Dinâmica populacional de plântulas de Rhizophora mangle L. no Sudeste do Brasil

• Autor(a) principal: Lima, Karen Otoni de Oliveira
• Data de Publicação: 2018
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/10663
• topic: Mangrove; Models; Life table; Cohorts and growth; Modelos; Tabela de vida; Coortes e crescimento; Ciências Ambientais; Plantas do manguezal - Brasil, Sudeste; Red mangrove - Crescimento; Plantas - População; 55

The analysis of the growth pattern and the knowledge of the population dynamics of seedlings are used as subsidies for the ecological understanding of mangroves. This thesis aimed to select and compare regression models that best describe the growth curves of Rhizophora mangle seedlings based on the variables: height (cm) and time (days) and to understand their population dynamics. Three plots were established in fringe mangrove forests in the Itaúnas river, located in the South Atlantic (Conceição da Barra, Espírito Santo). The present seedlings and the new recruits were tagged and monitored between 2008 and 2014. The Linear, Exponential, Power Law, Monomolecular, Logistic and Gompertz models were adjusted with non-linear formulations and minimization of the sum of the squares of the residues. The Monomolecular, Logistic of 3 parameters and Gompertz models presented the best performance to describe the growth of the seedlings, becoming the best options for the long-term studies. The different curves reflect the complexity of stem growth at this stage for species. The analysis of the joint distribution of the parameters (H0, r and K) allowed the study of the ecological attributes and allowed to observe their variability among the individuals in each model. Population dynamics were evaluated by constructing the life table of the annual cohorts and adjusting the Exponential model for the survival data. The results showed variability in recruitment and high mortality rates in the first two years of all cohorts. They showed Type III survival curve, corresponding to an exponential decay function and evidencing the mortality pattern at the seedling stage regardless of the evaluated temporal scale and the forest structure in which they are submitted. The values of b, slope of the curves, of the cohorts were different showing that the intensity in the decline of the number of seedlings varies between generations. The results presented reinforce the importance of long-term studies in mangroves and how seedling growth and cohort survival are variable over time, where few individuals can effectively reach the young stage. On the other hand, these characteristics reinforce the resilience of the ecosystem.