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Universidade de Aveiro (2008)

Avaliação do impacto de métodos florestais e de seca severa na população de coelho-bravo na mata nacional de Quiaios

Morgado, Rui Guilherme da Costa

Titre : Avaliação do impacto de métodos florestais e de seca severa na população de coelho-bravo na mata nacional de Quiaios

Auteur : Morgado, Rui Guilherme da Costa

Université de soutenance : Universidade de Aveiro

Grade : Mestrado em Ecologia, Biodiversidade e Gestão de Ecossistemas 2008

Résumé
The determinant role in trophic chain, makes wild rabbit (Oryctolagus cuniculus) a key species of Iberian ecosystems, being the main prey to a large number of predators, some of which of great conservation value. This factor confers a higher relevance to its marked decline observed on the majority of mediterranic ecosystems, caused by habitat loss and fragmentation, and diseases, predation and high hunting pressure. This work aimed to study and characterize the wild rabbit population dynamics in Quiaios National Forest, a coastal forest in the centre of Portugal included in a Natura 2000 network site. It was intended to study, in one hand, the impact of forest practices, such as activities of preventive forestry against the advance of invading species, and, in other hand, the impact of a severe drought on populations. Wild rabbit populations were monitorized twice a year, Summer and Winter, in predefined areas. Summer 2002 was the first studied season and Winter 2008 was the last. The determination of wild rabbit abundances was carried on through latrine counts along the sampling transects. Several biotopes were defined : (i) dense scrublands ; (ii) scrublands with low densities of Acacia longifolia ; (iii) scrublands with high densities of Acacia longifolia ; (iv) the 2005 intervention area ; (v) the 2006 intervention area ; (vi) sparse pine forest ; (vii) dense pine forest ; (viii) dune. The results confirm the effect of interventions suggesting, however, a differentiated impact depending on the applied methodology. The 2005 intervention was more aggressive provoking a higher mortality rate, while the 2006 intervention only cause the area abandonment. Concerning drought effects, results also point toward to an impact in populations given the strong reductions observed in its abundance, coincident to that period. However, it has to be referred that this impact showed to depend on the biotope, because in some of them, like dune and scrublands with high densities of Acacia longifolia, decreases in species abundance wasn’t detected. This fact is, probably, related with the dominant vegetation type of those areas, adapted to dry environments, with lower effects on the rabbit’s food availability. This work showed a how a wild rabbit monitorization, using simple and economical methodologies, can provide reliable and comparable results that may constitute an important contribute to a sustainable management of Iberian forest areas.

Mots clés : Gestão de ecossistemas ; Gestão florestal ; Coelhos ; Habitats

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Page publiée le 22 octobre 2013, mise à jour le 23 août 2018