Herpetofauna de fragmentos florestais do município de São Paulo
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Data
2020-10-29
Autores
Torello-Viera, Natália Ferreira
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A Floresta Atlântica é considerada um hotspot mundial, devido à sua riqueza de espécies, elevado número de endemismos e elevado grau de ameaça. Estima-se que restam de 11,4 a 16% de cobertura do bioma, devido, principalmente, à agricultura e expansão urbana, tendo sido reduzida a arquipélagos de fragmentos florestais. Tais áreas tornam-se mais homogêneas, alterando as dinâmicas ecológicas e impactando a biodiversidade local. O município de São Paulo, localizado na região sudeste do Brasil, está inserido no bioma da Mata Atlântica, sofreu intensa fragmentação e é um bom exemplo de ambiente em que ocorrem mudanças ecológicas. Anfíbios e répteis são considerados grupos de grande importância como indicadores de mudanças ambientais, devido à sua reduzida mobilidade, alta especificidade de hábitats e grandes exigências fisiológicas, sendo bons modelos de estudos em fragmentos florestais. Neste estudo, três fragmentos florestais da região metropolitana de São Paulo, de diferentes tamanhos e graus de isolamento, foram amostrados quanto á diversidade de herpetofauna. Além disso, a variação morfológica e o uso do habitat entre duas populações de Enyalius perditus (Squamata: Leiosauridae) foram analisados, também sob a perspectiva de tamanho e conectividade do fragmento florestal. A hipótese principal é de que o tamanho e conectividade destes fragmentos impacta a diversidade da herpetofauna, bem como a maneira como uma espécie de lagarto abundante utiliza o ambiente disponível. O Parque Estadual Serra da Canteira (PEC), o maior fragmento amostrado, abriga considerável 39 espécies de anfíbios e 28 de répteis. No fragmento intermediário, o Parque Estadual das Fontes do Ipiranga (PEFI), foram 26 e 23 espécies registradas de anfíbios e répteis, respectivamente. Por fim, no menor fragmento, Parque da Previdência (PP), 4 espécies de anfíbios e 9 espécies de répteis foram registradas. A extensa área de Mata Atlântica que cobre o PEFI, e principalmente o PEC, mantém a diversidade de guildas ecológicas dos grupos. Contudo, a riqueza e diversidade de guildas do PP são fortemente reduzidas. Em relação à ecologia de E. perditus, a morfologia e o uso do ambiente variaram entre sexos e populações. As variações ocorreram principalmente entre machos alopátricos, sendo que os do PEC apresentaram pernas e antebraços mais longos e exploraram mais o ambiente arbóreo quando comparados à população do PEFI. Tais aspectos parecem refletir as pressões de seleção natural e sexual que as populações estão submetidas. Ademais, estrutura da vegetação do PEC parece exercer influência na morfologia do grupo mais arborícola. De maneira geral, o tamanho e a conectividade dos fragmentos influenciaram na herpetofauna das áreas amostradas, tanto no nível de comunidades quanto de populações. A fragmentação teve impacto principalmente nos anfíbios, porém lagartos parecem ser mais resilientes nas áreas amostradas, e algumas espécies podem se adaptar às diferentes pressões. Novos levantamentos de riqueza e diversidade de herpetofauna nesses e em outros fragmentos de Mata Atlântica podem contribuir grandemente para o esclarecimento do papel dessas áreas na manutenção da biodiversidade.
The Atlantic Forest is considered a global hotspot for conservation, due to its species richness, high number of endemic species and high human threat. It is estimated that only 11.4 to 16% of its original cover still remains, mainly due to agriculture and urban sprawl, having been reduced to archipelagos of forest fragments. Such areas become more homogeneous, resulting in changes in their ecological dynamics, ultimately impacting their local biodiversity. São Paulo municipality, which is located at southeastern Brazil, is inserted at the Atlantic Forest biome, and has undergone intense fragmentation, being a clear example of an impacted environment. Amphibians and reptiles are important indicators of environmental changes, due to their reduced mobility, high habitat specificity and physiological requirements, being model organisms for forest fragmentation studies. In this study, three forest fragments at the metropolitan region of São Paulo, with different sizes and degrees of isolation, had their herpetofauna sampled. In addition, morphological variation and habitat usage between two populations of Enyalius perditus (Squamata: Leiosauridae) were analyzed, also from a forest fragmentation perspective. The main hypothesis is that the size and connectivity of these fragments impact their herpetofauna diversity, as well as how an abundant lizard uses the available environment. At Serra da Canteira State Park (PEC), the largest sampled fragment, 39 species of amphibians and 28 reptiles were recorded. In the intermediate fragment, Fontes do Ipiranga State Park (PEFI), 26 and 23 species of amphibians and reptiles, were recorded respectively. Finally, in the smallest fragment, Parque da Previdência (PP), 4 species of amphibians and 9 species of reptiles were recorded. The extensive Atlantic Forest area that covers PEFI, and especially PEC, manage to maintain their ecological guilds diversity. However, richness and guild diversity at PP are largely reduced. Regarding the ecology of E. perditus, its morphology and environment use varied between genders and populations. The variations occurred mainly among allopatric males, and those from PEC presented longer legs and forearms, and explored trees more often, when compared to those from PEFI. These aspects seem to reflect the natural and sexual selection pressures those populations are subjected to. Moreover, vegetation structure at PEC seems to influence morphology of the most arboreal group. In general, size and fragments connectivity influenced their herpetofauna, both at the community and population levels. Fragmentation has had an impact mainly on amphibians, but lizards seem to be more resilient in the sampled areas, and some species may adapt to different pressures. New surveys focusing on herpetofaunal richness and diversity at those and other fragments at the Atlantic Forest can greatly contribute to clarify the role of these areas in maintaining its biodiversity.
The Atlantic Forest is considered a global hotspot for conservation, due to its species richness, high number of endemic species and high human threat. It is estimated that only 11.4 to 16% of its original cover still remains, mainly due to agriculture and urban sprawl, having been reduced to archipelagos of forest fragments. Such areas become more homogeneous, resulting in changes in their ecological dynamics, ultimately impacting their local biodiversity. São Paulo municipality, which is located at southeastern Brazil, is inserted at the Atlantic Forest biome, and has undergone intense fragmentation, being a clear example of an impacted environment. Amphibians and reptiles are important indicators of environmental changes, due to their reduced mobility, high habitat specificity and physiological requirements, being model organisms for forest fragmentation studies. In this study, three forest fragments at the metropolitan region of São Paulo, with different sizes and degrees of isolation, had their herpetofauna sampled. In addition, morphological variation and habitat usage between two populations of Enyalius perditus (Squamata: Leiosauridae) were analyzed, also from a forest fragmentation perspective. The main hypothesis is that the size and connectivity of these fragments impact their herpetofauna diversity, as well as how an abundant lizard uses the available environment. At Serra da Canteira State Park (PEC), the largest sampled fragment, 39 species of amphibians and 28 reptiles were recorded. In the intermediate fragment, Fontes do Ipiranga State Park (PEFI), 26 and 23 species of amphibians and reptiles, were recorded respectively. Finally, in the smallest fragment, Parque da Previdência (PP), 4 species of amphibians and 9 species of reptiles were recorded. The extensive Atlantic Forest area that covers PEFI, and especially PEC, manage to maintain their ecological guilds diversity. However, richness and guild diversity at PP are largely reduced. Regarding the ecology of E. perditus, its morphology and environment use varied between genders and populations. The variations occurred mainly among allopatric males, and those from PEC presented longer legs and forearms, and explored trees more often, when compared to those from PEFI. These aspects seem to reflect the natural and sexual selection pressures those populations are subjected to. Moreover, vegetation structure at PEC seems to influence morphology of the most arboreal group. In general, size and fragments connectivity influenced their herpetofauna, both at the community and population levels. Fragmentation has had an impact mainly on amphibians, but lizards seem to be more resilient in the sampled areas, and some species may adapt to different pressures. New surveys focusing on herpetofaunal richness and diversity at those and other fragments at the Atlantic Forest can greatly contribute to clarify the role of these areas in maintaining its biodiversity.
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Palavras-chave
Herpetofauna, Fragmentação, Mata atlântica, Comunidades, Populações, Herpetofauna, Fragmentation, Atlantic forest, Communities, Populations