Lacertídeos como bioindicadores de contaminação agrícola

Doutoramento em Biologia - Ecotoxicologia e Biologia AmbientalApesar do recente aumento no número de estudos, os lagartos persistem como um dos grupos menos estudados em ecotoxicologia e o desconhecimento em relação à sua resposta à contaminação ambiental é enorme. A nível europeu, os lacertídeos têm sido identificados como potenciais espécies modelo para a ecotoxicologia com répteis. O principal objectivo deste projecto era determinar se um lacertídeo abundante pertencente ao género Podarcis, podia ser utilizado como bioindicador de exposição e toxicidade em zonas agrícolas. Para atingir este objectivo, utilizámos uma estratégia integrada com três fases. Numa primeira fase realizou-se um estudo de campo para documentar o tipo de exposição e parâmetros populacionais de populações de lacertídeos que ocorrem em zonas de uso intenso de pesticidas e zonas de agricultura orgânica. A segunda fase consistiu num estudo de mesocosmo em que se expuseram juvenis a um conjunto de pesticidas em condições controladas durante um período de um ano. Finalmente, a terceira fase incluiu um estudo laboratorial sobre os efeitos do clorpirifos, um dos insecticidas mais utilizado a nível global, em lagartixas. No término de cada um dos estudos, analisaram-se diversos biomarcadores e parâmetros de exposição e toxicidade a pesticidas nos diferentes indivíduos. Este conjunto abrangente de parâmetros foi analisado em diferentes níveis de organização biológica, incluindo parâmetros populacionais, bem como comportamentais, fisiológicos, bioquímicos e histológicos. Em geral, detectaram-se poucas diferenças estatísticas significativas entre as populações dos campos expostos a pesticidas e populações referência. Confirmando a dificuldade que existe em isolar os efeitos de diferentes contaminantes sobre as populações de outros factores locais, ciclos sazonais ou eventos estocásticos. As populações de P. bocagei parecem ser capazes de lidar com o nível observado de exposição a pesticidas. No entanto, indivíduos que vivem em locais expostos a pesticidas parecem estar menos adaptados ecologicamente do que aqueles que vivem em locais referência, apresentando um estado de depleção nutricional e sinais de stress metabólico. Os resultados obtidos com os animais da experiência de mesocosmo parecem reforçar estes resultados. Os animais prosperaram relativamente bem em todos os mesocosmos, independentemente do tratamento ou não com pesticidas, apresentando uma ampla gama de comportamentos naturais. A abordagem laboratorial confirmou P. bocagei como um valioso indicador de exposição sub-letal a doses ambientalmente realistas de clorpirifos. De acordo, com o conjunto d resultados obtidos, P. bocagei parece ser um bioindicador adequado de exposição a pesticidas.Lizards are among the least studied groups in ecotoxicology and despite a recent increase in the number of studies, there is still a lack of knowledge regarding their response to environmental contamination. In Europe, lacertid lizards have been identified as potential model species for reptile ecotoxicology. The main question of this project was to assess if a highly abundant lacertid lizard belonging to the genus Podarcis, could be used as a bioindicator of pesticide exposure and toxicity in agricultural areas. To achieve this end, we used a three-stage tiered approach. The first tier took the form of a field survey to document the nature of the exposure and the population parameters of lacertids occurring in areas of intensive pesticide usage as well as areas of negligible pesticide usage. The second tier consisted of a mesocosm study in which naïve lizards were exposed to pesticides in a controlled experiment. Finally, the third tier included a laboratory approach to the effects of one of the most common insecticides used worldwide, chlorpyrifos. We assessed pesticide impact in individuals from the different tiers using a comprehensive set of biomarkers applied at different levels of biological organization, including population parameters as well as behavioral, physiological, biochemical and histological biomarkers. We detected few statistically significant differences between reference and exposed populations in the field study. Confirming the difficulty to isolate the effects of contaminants on natural populations where other local factors, natural cycles or stochastic events occur. P. bocagei populations seem to be able to compensate with the observed level of pesticide exposure. Nevertheless, individuals living in exposed sites seem to be less ecologically fit than those living in reference sites, presenting a depleted nutritional status and signs of metabolic stress. The results from the mesocosm setting reinforce these results. Lizards prospered relatively well in all enclosures, treated or not with pesticides, presenting a broad range of natural behaviors. The laboratory approach confirmed P. bocagei as valuable indicator of sub-lethal exposure to environmental realistic doses of chlorpyrifos. According to our results, P. bocagei seems to be a suitable bioindicator of pesticide exposure

Composition and seasonal variation of epigeic arthropods in field margins of NW Portugal

Field margins act as shelters for different arthropod taxa in agricultural fields. Several factors may promote seasonal changes in arthropod communities, especially in regions with marked seasonality, such as Mediterranean areas. Epigeic arthropods were sampled from the margins of fields located in northwestern Portugal during 2 contrasting seasons, spring and autumn. Organisms were identified to family or order level and seasonal variation in arthropod communities was evaluated. Abundance, group richness, and feeding guild parameters were affected by sampling season, with both abundance and richness being higher in spring. Of the groups captured in both seasons, most evidenced either higher abundance in spring or similar abundance between seasons. Ants constituted one of the most abundant trophic guilds in spring but one of the least captured in autumn, while catches of parasitoids and parasites were not affected by sampling season. Results indicate that the higher taxa approach is useful to distinguish seasonally distinct communities

Floresta, política e trabalho: a exploração das madeiras-de-lei no Recôncavo da Guanabara (1760-1820) Forest, politics and labor: the extraction of timber in the Recôncavo da Guanabara (1760-1820)

O artigo procura contribuir para o adensamento da historiografia acerca das operações de extração das madeiras-de-lei, espécies de árvores particularmente propícias à construção naval e por isso legalmente reservadas à apropriação preferencial por parte da Coroa portuguesa no território colonial. O recorte espaço-temporal abarca os sertões do Recôncavo da Guanabara (Capitania do Rio de Janeiro) e, em particular, a bacia do rio Macacu no final do período colonial. Usa-se documentação variada (crônicas oficiais, descrições de viajantes, correspondência, lista nominativa de habitantes e inventário post-mortem) com o objetivo de mostrar que as relações socioeconômicas dos atores envolvidos (funcionários reais, proprietários fundiários, fabricantes, serradores etc.) entre si e com a floresta eram ditadas por negociações cotidianas que viabilizavam a 'letra fria' das leis metropolitanas.<br>The article aims to contribute for the still rarified historiography about the extraction of madeiras-de-lei, those tree species that are particularly suitable for shipbuilding and, for that reason, legally reserved for preferential appropriation by the Portuguese crown in the Brazilian colonial territory. The space-temporal outline embraces the inner lands of Recôncavo da Guanabara (Rio de Janeiro captaincy), in particular the Macacu river basin, at the end of the colonial period. Varied documentation (official chronicles, travelers accounts, letters, a economic-demographic census, and a post-mortem inventory) is used in order to show that socioeconomic relations among the actors involved (royal bureaucracy, landowners, timber producers, sawyers, etc.), and those between them and the forest were dictated by daily life negotiations which made the 'cold letter' of metropolitan laws viable

Resumos concluídos - Saúde Coletiva

Resumos concluídos - Saúde Coletiv

Resumos concluídos - Saúde Coletiva

Resumos concluídos - Saúde Coletiv

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora