Mammal choices in heterogeneous landscape of the Baixo Vouga Lagunar

• Autor(a) principal: Marques, Sara Isabel Ferreira
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/13762
• topic: Gestão de ecossistemas; Mamíferos - Baixo Vouga (Portugal); Zonas húmidas

The relation between landscape structure and species distribution is a major question in landscape ecology. Terrestrial mammals are particularly susceptible to the spatial features, such as habitat type and landscape complexity, as well as to resource availability (e.g. shelter and food supply). The main objective of this thesis was to describe and understand the patterns of terrestrial non-volant mammal species richness, distribution and abundance in the heterogeneous landscape of Baixo Vouga Lagunar, north-western Portugal. Thus, small mammals and carnivores were sampled using three different strategies: a capture programme focused on small mammals (Rodentia and Eulipotyphla), and sign surveys and camera trapping for carnivores. In general, wetland habitats, such as reed beds, rushes and marshlands, seemed to favour small mammal fauna, being reed bed the habitat with the highest values of diversity. Furthermore, carnivore richness appeared to be favoured by the length of freshwater lines, and consequently by the associated riparian vegetation. Contrary, exotic forest was negatively related to both small mammal fauna and carnivore richness, and presented the lowest small mammal diversity. Overall, carnivore richness was mainly driven by landscape features, rather than by human influence and prey availability, or a combination of them. Surprisingly, prey availability seemed not to influence carnivore richness, probably as a consequence of a spatiallly wide availability of small mammals through the landscape matrix. Although at a fine-scale of the landscape, heterogeneity did not seem to influence the abundance of small mammals, at a broad-scale, the landscape matrix seems to promote small mammal diversity, since species distribution fluctuated throughout the patchy landscape. Contrasting, carnivore richness was negatively influenced by landscape heterogeneity and fragmentation, since the landscape is mainly composed by open habitats. Overall, the main findings of this study support the importance of hedgerow habitats (e.g. riparian gallery) to carnivore assemblage by providing water, shelter and enhancing landscape connectivity, and of wetland habitats for small mammal community. Furthermore, the results obtained revealed the reduced biological value of monocultures, especially forests of exotic species. This study reinforces the importance of the Baixo Vouga Lagunar region to wildlife and provides crucial information to develop adequate management and conservation guidelines.