Estrutura e diversidade de comunidades e de populações vegetais em floresta atlântica de tabuleiros

• Ano de defesa: 2010
• Autor(a) principal: Soares, Michellia Pereira
• Orientador(a): Meira Neto, João Augusto Alves
• Banca de defesa: Saporetti Junior, Amilcar Walter , Souza, Agostinho Lopes de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Botânica
• Departamento: Botânica estrutural; Ecologia e Sistemática
• País: BR
• Palavras-chave em Português: Fitossociologia; Florística; Diversidade genética
• Palavras-chave em Inglês: Phytosociological; Floristic; Genetic diversity
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BOTANICA
• Link de acesso: http://locus.ufv.br/handle/123456789/363

Measure the diversity of species is fundamental for ecological research and biodiversity conservation. This measure is not restricted only to count or measure of species richness should be taken into account that biodiversity consists of several levels of biological organization including ecosystems, species and their genes. There is a very limited knowledge about the relationship between species richness and genetic variability. Thus, the following hypothesis has been raised: in the communities with great diversity and best preserved (unless altered by disturbances and structured over time) the genetic diversity of plant populations is different those communities less diverse in species and more altered by disturbances. The present study aimed: 1) determine and compare the diversity of three areas in the Tabuleiros Forest located in south Bahia and north Espírito Santo, 2) evaluate the genetic diversity of two plant species occurring simultaneously in three communities, 3) check the relationship between the degree of communities conservation and genetic variation of the species. The vegetation were sampling by contiguous plots method. In each fragment were installed 50 plots of 10 x 10 m. All individuals were measured and marked when presented length breast height (LBH) ≥10 cm. The identified species were grouped into successional categories. The structural analysis was performed by phytosociological parameters and distribution of individuals by diameter class. To compare these three areas were used estimators of richness, rarefaction of species-area curve and indices of biodiversity. Analysis of genetic diversity was done with the ISSR molecularmarker. In phytosociological surveys the area with the greatest number of species was Juerana (233), followed by Braço do Rio (193) and Mucuri (145). In the three fragments were observed 27 species listed as endangered and nine endemic to the region. Most of the species are representatives of groups advanced succession (early secondary and late), especially of the final steps. The pioneer species represent a minimum percentage, being more pronounced in Mucuri and lowest in Juerana. Individuals were distributed in diameter classes ranging from 3 to 173 cm. In the Forest of Mucuri the largest class was 88-93 cm, Braço do Rio of 98-103 cm and Juerana was the only area that had individuals assigned to the class of 168-173 cm. The values of intercept and slope of the species-area curve is no statistical difference between the three communities on alpha diversity. The beta diversity is different for Juerana and Braço do Rio, while for Mucuri that diversity is the same as the other two areas. According to the Shannon index, Braço do Rio and Juerana no significant differences in diversity, only Mucuri differs from the two areas. For the diversity index of Simpson three areas are totally different. The molecular variance analysis (MOVA) showed that the highest percentage of genetic variation occurred within populations for both species Astrocaryum aculeatissimum and Carpotroche brasiliensis. To Astrocaryum aculeatissimum revealed a consistent group of individuals from Braço do Rio, forming an isolated group. Individuals of Juerana and Mucuri share a greater genetic similarity. In Carpotroche brasiliensis was also shown a greater genetic similarity between individuals collected from Braço do Rio, however, these individuals share certain similarities with others from Juerana and Mucuri not establishing themselves as a single group. The results showed that Jureana fragment presented greater diversity and appear as a mature forest. Braço do Rio is in an advanced process of succession and Mucuri was the fragment with the lowest diversity and less advanced successionaly. The results for the genetic diversity rejected the hypothesis because there was no relationship between community and genetic diversity of populations. Fragments at different stages of succession have the same potential for genetic conservation of their species than areas of mature forest.