Effects of the urbanization gradient on amphibian assemblages in the far west of the Brazilian Amazon

Submitted by Weslei Santos (valteranweslei@yahoo.com.br) on 2021-03-18T19:43:17Z No. of bitstreams: 4 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) DISSERTA????O - Weslei V. dos Santos_vers??o final.pdf: 2182340 bytes, checksum: c66555257273b7877f2326f89b9e31ca (MD5) Carta encaminhamento.pdf: 139560 bytes, checksum: 316c0eda2072a4c666234ce0ecbdde16 (MD5) Ata de defesa Weslei Valteran dos Santos_cc (1).pdf: 2001129 bytes, checksum: e22f8435b85da87bd484b7a09f0675fd (MD5) Approved for entry into archive by PPGZOOL Zoologia (ppgzoo.ufam@gmail.com) on 2021-03-23T15:21:28Z (GMT) No. of bitstreams: 4 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) DISSERTA????O - Weslei V. dos Santos_vers??o final.pdf: 2182340 bytes, checksum: c66555257273b7877f2326f89b9e31ca (MD5) Carta encaminhamento.pdf: 139560 bytes, checksum: 316c0eda2072a4c666234ce0ecbdde16 (MD5) Ata de defesa Weslei Valteran dos Santos_cc (1).pdf: 2001129 bytes, checksum: e22f8435b85da87bd484b7a09f0675fd (MD5) Approved for entry into archive by Divis??o de Documenta????o/BC Biblioteca Central (ddbc@ufam.edu.br) on 2021-03-24T02:14:40Z (GMT) No. of bitstreams: 4 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) DISSERTA????O - Weslei V. dos Santos_vers??o final.pdf: 2182340 bytes, checksum: c66555257273b7877f2326f89b9e31ca (MD5) Carta encaminhamento.pdf: 139560 bytes, checksum: 316c0eda2072a4c666234ce0ecbdde16 (MD5) Ata de defesa Weslei Valteran dos Santos_cc (1).pdf: 2001129 bytes, checksum: e22f8435b85da87bd484b7a09f0675fd (MD5) Made available in DSpace on 2021-03-24T02:14:40Z (GMT). No. of bitstreams: 4 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) DISSERTA????O - Weslei V. dos Santos_vers??o final.pdf: 2182340 bytes, checksum: c66555257273b7877f2326f89b9e31ca (MD5) Carta encaminhamento.pdf: 139560 bytes, checksum: 316c0eda2072a4c666234ce0ecbdde16 (MD5) Ata de defesa Weslei Valteran dos Santos_cc (1).pdf: 2001129 bytes, checksum: e22f8435b85da87bd484b7a09f0675fd (MD5) Previous issue date: 2020-09-30 CNPQ - Conselho Nacional de Desenvolvimento Cient??fico e Tecnol??gico Urbanization promotes fragmentation and habitat quality degradation. Urban landscape variations can act as an environmental gradient influencing species composition, generating variations in the beta diversity of amphibian assemblages along this gradient. Were analyzed effects of local and landscape variables over richness, abundance and composition of anuran species, and whether beta diversity is promoted by the substitution or nestedness of species in 22 transects along a urban/forest gradient in the municipality of Tabatinga, in the extreme western of Brazilian Amazon. Were registered 52 species and 5.481 individuals belonging to nine amphibian families. Environments less disturbed by urbanization environments showed the highest richnesses, however, abundance had a pattern different to the expected for the gradient, with the most disturbed environments with the highest abundances of individuals. Beta diversity variation was promoted both by species substitution, with most of species with low abundance and few common species in all environments, as by nestedness, with a gradual loss of species along the gradient, indicating that all registered species at urban and periurban environments were a subset of the registered species at the rural environment. Two environmental variables of landscape (green area and distance from the river) influenced significatively the amphibian community structure along the urban/forest gradient, and for both variables, the species ordinations revealed a significantly nested pattern. Piecewise regression emphasize that, to preserve and conserve a higher species diversity and avoid the amphibian fauna homogenization in urban environments, is necessary to plan the maintenance of green areas as forest cover larger than 68 thousand m2 along urban landscape. A urbaniza????o promove a fragmenta????o e degrada????o da qualidade do habitat, e as varia????es na paisagem urbana podem atuar como um gradiente ambiental influenciando a composi????o de esp??cies, gerando varia????es na diversidade beta das assembleias de anf??bios ao longo desse gradiente. Foram analisados os efeitos de vari??veis locais e da paisagem sobre a riqueza, abund??ncia e a composi????o de esp??cies de anf??bios, e se a diversidade beta ?? promovida pela substitui????o ou aninhamento das esp??cies em 22 transectos ao longo de um gradiente urbano/florestal no munic??pio de Tabatinga, no extremo oeste da Amaz??nia brasileira. Foram registradas 52 esp??cies e 5.481 indiv??duos pertencentes a nove fam??lias de anf??bios. Os ambientes menos perturbados pela urbaniza????o apresentaram as maiores riquezas de esp??cies, entretanto, a abund??ncia teve um padr??o contr??rio ao esperado para o gradiente, tendo os ambientes mais perturbados as maiores abund??ncias de indiv??duos. A varia????o da diversidade beta foi promovida tanto pela substitui????o de esp??cies, com a maioria das esp??cies com baixa abund??ncia e com poucas esp??cies comuns em todos os ambientes, como pelo aninhamento, com uma perda gradual de esp??cies ao longo do gradiente, indicando que todas as esp??cies registradas nos ambientes urbano e periurbano eram um subconjunto das esp??cies registradas no ambiente rural. Duas vari??veis ambientais da paisagem (??rea verde e dist??ncia do rio) influenciaram significativamente a estrutura da comunidade de anf??bios ao longo do gradiente urbano/florestal, e para ambas vari??veis, as ordena????es de esp??cies revelaram um padr??o significativamente aninhado. As regress??es segmentadas enfatizam que, para preservar e conservar uma maior diversidade de esp??cies e evitar a homogeneiza????o da fauna de anf??bios em ambientes urbanos, ?? necess??rio planejar a manuten????o de ??reas verdes como cobertura florestais maiores que 68 mil m2 ao longo da paisagem urbana.