Browsing by Author "Azevedo, Eduardo B."
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- Arthropod assemblage homogenization in oceanic islands: The role of indigenous and exotic species under landscape disturbancePublication . Florencio, Margarita; Cardoso, Pedro; Lobo, Jorge M.; Azevedo, Eduardo B.; Borges, Paulo A. V.Human landscape disturbance can drive the degradation of natural environments, thereby contributing to indigenous (endemic and native nonendemic) species extinctions, facilitating the establishment of exotic species and ultimately resulting in more similar species compositions over time and space. We assessed whether similarities in epigean arthropod assemblages differ between indigenous and exotic species in an oceanic archipelago, and we also examined whether such assemblage similarities depend on the most dominant species, the island, the type of habitat, the degree of landscape disturbance or local environmental variables.
- Assessing the areas under risk of invasion within islands through potential distribution modelling: the case of Pittosporum undulatum in São Miguel, AzoresPublication . Hortal, Joaquín; Borges, Paulo A. V.; Jiménez-Valverde, Alberto; Azevedo, Eduardo B.; Silva, LuísNon-indigenous plant species have been frequently reported as successful invaders in island environments, changing plant community composition and structure. This is the case of the sweet pittosporum (Pittosporum undulatum), native from Australia, which is one of the most successful plant invaders in the Azores archipelago. Data extracted from recent forestry inventories were used to model and map the potential distribution of P. undulatum in São Miguel, the larger island of the Azores. Current distribution of P. undulatum is related to climate, altitude and some human activity effects. Further analysis of the areas under risk of invasion showed that protected areas are under potential threat, although only a few native forest remnants seem to be threatened due to future expansion of P. undulatum, since the current distribution of these native communities has been reduced due to clearing and competition with invasive plants. We discuss the threats that any further expansion of the species will represent for low-altitude native forests, as well as the utility of species distribution models in the assessment of the areas under risk of invasion.
- Assessing the efficiency of protected areas to represent biodiversity : a small island case studyPublication . Vergílio, Marta H. S.; Fonseca, Catarina; Calado, Helena; Borges, Paulo A. V.; Elias, Rui B.; Gabriel, Rosalina; Martins, António; Azevedo, Eduardo B.; Cardoso, PedroProtected areas (PAs) have been selected using either subjective or objective criteria applied to an extremely limited subset of biodiversity. Improved availability of species distribution data, better statistical tools to predict species distributions and algorithms to optimize spatial conservation planning allow many impediments to be overcome, particularly on small islands. This study analyses whether 219 species are adequately protected by PAs on Pico Island (theAzores, Portugal), and if they are as efficient as possible, maximizing species protection while minimizing costs. We performed distribution modelling of species’ potential distributions, proposed individual conservation targets (considering the context of each species in the archipelago and their current conservation status) to determine the efficiency of current PAs in meeting such targets and identify alternative or complementary areas relevant for conservation. Results showed that current PAs do not cover all taxa, leaving out important areas for conservation. We demonstrate that by using optimization algorithms it is possible to include most species groups in spatial conservation planning in the Azores with the current resources. With increasing availability of data and methods, this approach could be readily extended to other islands and regions with high endemism levels.
- Avaliar a eficiência das áreas protegidas para representar a biodiversidade: o caso de estudo de uma pequena ilhaPublication . Vergílio, Marta H. S.; Fonseca, Catarina; Calado, Helena; Borges, Paulo A. V.; Elias, Rui B.; Gabriel, Rosalina; Martins, António; Azevedo, Eduardo B.; Cardoso, Pedro[…]. Nos Açores podem ser encontradas inúmeras espécies endémicas que tornam este arquipélago importante, do ponto de vista da conservação dos valores naturais. A rede de APs nos Açores está organizada em Parques Naturais de Ilha, no Parque Marinho dos Açores e em APs de importância local. O Parque Natural de Ilha (PNI) engloba diferentes categorias de áreas terrestres e marinhas, que possuem diferentes objectivos de conservação. No sentido de avaliar a adequação dos actuais limites das APs do ponto de vista da conservação das espécies, tendo a Ilha do Pico como caso de estudo, foram analisadas 219 espécies nativas dos Açores (briófitos, plantas vasculares, moluscos, artrópodes e vertebrados), na sua maioria endémicas. […].
- A biogeographical perspective on species abundance distributions : recent advances and opportunities for future researchPublication . Matthews, Thomas J.; Borges, Paulo A. V.; Azevedo, Eduardo B.; Whittaker, Robert J.It has become increasingly recognized that multiple processes can generate similar shapes of species abundance distributions (SADs), with the result that the fit of a given SAD model cannot unambiguously provide evidence in support of a given theory or model. An alternative approach to comparing the fit of different SAD models to data from a single site is to collect abundance data from a variety of sites, and then build models to analyse how different SAD properties (e.g. form, skewness) vary with different predictor variables. Such a biogeographical approach to SAD research is potentially very revealing, yet there has been a general lack of interest in SADs in the biogeographical literature. In this Perspective, we address this issue by highlighting findings of recent analyses of SADs that we consider to be of intrinsic biogeographical interest. We use arthropod data drawn from the Azorean archipelago to further highlight how analyses of SAD form and function may be biogeographically informative. We hope that, by reviewing a number of novel approaches, our article may prove to be a catalyst for a greater interest in analysing SADs in biogeography.
- Complexo CLIMAAT-TERCEIRA-NARE para a monitorização da composição da atmosfera na camada limite do Atlântico NortePublication . Fialho, Paulo; Henriques, Diamantino; Carvalho, Fernanda; Barata, Filipe; Azevedo, Eduardo B.As a result of the partnership between the University of Azores, and the Association for the Study of the Insular Environment through the Environment Observatory and the Meteorological Institute, during the 2004 summer it took place the beginning of the installation of the CLIMAAT – TERCEIRA – NARE (INTERREG IIIB – Projecto CLIMAAT – MAC 2.3/A3) platform. In this stage, it was also installed in the José Agostinho observatory, near the city of Angra do Heroísmo, several equipments to monitoring the atmospheric and sun irradiation. Near the coast, at the moment, and beside the meteorological common parameters, pressure, temperature, relative humidity, precipitation, wind direction and intensity some measurements of the black carbon and iron oxide aerosol absorption coefficients were also done. The results of this project should contribute to the study of the evolution and composition of the North Atlantic atmosphere, and in that matter to the study of the Global Changes, namely as a land platform of reference to remote sensing satellite systems. This platform is part of the Azores Global Atmosphere Monitoring Complex (AGAMC).
- Designing a survey protocol to overcome the Wallacean shortfall: a working guide using bryophyte distribution data on Terceira Island (Azores)Publication . Aranda, Silvia C.; Gabriel, Rosalina; Borges, Paulo A. V.; Azevedo, Eduardo B.; Lobo, Jorge M.The increasing availability of open access data on species occurrences is leading researchers to generate more hypotheses about patterns of species distributions. However, when all of this information is mapped onto a particular geographical scale, gaps usually appear due to lack of knowledge and sampling spatial bias (the so-called Wallacean shortfall). To overcome these problems as efficiently as possible, field surveys should be designed after distinguishing well-surveyed places from those with incomplete inventories in order to carry out the extra survey effort in those areas not represented environmentally and spatially by the well-surveyed places. This procedure requires (1) gathering, cleaning and standardizing data; (2) selecting environmental variables that are important for the group considered according to field experience and the literature; and (3) making statistical decisions about the number and location of areas that should be surveyed according to the available resources. Here, we summarize most concepts and procedures devoted to the evaluation of biodiversity data, offering some general recommendations on how to use them for optimizing new survey designs. As a practical guide for potential users, we provide an example describing its application to a comprehensive database on bryophyte distribution on Terceira Island (Azores, Portugal). More than 8,000 bryophyte records were gathered, but (i) less than half of the island area has been surveyed at least once and (ii) less than 1% of these have reliable inventories (placed on the few remnants of laurel forests that have been traditionally better surveyed). Nevertheless, surveying just 15 additional localities evenly distributed across the major environmental regions and habitats on Terceira Island seems to represent the existing environmental diversity. We believe that the survey protocol presented here for bryophytes of Terceira Island could be flexibly applied to other taxa or areas.
- Dispersal syndromes are poorly associated with climatic niche differences in the Azorean seed plantsPublication . Leo, María; Steinbauer, Manuel J.; Borges, Paulo A. V.; Azevedo, Eduardo B.; Gabriel, Rosalina; Schaefer, Hanno; Santos, Ana M.C.AIM: Environmental niche tracking is linked to the species ability to disperse. While well investigated on large spatial scales, dispersal constraints also influence small-scale processes and may explain the difference between the potential and the realized niche of species at small scales. Here we test whether niche size and niche fill differ systematically according to dispersal syndrome within isolated oceanic islands. We expect that species with higher dispersal abilities (anemochorous or endozoochorous) will have a higher niche fill, despite their environmental niche size. LOCATION: Azores archipelago. TAXON: Native seed plants. METHODS: We combined a georeferenced database of the species distribution within the archipelago (Azorean Biodiversity Portal/GBIF) with an expert-based dispersal syndrome categorization and a high-resolution climatic grid (CIELO model). Using four climatic variables (Annual Mean Temperature, Mean Diurnal Range, Annual Precipitation, Precipitation Seasonality), we calculated a four-dimensional hypervolume to estimate the niche size of each species. Niche fill was quantified as the suitable climatic space of the island that was occupied by the focal species. RESULTS: We found a significant relationship between dispersal syndromes and niche size, and also between dispersal syndromes and niche fill. Such relationships presented no phylogenetic signal. Endozoochorous species display higher niche fill compared to epizoochorous and hydrochorous species, and larger niches than anemochorous and epizoochorous. Differences among the remaining groups are not significant for either niche size or for niche fill. MAIN CONCLUSIONS: The ability of a species to track its niche at small scales is not tightly related to its dispersal syndrome, although endozoochorous species track their niche more efficiently than the rest of groups. Despite being intuitively appealing, dispersal syndrome classifications might not be the most appropriate tools for understanding dispersal processes at small scales.
- Diversidade da fauna de insectos fitófagos e de inimigos naturais em culturas frutícolas da ilha Terceira, Açores: a importância do maneio e da heterogeneidade ambientalPublication . Santos, Ana M. C.; Borges, Paulo A. V.; Hortal, Joaquín; Rodrigues, Ana C.; Medeiros, Carlos; Azevedo, Eduardo B.; Melo, Catarina; Lopes, David João Horta"A evidência mostra que os artrópodes constituem uma fracção importante da biodiversidade estrutural e funcional dos habitats terrestres (Kim, 1993). Por outro lado, só é possível conservar os processos ecológicos associados aos artrópodes promovendo a gestão correcta dos seus habitats. Para tal, é necessária uma correcta identificação e caracterização das suas comunidades de forma a promover a sua boa gestão. Durante os últimos anos têm sido realizados nos Açores vários estudos de inventariação e caracterização ecológica dos artrópodes em alguns dos habitats mais importantes destas ilhas: i) habitat cavernícola (Borges & Oromí, 1994); ii) pastagens semi-naturais e intensivas (Borges & Brown, 2001, 2003, 2004); iii) florestas nativas dos Açores (Borges et al., 2000, 2005a, b, 2006; Ribeiro et al., 2005). No entanto, na diversidade de usos do solo das ilhas açoreanas, as fruteiras constituem um habitat mal estudado em termos da cadeia trófica de artrópodes (contudo ver Oliveira, 2002). […]" (da Introdução).
- Efeitos da hidrodinâmica em comunidades biológicas de praias de calhau rolado em áreas marinhas protegidasPublication . Álvaro, Nuno V.; Neto, Ana I.; Azevedo, Eduardo B.Estudos recentes revelaram que as mudanças abióticas e as respostas biológicas do oceano às alterações climáticas serão complexas. Impactos climáticos sobre uma ou mais espécies-chave podem resultar em mudanças significativas ao nível da comunidade através de um efeito em cascata. As espécies adaptam-se a uma variedade de condições ambientais que definem a sua capacidade de sobreviver e reproduzir. A rapidez a que a alteração climática ocorre e a dificuldade em recuperar a um conjunto de pressões de algumas espécies e sistemas, como a pesca, a perda da biodiversidade, a destruição do habitat, a poluição, a introdução de espécies invasoras e actividade patogénica vão limitar a biodiversidade no futuro. Pequenas ilhas, como os Açores, são especialmente vulneráveis. A fragilidade destes sistemas insulares, ricos em biodiversidade e agindo como berçário para muitas espécies comerciais, levou à criação de um parque natural para cada ilha. São Miguel e Terceira são as ilhas do arquipélago que sofrem maior pressão humana. Algumas das mudanças no litoral resultaram na perda de habitats e, consequentemente, há menos espaço disponível para os organismos marinhos. Estas circunstâncias, associadas às alterações climáticas, tornam imperativo compreender até que ponto as AMPs podem sofrer mudanças no seu biota. Este estudo investiga as praias de calhau rolado das ilhas Terceira e São Miguel, relativamente à sua geomorfologia e comunidades dominantes. Pretende-se caracterizar estes sistemas e compreender a distribuição, a abundância de espécies chave e as respostas das suas populações às mudanças que vêm ocorrendo nas últimas décadas.