Recursos de colección

Repositorio da Universidade dos Açores (8.840 recursos)

O Repositório Institucional da Universidade dos Açores desenvolvido no âmbito do projecto RCAAP.

Departamento de Ciências Agrárias

Mostrando recursos 1 - 20 de 251

  1. Marine biodiversity of Sete Cidades shallow coasts

    Barreiros, João P.
    Sendo os Açores a região mais isolada do Atlântico Norte, a sua biodiversidade marinha reflecte não apenas essa característica bem como influências de vários locais que o tornam único. O Arquipélago localiza-se perto da crista meso-atlântica estando as ilhas dos grupos central e oriental localizadas na microplaca dos Açores e as do grupo ocidental na placa americana. A latitude média do Arquipélago ronda os 39ºN, ou seja, quase a mesma de Lisboa ou de Nova Iorque embora sem os Invernos e Verões rigorosos daquelas cidades e caracterizando- se por uma baixa amplitude térmica com temperaturas entre valores de conforto térmico...

  2. The colonisation of exotic species does not have to trigger faunal homogenisation : lessons from the assembly patterns of arthropods on oceanic islands

    Florencio, Margarita; Lobo, Jorge M.; Cardoso, Pedro; Almeida-Neto, Mário; Borges, Paulo A. V.
    Human-caused disturbances can lead to the extinction of indigenous (endemic and native) species, while facilitating and increasing the colonisation of exotic species; this increase can, in turn, promote the similarity of species compositions between sites if human-disturbed sites are consistently invaded by a regionally species-poor pool of exotic species. In this study, we analysed the extent to which epigean arthropod assemblages of four islands of the Azorean archipelago are characterised by nestedness according to a habitat-altered gradient. The degree of nestedness represents the extent to which less ubiquitous species occur in subsets of sites occupied by the more widespread species,...

  3. The iterative process of plant species inventorying for obtaining reliable biodiversity patterns

    Aranda, Silvia C.; Hespanhol, Helena; Homem, Nídia; Borges, Paulo A. V.; Lobo, Jorge M.; Gabriel, Rosalina
    We require representative data of species occurrence to explain plant diversity patterns, but most of the available information is incomplete and biased. To improve our knowledge, we suggest that species inventorying should be an iterative process encompassing the following: (1) the detection of taxonomic and geographical gaps; (2) the planning of a survey design to reduce such gaps; and (3) the evaluation of field sampling results. Here, we focus on the latter phase for the bryophytes of Terceira Island (Azores) for which we have previously estimated < 1% of the area as well surveyed based on historical collections. To examine the...

  4. Avaliação da suscetibilidade a movimentos de vertente na zona oeste da ilha Terceira

    Miguel, Alonso Teixeira
    Tese de Doutoramento, Gestão Interdisciplinar da Paisagem, 9 de junho de 2017, Universidade dos Açores.

  5. Avaliação da suscetibilidade a movimentos de vertente na zona oeste da ilha Terceira

    Miguel, Alonso Teixeira
    Tese de Doutoramento, Gestão Interdisciplinar da Paisagem, 9 de junho de 2017, Universidade dos Açores.

  6. An approach to evaluate aerosol optical depth at marine boundary layer : the Pico-Graciosa measurement platform

    Henriques, Diamantino; Carvalho, Fernanda; Fialho, Paulo
    Workshop: An opportunity for international cooperation on atmospheric sciences, Lisboa, 2015 (Comunicação).

  7. An approach to evaluate aerosol optical depth at marine boundary layer : the Pico-Graciosa measurement platform

    Henriques, Diamantino; Carvalho, Fernanda; Fialho, Paulo
    Workshop: An opportunity for international cooperation on atmospheric sciences, Lisboa, 2015 (Comunicação).

  8. Some Aerosol Optical Measurements at Pico Mountain Observatory

    Fialho, Paulo; Mazzoleni, Claudio
    Workshop: An opportunity for international cooperation on atmospheric sciences, Lisboa, 2015 (Comunicação).

  9. Some Aerosol Optical Measurements at Pico Mountain Observatory

    Fialho, Paulo; Mazzoleni, Claudio
    Workshop: An opportunity for international cooperation on atmospheric sciences, Lisboa, 2015 (Comunicação).

  10. Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic

    Helmig, Detlev; Muñoz, Mauricio; Hueber, Jacques; Mazzoleni, Claudio; Mazzoleni, Lynn R.; Owen, Richard C.; Val-Martin, Maria; Fialho, Paulo; Plass-Duelmer, Christian; Palmer, Paul I.; Lewis, Alastair C.; Pfister, Gabriele
    A record spanning ten years of non-methane hydrocarbon (NMHC) data from the Pico Mountain Observatory (PMO), Pico Island, Azores, Portugal, was analyzed for seasonal NMHC behavior, atmospheric processing, and trends, focusing on ethane and propane. The location of this site in the central North Atlantic, at an elevation of 2225 m asl, allows these data to be used to investigate the background conditions and pollution transport events occurring in the lower free North Atlantic troposphere. The quantity ln([propane]/[ethane]) was used as an indicator of both photochemical processing and a marker for the occurrence of pollution transport events detected at the...

  11. Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic

    Helmig, Detlev; Muñoz, Mauricio; Hueber, Jacques; Mazzoleni, Claudio; Mazzoleni, Lynn R.; Owen, Richard C.; Val-Martin, Maria; Fialho, Paulo; Plass-Duelmer, Christian; Palmer, Paul I.; Lewis, Alastair C.; Pfister, Gabriele
    A record spanning ten years of non-methane hydrocarbon (NMHC) data from the Pico Mountain Observatory (PMO), Pico Island, Azores, Portugal, was analyzed for seasonal NMHC behavior, atmospheric processing, and trends, focusing on ethane and propane. The location of this site in the central North Atlantic, at an elevation of 2225 m asl, allows these data to be used to investigate the background conditions and pollution transport events occurring in the lower free North Atlantic troposphere. The quantity ln([propane]/[ethane]) was used as an indicator of both photochemical processing and a marker for the occurrence of pollution transport events detected at the...

  12. Molecular characterization of free tropospheric aerosol collected at the Pico Mountain Observatory : a case study with a long-range transported biomass burning plume

    Dzepina, Katja; Mazzoleni, Claudio; Fialho, Paulo; China, Swarup; Zhang, Bo; Owen, R. Chris; Helmig, Detlev; Hueber, Jacques; Kumar, Sumit; Perlinger, Judith A.; Kramer, Louisa; Dziobak, Michael P.; Ampadu, Marian T.; Olsen, Seth C.; Wuebbles, Donald J.; Mazzoleni, Lynn R.
    Free tropospheric aerosol was sampled at the Pico Mountain Observatory located at 2225 m above mean sea level on Pico Island of the Azores archipelago in the North Atlantic. The observatory is located ~ 3900 km east and downwind of North America, which enables studies of free tropospheric air transported over long distances. Aerosol samples collected on filters from June to October 2012 were analyzed to characterize organic carbon, elemental carbon, and inorganic ions. The average ambient concentration of aerosol was 0.9 ± 0.7 μg m−3. On average, organic aerosol components represent the largest mass fraction of the total measured...

  13. Molecular characterization of free tropospheric aerosol collected at the Pico Mountain Observatory : a case study with a long-range transported biomass burning plume

    Dzepina, Katja; Mazzoleni, Claudio; Fialho, Paulo; China, Swarup; Zhang, Bo; Owen, R. Chris; Helmig, Detlev; Hueber, Jacques; Kumar, Sumit; Perlinger, Judith A.; Kramer, Louisa; Dziobak, Michael P.; Ampadu, Marian T.; Olsen, Seth C.; Wuebbles, Donald J.; Mazzoleni, Lynn R.
    Free tropospheric aerosol was sampled at the Pico Mountain Observatory located at 2225 m above mean sea level on Pico Island of the Azores archipelago in the North Atlantic. The observatory is located ~ 3900 km east and downwind of North America, which enables studies of free tropospheric air transported over long distances. Aerosol samples collected on filters from June to October 2012 were analyzed to characterize organic carbon, elemental carbon, and inorganic ions. The average ambient concentration of aerosol was 0.9 ± 0.7 μg m−3. On average, organic aerosol components represent the largest mass fraction of the total measured...

  14. Alterações Climáticas : O valor estratégico dos Açores

    Fialho, Paulo
    A crescente preocupação com as alterações climáticas tem levado à expansão da rede de monitorização da atmosfera (GAW) na sua vertente química e física. Esta rede tem na sua base as diversas plataformas terrestres de observação da atmosfera que se encontram associadas aos Serviços Nacionais de Meteorologia e de Hidrologia (SNMH) dos diversos países envolvidos no programa. A Organização Mundial de Meteorologia (OMM) pediu aos seus membros (os SMH) que fossem tidas em consideração as medidas da composição química da atmosfera encorajando-os a integrarem nas suas atividades a observação da composição química da atmosfera. […].

  15. Alterações Climáticas : O valor estratégico dos Açores

    Fialho, Paulo
    A crescente preocupação com as alterações climáticas tem levado à expansão da rede de monitorização da atmosfera (GAW) na sua vertente química e física. Esta rede tem na sua base as diversas plataformas terrestres de observação da atmosfera que se encontram associadas aos Serviços Nacionais de Meteorologia e de Hidrologia (SNMH) dos diversos países envolvidos no programa. A Organização Mundial de Meteorologia (OMM) pediu aos seus membros (os SMH) que fossem tidas em consideração as medidas da composição química da atmosfera encorajando-os a integrarem nas suas atividades a observação da composição química da atmosfera. […].

  16. Morphology and Mixing State of Aged Soot Particles at a Remote Marine Free Troposphere Site : Implications for Optical Properties

    China, Swarup; Scarnato, Barbara; Owen, Robert C.; Zhang, Bo; Ampadu, Marian T.; Kumar, Sumit; Dzepina, Katja; Dziobak, Michael P.; Fialho, Paulo; Perlinger, Judith A.; Hueber, Jacques; Helmig, Detlev; Mazzoleni, Lynn R.; Mazzoleni, Claudio
    The radiative properties of soot particles depend on their morphology and mixing state, but their evolution during transport is still elusive. Here we report observations from an electron microscopy analysis of individual particles transported in the free troposphere over long distances to the remote Pico Mountain Observatory in the Azores in the North Atlantic. Approximately 70% of the soot particles were highly compact and of those 26% were thinly coated. Discrete dipole approximation simulations indicate that this compaction results in an increase in soot single scattering albedo by a factor of ≤2.17. The top of the atmosphere direct radiative forcing...

  17. Molecular characterization of free tropospheric aerosol collected at the Pico Mountain Observatory : a case study with long range transported biomass burning plumes

    Dzepina, Katja; Mazzoleni, Claudio; Fialho, Paulo; China, Swarup; Zhang, Bo; Owen, R. Chris; Helmig, Detlev; Hueber, Jacques; Kumar, Sumit; Perlinger, Judith A.; Kramer, Louisa; Dziobak, Michael P.; Ampadu, Marian T.; Olsen, Seth C.; Wuebbles, Donald J.; Mazzoleni, Lynn R.
    Free tropospheric aerosol was sampled at the Pico Mountain Observatory located at 2225 m above mean sea level on Pico Island of the Azores archipelago in the North Atlantic. The observatory is located ~ 3900 km east and downwind of North America, which enables studies of free tropospheric air transported over long distances. Aerosol samples collected on filters from June to October 2012 were analyzed to characterize organic carbon, elemental carbon, and inorganic ions. The average ambient concentration of aerosol was 0.9 ± 0.7 μg m−3. On average, organic aerosol components represent the largest mass fraction of the total measured...

  18. Molecular characterization of free tropospheric aerosol collected at the Pico Mountain Observatory : a case study with long range transported biomass burning plumes

    Dzepina, Katja; Mazzoleni, Claudio; Fialho, Paulo; China, Swarup; Zhang, Bo; Owen, R. Chris; Helmig, Detlev; Hueber, Jacques; Kumar, Sumit; Perlinger, Judith A.; Kramer, Louisa; Dziobak, Michael P.; Ampadu, Marian T.; Olsen, Seth C.; Wuebbles, Donald J.; Mazzoleni, Lynn R.
    Free tropospheric aerosol was sampled at the Pico Mountain Observatory located at 2225 m above mean sea level on Pico Island of the Azores archipelago in the North Atlantic. The observatory is located ~ 3900 km east and downwind of North America, which enables studies of free tropospheric air transported over long distances. Aerosol samples collected on filters from June to October 2012 were analyzed to characterize organic carbon, elemental carbon, and inorganic ions. The average ambient concentration of aerosol was 0.9 ± 0.7 μg m−3. On average, organic aerosol components represent the largest mass fraction of the total measured...

  19. The application of a multi-wavelength Aethalometer to estimate iron dust and black carbon concentrations in the marine boundary layer of Cape Verde

    Fialho, Paulo; Cerqueira, Mário; Pio, Casimiro; Cardoso, João; Nunes, Teresa; Custódio, Danilo; Alves, Célia A.; Almeida, S. M.; Almeida-Silva, M.; Reis, M. A.; Rocha, F.
    The two-component model (Fialho et al., 2006) was used to decouple the contributions of black carbon (BC) and iron oxides, present in dust, to the aerosol attenuation coefficient, measured with a multiwavelength Aethalometer. The model results were compared with the elemental carbon (EC) and iron concentrations determined in the laboratory from the analysis of aerosol particles collected with conventional samplers. The comparison was based on one year of data obtained at Praia, Santiago Island, Cape Verde, after side by side operation of the aerosol monitoring instruments. The linear regression equation that best describes the relationship between BC concentrations, derived from...

  20. Wet deposition of particulate carbon to the Central North Atlantic Ocean

    Custódio, Danilo; Cerqueira, Mário; Fialho, Paulo; Nunes, Teresa; Pio, Casimiro; Henriques, Diamantino
    Elemental carbon (EC) and water-insoluble organic carbon (WIOC) concentrations were measured in wet-only precipitation samples collected on Terceira Island (Azores, Portugal) between December 2009 and October 2010, to investigate temporal variations, source regions and wet deposition fluxes. The global volume-weighted average (vwa) concentrations were 134 ± 19 μgC L(-1) for WIOC and 15.0 ± 1.6 μgC L(-1) for EC, which fall within the range of values that have been found in the European background atmosphere. The WIOC concentration exhibited a temporal variation over the study period with a minimum in winter (vwa 88 ± 16 μgC L(-1)) and a maximum...

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