Browsing by Author "Oliveira, A.C."
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- An approach to cork oak forest management planning: a case study in southwestern PortugalPublication . Costa, A.; Oliveira, A.C.; Vidas, F.; Borges, J.G.This paper presents results of research aiming at the development of tools that may enhance cork oak (Quercus suber L.) forest management planning. Specifically, it proposes an hierarchical approach that encompasses the spatial classification of a cork oak forest and the temporal scheduling of cork harvests. The use of both geographical information systems and operations research techniques is addressed. Emphasis is on the achievement of cork even flow objectives. Results from an application to a case study in the Charneca Plioce´nica of Ribatejo in southern Portugal encompassing a cork oak forest extending over 4.8 thousand ha are discussed. They suggest that the proposed approach is capable of effective spatial classification of cork oak management units. They further suggest that it may be used to select optimal cork even flow scheduling strategies. Results also show that the proposed approach may lead to a substantial increase in net present value when compared to traditional approaches to cork oak forest management planning.
- Regeneration in multi-species in Serra da LousãPublication . Gonçalves, A.C.; Oliveira, A.C.Stand regeneration is one of the most important aspects of silviculture as it ensures stand and production perpetuity. Regeneration occurs after one or several disturbances releasing growing space, usually after the elimination of some adult trees. In Northern and Central Portugal many maritime pine old growth stands have natural regeneration of several broadleaved species, in particular sweet chestnut and English oak. In multi-species stands regeneration and recruitment analysis should consider both density and diversity measures. A series of permanent plots established in Serra da Lousã made it possible to characterise the existing natural regeneration and its evolution with two successive measurements in 2001 and 2009. All individuals with a diameter at breast height equal or less than 5 cm were considered as regeneration. Their recruitment was evaluated in 2009 and analysed as a function of absolute stand density measures and seven diversity indices. The results revealed that recruitment rate was high and that there was a trend towards a balance in terms of species and their proportions, while maintaining a tendency towards clustering and segregation according to the Clark and Evans and the Pielou indices, respectively