Browsing by Issue Date, starting with "2010-04"
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- Extinction debt on oceanic islandsPublication . Triantis, Kostas A.; Borges, Paulo A. V.; Ladle, Richard J.; Hortal, Joaquín; Cardoso, Pedro; Gaspar, Clara; Dinis, Francisco; Pereira, Enésima; Silveira, Lúcia M. A.; Gabriel, Rosalina; Melo, Catarina; Santos, Ana M. C.; Amorim, Isabel R.; Ribeiro, Sérvio P.; Serrano, Artur R. M.; Quartau, José A.; Whittaker, Robert J.Habitat destruction is the leading cause of species extinctions. However, there is typically a time-lag between the reduction in habitat area and the eventual disappearance of the remnant populations. These “surviving but ultimately doomed” species represent an extinction debt. Calculating the magnitude of such future extinction events has been hampered by potentially inaccurate assumptions about the slope of species–area relationships, which are habitat- and taxon-specific. We overcome this challenge by applying a method that uses the historical sequence of deforestation in the Azorean Islands, to calculate realistic and ecologically-adjusted species–area relationships. The results reveal dramatic and hitherto unrecognized levels of extinction debt, as a result of the extensive destruction of the native forest:>95%, in<600 yr. Our estimations suggest that more than half of the extant forest arthropod species, which have evolved in and are dependent on the native forest, might eventually be driven to extinction. Data on species abundances from Graciosa Island, where only a very small patch of secondary native vegetation still exists, as well as the number of species that have not been found in the last 45 yr, despite the extensive sampling effort, offer support to the predictions made. We argue that immediate action to restore and expand native forest habitat is required to avert the loss of numerous endemic species in the near future.
- O Ilhéu da Vila e os GarajausPublication . Neves, Verónica C.Os garajaus são aves marinhas muito elegantes e acrobáticas; pertencem à ordem charadriiformes, uma ordem muito diversa que inclui cerca de 350 espécies de aves, e à família Sternidae. São para muitos açoreanos uma espécie de equivalente insular das andorinhas - um prenúncio da Primavera. Não só porque chegam aos Açores no final de Março, mas também pela sua silhueta de cauda bifurcada e pelos seus voos ágeis. […]
- Metal concentration and structural changes in Corallina elongata (Corallinales, Rhodophyta) from hydrothermal vents.Publication . Couto, Ruben P.; Neto, Ana I.; Rodrigues, ArmindoShallow-water hydrothermal activity is widely present at Azores archipelago. Organisms in such environments present great potential as sentinels of the effects derived from chronically exposure to increased temperature, metal concentrations and reduced pH. This study aimed to evaluate metal concentration in Corallina elongata collected at locations exposed and not exposed to shallow-water hydrothermal activity and evaluate changes in its calcareous structure. Elemental concentration was determined and morphometric analysis was performed by scanning electron microscopy. Thicker cell walls and a bleached appearance were observed on C. elongata specimens from the hydrothermally active location, as well as increased concentrations of elements associated to volcanic activity. This study reports on metal accumulation and morphometric changes in the calcareous structure of C. elongata from a hydrothermally active location, adding new data for further research on such habitats and communities, providing an insight on how coralline algae might be affected by ocean acidification.
- Teacher evaluation, curricular autonomy and professional development: trends and tensions in the Portuguese educational policy.Publication . Morgado, José Carlos; Sousa, FranciscoFor the past two years, teacher evaluation has been the most visible aspect of educational policy in Portugal. The model that was established in 2008 has prompted not only strong reactions among teachers but also many passionate discussions in the context of the Portuguese society at large. In this article, we discuss issues of teacher evaluation by relating them to issues of teachers' curricular autonomy and professional development, considering that these may be regarded as three pillars of what we envisage as a renewed teacher professionalism that might contribute to improving the quality of teaching and learning. Our analysis of recent measures suggests that a deficit of formative devices in teacher evaluation is narrowing opportunities for teachers' professional development, which, combined with legislative initiatives that limit the alleged promotion of teachers' curricular autonomy, may pose serious threats to the advancement of Portuguese teachers' professionalism.
- Ecological quality of Azorean coastal waters.Publication . Neto, Ana I.; Patarra, Rita F.; Brotas, Vanda; Álvaro, Nuno V.; Gameiro, Carla; Silva, Alexandra A.; Diniz, Tania; Prestes, Afonso L.; Azevededo, José M. N.; Medeiros, Margarida C.; Pacheco, Dina M.; Gaspar, João L.
- Are species-area relationships from entire archipelagos congruent with those of their constituent islands?Publication . Santos, Ana C.; Whittaker, Robert J.; Triantis, Kostas A.; Borges, Paulo A. V.; Jones, Owen R.; Quicke, Donald L. J.; Hortal, JoaquínAIM To establish the extent to which archipelagos follow the same species–area relationship as their constituent islands and to explore the factors that may explain departures from the relationship. LOCATION Thirty-eight archipelagos distributed worldwide. METHODS We used ninety-seven published datasets to create island species–area relationships (ISARs) using the Arrhenius logarithmic form of the power model. Observed and predicted species richness of an archipelago and of each of its islands were used to calculate two indices that determined whether the archipelago followed the ISAR. Archipelagic residuals (ArcRes) were calculated as the residual of the prediction provided by the ISAR using the total area of the archipelago, standardized by the total richness observed in the archipelago. We also tested whether any characteristic of the archipelago (geological origin and isolation) and/or taxon accounts for whether an archipelago fits into the ISAR or not. Finally, we explored the relationship between ArcRes and two metrics of nestedness. RESULTS The archipelago was close to the ISAR of its constituent islands in most of the cases analysed. Exceptions arose for archipelagos where (i) the slopes of the ISAR are low, (ii) observed species richness is higher than expected by the ISAR and/or (iii) distance to the mainland is small. The archipelago's geological origin was also important; a higher percentage of oceanic archipelagos fit into their ISAR than continental ones. ArcRes indicated that the ISAR underpredicts archipelagic richness in the least isolated archipelagos. Different types of taxon showed no differences in ArcRes. Nestedness and ArcRes appear to be related, although the form of the relationship varies between metrics. MAIN CONCLUSIONS Archipelagos, as a rule, follow the same ISAR as their constituent islands. Therefore, they can be used as distinct units themselves in large-scale biogeographical and macroecological studies. Departure from the ISAR can be used as a crude indicator of richness-ordered nestedness, responsive to factors such as isolation, environmental heterogeneity, number and age of islands.
- Salvaguardar para comunicar: Arquivo Histórico da Misericórdia de Ponta DelgadaPublication . Gregório, Rute DiasO arquivo histórico da Santa Casa da Misericórdia de Ponta Delgada está em processo de organização. Fruto de acumulação sem controlo nem gestão, o respectivo conjunto documental de conservação permanente encontrava-se disperso, sem acondicionamento nem tratamento adequados, tão-pouco existindo um inventário de livros, maços e outras unidades instalações. O projecto agora em curso pretende intervir ao nível do seu controlo e salvaguarda, com o objectivo de disponibilizar, aos investigadores e outros interessados, o riquíssimo aporte informativo dos registos desta instituição secular.