Mestrado em Ecologia e Evolução (ICB)
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Item No limiar tênue entre teoria e realidade, sazonalidade e caos em sistemas planctônicos(Universidade Federal de Goiás, 2009-02-26) Ferreira, Heury Sousa; Marco Júnior, Paulo De; http://lattes.cnpq.br/2767494720646648; Marco Júnior, Paulo De; Diniz Filho, José Alexandre Felizola; Silva, Daniel Brito Candido daThe Chaos Theory is an alternative tool to stochastic dynamic modeling when target biological systems show irregular and no predictive behavior. The plankton is a model group of organisms to theoretical and experimental investigations in chaotic dynamics due to its intrinsic biological characteristics as small size, high reproductive rate and short life cycle, with the additional advantage of its public interest related to practical problems. In this work we investigated the dynamical aspects of a NutrientPhytoplankton-Zooplankton seasonal forced model, created by means of the addition of the Zooplankton level on a Nutrient-Phytoplankton seasonal forced model that show chaotic behavior, proposed by Huppert et al. (2005). An important outcome of the Huppert’s model is that the intensity of the seasonal forcing is the control parameter of the system. We investigated the zooplankton effect on the stability of the model, and the chaos control by means of pulses in the intensity of the seasonal forcing. Our results show that strong and weak seasonal forcing implicates in cyclical fluctuations of phytoplankton populations, and those cycles had higher amplitude in strong seasonal forcing. Between those two extremes, there is chaos. The zooplankton mortality is a fundamental component of the behavior of the model. In fact, despite of seasonal forcing values that can promote chaotic behavior, the model can show cyclic behavior to some values of mortality rates. This suggests that absence of top-down control in the models built to understand phytoplanktonic dynamics (blooms are only a consequence of this), result in an over-simplification and lack of conceptual comprehension of the system. Our results show that periodic pulses can be able to control the chaos on moderate seasonal forcing, and to promote chaos to weak and strong seasonal effects. The pulses are theoretical indicatives of how climatic changes influences a seasonal variable can to affect the dynamics aspects of planktonic systems.Item Impacto das cinzas de queimadas no ambiente aquático e na comunidade fitoplanctônica(Universidade Federal de Goiás, 2023-07-28) Jesus, Gabriel Sampaio de; Nabout, João Carlos; http://lattes.cnpq.br/3335844675689429; Bortolini, Jascieli Carla; http://lattes.cnpq.br/5475113165248615; Bortolini, Jascieli Carla; Carneiro, Fernanda Melo; Carvalho, Priscilla deAmong the main threats to biodiversity are anthropic fires, a joint event, especially during the dry period. However, studies on the indirect effects of fires on aquatic ecosystems are scarce. In this study, we investigated how water quality and phytoplankton community structure might be affected by ash from fires in the Brazilian Cerrado. We used a microcosm experiment to simulate the aquatic environment with different scenarios of ash concentrations, and we evaluated over time the abiotic conditions, composition, richness, and phytoplankton density. We detected an increase in total phosphorus ammoniacal nitrogen concentrations after ash insertion. Regarding the phytoplankton community, we identified changes in composition as a function of time, and we did not recognize changes in richness and density in response to treatment. Our results indicate that ash from fires in the terrestrial environment can affect water quality and the species composition of aquatic communities. However, we suggest longer-duration experiments to evaluate the phytoplankton community's delayed responses.Item Áreas prioritárias para restauração no estado de Goiás(Universidade Federal de Goiás, 2020-07-03) Silva, Thalline Rodrigues da; Loyola, Rafael Dias; http://lattes.cnpq.br/7649189080736923; Loyola, Rafael Dias; Diniz Filho, José Alexandre Felizola; Brum, Fernanda ThiesenIn parallel with strategies and actions focused on the conservation of biodiversity, scientists, decisionmakers, and different sectors of our society have been developing on strategies focused on the restoration of degraded areas. This is a particularly important issue for Brazil as signatory to the Paris Agreement, in which the Brazilian government is committed to restoring 12 million hectares of degraded areas by 2030. Such restoration will be regionalized, and the states of Brazil will need to indicate their priorities, strategies and tools to accomplish such task. Here, we identified priority areas for restoration in the state of Goiás in order to build scenarios in which the retention of soil carbon stock is maximized, as well as the representation of plant species, while seeking the lowest cost of opportunity to perform this restoration on rural landowners. We ran prioritizations following the principles of systematic conservation planning. We also considered the environmental debt within rural properties and, based on that, we evaluated all types of agricultural culture found on the properties to generate opportunity costs associated with restoration. After analyzing 166,635 rural properties across the state, we found a total debt of approximately 1,682,804.1330 hectares within properties’ Legal Reserve. We also observed that most rural properties that should be restored have an opportunity cost below R$5,000. In all prioritization scenarios, areas to the east and northeast of the state of Goiás were considered as priority. Our best restoration scenario captured ~35% of the state's entire carbon stock, nearly 70% (on average) of the distribution of endangered plant species included in the study and a reduction in opportunity cost of more than 70%. Systematic planning for restoration, as proposed here, if carried out in an organized and accountable way, can maximize the connectivity of protected areas within rural properties, bringing greater protection of species and guarantee of the provision of ecosystem services.