AbstractsBiology & Animal Science

Tese de doutoramento, Biologia (Ecologia), Universidade de Lisboa, Faculdade de Ciências, 2012 Cork oak woodlands (montados) are agro-forestry-pastoral systems that, in general, conciliate social and economical value with a rich biodiversity, representing remarkable components of Mediterranean landscapes. The overall goal of this thesis was to investigate the effects on biodiversity of management practices widely used in montados. Passerine birds were used as models, since they are a prominent group in montados, occupy a broad diversity of ecological niches, and are strongly responsive to changes in the environment. Starting with management practices applied to trees, we investigated (1) the impact of cork extraction, and found that only birds that forage directly on cork are affected by this activity. Consequently, cork extraction is compatible with maintaining a rich bird community. We also analysed (2) the consequences of tree pruning and concluded that it does not have an effect on overall species diversity, although foliage-gleaning species tend to be considerably less abundant in recently-pruned areas. On a landscape scale, we assessed (3) the effect of the presence of fragments of olive groves and riparian vegetation in montados dominated landscapes, and found that it would be desirable to reverse the decline of such habitats. Finally (4) we manipulated the extension of riparian vegetation and olive groves using spatially-explicit modelling to generate future scenarios, and concluded that simple measures like protecting riparian habitats and traditional olive groves could have positive effects on birds of montados landscapes. Montados are threatened by an increasing number of factors that extend from the lack of natural regeneration, to pressure from the decreasing market share of cork bottle stoppers, which can lead to changes in their structure and thus threaten biodiversity. The results of this study are a contribution for a science based improvement of management practices of montados, aiming to preserve this system by facilitating the conciliation between economic exploitation and wildlife conservation. Os montados de sobro (Quercus suber) são sistemas de uso múltiplo agro-silvo-pastoril, que resultam da intervenção humana continuada sobre as florestas de carvalhos originais, sendo uma paisagem comum no Mediterrâneo. São assim sistemas geridos pelo Homem nos quais, dependendo da componente que se quer valorizar (agricultura, pastorícia ou floresta), podem ser aplicadas várias práticas de gestão, tanto à escala da árvore como à da paisagem. Os montados de sobro têm ainda a particularidade de muito do seu rendimento económico ser obtido através de uma prática sustentável que é aplicada directamente à árvore: a extracção da cortiça. Apesar do seu elevado valor económico, os montados são tradicionalmente sistemas de uso extensivo que conciliam desenvolvimento económico e social com conservação da natureza. Os montados de sobro são reconhecidos pelos elevados níveis de biodiversidade que suportam, sendo…