.4%). In chapter two, using the data from chapter one, I tested the relationship between fruit and seed size, seed number, fruit colour and plant height and quantified the influence of these characters on speciation rates in Neotropical Myrtaceae. Only fruit diameter was able to predict speciation rates, i.e. small fruit sizes have high speciation rates. Since fruit diameter is a limiting factor for dispersal, it is expected that this morphology will be selected over time, but contrary to expectations, the other traits are not associated with speciation in the Myrteae tribe, indicating that other abiotic and biotic factors shape current species diversity. In Chapter 3, I tested the visual-attractiveness hypothesis, which predicts that fruits at an intermediate stage of ripeness and with conspicuous colouring increase the attractiveness of the canopy and have an earlier germination capacity. The multicoloured display proved to be more attractive when removed than the unicoloured display, but germination was independent of the type of display of the species, i.e. the seeds were able to germinate at all stages of ripeness. The results found contribute to advancing the understanding of fruit and seed morphological patterns linked to dispersal and their role in the diversity of the Myrtaceae family.Master Thesis Avaliando a influência da diversidade e facilitação na disponibilidade de flores e frutos em comunidades arbóreas restauradas(Universidade Federal do Rio Grande do Norte, 2024-02-29) França, Niege Felix Caetano; Ganade, Gislene Maria da Silva; Fagundes, Marina Vergara; http://lattes.cnpq.br/4534506918968475; http://lattes.cnpq.br/3024078007563102; http://lattes.cnpq.br/1574387403489081; Silva, Andrea Leme Da; Antongiovanni , Marina; http://lattes.cnpq.br/6734509642838870Given the current state of degradation of the Caatinga Biome, ecological restoration strategies are of the utmost importance, not only to halt this degradation process, but also to restore the affected communities, making them stable and productive over time. Caatinga restoration programs that seek out new ecological restoration technologies have shown themselves to be promising alternatives for combating the desertification process. This study was carried out in a large-scale, long-term Caatinga restoration experiment (BrazilDry) implemented in 2016. This experiment is linked to the international Tree Div Net, which includes 29 experiments in 20 countries that test the influence of tree species diversity on the functioning of planted forests. The difference is that we have added the facilitation factor that influences the performance of restored plant communities and thus measured their potential in seasonally dry tropical forests. This study is divided into two chapters, both carried out in the BrazilDry Experiment, and aims to understand how diversity and facilitation mechanisms influence the flowering and fruiting patterns of restored communities. In the first chapter, the main objective is to test whether the diversity of tree plants in restored communities and their facilitation potential influence the number of reproductive individuals in the first 7 years of restoration, and thus answer: I - How many individuals and of which plant species in the restored communities have managed to reproduce in the last 7 years of restoration? II - Is there an effect of diversity and/or facilitation on the presence or absence of flowering and fruiting patterns? As a result, we observed that the diversity of trees planted did not influence the flowering capacity of the species. However, there was a positive effect of facilitation on the flowering capacity of species in the first 7 years of restoration. Diversity and facilitation did not influence fruiting patterns. This may have been due to low rainfall causing many flowers to abort, as well as fruit abscission, which may also be produced in smaller quantities when under great water stress. The second chapter assesses how the diversity of species that make up the restored communities affects the phenophases of the species Piptadenia retusa, popularly known as jurema-branca, in terms of the quantity and synchronization of fruit, flower and leaf production by this species. With the specific objectives of: I - Test whether the diversity of trees in the restored community influences the number and timing of flower and fruit production by the P. retusa species, and which months produce these food resources for the fauna; II - Test whether the diversity of species in the restored tree communities influences the maximum production capacity of flowers, fruit and leaves produced by Piptadenia retusa over the course of a year. As a result, we observed flowering peaks in the wettest months between March and June, while fruiting also occurred in the first half of the dry season between June and November. The production of floral resources (buds and flowers) and seed production (ripe and immature fruit) differed not only in relation to the months, but also increased significantly with the increase in the diversity of trees making up the restored community. In terms of maximum production capacity expressed by the Fournier index, only the explanatory variable, time, had a significant influence. All the variables showed maximum production in the wetter months, with the exception of the production of ripe fruit, which occurred more intensely in the drier months. Leaf production was, on average, 75% of its production capacity in the wettest months, but still maintained 25% of its production capacity during the driest months. This work indicates that restoration models with the presence of nurse or facilitator species should be implemented, given the potential of these species to increase the reproductive capacity of neighboring trees The results also show that the diversity of trees planted in restoration programs can increase the reproductive capacity of some species, promoting the replacement of individuals in the community and the availability of food for the pollinator faunaMaster Thesis Características funcionais de sementes e estratégias de germinação em uma floresta tropical sazonalmente seca(Universidade Federal do Rio Grande do Norte, 2024-02-26) Rocha, Thomaz Gabriel Barros da; Ganade, Gislene Maria da Silva; Voigt, Eduardo Luiz; http://lattes.cnpq.br/3024078007563102; https://orcid.org/0000-0001-5684-8156; http://lattes.cnpq.br/4763391544397054; Staggemeier, Vanessa Graziele; Pinto, Leonardo Henrique TeixeiraIn seasonally dry tropical forests, water is a limiting resource for germination and plant growth. Therefore, dormancy, orthodoxy and storage of reserves represent functional traits that coordinate strategies of resistance to desiccation in seeds, and are crucial for ensuring the survival of species, especially during periods of water restriction. Combining this theoretical knowledge with restoration initiatives is the key to ensuring the successful restoration of these forests. This dissertation intends to understand the dynamics of investment in functional characteristics of seeds and how they affect the germination process in seasonally dry forests of the Caatinga. For this purpose, we used germination tests and quantified seed size, stored reserves and seed coat investment for 22 native tree species. In the first chapter, we aimed to answer how the occurrence of seed dormancy modulates germination strategies, and to propose suitable methodologies for seedling production. We found species that produce non-dormant seeds, physical and physiological dormant seeds, presenting two strategies for colonizing the environment that are influenced by the size of the seeds and the speed of germination. The species produce seeds that use dormancy or orthodoxy as strategies to distribute germination over time and tolerate the dry period in the seed banks. In the second chapter, we tested how the functional traits of seed protection and nutrition affect germination strategies. Trade-offs related to size, stored reserves, tegument and germination speed, coordinate acquisitive and conservative strategies to scape or tolerate the period of low water availability, generating a desynchrony in the recruitment period. In the acquisitive group, small seeds with few reserves invest in more seed coat as a form of protection and germinate fast. In the conservative group, large seeds invest in storing more reserves and germinate slowly. Therefore, this research provides an insight into the different strategies used by plants to produce seeds in the seasonally dry forests of Caatinga, ensuring the survival and colonization of this dry environment. In addition, we have contributed to methodological advances for ecological restoration, maximizing seedling production in the greenhouse.