623 resultados para generalist herbivore
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L’utilisation de l’espace par une proie herbivore est souvent modulée par le compromis entre l’acquisition de fourrage et l’évitement de la prédation. Nous avons testé l’effet de la manipulation de la disponibilité de fourrage et du ratio couvert forestier/ouverture sur l’utilisation de l’espace par le cerf de Virginie (Odocoileus virginianus) et sa vulnérabilité à la chasse sportive sur l’île d’Anticosti. Nos résultats ont démontré que l’utilisation de l’espace par le cerf et sa vulnérabilité à la chasse peuvent être modifiées par différentes composantes structurales de l’habitat. L’augmentation de la disponibilité de fourrage a entrainé une plus grande utilisation des prairies fertilisées par le cerf, tandis que la diminution du ratio couvert forestier/ouverture a augmenté sa vulnérabilité à la chasse. Ces résultats procurent des pistes de solutions pour les gestionnaires fauniques qui doivent à la fois réduire les dommages causés par les hautes densités de cerfs et satisfaire les chasseurs en maintenant un nombre élevé d’observation de cerfs.
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Large plants are often more conspicuous and more attractive for associated animals than small plants, e.g. due to their wider range of resources. Therefore, plant size can positively affect species richness of associated animals, as shown for single groups of herbivores, but studies usually consider intraspecific size differences of plants in unstandardised environments. As comprehensive tests of interspecific plant size differences under standardised conditions are missing so far, we investigated effects of plant size on species richness of all associated arthropods using a common garden experiment with 21 Brassicaceae species covering a broad interspecific plant size gradient from 10 to 130 cm height. We recorded plant associated ecto-and endophagous herbivores, their natural enemies and pollinators on and in each aboveground plant organ, i.e. flowers, fruits, leaves and stems. Plant size (measured as height from the ground), the number of different plant organ entities and their biomass were assessed. Increasing plant size led to increased species richness of associated herbivores, natural enemies and pollinating insects. This pattern was found for ectophagous and endophagous herbivores, their natural enemies, as well as for herbivores associated with leaves and fruits and their natural enemies, independently of the additional positive effects of resource availability (i.e. organ biomass or number of entities and, regarding natural enemies, herbivore species richness). We found a lower R-2 for pollinators compared to herbivores and natural enemies, probably caused by the high importance of flower characteristics for pollinator species richness besides plant size. Overall, the increase in plant height from 10 to 130 cm led to a 2.7-fold increase in predicted total arthropod species richness. In conclusion, plant size is a comprehensive driver of species richness of the plant associated arthropods, including pollinators, herbivores and their natural enemies, whether they are endophagous or ectophagous or associated with leaves or fruits.
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Endophytic fungi, which live within host plant tissues without causing any visible symptom of infection, are important mutualists that mediate plant-herbivore interactions. Thrips tabaci (Lindeman) is one of the key pests of onion, Allium cepa L., an economically important agricultural crop cultivated worldwide. However, information on endophyte colonization of onions, and their impacts on the biology of thrips feeding on them, is lacking. We tested the colonization of onion plants by selected fungal endophyte isolates using two inoculation methods. The effects of inoculated endophytes on T. tabaci infesting onion were also examined. Seven fungal endophytes used in our study were able to colonize onion plants either by the seed or seedling inoculation methods. Seed inoculation resulted in 1.47 times higher mean percentage post-inoculation recovery of all the endophytes tested as compared to seedling inoculation. Fewer thrips were observed on plants inoculated with Clonostachys rosea ICIPE 707, Trichoderma asperellum M2RT4, Trichoderma atroviride ICIPE 710, Trichoderma harzianum 709, Hypocrea lixii F3ST1 and Fusarium sp. ICIPE 712 isolates as compared to those inoculated with Fusarium sp. ICIPE 717 and the control treatments. Onion plants colonized by C. rosea ICIPE 707, T. asperellum M2RT4, T. atroviride ICIPE 710 and H. lixii F3ST1 had significantly lower feeding punctures as compared to the other treatments. Among the isolates tested, the lowest numbers of eggs were laid by T. tabaci on H. lixii F3ST1 and C. rosea ICIPE 707 inoculated plants. These results extend the knowledge on colonization of onions by fungal endophytes and their effects on Thrips tabaci.
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Coffee is predicted to be severely affected by climate change. We determined the thermal tolerance of the coffee berry borer, Hypothenemus hampei, the most devastating pest of coffee worldwide, and make inferences on the possible effects of climate change using climatic data from Colombia, Kenya, Tanzania, and Ethiopia. For this, the effect of eight temperature regimes (15, 20, 23, 25, 27, 30, 33 and 35 degrees C) on the bionomics of H. hampei was studied. Successful egg to adult development occurred between 20-30 degrees C. Using linear regression and a modified Logan model, the lower and upper thresholds for development were estimated at 14.9 and 32 degrees C, respectively. In Kenya and Colombia, the number of pest generations per year was considerably and positively correlated with the warming tolerance. Analysing 32 years of climatic data from Jimma (Ethiopia) revealed that before 1984 it was too cold for H. hampei to complete even one generation per year, but thereafter, because of rising temperatures in the area, 1-2 generations per year/coffee season could be completed. Calculated data on warming tolerance and thermal safety margins of H. hampei for the three East African locations showed considerably high variability compared to the Colombian site. The model indicates that for every 1 degrees C rise in thermal optimum (T(opt)), the maximum intrinsic rate of increase (r(max)) will increase by an average of 8.5%. The effects of climate change on the further range of H. hampei distribution and possible adaption strategies are discussed. Abstracts in Spanish and French are provided as supplementary material Abstract S1 and Abstract S2.
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O golfinho-comum (Delphinus delphis) é uma das espécies de cetáceos mais abundantes e mais amplamente distribuídas em todo o planeta, sendo a espécie mais abundante ao longo da costa continental portuguesa. Algumas das suas principais presas apresentam um elevado interesse comercial estando por isso, muitas vezes, associado a capturas acidentais em artes de pesca. Contudo, estudos mais recentes sobre os hábitos alimentares desta espécie na costa portuguesa são escassos. Assim, este estudo visa contribuir para a avaliação da ecologia alimentar deste cetáceo na costa portuguesa através de índices de importância numérica, ocorrência e do peso estimado, permitindo descrever a dieta não só em termos qualitativos, mas também em termos quantitativos. Foram examinados os conteúdos estomacais de 55 golfinhoscomuns arrojados na costa continental portuguesa (norte e centro) entre 2004 e 2015. De um total de 6699 presas identificadas, 66% pertenciam à classe dos peixes, 32% eram cefalópodes e 3% eram crustáceos. As espécies-presa de peixes mais importantes em termos de importância numérica foram os góbios (Gobiidae) e o carapau (Trachurus sp.). Em relação à ocorrência foram o góbio (Gobiidae) e a sardinha (Sardina pilchardus), seguidas de carapau, as espécies predominantes. Relativamente ao peso, a sardinha foi a espécie-presa predominante, seguida de faneca (Trisopterus luscus) e carapau. Quanto aos cefalópodes, a lula-bicuda (Alloteuthis sp.) foi a espécie mais importante, tanto em termos de importância numérica como em termos de ocorrência. A lula-comum (Loligo sp.) foi a mais importante em termos de peso total estimado. As espécies demersais dominaram a dieta do golfinho-comum, com uma percentagem numérica de 40%. Foram detetadas diferenças entre machos e fêmeas na composição da dieta relativamente à sardinha. Foram detetadas diferenças entre indivíduos maturos e imaturos na composição da dieta relativamente à lula-bicuda. A diversidade de presas observada nos conteúdos estomacais do golfinho-comum sugere um comportamento oportunista, consumindo as presas mais abundantes, localmente. As interações com as artes de pesca podem levar a uma elevada mortalidade destes mamíferos marinhos. Deste modo, a realização de estudos sobre os hábitos alimentares de cetáceos permitem uma melhor compreensão das possíveis interações com a pesca, e a melhoria de estratégias de conservação para evitar a morte destes animais.
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The annual fish yields from Lake Victoria have been increasing when the species diversity was dramatically declining. The new fishery is dominated by the introduced predator (Lates niloticus Linne), the exotic herbivore (Oreochromis niloticus Linne) and an indigenous zooplanktivore (Rastrineobola argentea Pellegrin). While the three predominant fish species could sustain the high catch levels, the future viability for the fishery will depend on prudent exploitation regimes and effective management and conservation strategies.
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Relatório de Estágio apresentado à Escola Superior de Educação de Paula Frassinetti para obtenção de grau Mestre em Educação Pré-Escolar e Ensino 1º ciclo do Ensino Básico.
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Relatório de Estágio apresentado à Escola Superior de Educação de Paula Frassinetti para obtenção de grau Mestre em Educação Pré-Escolar e Ensino 1º ciclo do Ensino Básico.
Resumo:
O presente relatório de qualificação profissional surgiu no âmbito da Unidade Curricular de Prática Pedagógica Supervisionada, pertencente ao plano de estudos do Mestrado em Educação Pré-Escolar e Ensino do 1.º Ciclo do Ensino Básico. Deste modo, pretende evidenciar o percurso formativo da mestranda, refletindo as experiências e as competências desenvolvidas nos dois níveis educativos, tendo em vista a construção de um perfil duplo. Neste documento reflexivo espelha-se, portanto, o desenvolvimento de práticas sustentadas num quadro teórico e legal, construído ao longo do percurso formativo da mestranda, nas caraterísticas do contexto onde foram desenvolvidas as práticas nos dois níveis educativos e nos conhecimentos obtidos sobre a individualidade de cada criança, os seus interesses e necessidades. Finda-se este mesmo documento, com uma análise reflexiva de todo o percurso desenvolvido, focando-se as competências adquiridas, evidenciando-se, deste modo, a progressão da mestranda ao longo do mesmo. Durante as suas ações a mestranda perfilhou a metodologia de investigação-ação, espelhada ao longo deste relatório de estágio, desenvolvendo os processos de observação, planificação, ação, avaliação e reflexão, de uma forma cíclica, articulando-os. Esta metodologia e os instrumentos e estratégias desenvolvidos com base na mesma permitiram à mestranda a melhoria das suas práticas, possibilitando-lhe um olhar crítico e reflexivo sobre as mesmas, bem como, sobre a educação na Educação Pré- Escolar e no 1.º Ciclo do Ensino Básico, proporcionando, desta forma, o desenvolvimento de competências investigativas e reflexivas. Todo este percurso formativo possibilitou à mestranda o desenvolvimento de competências pessoais e profissionais na construção de um perfil generalista, apresentando-se como as primeiras “pegadas” de uma aprendizagem ao longo da vida.
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Increasing abundance of non-commercial sprats and decreasing biomass and landings of commercial anchovies and sardines justify the need to study the feeding ecology and trophic niche overlap of these planktivorous species in the Gulf of Lions. Their diet has been investigated on the basis of stomach content and stable isotope analyses in 2011 and 2012 according to different depths and regions in the study area. The main prey were Corycaeidae copepods, Clauso/Paracalanus, Euterpina acutifrons and Microsetella, for sprats and small copepods, such as Microsetella, Oncaea and Corycaeidae, for anchovies and sardines. This is the first time that the diet of sprats is described in the Gulf of Lions. Sprats fed on a larger size spectrum of prey and seem to be more generalist feeders compared to anchovies and sardines. Ontogenetic changes as well as spatial and temporal variations of the diet occurred in the three species. Stable isotope analysis revealed mobility of sardines and sprats among feeding areas while anchovies exhibited preferred feeding areas. Sprats showed a higher relative condition assessed by C/N ratios than sardines and anchovies. Our results showed an overlap of the trophic niches for the three species, indicating a potential trophic competition in the Gulf of Lions.
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Relatório de estágio apresentado à Escola Superior de Educação de Paula Frassinetti para a obtenção do grau de Mestre em Ensino do 1º e 2º Ciclo do Ensino Básico
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Relatório de estágio apresentado à Escola Superior de Educação de Paula Frassinetti para obtenção do grau de mestre em ensino do 1º e 2º ciclo do ensino básico
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Relatório de estágio apresentado à Escola Superior de Educação de Paula Frassinetti para obtenção de grau de Mestre em Ensino do 1º e do 2º Ciclo do Ensino Básico
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Relatório de Estágio apresentado à ESEPF para obtenção do grau de Mestre em Ensino do 1º e 2º ciclo do Ensino Básico
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Co-management, or participative management of fisheries, consists of returning or opening to the community the management of fisheries. This work, carried out in northern Mozambique, analyzed the ecological and social impacts of the implementation of co-management of fisheries. Firstly 198 species of fish were found and photographed and a guide to identification of species - essential to who works in the marine environment – was produced. Following, the spill-over effect was identified in a marine sanctuary. It occurred after 6 years and only for herbivore fishes and not to the carnivores. In order to evaluate co–management of fisheries effects, the captures of the entire province were analyzed. No differences were found in the diversity of the species caught, but an increase of the fish size was detected: this size was smaller in the fishing centers with no CCP (Community Fishing Councils), slightly bigger in the fishing centers with CCP and even bigger in the fishing centers with a more efficient management. At the same time it was observed that the size of the fish caught is bigger in the fishing centers further away from the markets. In addition to the ecological effects and the effects on fisheries, it was also analyzed the point of view of those who live the co-management. The socioeconomic factors that have a stronger influence in their perceptions are the age and the wealth. Finally and according to the CCP members, their main achievements are in the fisheries inspection and in the creation of conservation areas. Their main difficulties are the lack of means of transportation and the lack of recognition of the CCP's authority; both among the population and in the coordination with local authorities. This thesis pioneered in Mozambique in assessing the effects of Community sanctuaries and the effects of CCP on fisheries as well as by revealing the profile of the supporters of co-management and marine sanctuaries. Finally, an assessment of the matter of fact problems that the communities have to face when implementing co-management was also made.