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Seminarios

Grabaciones en vídeo de los seminarios de la EBD
Documentos
— 20 Resultados por página
Mostrando el intervalo 61 - 80 de 90 resultados.
Nombre Tamaño Descargas
23_03_2017, Maria Jesus Rodriguez
Título: Ecological interactions between amphibian larvae and aquatic macrophytes Resumen: Despite the wealth of knowledge of ecology of amphibian larvae, their functional role within aquatic systems is relatively poorly studied. In this thesis we study the interactions between amphibian larvae and other trophic levels present in temporary ponds, especially with aquatic macrophytes. We focus on the effects of tadpole herbivory on native aquatic macrophytes, studying the consequences for the reproductive phenology and effort of the plants, under different contexts of long lasting vs. dry down water levels. Moreover, we are also assessing the effects of an invasive plant, Azolla filoculoides on native macrophytes and zooplankton, and how these effects can cascade onto amphibian larvae. Finally, we are also studying different aspects of the dispersal of seeds of aquatic macrophytes by tadpoles, and the possibility of secondary long distance dispersal as a consequence of bird predation on amphibian larvae.
244,4MB 260
23_06_2016, Simone Fontana, Regularity in the traits of individuals outcompetes other biodiversity metrics in explaining ecosystem properties
Simone Fontana Department of Aquatic Ecology Eawag: Swiss Federal Institute of Water Science and Technology Títle: Regularity in the traits of individuals outcompetes other biodiversity metrics in explaining ecosystem properties Abstract: Biodiversity affects ecosystem properties through changes in the trait composition and variation of natural communities. Using phytoplankton data obtained across 28 lakes we found that trait evenness - the regularity in distribution of morpho-physiological traits of individual organisms - was the strongest predictor of community resource use and biomass yield. Our results suggest that elucidating the mechanisms linking individual-level trait variation to community dynamics could improve our ability to forecast changes in ecosystem properties across environmental gradients.
533,9MB 337
23_11_2017, Miquel Arnedo
Miquel Arnedo Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Fac. Biologia, Universitat de Barcelona. Hopping, splitting or shifting: How to diversify in isolation? Insights from the spider world Islands are the test-tube experiments of evolutionary biologist and have played a fundamental role in our current understanding of diversification. Processes such as adaptive radiation and convergent evolution are trademarks of island biotas. However, isolated ecosystems do also offer ample opportunities for non-ecologically driven speciation. Because of their airborne dispersal capabilities, spiders are among the first settlers of remote islands and their predatory habits and ability to endure starvation makes them important component of other isolated ecosystems, such as caves and mountain tops. In this presentation, I will review some of the research conducted in my lab on the diversification of spiders on island-like systems and will discuss its main drivers, and the underlying similarities and idiosyncrasies of the evolutionary process in remote and extreme habitats.
731,1MB 7
24_02_2015 Magdalena Zabek, Population dynamics of feral horses in Australia
Australia has the largest population of feral horses (Equus ferus caballus) in the world, with some one million feral horses occupying the diverse and often remote Australian environments. Despite numerous concerns raised by government agencies, private landholders, and the general public on feral horse presence in the Australian ecosystems, there is lack of collective solutions on the management of this overabundant species. In this talk I focus on two studies from my PhD research that relate to measurement of the main vital parameters of the population of feral horses, which occupies a unique coniferous environment in Australia. I will first discuss a method for measuring reproduction and survivorship of the population. I show that estimation of these parameters could be used for modelling the annual population growth rate, which in turn could be used for long-term population management. I will then screen a documentary, which depicts for the first time the social organisation of feral horses in Australia in an attempt to understand the biology of the species and their relationship with the environment. With this work I demonstrate the value of understanding the ecology of feral animals and encourage future managers and government organisations to cooperate in the formulation of the appropriate feral horse management programs in Australia and elsewhere.
299,4MB 39
25_02_2016, Candelaria Rodríguez, Opportunistic pollination by birds and lizards in the Canary Islands
The reproductive success depend on the animal’s effectiveness and the context in which the mutualism occurs. The present thesis is about the interplay between these two aspects in the mutualism of pollination. We try to meet the challenge with a particular group of pollinators, opportunistic nectar-feeding vertebrates, in a particular context, oceanic islands. Due to their intrinsic ecological conditions, oceanic islands favour the appearance of depauperate and disharmonic assemblages of opportunistic pollinators, whose effectiveness and level of context dependence may differ significantly from those of continental systems. In the concrete case of the Canary Islands, passerine birds and lacertid lizards are frequent floral visitors of native flora, but their pollination ecology has remained almost unknown. For this reason, the present thesis follows a dual objective: first to experimentally demonstrate the effectiveness of birds and lizards as pollinators and analyse the potential differences between both functional groups, to then understand how their benefits on plant fitness vary under the presence of antagonists.
377,5MB 509
25_11_2015 Agustin Paviolo Proyecto Yaguarete, Investigaciones para conservar el jaguar en el Bosque Atlántico de Argentina
Dr. Agustín Paviolo Investigador del CONICET-Instituto de Biología Subtropical Facultad de Ciencias Forestales, Univ. Nac. de Misiones "Proyecto Yaguareté: Investigaciones para conservar el jaguar en el Bosque Atlántico de Argentina" El jaguar ha pedido cerca del 95% de su distribución en Argentina y esta críticamente amenazado. Desde el año 2003 desarrollamos investigaciones sobre el estado poblacional de la especie y sus principales amenazas para generar información que sirva de base para el desarrollo de estrategias de conservación. Para obtener la información básica hemos utilizado distintas metodologías incluyendo relevamientos con cámaras trampas, muestreo de participativos, seguimiento de individuos mediante collares GPS y técnicas genéticas. Para el análisis de datos hemos usado distintos enfoques desarrollando diferentes modelos de hábitat, y hemos utilizado modelos de captura-recaptura para la estimación de densidad. Hemos desarrollado un análisis de viabilidad poblacional y utilizamos modelos de conectividad del paisaje para evaluar distintas alternativas para mantener el hábitat de la especie. Durante la charla recorreré los distintos pasos que hemos dado durante el proceso y las nuevas investigaciones en marcha. Para más información sobre nuestro trabajo pueden visitar www.proyectoyagurete.com.ar o www.facebook.com/proyaguarete
297,9MB 27
26_01_2016, Love Dalén, Using palaeogenomes to explore the evolutionary history of Pleistocene Megafauna
Genomic data from samples that originate from different time periods (heterochronous samples) provide a unique opportunity to directly examine temporal changes in genome-wide diversity. Moreover, genomic data from different points in time can also be used to infer genome-wide mutation rates, which in turn can be used to assess the timing of demographic changes and population divergence events. The aim of this presentation is to showcase how such analyses can be done, using data from woolly mammoth and wolf as examples.
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26_01_2017, Irene Paredes
Ponente: Irene Paredes Losada (Departamento de Ecología de Humedales) Título: Presión antrópica y calidad del agua en Doñana Resumen: Doñana es uno de los humedales más emblemáticos y de mayor extensión en Europa, aunque al igual que muchos otros humedales en el mundo, se encuentra amenazado por la continua presión de las actividades humanas. Una de las principales amenazas en Doñana es la contaminación por nutrientes debido a la intensa actividad agrícola, industrial y a los núcleos urbanos del entorno que, junto con las condiciones climáticas de esta región, han provocado episodios de eutrofización y han contribuido al establecimiento de nueva especies invasoras en la marisma. En este contexto, el objetivo de esta tesis es precisamente ampliar el conocimiento sobre el origen y la contribución relativa de las principales fuentes de nutrientes, en especial del nitrógeno, que llegan a la marisma a través de los arroyos vertientes. En primer lugar, se usarán datos históricos de concentración de nutrientes en la marisma de Doñana para determinar las variaciones interanuales y los factores potenciales (antrópicos y climáticos) que puedan explicar dichas variaciones durante el periodo de estudio (1995-2010). En segundo lugar, se explorarán las variaciones intranuales y espaciales de datos de concentración de nutrientes recogidos en la marisma y arroyos vertientes entre 2013 y 2016. En tercer lugar, se emplearán los isótopos estables para determinar el origen del nitrógeno que llega a los arroyos y a la marisma usando como indicadores dos especies de macrófitas acuáticas (castañuela y espadaña) y los nitratos (NO3-) disueltos en el agua. De ellos se obtendrá la firma isotópica del nitrógeno (?15N) con la que se analizará la variación espacial y se intentará cuantificar la contribución relativa de las distintas fuentes antrópicas (fertilizantes, aguas residuales) en el aporte de nitrógeno a estos sistemas acuáticos. Finalmente, tanto los resultados de concentración de nutrientes como los de isótopos estables se cruzarán con datos climáticos y de usos del suelo del entorno de Doñana para la interpretación de los mismos.?
271,3MB 209
26_01_2017, Vanessa Cespedes
Ponente: Vanessa Céspedes Castejón (Departamento de Ecología de Humedales) Título: El hemiptero invasor Trichocorixa verticalis y sus interacciones con los coríxidos nativos y los ácaros acuáticos Resumen: El coríxido invasor americano Trichocorixa verticalis verticalis se citó por primera vez en la Península Ibérica en el Algarve en 1997 y desde entonces se ha extendido dentro y fuera de Doñana, encontrándose en el delta del Guadalquivir, así como en otros lugares de interés de conservación de Andalucía, incluyendo humedales RAMSAR y Reservas Naturales. El éxito de una invasión depende en gran medida de cómo se enfrente a nuevas condiciones ambientales, tanto abióticas (requerimientos fisicoquímicos) como biológicas (interacciones con competidores nativos, con depredadores y parásitos (especialmente ácaros acuáticos)). La presente tesis investiga el papel de estos factores (abióticos -bióticos) involucrados en una invasión, haciendo hincapié en el papel de los ácaros acuáticos como limitante de la invasión.
312,7MB 233
26_10_2015, Mark JF Brown, Emerging diseases in bumblebees
Mark JF Brown (Professor in Evolutionary Ecology & Conservation Royal Holloway, University of London) Título: Emerging diseases in bumblebees Resumen: Emerging infectious diseases are a major threat to biodiversity and human health. Such diseases and the parasites/pathogens that cause them - in particular the Varroa mite and viruses - are known to be one of the main drivers of honey bee declines. I will talk about evidence for emerging infectious diseases in wild bees, particularly bumble bees, and whether they may play a role in bumble bee declines.
193,7MB 29
27_04_2017, Bruno Suarez
Título: Assembly patterns of mammal communities in a fragmented agroecosystem Resumen: The recognition of the structure of ecological communities is the main objective of community ecology. Observed patterns are fundamental to know the relative importance of the different factors that determine the structure of these ecological communities. This is because once the pattern is recognized, the question is to investigate which are the underlying processes causing that pattern. Currently, species local coexistence is better understood considering not only environmental factors or interactions among species, but also the regional distribution of the species under study. The general aim of the Thesis is to describe the assembly patterns of mammal communities in a fragmented agroecosystem and infer possible underlying processes that may cause these patterns. To do this, we follow a regional-to-local perspective.
267,4MB 260
27_04_2017, Fran Oficialdegui
Invasión del cangrejo rojo americano, Procambarus clarkii: origen, mecanismos responsables de su éxito invasor y consecuencias de la invasión. Resumen: Las invasiones biológicas son consideradas, hoy en día, una de las principales y más severas causas de pérdida de biodiversidad, y específicamente, en ecosistemas dulceacuícolas. Desde un punto de vista multidisciplinar, esta tesis se centra en el estudio de una de las especies invasoras más conocidas y extendidas a lo largo de todo el mundo: el cangrejo rojo americano (Procambarus clarkii). En grandes líneas, los objetivos son (1) conocer la historia de la invasión en Europa desde un punto de vista filogeográfico, la estructura y conectividad entre las distintas poblaciones; (2) estudiar la expresión de proteínas para saber cómo los individuos hacen frente a nuevas condiciones abióticas; (3) evaluar la compleja interacción entre dos especies invasora de cangrejo (Procambarus clarkii y Pacifastacus leniusculus); y finalmente, evaluar las consecuencias de la invasión sobre (4) especies de macroinvertebrados, (5) anfibios a causa de la quitridiomicosis y (6) otras especies de cangrejos nativos europeos a consecuencia de la afanomicosis o peste del cangrejo.
310,1MB 264
27_07_2017, Gregorio Moreno Rueda
The cost of begging: Does it exist? And if so, is it necessary to guarantee honest parent-offspring communication? Several theoretical models on the evolution of begging predicts that begging must be costly to be an honest, and evolutionarily stable, signal of need. However, the empirical search for begging cost has been unsuccessful, with proposed costs of begging, such as energy, attraction of predators, or reduced growth, not being universal or sufficient to explain the evolution of begging. Nonetheless, recent research points to a cost of begging in the form of reduced immunocompetence. Laboratory experiments with an array of bird species repetitively support the contention of a negative correlation between begging effort and immunocompetence. Moreover, my co-workers and I have shown that the negative impact of begging on immune system is not compensated by the increased ingest of food in fiercely begging nestlings. Furthermore, in a long-term field experiment, we have modified begging behaviour of pied flycatcher (Ficedula hypoleuca) nestlings, finding that begging level is under natural selection, and that its trade-off with immune system is key for understanding the impact of begging on fitness. In overall, although the subjacent cause of the relationship between begging and immune system remains unclear, recent findings suggest that offspring begging exaggeratedly may incur in an immunological cost, which has shaped the evolution of begging. However, these empirical results, demonstrating that begging is associated with a “cost”, do not demonstrate that such a cost is necessary for begging to be honest and evolutionarily stable. Begging, as other behaviours, might be inevitably associated to physiological processes, conducing to unavoidable trade-offs. In fact, several mathematical models predict that cheap begging may be honest and evolutionarily stable. The model in which I am working, as other models, predicts that begging does not require be costly to be honest, but the cost increases information contained in the signal.
315,5MB 256
27_10_2015 Thomas Lenormand, Measures of fitness opening the Pandora’s box
Although there is no difficulty in theory in estimating fitnesses, in practice, the difficulties are virtually insuperable” (Lewontin, 1974).Fitness is a key concept in evolutionary biology. In many models, this is a quantity that can be defined without (too much) ambiguity. When it comes to test these models of evolution and measure fitness empirically, however, many difficulties arise, in addition to these definitional problems. In this presentation, I will try to summarize and provide an overview of these issues. I will present different approaches to measure fitness in the lab or in the field, distinguishing 'forward' and 'backward' methods. To illustrate each case, I will use examples from my work that include some of the most precise estimates that have been obtained to date. I will finally relate the problems of fitness measures to important debates in evolutionary biology.
288,6MB 31
27_10_2016, Maria Lumbierres
Título: Modelling the biomass of Doñana's marsh vegetation using land surface phenology Resumen: Doñana marsh is one of the most important wetlands in Europe; however, it is under extreme human pressure. Remote sensing techniques have proved to be an effective method for modeling and monitoring biomass. The main objective of this project was to model the Doñana marsh biomass, to study the vegetation dynamics of the last 15 years and at the same time to predict the biomass in the future. This project consisted in four different steps: first, to mode the phenological curve, second, to calibrate the metrics of the phenological curve with the biomass production, third, to validate the model, and fourth, to map the biomass and analyze the main patterns of distribution and production. The results showed that it was possible to model the biomass production on the marsh using the NDVI; however it was clear that the high variability of the marsh made the process of modelling challenging. This variability is the result of a highly dynamic ecosystem that interplays water, soil, vegetation, and the presence of cattle. We hope this research can be a starting point to a more deeply research into the Doñana marsh biomass and be a tool for scientifically based management of the cattle in the marsh.?
495,9MB 421
28_005_2015, Jonathan Evans, Why and how do sperm find their way to particular conspecific egs
, Why (and how) do sperm find their way to particular conspecific eggs?Sexual selection (essentially the competition for mates) is traditionally studied in highly mobile organisms with complex behavioural repertoires, sophisticated visual systems, and obvious adaptations that function in the context of increasing reproductive fitness. It is far less obvious how sexual selection operates in organisms that are immobile (e.g. clamped to the seabed) and release gametes seemingly haphazardly into the external environment (i.e. sessile or sedentary external fertilizers). Indeed, Charles Darwin comically dismissed the possibility of sexual selection in such taxa in his original treatise of the topic, arguing that these organisms have ‘too low mental powers’ to be capable of the subtleties of mate choice and mating competition. The aim of this talk will be to convince you otherwise. I will summarise a series of playful experiments on mussels and sea urchins that led to the observation that these taxa exhibit sophisticated processes of sperm-egg interaction that ultimately facilitate sexual selection at the level of the gamete. Our work on these systems has revealed preliminary insights into the complex patterns of selection on ejaculates and tantalizing evidence that eggs release subtle variations in chemical signals that may facilitate the fusion of genetically compatible gametes. I’ll end the talk with some inevitable speculation on the mechanisms that might drive these processes, with the firm hope that someone far more qualified than me will put me on the right track.
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28_04_2016 Alazne Diez, Olfactory clues related to mosquito attraction
Vector-borne pathogens play an important role in the regulation of wild populations and are model systems for ecological and evolutionary studies. The evolution of these systems is the result of triangular affairs between the parasite, the vector (mosquito) and the vertebrate host. Vectors present important interspecific and interpopulation differences in their feeding behaviour and consequently, interact with their pathogens with different frequencies. As model systems, we will use two multi-host/multi-vector pathogens (Plasmodium and West Nile virus), both transmitted by mosquitoes, and Turdus merula and Passer domesticus like a host. In particular, we will analyse how different host individual characteristics may affect vector attraction and how the heterogeneity on host attractiveness may affect the transmission dynamics of pathogens. We will focus special attention of odorant bird, the feeding behaviour of mosquitoes (mammals vs birds) and the influence of the parasite in the vector and host behaviour. This information may increase our understanding on the dynamics of transmission of numerous vector borne diseases, including pathogens potentially dangerous for humans and wildlife.
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28_05_2016 Jiayue Yan
Epidemiological models for the transmission of infectious diseases used to assume that different hosts are equally appealing to their vectors, that vectors and hosts interact randomly and tended to ignore the impact of host-trait heterogeneity on disease transmission. However, recent studies have shown that mosquitoes feed disproportionately on some host species in relation to what may be expected from their relative abundance. This phenomenon may dramatically alter the host-pathogen contact rate and thus the transmission dynamics of infectious diseases. My thesis will focus on identifying the impact of host morphology, infection status and condition of the attractiveness for blood-seeking mosquitoes. First, we will review what sort of traits may serve as searching cues for host-seeking mosquitoes. Second, we will investigate the relationship between different bird traits (e.g. morphology, metabolism, infection status,) and mosquito attraction at intra- and interspecific levels. Finally, how the competence of different bird species as host of West Nile virus is related to taxonomy and immune system characteristics. By far, we have achieved some preliminary results but your suggestions will be highly welcome for our upcoming works.
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28_09_2017, Camila Mazzoni
Can RAD-Seq help sea turtle conservation? Leibniz Institute for Zoo and Wildlife Research , Berlin. Department of Evolutionary Genetics From vulnerable to critically endangered, the seven existing sea turtle species have long suffered from anthropogenic actions, such as overhunting/poaching, large-scale fishing activities, pollution and habitat degradation. Different phenomena such as hybridization and extreme low molecular diversity have been detected for some populations in different studies, but it is unclear how the recent pressures have been involved in changes in the evolutionary history of sea turtles. The amount and diversity of molecular markers available to study such influences is still very low and analyses lack statistical confidence in many cases due to low variation and/or high levels of shared SNPs. We have decided to use one single genomic approach that can boost the number and variety of nuclear molecular markers available for all sea turtle species. Assuming a deceleration of evolutionary rates in sea turtles, we have used the same Double-Digest Restriction Associated DNA (ddRAD) sequencing methodology for the five sea turtle species with worldwide distribution and generated thousands of new molecular markers that will be useful for a large number of important conservational questions, such as levels of population structuring and composition of mixed-stock. The approach we present in this study is a simple but effective solution to largely deepen the knowledge upon ddRAD data produced that can be transferred to virtually any given species or population
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29_09_2015, Eduardo de la Peña, Interacciones planta_suelo en sistemas naturales, mecanismos de funcionamiento e implicaciones para conservación y manejo de ecosistemas
Eduardo de la Peña (IHSM-CSIC/ Univ. Gent), A pesar de la inmensa diversidad de especies que habitan en el suelo y de su importancia funcional tanto a nivel de comunidad como de ecosistema, la teoría ecológica ha tenido principalmente en cuenta las interacciones que ocurren en la parte aérea de las plantas dando menor importancia a lo que ocurre en el suelo. Sin embargo, durante la última década se ha revelado la importancia que tienen las interacciones planta-suelo sobre diferentes procesos que se dan en la parte aérea. Estos estudios han demostrado que estas interacciones son imprescindibles no sólo para entender la dinámica de la comunidad vegetal sino también las respuestas de otros niveles tróficos como son los herbívoros foliares, sus enemigos naturales, polinizadores, etc. Durante mi presentación analizaré este tipo de relaciones en algunos sistemas naturales (dunas costeras, brezales atlánticos, bosques templados caducifolios) que ilustran la importancia de estas interacciones para el funcionamiento y dinámica de la comunidad vegetal y sus implicaciones en el manejo y la restauración de ecosistemas
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— 20 Resultados por página
Mostrando el intervalo 61 - 80 de 90 resultados.