Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-08-04T15:33:18Z No. of bitstreams: 1 2009 - Fl?vio Guerra Barroso.pdf: 2034037 bytes, checksum: 1635fb4534d6b8f1c27887b03f88ac56 (MD5) / Made available in DSpace on 2017-08-04T15:33:18Z (GMT). No. of bitstreams: 1 2009 - Fl?vio Guerra Barroso.pdf: 2034037 bytes, checksum: 1635fb4534d6b8f1c27887b03f88ac56 (MD5) Previous issue date: 2009-08-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico. CNPQ / The biological contamination by invasive alien species is considered one of the greatest threats to biodiversity worldwide. However, in Brazil the information on this subject are still scarce, especially regarding the occurrence, distribution and influence of alien species on native communities, mainly in protected areas. The objective of this study was to identify exotic plant species present in the intensive use zone of Serra dos ?rg?os National Park and determine their occurrence, distribution and influence on the native plant community. The study area is located in Teres?polis and concentrates on the barragem road, which cuts across the zone of intensive use. To determine the occurrence of exotic plant species were allocated, randomly, 30 plots of 10 x 10 m along the road, located at different distances in edge-interior gradient of forest in order to identify the penetration and distribution of these species in the forest. Individuals with circumference at breast height (cbh) above 8 cm were included in the sample. To characterize plant community, phytosociological parameters were calculated as basal area, density, frequency, dominance and rates of coverage and importance. For the herbaceous layer, sub-plots of 5 x 5 m plots were installed within the existing plots, and those sampled by the method of points. We found 1,274 individuals of shrub-tree layer, distributed in 53 families, and 362 individuals of the herbaceous layer, distributed in 15 families. Only two exotic species were sampled: Impatiens walleriana Hook. f. e Hedychium coronarium J. K?nig, both herbaceous. These species were restricted to plots of class A, with penetration less than 10 meters. Its distribution is aggregated and, in the plots, they were found only in low densities, but with high frequency, suggesting behavior of weeds. The presence of these species have no influence on the tree-shrub layer but in the herbaceous layer, values of richness and abundance showed a negative correlation in the presence of these exotic species. / A contamina??o biol?gica por esp?cies ex?ticas invasoras ? considerada uma das maiores amea?as ? biodiversidade mundial. No entanto, no Brasil as informa??es sobre este assunto ainda s?o escassas, principalmente em rela??o ? ocorr?ncia, distribui??o e influ?ncia de esp?cies ex?ticas sobre as comunidades nativas, especialmente em ?reas protegidas. O objetivo deste estudo foi identificar as esp?cies vegetais ex?ticas presentes em um trecho da zona de uso intensivo do Parque Nacional da Serra dos ?rg?os e determinar sua ocorr?ncia, distribui??o e influ?ncia sobre a comunidade vegetal nativa. A ?rea de estudo localiza-se na sede Teres?polis do parque e concentra-se na estrada da barragem, que corta toda a zona de uso intensivo. Para determinar a ocorr?ncia de esp?cies vegetais ex?ticas foram alocadas 30 parcelas de 10 x 10 m ao longo da estrada, situadas a diferentes dist?ncias no gradiente borda-interior de mata a fim de identificar a penetrabilidade e distribui??o dessas esp?cies na floresta. Indiv?duos arb?reos com CAP igual ou superior a 8 cm foram inclu?dos na amostragem. Para caracterizar comunidade vegetal foram calculados par?metros fitossociol?gicos como ?rea basal, densidade, freq??ncia, domin?ncia absolutas e relativas e os ?ndices de cobertura e import?ncia. Para o estrato herb?ceo, sub-parcelas de 5 x 5 m foram alocadas dentro das parcelas j? existentes, e os indiv?duos foram amostrados atrav?s do m?todo de pontos. Foram encontrados 1.274 indiv?duos do estrado arbustivo-arb?reo, distribu?dos em 53 fam?lias, e 362 indiv?duos do estrato herb?ceo, distribu?dos em 15 fam?lias. Apenas duas esp?cies ex?ticas foram amostradas: Impatiens walleriana Hook. f. e Hedychium coronarium J. K?nig, ambas herb?ceas. Essas esp?cies estavam restritas as parcelas da classe A, com penetrabilidade inferior a 10 metros. Sua distribui??o ? agregada e, nas parcelas, elas foram encontradas somente em baixas densidades, por?m com alta freq??ncia, sugerindo um comportamento invasor. A presen?a dessas esp?cies parece n?o exercer influ?ncia sobre o estrato arbustivo-arb?reo por?m, no estrato herb?ceo, valores de riqueza e abund?ncia apresentam uma correla??o negativa quanto a presen?a dessas esp?cies ex?ticas.