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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Efeitos da perda de habitat sobre a comunidade de aves de uma floresta estacional seca do Brasil

Melo, Vanicl?zia de Andrade 31 January 2013 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-04-01T22:28:22Z No. of bitstreams: 1 Disserta??o Vanicl?zia de Andrade Melo.pdf: 1015149 bytes, checksum: f174db068eeaabe1f7c9615543e4f0a6 (MD5) / Made available in DSpace on 2016-04-01T22:28:22Z (GMT). No. of bitstreams: 1 Disserta??o Vanicl?zia de Andrade Melo.pdf: 1015149 bytes, checksum: f174db068eeaabe1f7c9615543e4f0a6 (MD5) Previous issue date: 2013-01-31 / Birds are considered sensitive to human disturbance because they have a close relationship with the environmental conditions. In the caatinga, modification of habitat ocurred by a historical process of environmental deterioration as a result of unsustainable use of natural resources. Due to the extreme climatic conditions of the caatinga, it is expected that a more resilient biota survives in this vegetation under to human interventions than those in more stable environments, such as tropical rainforests. Thus, the present study aimed to investigate the effects of habitat loss on a bird community of caatinga area type seasonal dry forest in the municipality of Candiba, Bahia, Brazil, comparing avifaunas occurring in an area of remnant forest (Area I) with adjacent matrix cleared of area (Area II). Six expeditions were conducted, three in the dry season and three in the rainy season, between November 2011 and July 2012. The method of Mackinnon lists was used for recording auditory and visual species. It was recorded 138 species, 92 in the Area I and 94 in the Area II. Both areas showed a low similarity (38%) between their specific compositions, demonstrating that only a small portion of the bird community in the region occurs in both habitat types, tolerating the different states of preservation. Regarding the trophic structure, insectivorous species predominated in both areas, with emphasis on the occurrence species of more specialized habits in only Area I, indicating that they are intolerant to habitat loss. In Area II, were representative species of bird generalist habits, such as granivorous and omnivorous, they seem to benefit from the replacement of native forests by agricultural lands. Although bird species of high sensitivity and forest dependents represented the minority, such species were directly affected by habitat change, since many of them were not recorded in the cleared matrix. Thus, habitat loss is a process that leads to negative effects on the bird community of seasonal dry forest, especially in species composition, which changes as the forest vegetation is removed. / As aves s?o consideradas sens?veis a perturba??es por apresentarem uma estreita rela??o com as condi??es em que o ambiente se encontra. Na catinga, a modifica??o do habitat tem se dado por um hist?rico processo de deteriora??o ambiental, em decorr?ncia do uso insustent?vel dos seus recursos naturais. Em fun??o das condi??es clim?ticas extremas da caatinga, espera-se que nesta vegeta??o sobrevivam biotas mais resilientes a interven??es humanas do que aquelas de ambientes mais est?veis, como as florestas tropicais ?midas. Deste modo, o presente estudo objetivou investigar os efeitos da perda de h?bitat sobre uma comunidade de aves de ?rea de caatinga do tipo floresta estacional seca, no munic?pio de Candiba, Bahia, Brasil, comparando as avifaunas ocorrentes em uma ?rea de remanescente florestal (?rea I) com a da matriz desmatada adjacente (?rea II). Foram realizadas seis expedi??es, tr?s na esta??o seca e tr?s na chuvosa, entre novembro de 2011 e julho de 2012. O m?todo de listas de Mackinnon foi utilizado para o registro auditivo e visual das esp?cies. Foram listadas 138 esp?cies, sendo 92 na ?rea I e 94 na ?rea II. As duas ?reas apresentaram uma baixa similaridade (38%) entre suas composi??es espec?ficas, demonstrando que apenas uma pequena por??o da comunidade de aves da regi?o em ambos os tipos de habitat, tolerando os distintos estados de conserva??o dos mesmos. Quanto ? estrutura tr?fica, as aves inset?voras predominaram tanto na ?rea I como na ?rea II, com destaque para ocorr?ncia de esp?cies de h?bitos mais especializados somente na ?rea I, indicando que s?o intolerantes ? modifica??o de seu habitat. Na ?rea II, foram representativas as esp?cies de aves h?bitos mais generalistas, como as gran?voras e on?voras, que parecem se beneficiar da substitui??o de florestas nativas por ?reas de cultivo agr?cola. Ainda que as esp?cies de aves de alta sensibilidade e dependentes florestais representaram a minoria, tais esp?cies foram diretamente afetadas pela altera??o do habitat, uma vez que muitas delas n?o foram registradas na matriz desmatada. Deste modo, a modifica??o do habitat se mostra como um processo que acarreta em efeitos negativos sobre a comunidade de aves de caatinga arb?rea, sobretudo na composi??o das esp?cies, que ? alterada ? medida que a vegeta??o florestal ? substitu?da por ?reas agr?colas.

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