Metacomunidades de riachos ao longo de um gradiente de cobertura florestal: existem limiares de perda de diversidade funcional?

• Autor(a) principal: Inácio, Cezar Gonçalves [UNESP]
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/156044; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-08-24/000890130.pdf
• topic: Ecologia aquatica; Inseto aquatico; Biodiversidade - Conservação; Ecologia da paisagem; Habitat (Ecologia); Bacias hidrograficas; Microbacias Hidrográficas; Corumbataí, Rio, Bacia (SP)

A great number of empirical studies have modeled the loss of biodiversity as a function of natural vegetation loss in modified landscapes. This relationship in general is not linear, due to the combined effects of habitat reduction and isolation of patches. In aquatic environments reductions of forest cover of the hydrographic basin have been used as a proxy of habitat loss. In the present study we present a functional approach to the relationship between environment and community using functional traits of the order Ephemeroptera (Insecta), in a gradient of forest cover ranging from 15-50% of total cover within the basin. We tested if the same model usually found for species richness also describes the relationship with functional traits. Samples were collected in micro basins of the Corumbatai River basin (central region of São Paulo State). The selected traits were: feeding behavior; number of gills; shape of the gills; shape of the immature body; size of the immature body; size of the adult wings. With these data we were able to measure dissimilarity and functional diversity (Rao metric), and test which model best described the relationship. The model that best fitted our data was a linear model that showed a negative relationship between forest cover and functional diversity in the community. The model pointed to the necessity to interpret functional traits interacting with other dependent traits, and the importance of the local context to those kind of studies. Finally we propose a methodological approach aimed at enhancing the prediction power of studies with a functional approach avoiding mistaken biological interpretations. We also showed a relationship between stream pH and possible damage in the gills that may difficult metabolic activities of aquatic insects