942 resultados para Iluminura - Portugal - séc.15


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Commercial capture fisheries produce huge quantities of offal, as well as undersized and unwanted catch in the form of discards. Declines in global catches and legislation to ban discarding will significantly reduce discards, but this subsidy supports a large scavenger community. Understanding the potential impact of declining discards for scavengers should feature in an eco-system based approach to fisheries management, but requires greater knowledge of scavenger/fishery interactions. Here we use bird-borne cameras, in tandem with GPS loggers, to provide a unique view of seabird/fishery interactions. 20,643 digital images (one min 21) from ten bird-borne cameras deployed on central place northern gannets Morus bassanus revealed that all birds photographed fishing vessels. These were large (>15 m) boats, with no small-scale vessels. Virtually all vessels were trawlers, and gannets were almost always accompanied by other scavenging birds. All individuals exhibited an Area-Restricted Search (ARS) during foraging, but only 42% of ARS were associated with fishing vessels, indicating much 'natural' foraging. The proportion of ARS behaviours associated with fishing boats were higher for males (81%) than females (30%), although the reasons for this are currently unclear. Our study illustrates that fisheries form a very important component of the prey-landscape for foraging gannets and that a discard ban, such as that proposed under reforms of the EU Common Fisheries Policy, may have a significant impact on gannet behaviour, particularly males. However, a continued reliance on 'natural' foraging suggests the ability to switch away from scavenging, but only if there is sufficient food to meet their needs in the absence of a discard subsidy.

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New records of vascular plants from Sierra del Rincón Biosphere Reserve and surroundings (Spain, Madrid province) are provided. It is noteworthy the presence of atlantic flora in this continental area and the different shrubby communities in different sectors with different litology: in areas with gneiss they are dominated by leguminous genisteae; where it is schistous, shale or quartzite they are heathlands.

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Information on 12 exotic plants of diverse interest for the Galician flora are presented. All of them were collected in Ribeira council (SW of the A Coruña province). The total includes 8 novelties at a regional level (Aeonium haworthii, Aloe mitriformis, Brugmansia × candida, Nephrolepis cordifolia, Osteospermum ecklonis, Pelargonium capitatum, Sedum mexicanum, Sparaxis tricolor), and 2 provincial novelties. In addition, information on two taxa hardly mentioned in the literature on Galician vascular flora is also included. All the cited specimens are deposited at the SANT Herbarium.

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The botanic origin and the protein content of 15 honeys from small bee farms exploitations of Galicia, for family consume, were studied; the aim is to check if the protein wealth and the pollen wealth are dependent parameters. Seven honeys resulted to be Rhamnus frangula unifloral (pollen patterns with low diversity), two Castanea sativa Miller unifloral, other one heather unifloral, and five was multifloral honeys of various pollen patterns (four Castanea predominant and one Rhamnus frangula predominant). Their pollen wealth was low; eight honeys classified in the Maurizio Class I, 3 in Class II, 2 in Class III, and one in Maurizio Class IV. There has been a wide variability in its protein content (0.09- 4.83 mg prot./g honey). The relative amount of pollen from different taxa has a direct or inverse proportionality to wealth protein.

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We investigated the relationship between picoeukaryote phytoplankton (< 2 mu m) and the deep layer of new production (NO3- uptake) in the nitracline of the eastern subtropical North Atlantic Ocean. Indices of NO3- uptake kinetics obtained within the lower 15 % of the euphotic zone demonstrate that subsurface NO3- uptake maxima are coincident with localised peaks in maximum uptake rates (V-max) and, crucially, with maximum picoeukaryote abundance. The mean rate of NO3- utilization at the nitracline is typically 10-fold higher than in surface waters despite much lower in situ irradiance. These observations confirm a high affinity for NO3-, most likely by the resident picoeukaryote community, and we conservatively estimate mean cellular uptake rates of between 0.27 and 1.96 fmol NO3- cell(-1) h(-1). Greater scrutiny of the taxonomic composition of the picoeukaryote group is required to further understand this deep layer of new production and its importance for nitrogen cycling and export production, given longstanding assumptions that picoplankton do not contribute directly to export fluxes.

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The European Slope Current (SC) is a major section of the warm poleward flow from the Atlantic to the Arctic, which also moderates the exchange of heat, salt, nutrients and carbon between the deep ocean and the European shelf seas. The mean structure of the geostrophic flow, seasonality, interannual variability and long-term trend of SC are appraised with an unprecedented continuous 20-year satellite altimeter dataset. Comparisons with long term in situ data showed a maximum correlation of r2=0.51 between altimeter and Acoustic Doppler Current Profilers (ADCP), with similar results for drogued buoy data. Mean geostrophic currents were appraised more comprehensively than previous attempts, and the paths of 4 branches of the North Atlantic Current (NAC) and positions of 5 eddies in the region were derived quantitatively. A consistent seasonal cycle in the flow of the SC was found at all 8 sections along the European shelf slope, with maximum poleward flow in the winter and minimum in the summer. The seasonal difference in the altimetry current speed amounted to ~8-10 cm s-1 at the northern sections, but only ~5 cm s-1 on the Bay of Biscay slopes. This extended altimeter dataset indicates significant regional and seasonal variations, and has revealed new insights into the interannual variability of the SC. It is shown that there is a peak poleward flow at most positions along a ~2000 km stretch of the continental slope from Portugal to Scotland during 1995-1997, but this did not clearly relate to the extreme negative North Atlantic Oscillation (NAO) in the winter of 1995-1996. The speed of the SC exhibited a long term decreasing trend of ~1% per year. By contrast the NAC showed no significant trend over the 20-year period. Major changes in the NAC occurred three times, and these changes followed decreases in the NAO index.

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The ERSEM model is one of the most established ecosystem models for the lower trophic levels of the marine food-web in the scientific literature. Since its original development in the early nineties it has evolved significantly from a coastal ecosystem model for the North-Sea to a generic tool for ecosystem simulations from shelf seas to the global ocean. The current model release contains all essential elements for the pelagic and benthic part of the marine ecosystem, including the microbial food-web, the carbonate system and calcification. Its distribution is accompanied by a testing framework enabling the analysis of individual parts of the model. Here we provide a detailed mathematical description of all ERSEM components along with case-studies of mesocosm type simulations, water column implementations and a brief example of a full-scale application for the North-West European shelf. Validation against in situ data demonstrates the capability of the model to represent the marine ecosystem in contrasting environments.

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The European Regional Seas Ecosystem Model (ERSEM) is one of the most established ecosystem models for the lower trophic levels of the marine food web in the scientific literature. Since its original development in the early nineties it has evolved significantly from a coastal ecosystem model for the North Sea to a generic tool for ecosystem simulations from shelf seas to the global ocean. The current model release contains all essential elements for the pelagic and benthic parts of the marine ecosystem, including the microbial food web, the carbonate system, and calcification. Its distribution is accompanied by a testing framework enabling the analysis of individual parts of the model. Here we provide a detailed mathematical description of all ERSEM components along with case studies of mesocosm-type simulations, water column implementations, and a brief example of a full-scale application for the north-western European shelf. Validation against in situ data demonstrates the capability of the model to represent the marine ecosystem in contrasting environments.

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Se ha realizado la revisión de ejemplares de Plagiomnium T. Kop., en la Península Ibérica, registrados en los Herbarios de España, Portugal y Francia, así como en algunas colecciones privadas. Siete taxones de Plagiomnium están representados en España: P. affine, P. cuspidatum, P. elatum, P. ellipticum, P. medium subsp. medium, P. rostratum y P. undulatum, y en Portugal cuatro taxones: P. affine, P. medium subsp. mediurn, P. rostratum y P. undulatum. En Mallorca (Illes Balears), queda excluido P. cuspidatum y P. elatum es nuevo para estas islas. P. undulatum, P. affine y P. rostratum son las especies más comunes en los bosques y zonas montañosas de la Península; P. cuspidatum y P. elatum son frecuentes en la mitad septentrional de España, siendo muy escasos en la parte meridional; los más raros son: P. ellipticum y P. medium subsp. medium, que están restringidos a los hábitats mesofíticos, suelos oligotrofos y húmedos de Pirineos, Cordillera Cantábrica y el piso supra-oromediterráneo de los Montes de Cataluña, Sistema Ibérico septentrional (Macizo de La Demanda) y Sistema Central. Se aportan fotografías de las esporas al SEM de P. affine, P. medium subsp. medium, P. rostratum y P. undulatum así como los mapas de distribución de cada taxon.

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Se comentan 12 especies de líquenes que no estaban citadas anteriormente para la isla de Madeira. Blarneya hibernica es nueva cita para la región Macaronésica.

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En el presente trabajo se estudian cariológicamente  8 taxones del género Amaranthus L.