Дисертації з теми "Freshwater dispersal"
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Banha, Filipe Miguel Santos. "Human dispersal of freshwater invasive fauna." Doctoral thesis, Universidade de Évora, 2016. http://hdl.handle.net/10174/18152.
Повний текст джерелаVan, der Heyden Sophie. "Testing ubiquitous dispersal and freshwater/marine divergence in free-living protist groups." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409856.
Повний текст джерелаGillilland, Merritt Gale. "Dispersal ecology and control of the invasive land snail Cepaea nemoralis (L. 1758), from Ingham County, Michigan." Diss., Connect to online resource - MSU authorized users, 2006.
Знайти повний текст джерелаTitle from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references (p. 161-168). Also issued in print.
McGlashan, Dugald James, and piscador@hotmail com. "Consequences of Dispersal, Stream Structure and Earth History on Patterns of Allozyme and Mitochondrial DNA Variation of Three Species of Australian Freshwater Fish." Griffith University. Australian School of Environmental Studies, 2000. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030226.152217.
Повний текст джерелаCox, Andrea Joan. "Freshwater phylogeography, the impact of life history traits on the post-glacial dispersal of zooplankton in North America." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ58330.pdf.
Повний текст джерелаUllberg, Jörgen. "Dispersal in free-living, marine, benthic nematodes : passive or active processes?" Doctoral thesis, Stockholm University, Department of Zoology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-77.
Повний текст джерелаMeiofauna, and especially marine nematodes are common in sediments around the world. Despite very wide ranging distributions in many nematode species, little is presently known about their dispersal mechanisms shaping these patterns. Rafting, and perhaps ballast water transport has been suggested as viable means for nematode long-range transport. On a much smaller scale other processes have been suggested for their dispersal. They generally include some form of passive suspension into the water column and later on a passive, haphazard settling back towards the bottom.
Small-scale phenomena in nematode dispersal were studied by conducting a series of studies at Askö field station, Trosa Archipelago, Baltic proper. Studied aspects were one case of macrofaunal influence on nematode dispersal rate, using an amphipod, Monoporeia affinis as disturbing agent, and three different studies on mechanisms related to settling. The experiments were conducted both in laboratory and field settings.
The amphipod Monoporeia affinis did not exert any influence on the dispersal rate in the nematodes. The nematode dispersal was only an effect of time, in the aspect that the more time that past, the more nematodes dispersed from their place of origin. The settling experiments revealed that nematodes do have an active component in their settling behaviour, as they were able to exert influence on the spot where they were to settle. They were able to choose settling spot in response to the food quality of the sediment. It also became evident that contrary to common belief, nematodes are able to extend their presence in the water column far beyond the times that would be predicted considering settling velocities and hydrodynamic conditions alone.
Zha, Yinghua. "Assembly of Gut Microbial Communities in Freshwater Fish and Their Roles in Fish Condition." Doctoral thesis, Uppsala universitet, Limnologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-314235.
Повний текст джерелаVilmi, A. (Annika). "Assessing freshwater biodiversity:insights from different spatial contexts, taxonomic groups and response metrics." Doctoral thesis, Oulun yliopisto, 2017. http://urn.fi/urn:isbn:9789526216669.
Повний текст джерелаTiivistelmä Makeanveden ekosysteemit ovat hyvin alttiita ihmistoiminnalle. Ekosysteemissä mahdollisesti tapahtuvien muutosten havaitseminen vaatii tehokkaita vesistöjen ekologisen tilan ja luonnon monimuotoisuuden arviointi- ja seurantamenetelmiä. Näiden menetelmien toimintaperiaatteen yleisenä tausta-ajatuksena on, että biologiset yhteisöt määräytyvät paikallisten ympäristöolojen mukaan. Tietyn paikan yhteisön oletetaan siis heijastavan kyseisen paikan ympäristön tilaa. Viime aikoina tausta-ajatus paikallisten ympäristöolojen merkityksestä ainoana eliöyhteisöjä muovaavana tekijänä on kuitenkin kohdannut kritiikkiä. Kriitikot painottavat, että biologisten yhteisöjen rakenteeseen vaikuttavat monet muutkin asiat kuin paikalliset ympäristöolosuhteet ja niissä tapahtuvat ihmisperäiset muutokset. Väitöskirjassani tutkin sisävesien luonnon monimuotoisuuteen vaikuttavia tekijöitä. Olin erityisen kiinnostunut siitä, näkyykö tutkituissa biologisissa parametreissa maantieteellisessä tilassa ilmeneviä spatiaalisia säännönmukaisuuksia. Saadakseni mahdollisimman laaja-alaisen käsityksen luonnon monimuotoisuudessa esiintyvistä spatiaalisista säännönmukaisuuksista, tutkin useaa spatiaalista kontekstia, eliöryhmää ja indeksiä. Tutkimuksessa selvisi, että paikalliset ympäristöolosuhteet eivät ole ainoita luonnon monimuotoisuuteen vaikuttavia tekijöitä. Erilaiset spatiaaliset säännönmukaisuudet, todennäköisesti eliöiden levittäytymiseen liittyvien seikkojen aiheuttamina, olivat yllättävän yleisiä makeiden vesien eliöyhteisöjen rakenteessa ja niihin perustuvien indeksien arvoissa. Tutkimussysteemien spatiaalinen konteksti (alueen laajuus ja paikkojen väliset spatiaaliset suhteet) selvästi vaikutti luonnon monimuotoisuutta kuvastavien indeksien arvojen vaihteluun. Lisäksi selvisi, että eri eliöryhmät ja indeksit olivat useimmiten liitoksissa hyvin erilaisiin selittäviin muuttujiin, osoittaen, että nämä mittarit kuvastavat eri asioita. Väitöskirjassa esitetyt havainnot on tärkeää huomioida vesistöjen ekologisen tilan ja luonnon monimuotoisuuden arviointi- ja seurantamenetelmiä kehitettäessä. Spatiaalisen kontekstin merkitys olisi hyvä huomioida myös nykyisten arviointi- ja seurantamenetelmien tuottamien tulosten tulkinnassa
Hunter, Brena Elese. "Population genetic structure and patterns of dispersal in the Giant Long-Armed Prawn, Macrobrachium lar (Fabricius, 1798) (Decapoda : Palaemonidae)." Thesis, Queensland University of Technology, 2011. https://eprints.qut.edu.au/46131/1/Brena_Hunter_Thesis.pdf.
Повний текст джерелаMcGlashan, Dugald James. "Consequences of Dispersal, Stream Structure and Earth History on Patterns of Allozyme and Mitochondrial DNA Variation of Three Species of Australian Freshwater Fish." Thesis, Griffith University, 2000. http://hdl.handle.net/10072/366647.
Повний текст джерелаThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
Full Text
Hitt, Nathaniel Patterson. "Effects of stream network topology on fish assemblage structure and bioassessment sensitivity in the mid-Atlantic highlands, USA." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/27218.
Повний текст джерелаPh. D.
Strecker, Angela Lee. "Responses of zooplankton community structure and ecosystem function to the invasion of an invertebrate predator, Bythotrephes longimanus." Thesis, Kingston, Ont. : [s.n.], 2007. http://hdl.handle.net/1974/454.
Повний текст джерелаLogue, Jürg Brendan. "Factors influencing the biogeography of bacteria in fresh waters - a metacommunity approach." Doctoral thesis, Uppsala universitet, Limnologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-130009.
Повний текст джерелаFerguson, Chad D. "Conservation genetics of a near threatened freshwater mussel species (Lampsilis cardium) and improved prospects for recovery: how nuclear and mitochondrial DNA analyses inform natural history and conservation." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1244144062.
Повний текст джерелаLudington, Timothy Shane Ludington. "The degree of impairment of foraging in crayfish (Orconectes virilis) due to insecticide exposure is dependent upon turbulence dispersion." Bowling Green State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1466173210.
Повний текст джерелаGudmundson, Sara. "Stabilizing factors in spatially structured food webs." Thesis, Linköping University, Linköping University, Theoretical Biology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-18657.
Повний текст джерелаEcological models have problems showing the positive relationship between diversity and stability found in nature. Theory states that complex food webs have high extinction risks and low stability. However, persistent food webs found in nature are large and complex containing many interconnections between species. There are many possible mechanisms enabling persistent food webs such as; complex interaction patterns, asynchronous fluctuations of species densities, environmental fluctuations and spatial distribution. These factors have not been used in classical models. In this study, coloured environmental 1/f noise and dispersal between subpopulations were incorporated into a diamond shaped food web based on a model by Vasseur and Fox 2007. Contradictions between theoretical and empirical results regarding food webs can be resolved by detailed analyses of models, withholding stabilizing mechanisms. Weak environmental 1/f noise generated an increased coefficient of stability but the stabilizing effect of noise can be questioned because of a decreased mean food web biomass and reduced stabilizing effect when reddened. However, detailed studies of the food web revealed that noise can redistribute density proportions between species, evading lowest species density and thereby increase food web resistance to demographic stochasticity and catastrophes. Noise induced density proportion shifts imply that large population sizes are no insurance towards future increase in environmental variance. Synchrony of species environmental responses and dispersal between subpopulations can both have major influences on stability and extinction risk of smaller food webs indicating that spatial structure could be one of the dominating factors stabilizing complex food webs found in nature.
Snäll, Tord. "Distribution Patterns and Metapopulation Dynamics of Epiphytic Mosses and Lichens." Doctoral thesis, Uppsala University, Department of Evolutionary Biology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3904.
Повний текст джерелаThis thesis examines the relative importance of local conditions, dispersal and dynamics of the trees on epiphyte distribution patterns and colonization-extinction dynamics. Study species are the mosses Orthotrichum speciosum and O. obtusifolium, and the red-listed Neckera pennata. The thesis also includes an attempt to parameterize a model for a lichen metapopulation (Lobaria pulmonaria) in a dynamic landscape, based on only presence/absence data of the epiphyte and its host trees.
The results show that epiphyte colonization of trees is affected by both local conditions, and by connectivity to occupied trees. The positive effect of connectivity, implying a restricted dispersal range, was established by both demographic and genetic studies. The important local conditions were tree diameter and vitality, and shade. Local extinctions from trees occurred among small trees with low local epiphyte abundance, but more often, were the results of tree fall.
The observed importance of connectivity on epiphyte colonization agrees with the assumptions of the classic metapopulation model. However, the classic metapopulation model assumes that the landscape is static, and that local extinctions occur for stochastic reasons. The dynamics of epiphytes are different. A new conceptual model is therefore suggested, the patch-tracking metapopulation model. It differs from the classic metapopulation model in that it includes dynamics of the patches, and in that local extinctions only occur as patches are destroyed.
Simulations of the dynamics of N. pennata showed that its future metapopulation size will be overestimated unless the dynamics of the trees are accounted for. The simulation results further suggest that the dynamics of N. pennata can be characterised by the patch-tracking metapopulation model.
The attempt to parameterize the L. pulmonaria metapopulation model showed that more information are required for rigorous parameterization, preferably of the past historic fire regime.
Krosch, Matthew Neil. "Evolutionary biology of Gondwanan non-biting midges (Diptera: Chironomidae)." Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/41749/1/Matthew_Krosch_Thesis.pdf.
Повний текст джерелаHoffsten, Per-Ola. "Rarity in boreal stream insects : patterns, causes and consequences /." Doctoral thesis, Umeå University, Ecology and Environmental Science, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-142.
Повний текст джерелаPatterns of site occupancy among boreal stream insects were studied in central Sweden with focus on sparsely distributed species and the role of dispersal and niche limitations.
In the study of dispersal limitation, I found that effects of an extraordinarily harsh winter in small to medium-sized streams were strongest in sites located in small streams and far from lake outlets. Species richness and the total abundance of macroinvertebrates and trout returned to pre-disturbance levels after three years. However, some species showed slow recolonization and the proportion of holoaquatic taxa was still reduced after three years. In a second study, I found a positive correlation between site occupancy in stream caddisflies and morphological traits associated with fast and energy-efficient flight, whereas specialized spring caddisflies showed a negative correlation to these traits compared to stream species. This suggested that streams, but not springs, select for strong dispersal ability in caddisflies. In a survey of springs in central Sweden, hydrogeology was found to be a useful predictor of the occurrence of spring specialists. Two of these, Crunoecia irrorata Curtis and Parachiona picicornis (Pictet), were found exclusively in glaciofluvial springs, characterized by a stable discharge and temperature. Less specialized members of the spring fauna (i.e. species also occurring in streams, ponds or lakes) also occurred in moraine and limestone springs characterized by more unstable conditions.
Niche limitations were studied by contrasting large-scale distributions of closely related rare and common stoneflies. Differences in temperature requirements in the juvenile stages and life cycles suggested that the rare species, Isogenus nubecula Newman, was restricted by a limited tolerance to low stream temperatures, whereas the two common species, Isoperla grammatica (Poda) and Diura nanseni (Kempny), appeared to have a broader tolerance to climatic conditions in the study area. In a second study of niche limitations, macroinvertebrate assemblages in 88 streams in Central Sweden showed a nested distribution pattern. Most species deviating from expected distributions occurred in small streams, indicating competitive exclusion from species-rich sites, predator avoidance, or specialization to unique habitat features of small streams. In the last paper, the longitudinal distribution of filter-feeding caddisflies in a lake-outlet stream demonstrated patterns concordant to feeding specialization.
Baumart, Joele Schmitt. "Dinâmica espacial, migração e preferência de micro-hábitat de Aegla longirostri bond-buckup e buckup, 1994 (crustacea, anomura, aeglidae)." Universidade Federal de Santa Maria, 2014. http://repositorio.ufsm.br/handle/1/3289.
Повний текст джерелаUnderstanding the population dynamic processes is fundamental to access its viability (health). Great part of these processes is closely related to the organism densities in a studied population. These data can reveal how the population is arranged in the environment and, in adverse conditions, it is possible to forecast the occurrence of dispersion/migration. This study aims to investigate some ecological parameters of an Aegla longirostri population, a freshwater anomuran from the southern Brazil: (i) to estimate the population density, (ii) the substrate preference, (iii) the home range and (iv) the possible dispersion patterns. The study site was the first order stream Sanga do Caranguejo, located in the central region of Rio Grande do Sul State, during 2010 and 2011. For population density and dispersion investigation covo traps were used, distributed through the stream, in different times in the year. The study of the substrate preference used PVC gutters covered by mesh and arranged on the stream substrate, with controlled density population; a surber was used for active search in the stream. The home range analysis used radio telemetry techniques. The population size was estimated in 950 individuals in spring and 210 in autumn (estimated according to the Bayesian Method). With respect to the substrate preference, we found that there is an ontogenetic association regarding the choice. The juveniles, in the first development stages, prefer sandy substrates, while adults (males and females) prefer more complex substrates. The estimates of home range of eglids vary between 8,41 to approximately 45,49 linear meters of stream, and these crustaceans showed the local dislocation, once they perform their activities around a specific point in the stream. To finalize, we identified that the juveniles and adults of eglids are active walkers, not being carried by the flow in a passive way as occurs in larvae stage in other crustaceans. Its activities are related to the environment temperature and density of adult males. We believe that the knowledge about the group has increased, however, as it is a complex group, with a rich evolutionary history, much remain to be investigated about these freshwater crustaceans.
A compreensão dos processos de dinâmica populacional é fundamental para se avaliar a viabilidade (saúde) de uma população. Grande parte desses processos estão estreitamente relacionados com a densidade de organismos da população estudada. Estes dados podem revelar como a população está distribuída no ambiente e, em condições de adversidade ambiental, é possível prever a ocorrência de dispersão/migração. Neste estudo, alicerçado nos fatores ecológicos e biológicos do aeglídeo Aegla longirostri foram investigados: (i) estimativa da densidade populacional, (ii) as preferências de substrato, (iii) a área de vida e (iv) os possíveis padrões de dispersão. Este estudo foi conduzido em um riacho de primeira ordem, Sanga dos Caranguejos, que se localiza na região central do Rio Grande do Sul, durante os anos de 2010 e 2011. Nas investigações sobre densidade populacional e dispersão foram utilizados coletores do tipo covo espaçados pelo riacho, em diferentes estações climáticas do ano. A investigação de preferência de substrato foi conduzida com o uso de calhas de PVC cobertas por malha e dispostas no riacho para o experimento em condições de densidade controlada, e com surber, para busca ativa no riacho. A análise de área de vida foi realizada com a utilização da técnica de rádio telemetria. A população em questão foi estimada em 950 indivíduos na primavera e 210 indivíduos no outono (estimativas segundo o Método Bayesiano). Com relação à preferência de substrato, verificamos que há associação ontogenética quanto à escolha. Os juvenis, nos primeiros estágios de desenvolvimento, preferem substratos arenosos, enquanto que adultos (machos e fêmeas) preferem substratos mais complexos. Estimou-se também que a área de vida desses eglídeos varia desde 8,41 metros até, aproximadamente, 45,49 metros lineares de riacho, e que estes crustáceos apresentam comportamento de deslocamento local, já que realizam suas atividades em torno de um ponto específico do riacho. Observou-se ainda que os juvenis eglídeos, assim como os adultos, são caminhadores ativos, não sendo carregados pela correnteza de forma passiva como ocorre nas fases larvais de outros crustáceos. Suas atividades estão relacionadas com a temperatura do ambiente e com a densidade de adultos machos no riacho. Acreditamos que muito se avançou em termos de conhecimento da ecologia do grupo como um todo, e não apenas para a espécie estudada, servindo este estudo de base para estudo futuros sobre dispersão e área de vida principalmente.
Branco, Magno Botelho Castelo. "Comunidade de aves aquáticas e suas interações em sistemas límnicos do sudeste brasileiro." Universidade Federal de São Carlos, 2008. https://repositorio.ufscar.br/handle/ufscar/1631.
Повний текст джерелаFinanciadora de Estudos e Projetos
Aquatic birds do interact in many ways with freshwater ecosystems. Birds can be considered the most important dispersers of freshwater algae between water bodies. Moreover, birds also can contribute to nutrient loading in freshwater lakes and reservoirs. In this paper the ecto and endozoochoric dispersal potential of freshwater algae by waterbirds was acessed. The places of study were the Monjolinho reservoir, in São Carlos municipality (SP), and Tropeiros lake, in Piumhi municipality (MG). Also studied was the contribution to nutrient loading by two colonies of Bubulcus ibis, the cattle egret, in two freshwater bodies: Tropeiros lake and Iembó reservoir, locate at Parque Itaipu, São Carlos municipality. By means of culture inoculation with material obtained from washing the body of the birds, it was observed that these species of birds are potential dispersers of phytoplanktonic algae and can carry up to 22 species of algae attached to feathers per individual (ectozoochory). A minor number of species of algae was also observed in cultures inoculated with material derived from faeces of birds, featuring a potential case of endozoochoric transport potential. Regarding the nutrient loading by colony of cattle egrets, was detected a change both in the content of organic matter in the sediment located in areas where the birds sleep as well as greater eutrophication of water in these regions. It was also observed a trend to higher density of biomass in banks of aquatic macrophytes used for night rest, with a consequent increase in the density of organisms associated with aquatic macrophytes. However, no significant differences were observed in the benthic fauna, when comparing the samples of sediment obtained in both points located in the rest areas as in nonrest areas, but it was found that these colonies contribute significantly to the nutrient loading in these systems.
As aves aquáticas interagem de diversas maneiras com os ambientes de água doce. Por um lado, as aves podem ser consideradas como os mais importantes dispersores de algas fitoplancônicas entre os corpos de água doce e, por outro lado, podem contribuir de maneira significativa ao aporte de nutrientes nos ecossitemas aquáticoss. Nesse trabalho foi estudado o potencial de dispersão ecto e endozoocórico de algas fitoplanctônicas por aves aquáticas no reservatório do Monjolinho (município de São Carlos, SP) e na lagoa dos Tropeiros (município de Piumhi, MG), bem como a contribuição de colônias de garças-vaqueira Bubulcus ibis para o aporte alóctone de nutrientes em dois sistemas límnicos: a lagoa dos Tropeiros e o reservatório Iembó, localizado no condomínio Parque Itaipu, no município de São Carlos, SP. Através da inoculação de meios de cultura com material oriundo da lavagem do corpo das aves, foi observado que estas espécies de aves são potenciais dispersoras de algas fitoplanctônicas, podendo transportar até 22 espécies de algas aderidas às penas por indivíduo (ectozoocoria). Um número menor de espécies de algas também foi observado em culturas inoculadas com material oriundo das fezes das aves, caracterizando um potencial de transporte endozoocórico. Em relação ao aporte de nutrientes por colônia de garças-vaqueira, foi verificado uma alteração no teor de matéria orgãnica no sedimento localizado em áreas de poleiro como uma maior eutrofização da água nestas regiões. Foi observada também uma tendência a maior densidade de biomassa vegetal em bancos de macrófitas aquáticas utlizados como poleiro, com um conseqüente aumento na densidade de organismos associados às macrófitas aquáticas. Entretanto, não foram observadas diferenças significativas na fauna bentônica, ao se comparar as amostras de sedimento obtidas em pontos localizados na área de poleiro e área não-poleiro, mas foi constatado que essas colônias contribuem para o estoque de nutrientes nesses sistemas límnicos.
Chen, Min-Wan, and 陳旻宛. "Dispersal ability of Taiwanese freshwater crabs revealed by salinity tolerance." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/62514488950771149365.
Повний текст джерелаBogan, Michael T. "Drought, dispersal, and community dynamics in arid-land streams." Thesis, 2012. http://hdl.handle.net/1957/31292.
Повний текст джерелаGraduation date: 2013
Access restricted to the OSU Community at author's request from July 18, 2012 - July 18, July 2013
Zhang, Weifeng. "Coastal ocean modeling using variational methods for freshwater dispersal study, data assimilation and observing system design." 2009. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000051597.
Повний текст джерелаBott, Kristin Janet. "Genetic analyses of dispersal, harvest mortality, and recruitment for remnant populations of Lake Sturgeon, Acipenser fulvescens, in open-water and riverine habitats of Lake Michigan." Diss., 2006.
Знайти повний текст джерелаQUAGLIETTA, LORENZO. "Ecologia e comportamento della lontra eurasiatica (Lutra lutra) in un'area mediterranea (Alentejo, Portugal)." Doctoral thesis, 2012. http://hdl.handle.net/11573/918729.
Повний текст джерела