Browsing by Author "Freitas, Helena"
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- Avaliação ambiental estratégica do programa de desenvolvimento rural de Portugal 2007-2013: ContinentePublication . Domingos, Tiago; Rosas, Cátia; Teixeira, Ricardo Miguel Sampaio; Aguiar, Carlos; Calouro, Fátima; Borges, José C.; Belo, C. Carmona; Domingos, José J.D.; Ferreira, Teresa; Freitas, Helena; Magalhães, Manuela Raposo; Ribeiro, Luis; Malcata, Francisco X.O Programa de Desenvolvimento Rural (PDR) 2007-2013 estabelece o conjunto de medidas, e dentro de cada uma destas as acções e subacções, conducentes ao cumprimento dos objectivos estabelecidos pelo Plano Estratégico Nacional (PEN) de Desenvolvimento Rural 2007-2013. O PEN surge num momento em que a situação do mundo rural português tem apresentado melhorias em termos de bem-estar social, mas ainda assim com perda de competitividade económica local e nacional e de forma assimétrica em termos territoriais. Isto é particularmente verdade para os sectores agrícola, florestal e agro-industrial, que porém falharam o objectivo essencial de criação de riqueza, sendo que os resultados mais visíveis foram a estagnação da produção e o aumento do deficit da balança alimentar. É então dentro das actividades agro-florestais que o PEN elege o seu raio preferencial de acção, dada a sua importância ao nível económico, ambiental e social. Assim, o factor determinante das políticas do próximo período deve ser o aumento da competitividade de empresas e territórios agrícolas, numa lógica de desenvolvimento sustentável. Para atingir este objectivo, é essencial que exista um forte envolvimento de todos os agentes e partes interessadas, o que requer uma aposta adicional na qualificação dos envolvidos
- Drivers of degradation and other threatsPublication . Doblas Miranda, Enrique; Attorre, Fabio; Azevedo, João; Belen, Ismail; Alcalde, Elsa Enríquez; Freitas, Helena; Garavaglia, Valentina; Hódar, José Antonio; Iritas, Özlem; Karaaslan, Yakup; Khater, Carla; Koutsias, Nikos; Lahlou, Mehdi; Malkinson, Dan; Mansour, Sophie; Pettenella, Davide; Picard, Nicolas; Pino, Joan; Vieira, Joana; Vitale, MarcelloForests in the Mediterranean region have been subject to environmental changes since time immemorial. The region’s geography and location has made it a conducive environment between biomes, resulting in significant biodiversity. Since the beginning of human history, forests have adapted to pressures caused by human development, resulting in a complex socio-ecological balance. These pressures, however,have never been more extreme than they are today. Global change, understood as the wide range of global forces resulting from human activity, is affecting the entire Mediterranean basin (Doblas-Miranda et al., 2017). The threats caused by global change pose particular risks to the principal characteristics of Mediterranean forests and forested habitats described in previous chapters: 1. Mediterranean forests and shrublands are highly sensitive to global atmospheric changes due to their proximity to arid regions; 2. a long history of land-use change may result in more frequent and intense fires, water scarcity and land degradation and; 3. a singular biota is linked to a higher vulnerability to global change-induced extinction. Moreover, the wide range of socioeconomic conditions and government policies that characterize the Mediterranean basin affect the intensity and dynamics of these threats.This chapter outlines the different threats to Mediterranean forest landscapes, structured according to indirect and direct causes of degradation. The anthropogenic origin of current global changes directly affecting Mediterranean forests is considered the underlying cause of degradation. Although in many cases these human forces have a global impact (such as greenhouse gas emissions caused by climate change), this chapter will consider their effect on the Mediterranean region in particular. This chapter will also consider the consequences of direct and indirect threats and the combination of both.
- Leaf decomposition of cork oak under three different land uses within a montado of southern PortugalPublication . Arosa, Maria Luísa; Costa, Sofia R.; Freitas, HelenaThis study compared litter decomposition dynamics of cork oak at three sites under different land-uses (grassland, shrubland and woodland), in a montado ecosystem in Southern Portugal. The montado is a protected habitat within the EU Habitats Directive, but the long-term persistence of cork oak is endangered in these ecosystems, with health of poor cork oak and low natural regeneration rates being the main causes of degradation. Moreover, human management has resulted in the conversion of woodlands to grasslands and may have long-term effects on soil nutrient availability, eventually modifying soil nutrient budgets. Knowledge of the ecological processes is therefore relevant for ecosystem management and species conservation. In the study, the estimated amount of leaf fall from cork oak showed no significant differences between land uses, despite the positive influence of tree crown size on leaf fall. Decomposition was affected by season, vegetation cover, leaf thickness and litter quality. Differences in land use that exposed soil to harsh climate conditions negatively affected soil microbial dynamics, resulting in lower decomposition rates in the more disturbed sites with lower canopy cover.
- Long-term sustainability of cork oak agro-forests in the Iberian Peninsula: A model-based approach aimed at supporting the best management options for the montado conservationPublication . Arosa, Maria Luísa; Bastos, Rita; Cabral, João Alexandre; Freitas, Helena; Costa, Sofia R.; Santos, MárioThe future of the montado, a human shaped agro-forestry ecosystem of South Western Europe, is questioned due to the observed lack of cork oak health and low natural regeneration. We developed a System Dynamics Modelling approach to predict the long-term sustainability of this agro-forest, by recreating cork-oak population dynamics, management practices and the main environmental and biological constrains associated with this ecosystem. Our results indicate that the leading limitations to cork oak regeneration in montado ecosystems result from the intensity and interaction of land management practices, namely livestock and the use of heavy machinery. The main conclusions indicate that limiting the quantity of livestock up to 0.40 LU.ha -1 , and considering soil ploughing with a minimum periodicity of 5 years, are crucial to maintaining sustainable cork oak populations. This study represents a first step to support strategic options for cork oak montado management by providing projections of long-term population trends under realistic social-ecological change scenarios.