Os holandeses ocuparam durante 24 anos o nordeste brasileiro: Pernambuco, Paraíba, Rio Grande do Norte e Itamaracá. (1630-1654). Nesse período, Pernambuco se transformou numa verdadeira metrópole, com uma vida cultural intensa, onde poetas, cientistas e filósofos tornaram o Brasil num centro intelectual único na América do Sul. Nesse contexto, os judeus puderam constituir uma comunidade com escolas, sinagogas e cemitério, dando sua contribuição ao enriquecimento da vida cultural da região. No ano de 1654, os portugueses reconquistaram o Nordeste e os holandeses foram expulsos. Junto com os holandeses, foram também expulsos cerca de 600 judeus, pois no império português só a religião católica era permitida. Após sofrerem várias vicissitudes durante a viagem, vinte e três brasileiros; homens, mulheres e crianças, conseguiram chegar à Nova Amsterdã, atual Nova Iorque. O início da vida foi difícil. Nova Iorque era então uma insignificante vila, semideserta, governada por um calvinista fanático, que impôs sérias dificuldades aos recém-chegados. Depois de numerosas atribulações, os vinte e três judeus conseguiram sobreviver exercendo um pequeno comércio que logo se expandiu. Depois da guerra pela independência norte-americana, os descendentes dos sefaraditas alcançaram plena cidadania. A religião deixou de ser empecilho. Os judeus não eram mais uma minoria tolerada, mas cidadãos norte-americanos plenos. Os brasileiros e seus descendentes espalharam-se por diversas regiões dos Estados Unidos, e se sobressaíram na luta pelos direitos civis, pela tolerância e liberdade. Os Henrique, os Lucena, os Andrade, os Costa, os Gomes, os Ferreira ajudaram a construir um novo mundo de cidadãos livres e iguais / The Dutch invaded and occupied the Brazilian Northeast (Pernambuco, Paraíba, Rio Grande do Norte and Itamaracá) for 24 years (1630-1624); In this period, Pernambuco evolved into a real metropolis, with an intense cultural life, where poets, scientists and philosophers transformed Brazil into an intellectual center unique in South America. In this context the Jews were able to constitute a community with schools, synagogues and a cemetery, and to give their contribution to the enrichment of the cultural life of the region. In the year of 1654 the Portuguese conquered the Northeast and expelled the Dutch. With them were also expelled about 600 Jews, because in the Portuguese Empire only Catholics were allowed. After a dangerous voyage, 23 jews from Brazil, men, women and children were able to arrive to New Amsterdam, today New York. The beginning of life in North America was hard. New Amsterdam was a small village, hardly populated and ruled by a fanatic Calvinist that imposed serious difficulties to the newly arrived. After various vicissitudes, the 23 sephardim were able to survive, by a small merchant business that soon grew up. After the American war of Independence, the descendants of these Jews obtained their citizenship. The religion was not anymore an obstacle. Jews were not anymore a tolerated minority, but North Americans citizens. The Brazilians and their descendants sprayed for various regions of the United States and were important in the struggle for the civil rights, for tolerance and freedom. The Henrique, Lucena, Andrade, Costa, Gomes and Ferreira helped to build a new world of free and equal citizens

M.Sc. / Invasive species are a considerable threat to ecosystems globally, especially on islands where species diversity can be relatively low. Understanding the drivers of invasion is the first step towards an adequate management plan. Although Darwin’s naturalisation hypothesis has fuelled our understanding in this regard, several studies provided mixed results, suggesting that invasion success might be context-dependent. The main objectives of this study are two-fold: (1) testing Darwin hypothesis on Robben Island, and (2) investigating the relative role of invasive alien plants on phylogenetic diversity (PD) loss in native community. I sampled extensively the flora of the island, and using a Bayesian analysis, I reconstructed its phylogeny based on two plastid DNA loci, rbcLa and matK. I also surveyed a total of 127 plots of 50 x 50 m (i.e. local communities) where species presence/absence was recorded. Analysing phylogenetic patterns of the native and invasive floras at both regional (phylogeny level) and smaller scales (plots level), I found that invasive species are, on average, more distantly related to the native communities, giving strong support to the hypothesis tested. Furthermore I found that native communities have accumulated lower PD than alien communities; and that local communities are more overdispersed than expected. These findings suggest that competitive interactions might be the major ecological forces shaping plant communities, with the possibility of alien being higher competitors than native, and therefore decreasing native plant diversity. The implications of these findings for the recovery of native plants are also discussed. Key words: Invasion biology - Darwin’s naturalisation hypothesis - Phylogenetic diversity - Community structure - Conservation - Robben Island, South Africa.

Colonisation theory relative to introduced populations was examined with a view to determining the usefulness of theoretical concepts in the prediction of the success of an invasion by a species. To this end, the Great Fish River, with reference to species introduced by the Orange/Fish Tunnel, was used as a case history. It was concluded that theoretical descriptions of population growth, control and decline are useful only when considering individual ecosystems or species. The highly variable nature of species and environments nullifies attempts to simplify behavioural characteristics into a predictive framework. There is an abundance of terminology associated with introduced organisms and frequently many of these terms are used synonymously. Eleven terms have been defined in this thesis with a view to standardising terminology. Characteristics of species and environments which enhance their susceptibility to invasions by exotic ichthyofauna were discussed and summarised. Distribution data concerning exotic fish introduced into the Great Fish River by the Orange/Fish Tunnel has demonstrated that, with the exception of Clarias gariepinus, all remaining exotics have restricted distributions. Only Barbus aeneus appears to be extending its range down the drainage. Age, Growth, reproduction and condition data support the conclusion that, excluding B. aeneus and C. gariepinus, invasive species in the drainage are not performing well. Of the five invasive species (B. aeneus, Labeo capensis, L. umbratus, Gephyroglanis sclateri and Cyprinus carpio), only two have established populations (B. aeneus· and C. gariepinus). Labeo umbratus and C. carpio were present on the Great Fish River prior to the construction of the tunnel and populations of the species could not be distinguished. It was concluded that there is no evidence to suggest that exotic species introduced into the Great Fish River are having a deleterious effect on indigenous, endangered ichthyofauna. Monitoring of the drainage should be continued to ensure that a danger to indigenous species does not develop.

The study of biological invasions is not only essential to regulate their vast potential for ecological and economical harm, they offer a unique opportunity to study adaptive evolution in the context of recent range expansions into novel environments. The North American invasion of the gypsy moth, Lymantria dispar L., since its introduction in 1869 to Massachusetts, has expanded westward to Minnesota, northward to Canada, and southward to North Carolina. Fluctuating range dynamics at the southern invasive edge are heavily influenced by heat exposure over their optimal (supraoptimal) during the larval stage of development. We coupled genomic sequencing with reciprocal transplant and laboratory-rearing experiments to examine the interactions of phenotypic, genetic, and environmental variation under selective supraoptimal regimes. We demonstrate that while there is no evidence to support local adaptation in the fitness-related physiological traits we measured, there are clear genomic patterns of adaptation due to differential survival in higher temperatures. Mapping of loci identified as contributing to local adaptation in a selective environment and those associated with phenotypic variation highlighted that variation in larval development time is partly driven by pleiotropic loci also affecting survival. Overall, I highlight the necessity and inferential power gained through replicating environmental conditions using both phenotypic and genome-wide analyses.

Les modèles climatiques prédisent une augmentation globale de la température de 1 à 4°C d’ici 2100. Les modifications de climat engendrées par ce réchauffement devraient favoriser les invasions biologiques. L’objectif général de cette thèse est d’explorer l’impact du réchauffement et du changement climatique sur quatre espèces de macrophytes invasifs en Europe. Le travail réalisé a porté sur la germination, la croissance, la physiologie et la distribution des ces espèces à travers des expérimentations en conditions contrôlées, en jardin expérimental, et via des modèles de distribution d’espèces. Nous avons montré que i) des températures plus élevées améliorent modérément les capacités de germination de Ludwigia hexapetala et Ludwigia peploides subsp. montevidensis, diminuent la survie des plantules mais augmentent leur production de biomasse, ii) l’effet d’une augmentation de température sur les macrophytes dépend de la saison à laquelle elle a lieu, iii) une augmentation de 3°C peut avoir des conséquences sur le métabolisme sans pour autant affecter la croissance, iv) la Jussie L. hexapetala est la seule espèce qui a de meilleures capacités de croissance à la fois apicale et latérale face à un réchauffement, v) les modèles prédisent une augmentation de l’aire de distribution de Ludwigia spp., Myriophyllum aquaticum et E. densa dans leurs aires d’invasion, et une diminution de leur distribution sur les autres continents, y compris dans leur aire d’indigénat. Ce travail permet de mieux comprendre les conséquences possibles des modifications climatiques sur les macrophytes invasifs, afin d’appréhender et d’anticiper leur potentiel de colonisation futur. / Climatic models predict a rise of globale surface temperature about 1 to 4°C by 2100. Climate modifications generated by this warming might favor biological invasions. The general objectif of this thesis was to explore the impacts of climate warming and climate change on four macrophytes invasive in Europe. This work focused on germination, growth, physiology and distribution of these species, through experiments in controlled conditions, in experimental garden and by using species distribution models. We showed that i) higher temperatures favor moderately the germination capacity of Ludwigia hexapetala and Ludwigia peploides subsp. montevidensis, decrease the seedlings survivorship but improve their biomass production, ii) the effect of increased temperature on macrophytes depends on the season, iii) a 3°C warming can modify metabolism without generating changes on the growth, iv) the water primroses L. hexapetala is the only species that showed both better apical and lateral growth when facing a warming, v) models predict an increase of the distribution surface of Ludwigia spp., Myriophyllum aquaticum and E. densa in their invasive ranges, and a decrease of their distribution area in the other continents, including their native range. This thesis offer a better understanding of climate changes consequences on invasive macrophytes in order to anticipate their futur colonisation potential.

The disruption of mutualisms by invasive species has consequences for biodiversity loss and ecosystem function. Although invasive plant effects on the pollination of individual native species has been the subject of much study, their impacts on entire plant–pollinator communities are less understood. Community-level studies on plant invasion have mainly focused on two fronts: understanding the mechanisms that mediate their integration; and their effects on plant–pollinator network structure. Here we briefly review current knowledge and propose a more unified framework for evaluating invasive species integration and their effects on plant–pollinator communities. We further outline gaps in our understanding and propose ways to advance knowledge in this field. Specifically, modeling approaches have so far yielded important predictions regarding the outcome and drivers of invasive species effects on plant communities. However, experimental studies that test these predictions in the field are lacking. We further emphasize the need to understand the link between invasive plant effects on pollination network structure and their consequences for native plant population dynamics (population growth). Integrating demographic studies with those on pollination networks is thus key in order to achieve a more predictive understanding of pollinator-mediated effects of invasive species on the persistence of native plant biodiversity.

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Watercourses and especially their riparian vegetation are habitats that are very sensitive to spreading of invasive plant species. Rivers create natural migration routes (corridors) and help propagules to spread quickly and easily. The theoretical part of this thesis is focused on plant invasions and covers also the most recent knowledge in the field of invasion ecology. In the practical part of this thesis the spread of invasive neophytes in the riparian vegetation of the Kamenice river in Northern Bohemia is described. The plant species were examined during the field survey along the entire stream of the Kamenice river. In total, common occurence of 7 invasive taxa were recorded, namely Impatiens parviflora, I. glandulifera, Reynoutria japonica, R. sachalinensis, R. bohemica, Solidago gigantea and S. canadensis. The distribution of observed taxa along the stream as well as on the banks was relatively uneven.

No description available.

No description available.