Doutorado em Ecologia e Evolução (ICB)

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Navegando Doutorado em Ecologia e Evolução (ICB) por Por Unidade Acadêmica "Instituto de Ciências Biológicas - ICB (RMG)"

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    Modelo matemático para dinâmica de range sob uma ótica não linear
    (Universidade Federal de Goiás, 2023-07-17) Ferreira, Heury Sousa; Marco Junior, Paulo De; http://lattes.cnpq.br/2767494720646648; Marco Junior, Paulo De; Vieira, Ludgero Cardoso Galli; Petrene Junior, Miguel; Agelini, Ronaldo; Silva, Daniel de Brito Candido da
    This paper presents a model for the study of dynamic range built on mechanisms of spatiotemporal dynamics and nonlinear interaction of species. The approach proposes a reformulation of the principle of competitive exclusion (expanding it by adding the factor of overlap between the ranges of competing species), explores the weaknesses of the traditional model of Lotka-Volterra to the understanding of issues related to the invasion of species, shows that under circumstances of migration and the diffusion the range dynamics can be chaotic, and presents the derivation of an equation for estimating population size based on the degree of overlap of their range with the range of a species with which it interacts.
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    Projeções futuras de índice de vegetação e os efeitos das mudanças climáticas em regiões áridas e semiáridas
    (Universidade Federal de Goiás, 2019-02-28) Joner, Daiany Caroline; Loyola, Rafael Dias; http://lattes.cnpq.br/7649189080736923; Loyola, Rafael Dias; Nobre, Carlos Afonso; Faleiro, Frederico Augusto Martins Valtuille; Terribile, Levi Carina; Marco Júnior, Paulo De
    Uncertainties with the effects of climate change has increased the need for more studies in recent years. Some regions in the world are more vulnerable, such as arid and semiarid ecosystems whose future projections indicate an increase in the frequency of extreme climate events. Vegetation cover has a fundamental role in maintaining these environments for biodiversity and population. Generalize about the response to climate change of endemic species from arid and semiarid environments to climate change is difficult to make due to information gaps. In the first part, we generated climatic niche models of the vertebrate species of these ecosystems using the results in meta-analysis statistics to evaluate if there was any tendency. The 166 species used totaled 1660 results due to the combination of climate models and methods. Of these results, 37% indicated loss of favorable climate areas, 40.92% were inconclusive and 22.08% indicated a gain in favorable climate areas. The heterogeneity of the results as well as the inconclusive results indicates the influence of different methods used in niche modeling. Even so, there is a tendency at global level to reduce favorable climate areas for endemic vertebrates. In the second part, we considered the Normalized Difference Vegetation Index (NDVI) a proxy of the vegetal cover. We used the ARIMA time series model to design this variable for the future based on NDVI data between 2001 and 2017. The NDVI data are available every 16 days at 250m resolution. We converted into monthly data and 0.1° degree resolution. We used the Brazilian semiarid as model to project NDVI to the present, validate the results and subsequently to projected for the future (2050 and 2070). We obtained good results with of 0.7552 between the estimated and the observed. Pearson correlation values also varied between months, with January being the highest value (0.8887). The root mean square deviation (RMSE) values were also low, indicating good performance of the models. The observed differences between the months, lowest values of correlation and errors can be related to the presence of climatic anomalies as well as the effects of land use changes. The good performance indicates a great potential of use of the NDVI as proxy of vegetation cover, thus contributing in climate change research. The third part, we evaluated niche models of endemic vertebrates of the Brazilian semi-arid with the use of NDVI integrated with climatic variables. The five species studied lost favorable climatic areas with or without the use of NDVI. However, the frequency of the number of areas changes with the use of NDVI can indicate refuges for some species. Vegetation cover should be considered in biodiversity research investigating climate change. There is great potential for research into drought periods. These studies can provide important information both for the effects of biodiversity and population that depends on these natural resources for survival.
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    Efeitos espaciais e ambientais sobre diferentes medidas de diversidade beta em ecossistemas continentais
    (Universidade Federal de Goiás, 2023-10-30) Rezende, Breno Laio Medeiros de; Melo, Adriano Sanches; http://lattes.cnpq.br/4602365265261727; Melo, Adriano Sanches; Granzotti, Rafaela Vendrametto; Terribile, Levi Carina; Becker, Fernando Gertum; Teresa, Fabrício Barreto
    It has been many years since the term beta diversity has been the subject of discussion and application in Ecology studies, and apparently its methodological approaches and applications seems to be inexhaustible, as different measures of beta diversity have emerged over the years. The first chapter of this thesis is a systematic review in which I investigated whether the amplitude of environmental differences is responsible for influencing effect sizes in studies that assessed the relationship between beta dissimilarity and environmental variables in freshwater environments. According to the results obtained, the amplitude does not seem to influence effect sizes. In the second chapter I investigate whether dispersal costs effects in lotic metacommunities are responsible for determining the beta dissimilarity of fishes. The results revealed the influence of dispersal costs associated with distances between locations along rivers and streams for three basins, while dispersal costs represented by the combination of distances and channel slope were only observed in a single basin. Furthermore, for one of the river basins, the influence of dispersal costs was represented by mutual effects of the distance between locations and the total area of reservoirs formed by dams between locations. In the third chapter I investigate whether the latitudinal gradient is responsible for influencing the relationships between environmental differences and beta dissimilarity obtained in square cell format for the entire continent of America using records of distribution of terrestrial birds and mammals. Beta dissimilarity in both terrestrial birds and mammals was explained by environmental variables, but only the relationship between environmental differences and beta diversity of mammals appears to be influenced by latitudinal patterns.