Detecção remota por satélite de matos mediterrânicos de cistáceas

Dissertação apresentada para obtenção do Grau de Doutor em Ciências do Ambiente,na especialidade de Sistemas Naturais, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologiao uso milenar pelo homem da Bacia do Mediterrâneo conduziu a problemas graves de degradação ambiental, encontrando-se algumas zonas em elevado risco de desertificação. As zonas mais degradadas são colonizadas, essencialmente, por plantas da família Cistaceae. Tem-se verificado que estas espécies desempenham um importante papel não só na defesa do solo contra a erosão mas também na melhoria das condições edáficas, proporcionando, eventualmente, situações propícias para a instalação de outras espécies, mais exigentes. Toma-se, por isso, indispensável conhecer a dinâmica espacio-temporal das comunidades vegetais formadas por Cistáceas, especialmente no que diz respeito à variação da biomassa. Actualmente, o único método realista, objectivo e prático para monitorizar a fitomassa à escala regional consiste na utilização de imagens obtidas por radiómetros a bordo de satélites. Existem vários tipos de radiómetros com diferentes resoluções radiométrica, espacial, temporal e espectral, fornecendo, por isso, imagens com características distintas. Para se poder conjugar as imagens provenientes dos vários radiómetros são necessários estudos comparativos. Assim, para a determinação do potencial das imagens de satélite na determinação da fitomassa dos matos mediterrânicos à base de Cistáceas foram usadas imagens de Verão de três radiómetros diferentes (TM, HRV e VNIR) e ainda uma imagem TM de Inverno para comparação do comportamento espectral da vegetação em duas estações distintas do ano. Foi efectuado trabalho de campo para avaliação directa da fitomassa e validação da informação radiométrica. Os resultados obtidos no presente trabalham revelam que as adaptações morfológicas das Cistáceas às condições ambientais adversas durante o Verão (temperaturas elevadas, carência hídrica e excesso de radiação) influenciam, de maneira decisiva, o comportamento espectral das plantas. Deste modo, os matos de Cistáceas podem distinguir-se, nas imagens, de outras comunidades vegetais existentes na mesma região mas com adaptações morfológicas distintas, como é o caso de matos mediterrânicos esclerófilos. Ou seja, é possível, cartografar as diferentes formações vegetais mediterrânicas com base em informação espectral.Junta Nacional de Investigação Científica e Tecnológica (contrato PEAM/CIRNT/57/91), Programa PRODEP (Concurso 4/95

Fundação de Capelas na Lisboa quatrocentista: da morte à vida eterna

Based on analysis of a series of chapel tombs, this article outlines of the last wishes of their respective founders. Drawing up a will was a way of creating a link between the profane and the sacred worlds, the background for this study. Our aim was to establish the conditions under which chapels were founded and what earthly rewards were received in return for saving the founder’s soul. Other aspects that emerge from analysis of these wills are an idea of life after death and the nature of God. Fundamentally, it is an attempt to understand the experience of death in Lisbon during the Late Middle Ages.Partindo da análise de uma série de tombos de capelas, o presente artigo traça um esboço das últimas vontades dos seus instituidores. A elaboração do testamento permite a ligação entre os mundos profano e sagrado, pano de fundo deste estudo. Assim, procuramos estabelecer em que condições se instituíam capelas e que contrapartidas terrenas se apresentavam para a salvação da alma. Por outro lado, a construção de uma ideia de vida após a morte e da natureza da identidade divina são outros aspectos que a análise deste conjunto de testamentos propicia. No fundo, tentamos perceber a forma como se vivia a morte na Lisboa da Baixa Idade Média

Large scale shrub biomass estimates for multiple purposes

With the increase of forest fires in Portugal in recent decades, a significant part of woodlands is being converted into shrubland areas. Background: From an ecological point of view, woodlands and shrublands play an essential role, as they not only prevent soil erosion and desertification, but also contribute to soil protection, habitat preservation and restoration, and also increased biodiversity for carbon sequestration. Concerning the shrublands, the assessment of their biomass is essential for evaluating the fuel load and forest fire behavior and also beneficial for obtaining estimates of carbon and biomass for energy use. Methods: In this study, we collected data about the potential shrub biomass accumulation along fifteen years in former burnt areas within North Portugal. Results: The achieved results showed that for a post-fire period ranging from one to 15 years, the accumulated shrubs’ biomass ranged from 0.12 up to 28.88 Mg ha1. The model developed to estimate the shrub biomass using the time after a fire (age) as a predictor variable presented a high adjustment to data (p-value of the F statistic <0.01 and R2 = 0.89), allowing estimating shrub biomass regeneration within former burnt areas with an RMSE of 3.31 Mg ha1. Conclusions: This paper provides practical information on the availability and assessment of shrub biomass in North Portugal, highlighting the suitability of shrubs as potential sources of biomassinfo:eu-repo/semantics/publishedVersio

Validation of a food frequency questionnaire for the adult population

OBJETIVO: Investigar a validade e a reprodutibilidade de um questionário de freqüência de consumo alimentar desenvolvido para a população adulta. MÉTODOS: Foram entrevistados, em três momentos, 69 indivíduos, de ambos os sexos, freqüentadores de restaurantes industriais em dois órgãos públicos de Brasília, Distrito Federal. Na primeira e terceira entrevistas foram aplicados um recordatório 24 horas e um questionário de freqüência de consumo alimentar, e na segunda entrevista, um recordatório 24 horas. A duração média do estudo foi de 181 dias. Macronutrientes, vitaminas A e C, cálcio, ferro, zinco, colesterol, fibras e energia total foram analisados utilizando-se os coeficientes de correlação intraclasse e de Pearson, este último na forma bruta e deatenuada. RESULTADOS: Quanto à reprodutibilidade, o questionário de freqüência de consumo alimentar obteve desempenho adequado, apresentando resultados acima de 0,7 para lipídeo, colesterol, energia e proteína. Para a validade, os melhores coeficientes deatenuados foram observados para vitamina C (r=0,66), ferro (r=0,58), proteína (r=0,55) e carboidrato (r=0,55) e os piores, para colesterol (r=0,32) e vitamina A (r=0,37). CONCLUSÃO: A obtenção de coeficientes de correlação expressivos para alguns nutrientes indica que este questionário de freqüência de consumo alimentar constitui-se em um bom instrumento de pesquisa para estudos epidemiológicos em população adulta, podendo fornecer informações importantes para a implementação de ações na área de saúde e nutrição.OBJECTIVE: The aim of the present study was to investigate the validity and reproducibility of a food frequency questionnaire developed for the adult population. METHODS: Sixty-nine individuals from both genders who attended industrial restaurants from two government divisions in Brasília, Federal District, Brazil, were interviewed on three different occasions. In the first and third interviews, a 24h recall and a food frequency questionnaire were applied, and in the second interview only a 24h recall was applied. The study lasted 181 days. Macronutrients, vitamins A and C, calcium, iron, zinc, cholesterol, fibers and total energy were analyzed using the intraclass and Pearson's correlation coefficients, this last one in a crude and deattenuated manner. RESULTS: Regarding reproducibility, the food frequency questionnaire provided adequate results, presenting correlation coefficients above 0.7 for lipid, cholesterol, energy and protein. For validity, the best deattenuated coefficients were observed for vitamin C (r=0.66), iron (r=0.58), protein (r=0.55) and carbohydrate (r=0.55) and the worst for cholesterol (r=0.32) and vitamin A (r=0.37). CONCLUSION: The expressive correlation coefficients obtained for some nutrients indicates that this food frequency questionnaire constitutes a good research instrument for epidemiological studies in the adult population, as it can supply important dietary information allowing the implementation of actions in the health and nutrition areas

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Remote sensing in food production - A review

FAO's most recent assessments indicate that, globally, in 2011-13, about one in eight people in the world are likely to have suffered from chronic hunger, not having adequate food supplies for an active and healthy life. Food security crises are now caused, almost exclusively, by problems in access to food, not absolute food availability, but, monitoring agricultural production remains fundamental. Traditional ground-based systems of production estimation have many limitations which have restricted their use. However, remotely sensed satellite data offer timely, objective, economical, and synoptic information for crop monitoring. The objective of this paper is to review the contribution of remote sensing techniques in the classification, monitoring of crop phenology and condition and estimation of production.publishersversionpublishe

Redécouverte et Écologie d´Onopordum algeriense (Munby) Pomel = Carduus algeriensis Munby, endémique stricte en voie d’extinction du secteur algérois

Onopordum algeriense is a strict endemic species of the Algerian sector, limited more precisely to the hills and mountains of the Puits des Zouaves (Baïnem Forest). Given its very restricted distribution its conservation is essential. It is indeed strictly protected in Algeria by Executive Decree.The objective of this paper is to assess the population size and conservation status of Onopordum algeriense according to IUCN criteria as well as its vulnerability. Exhaustive sampling by the quadrat method was carried out in two sites in the Baïnem forest.In order to study the spatial distribution of the species, the method of Thiessen Polygons and Moran Index followed by a canonical correlation analysis was applied to elucidate the relationship between the environment variables and the spatial distribution of the species. The results revealed a trend towards aggregation.The population has a reduce size (1648 feet by 320 m2). Onopordum algeriense seems to be disturbed by the presence of wild boar and probably also by the presence of a beetle (the evil ketone). The particular conditions of its natural habitat do not seem indispensable to its survival but the absence of competitors in this habitat will, no doubt, represent a strong advantage. According to the adopted IUCN criteria, the species is Critically Endangered. If there is not conservation effort the future of the species seems uncertain also because of the pressure for urbanization in this area.Onopordum algeriense est une espèce endémique stricte du secteur algérois, limitée plus précisément aux collines et montagnes du Puits des Zouaves (Forêt de Baïnem). Compte tenu de sa distribution très restreinte on comprend l´importance de sa conservation. Elle est effectivement strictement protégée en Algérie par Décret Exécutif.L’objectif de cet article consiste dans l´évaluation de la dimension de la population et du statut de conservation d’Onopordum algeriense selon les critères de l’UICN ainsi que sa vulnérabilité. Un échantillonnage exhaustif par la méthode des quadrats a été réalisé dans deux sites dans la forêt de Baïnem.Afin d´étudier la distribution spatiale de l´espèce on a appliqué la méthode des Polygones de Thiessen et l´Indice de Moran suivie d’une analyse canonique de corrélation pour élucider la relation entre les variables du milieu physique et la répartition des individus de l´espèce. Les résultats ont révélé une tendance à l’agrégation de l´espèce.La dimension de la population est réduite (on a recensé 1648 pieds sur 320 m2). Onopordum algeriense semble perturbé par la présence du sanglier et probablement aussi par la présence d´un coléoptère (la cétoine funeste). Les conditions particulières de son habitat naturel ne semblent pas indispensables à sa survie mais l’absence de compétiteurs dans cet habitat représentera, sans doute, un fort avantage.Selon les critères de l’UICN adoptées, l’espèce est en danger critique. S´il n’y a pas un effort de conservation l´ avenir de l´espèce semble incertain aussi du fait de la pression pour l’urbanisation dans cette zone

Diversité floristique et espace urbain: cas de l´'algglomération d'Alger

In Algiers, there is no environment that can be described as natural. The objective of this work is to evaluate floristic diversity in cities.This approach is conducted on a scale of the agglomeration of Algiers (Northern Algeria). In order to study the urban biodiversity of the latter, the inventory involved 36 sites spread over 11 habitats and for which we calculated a new index, namely the Floristic Interest Index (IFI), including information on the richness, indigenate, typicity and rarity of the species. This index makes it possible to identify sites and habitats of great interest for conservation. 420 vascular species were identified of which 367 indigenous (87.3%) against 53 naturalized (12.6%), representing 75 families with a predominance of the Asteraceae family with 57 species. Biological types are predominantly therophytic with 42.2%, there is also a high proportion of Mediterranean species in terms of biogeographic origin. Forest environments (urban and suburban) are high IFI habitats this is explained by moderate human activity weakly impacting these spaces. Multivariate analyses identified three groups differentiated by the degree of anthropization, combined with other ecological factors acting simultaneously. This study shows an unsuspected biodiversity in these urbanized environments that can play an important role in urban green frameworks.A Alger, il ne reste aucun milieu que l’on puisse qualifier de naturel. L’objectif de ce travail consiste à évaluer la diversité floristique en milieu urbain. Cette approche est conduite à une échelle de l’agglomération d’Alger (Nord de l’Algérie). Afin d’évaluer la biodiversité urbaine de cette dernière, l’inventaire a concerné 36 sites répartis sur 11 habitats et pour lesquels nous avons calculé un nouvel indice à savoir l’indice d’intérêt floristique (IFI), intégrant des informations sur la richesse, l’indigénat, la typicité et la rareté des espèces. Cet indice permet d’identifier les sites et habitats d'un grand intérêt pour la conservation. Ainsi, 420 espèces vasculaires ont été identifiées, dont 367 indigènes (87,3%) contre 53 naturalisées (12,6%), représentant 75 familles avec une prédominance de la famille des Asteraceae avec 57 espèces. Les types biologiques sont à dominance therophytique avec 42,2%, sur le plan de l’origine biogéographique, on y note une forte proportion d’espèces méditerranéennes. Les milieux forestiers (urbains et suburbains) sont les habitats à fort IFI cela s’explique par un impact humaine modéré. Des analyses multivariées ont permis d’identifier trois groupes qui se différencient par le degré d’anthropisation, couplé à d’autres facteurs écologiques agissant simultanément. L’étude montre une diversité floristique insoupçonnée dans ces milieux urbanisés pouvant jouer un rôle important dans le cadre des trames vertes urbaines