• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • 2
  • 1
  • Tagged with
  • 7
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Organic matter and macrobenthos dynamics analyzed with stable isotopes in the anthropogenically transformed mangrove ecosystem of Batan Bay Estuary, Philippines / フィリピン、バタン湾の人為改変されたマングローブ生態系における安定同位体を用いた有機物とマクロベントスの動態

Ogawa, Yuya 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(農学) / 甲第23943号 / 農博第2492号 / 新制||農||1090(附属図書館) / 学位論文||R4||N5378(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 神﨑 護, 教授 北島 薫, 教授 舘野 隆之輔 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM
2

Towards a Multiscale, Spatially Explicit Analysis of the Littoral Zone Macrobenthos Along the North Shore of Hamilton Harbour / Macrobenthos of Hamilton Harbour

Conrad, Mark Stephen 12 1900 (has links)
Macrobenthos and macrophytes of the north shore littoral zone of Hamilton Harbour were extensively sampled in late August 1994. Benthic community structure is described, including the presence of several oligochaete and chironomid genera previously unreported in the harbour. Community structure is scale dependent and identifying which spatial scales contribute important structure is a useful step in determining which environmental factors have the greatest impact on the benthic community. This information can be used to plan efficient benthos monitoring programs, and to construct spatially explicit models of the harbour ecosystem. Most of the variation in the data set (approx. 88%) is due to small scale patchiness, probably related to patchiness of the macrophyte community and sediment grain size, as well as biotic processes such as predation and competition. Large scale structure is related to a water depth gradient, probably involving changes in dissolved oxygen concentrations, light attenuation, and sediment grain size. Macrophytes also respond to this gradient. There is little important structuring of the benthos community at intermediate spatial scales. Models of benthic communities in the harbour must deal with spatial pattern effects such as autocorrelation. Additionally, spatial patterns provide information useful for understanding causes of community structure. A method is developed for the spatial pattern analysis of the benthic community data, which allows the simultaneous evaluation of patterns at various scales, with minimal mixing of information between scales. / Thesis / Master of Science (MS)
3

The Vertical Stratification of the Macrobenthos in the Brazos River, Texas

Poole, Walton Charles 12 1900 (has links)
Quantification of stream macrobenthos populations has remained a perplexing problem in rivbrine ecology, despite numerous attempts at improvement. This is in part due to well documented variations in chemical and physical parameters locally and geographically, and resultant adapted macrobenthos populations. Southwood (1968) and Hynes (1970a) have reviewed the various sampling techniques developed'for the census of lotic macrobenthos populations. Needham and Usinger (1956), Chutter (1969), and others have pointed out the difficulty in obtaining adequate numbers of samples which will yield population estimates with desired statistical confidence, and still maintain some degree of sampling economy. Needham and Usinger (1956) and Gaufin et al. (1956) mentioned the "patchy" distribution of aquatic insect populations as the primary source of this difficulty. The concept of patchy distribution in insect populations was originally discussed by Andrewartha (1961). Attempts to improve confidence through improved sampling devices and techniques have led to development of numerous types of samplers. Cummins (1962) indicated that there were almost as many samplers as there were researchers.
4

Proposta de tratamento e modelagem de dados espaciais para uso em infraestrutura de dados espaciais - IDEs: estudo de caso de macrobentos para a área costeira da Baixada Santista. / Proposal of processing and database modeling of spatial data infrastructure -SDI: macrobenthos study case for coastal zone of Santos metropolitan region.

Carvalho, Gabriel Niero de 12 August 2013 (has links)
As zonas costeiras são áreas complexas que contemplam ambientes terrestres e marinhos que, além de possuírem enorme riqueza ambiental, também são áreas atrativas aos seres humanos por oferecer alimentos, lazer, negócios, transporte, entre outros. Algumas dificuldades de gerenciamento ocorrem pela complexidade, conflito de interesses e pelo fato de não haver padronização no levantamento de dados e disponibilização para a comunidade científica, órgãos públicos, etc. O uso de geotecnologias pode auxiliar na organização, padronização e compartilhamento destas informações em Atlas Web além de apoiar no planejamento e tomada de decisão pois agregam, em um único ambiente, diversos dados provenientes de fontes distintas. A construção de um modelo de dados espacial voltado à área ambiental, para ser utilizada em Infraestrutura de Dados Espaciais (IDE) é exemplificada a partir da modelagem de um bioindicador, Macrobentos, de qualidade de sedimentos. Este trabalho apresenta as etapas necessárias para a construção de modelo de dados espacial de Macrobentos e emprega a Região Metropolitana da Baixada Santista como referência, além de ilustrar e discutir as principais dificuldades para organizar os dados não padronizados. Conclui-se que a estruturação do conhecimento quando se trabalha com dados ambientais em um modelo é essencial para sua posterior integração em IDE. Constatou-se no processo de modelagem que questões metodológicas relativas ao processo de coleta podem dificultar ou até mesmo inviabilizar a integração de dados provenientes de diferentes estudos. A construção de um modelo de dados espacial e sua posterior publicação via Geoportal, como o apresentado neste estudo, poderá ser utilizado como referência para novas pesquisas com objetivos semelhantes. / Coastal zones are complex areas that include marine and terrestrial environments. Besides its huge environmental importance, they also attract humans because they provide food, recreation, business, transportation, among others. Some difficulties to manage these areas are related with their complexity, diversity of interests and the absence of standardization to collect and share data to scientific community, public agencies, among others. The use of geo-technologies can be used in the organization, standardization and sharing of this information through Atlas Web and assists planning and decision making issues because it aggregates different files from distinct sources. The construction of a spatial database integrating the environmental business, to be used on Spatial Data Infrastructure (SDI) is illustrated by a bioindicator, Macrobenthos, that indicates the quality of the sediments. This research shows the required steps to build Macrobenthos spatial database based on Santos Metropolitan Region as a reference. Besides, it tries to illustrate the problems related to organize non standardized data. It can be concluded, when working with environmental data, that the structuring of knowledge in a conceptual model is essential for their subsequent integration into the SDI. During the modeling process it can be noticed that methodological issues related to the collection process may obstruct or make impracticable the data integration from different studies of the same area. The development of a database model and its subsequent publication in a Geoportal can be used as a reference for further research with similar goals.
5

Influence des facteurs environnementaux et anthropiques sur la structure et le fonctionnement des peuplements benthiques du Golfe Normano-Breton.

Trigui, Rima Jihane 06 October 2009 (has links) (PDF)
En Manche, le golfe normano-breton se distingue par plusieurs particularités environnementales telles que la présence de structures hydrodynamiques tourbillonnaires autour des îles anglo-normandes, un des plus large estran européen en baie du Mont-Saint-Michel en raison d'un marnage exceptionnel, et de nombreuses activités humaines liées au tourisme, à la conchyliculture ou à la pêche artisanale. Au regard de son grand intérêt écologique et économique, le golfe constitue ainsi l'une des principales zones côtières pour laquelle des mesures coordonnées de gestion prenant en considération les impacts des activités humaines existantes est nécessaire. Dans ce contexte, afin d'évaluer l'impact des contraintes environnementales naturelles ou anthropiques sur la structure des communautés benthiques, deux systèmes à deux échelles spatiales différentes ont été étudiés : la communauté des sédiments grossiers à Glycymeris glycymeris du golfe normano-breton et l'estran de la baie du Mont-Saint-Michel. Les principales questions que nous avons traitées sont : (1) Comment les spécificités hydrodynamiques du golfe (i.e. structures ourbillonnaires) influencent la structure et la dynamique des communautés benthiques ? Quel est le rôle relatif des gradients environnementaux et de la conchyliculture sur les communautés benthiques de la baie ? Quel est le statut écologique de la baie ? A l'échelle du golfe, une très faible relation a été observée entre les cinq principales structures tourbillonnaires (i.e. Flamanville, Jersey, Guernesey, la baie de Saint-Brieuc et la baie du Mont-Saint-Michel) et la structure de la communauté des sables grossiers à G. glycymeris. La relative homogénéité de cette communauté est ainsi favorisée par la relative perméabilité des tourbillons et la distribution des espèces est plutôt contrôlée par la présence de fronts thermiques. Toutefois, des différences ont été observées dans les structures démographiques des principales espèces de bivalves (i.e. Paphia rhomboides, G. glycymeris et Timoclea ovata) entre les gyres, suggérant que la connectivité entre eux peut-être réduite. En dépit d'une élévation de la température d'environ 1,5°C au cours des 30 dernières années, une étude comparative de la distribution de quelques espèces entre nos données et des données acquises dans les années 70 ne met pas en évidence de profondes modifications à de rares exceptions près. A cette échelle, l'effet du réchauffement peut être associé aux perturbations induites par la pêche pour expliquer le déclin ou le développement des espèces. A l'échelle de la baie du Mont-Saint-Michel, les distributions des assemblages benthiques et des 4 principales espèces de bivalves (i.e. Abra alba, Cerastoderma edule, Macoma balthica et Spisula ovalis) suivent un gradient altitudinal conventionnel. Elles sont fortement contrôlées par des facteurs environnementaux naturels (i.e. hauteur sur l'estran, granulométrie) alors que la conchyliculture joue un rôle mineur : celle-ci favorise uniquement localement le développement d'espèces opportunistes, en particulier des oligochètes et des polychètes cirratulidae. La principale conséquence environnementale de la conchyliculture a vraisemblablement été l'introduction du gastéropode Crepidula fornicata qui régule fortement la production primaire au sein de la baie. L'analyse des structures démographiques des bivalves suggère que l'instabilité du sédiment influence fortement les patrons de recrutement de certaines espèces. Le statut écologique de la baie du Mont-Saint-Michel a été déterminé à partir de 6 indices biologiques développés dans le cadre de la Directive Cadre sur l'Eau (i.e. H', AMBI, BOPA, M-AMBI, UK index, DK index). La baie apparaît globalement classée dans un statut ‘bon' ou ‘fort' bien que les valeurs du statut écologique calculées par les différents indices puissent différer. Par exemple, dans un milieu soumis à de fortes contraintes environnementales naturelles qui influencent fortement la richesse spécifique ou les densités totales, la qualité de certains indices est altérée. Finalement, une carte des habitats de la baie a été dressée sur la base des cahiers d'habitats mise en place avec Natura 2000.
6

Proposta de tratamento e modelagem de dados espaciais para uso em infraestrutura de dados espaciais - IDEs: estudo de caso de macrobentos para a área costeira da Baixada Santista. / Proposal of processing and database modeling of spatial data infrastructure -SDI: macrobenthos study case for coastal zone of Santos metropolitan region.

Gabriel Niero de Carvalho 12 August 2013 (has links)
As zonas costeiras são áreas complexas que contemplam ambientes terrestres e marinhos que, além de possuírem enorme riqueza ambiental, também são áreas atrativas aos seres humanos por oferecer alimentos, lazer, negócios, transporte, entre outros. Algumas dificuldades de gerenciamento ocorrem pela complexidade, conflito de interesses e pelo fato de não haver padronização no levantamento de dados e disponibilização para a comunidade científica, órgãos públicos, etc. O uso de geotecnologias pode auxiliar na organização, padronização e compartilhamento destas informações em Atlas Web além de apoiar no planejamento e tomada de decisão pois agregam, em um único ambiente, diversos dados provenientes de fontes distintas. A construção de um modelo de dados espacial voltado à área ambiental, para ser utilizada em Infraestrutura de Dados Espaciais (IDE) é exemplificada a partir da modelagem de um bioindicador, Macrobentos, de qualidade de sedimentos. Este trabalho apresenta as etapas necessárias para a construção de modelo de dados espacial de Macrobentos e emprega a Região Metropolitana da Baixada Santista como referência, além de ilustrar e discutir as principais dificuldades para organizar os dados não padronizados. Conclui-se que a estruturação do conhecimento quando se trabalha com dados ambientais em um modelo é essencial para sua posterior integração em IDE. Constatou-se no processo de modelagem que questões metodológicas relativas ao processo de coleta podem dificultar ou até mesmo inviabilizar a integração de dados provenientes de diferentes estudos. A construção de um modelo de dados espacial e sua posterior publicação via Geoportal, como o apresentado neste estudo, poderá ser utilizado como referência para novas pesquisas com objetivos semelhantes. / Coastal zones are complex areas that include marine and terrestrial environments. Besides its huge environmental importance, they also attract humans because they provide food, recreation, business, transportation, among others. Some difficulties to manage these areas are related with their complexity, diversity of interests and the absence of standardization to collect and share data to scientific community, public agencies, among others. The use of geo-technologies can be used in the organization, standardization and sharing of this information through Atlas Web and assists planning and decision making issues because it aggregates different files from distinct sources. The construction of a spatial database integrating the environmental business, to be used on Spatial Data Infrastructure (SDI) is illustrated by a bioindicator, Macrobenthos, that indicates the quality of the sediments. This research shows the required steps to build Macrobenthos spatial database based on Santos Metropolitan Region as a reference. Besides, it tries to illustrate the problems related to organize non standardized data. It can be concluded, when working with environmental data, that the structuring of knowledge in a conceptual model is essential for their subsequent integration into the SDI. During the modeling process it can be noticed that methodological issues related to the collection process may obstruct or make impracticable the data integration from different studies of the same area. The development of a database model and its subsequent publication in a Geoportal can be used as a reference for further research with similar goals.
7

New Approaches in Measuring Sediment-Water-Macrobenthos Interactions

Kaltenberg, Eliza Maria 01 June 2016 (has links)
No description available.

Page generated in 0.0384 seconds