A size-based model of carbon and nitrogen flows in plankton communities

Simple item page
dc.contributor.advisorField, John Gen_ZA
dc.contributor.advisorLucas, Michael Ien_ZA
dc.contributor.authorMoloney, Coleen Lynen_ZA
dc.date.accessioned2016-10-14T06:26:40Z
dc.date.available2016-10-14T06:26:40Z
dc.date.issued1988en_ZA
dc.descriptionBibliography: pages 163-183.en_ZA
dc.description.abstractA generic, size-based simulation model is developed to investigate the dynamics of carbon and nitrogen flows in plankton communities. All parameters in the model are determined by body size using empirically-determined relationships calculated from published data. The model is robust with respect to most parameters and assumptions. Because the model is based on general ecological principles, it can be used to simulate microplankton community interactions in any planktonic ecosystem. Two coastal ecosystems from the southern Benguela region in South Africa are simulated; one typical of the relatively stable surface waters on the Agulhas Bank and one typical of upwelling plumes, usually found off the west coast of South Africa. Simulated communities compare well with field observations in terms of standing stocks and size composition, and simulation results indicate that the small-scale structure of the two ecosystems and the processes occurring within them are relatively well understood. Consequently, the dynamic functioning of the two systems is investigated at the ecosystem level, using the simulation results. Hypothetical carbon flow networks are constructed, and the average importance of different flow pathways at different times is assessed. In both ecosystems, the vast majority of carbon flows pass through short, efficient-transfer pathways, although longer pathways are potentially possible. Simulation analyses are extended from coastal to oceanic food webs, and the model results are consistent with the hypothesis that oceanic phytoplankton have rapid rates of primary production. At-sea sampling of a phytoplankton bloom is mimicked by "sampling" from simulation output, and interpretation of the data using standard techniques is compared with the model output. The dangers of extrapolating from snapshot measurements is highlighted, and the experiment emphasizes the importance of size-fractionated sampling of phytoplankton. A hypothetical pelagic food web is described, consisting of at least five different trophic pathways from phytoplankton to pelagic fish. It is suggested that coastal waters probably have all the different pathways, and the relative importance and efficiency of the different pathways will determine the total fish production in an ecosystem.en_ZA
dc.identifier.apacitationMoloney, C. L. (1988). <i>A size-based model of carbon and nitrogen flows in plankton communities</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/22132en_ZA
dc.identifier.chicagocitationMoloney, Coleen Lyn. <i>"A size-based model of carbon and nitrogen flows in plankton communities."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 1988. http://hdl.handle.net/11427/22132en_ZA
dc.identifier.citationMoloney, C. 1988. A size-based model of carbon and nitrogen flows in plankton communities. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Moloney, Coleen Lyn AB - A generic, size-based simulation model is developed to investigate the dynamics of carbon and nitrogen flows in plankton communities. All parameters in the model are determined by body size using empirically-determined relationships calculated from published data. The model is robust with respect to most parameters and assumptions. Because the model is based on general ecological principles, it can be used to simulate microplankton community interactions in any planktonic ecosystem. Two coastal ecosystems from the southern Benguela region in South Africa are simulated; one typical of the relatively stable surface waters on the Agulhas Bank and one typical of upwelling plumes, usually found off the west coast of South Africa. Simulated communities compare well with field observations in terms of standing stocks and size composition, and simulation results indicate that the small-scale structure of the two ecosystems and the processes occurring within them are relatively well understood. Consequently, the dynamic functioning of the two systems is investigated at the ecosystem level, using the simulation results. Hypothetical carbon flow networks are constructed, and the average importance of different flow pathways at different times is assessed. In both ecosystems, the vast majority of carbon flows pass through short, efficient-transfer pathways, although longer pathways are potentially possible. Simulation analyses are extended from coastal to oceanic food webs, and the model results are consistent with the hypothesis that oceanic phytoplankton have rapid rates of primary production. At-sea sampling of a phytoplankton bloom is mimicked by "sampling" from simulation output, and interpretation of the data using standard techniques is compared with the model output. The dangers of extrapolating from snapshot measurements is highlighted, and the experiment emphasizes the importance of size-fractionated sampling of phytoplankton. A hypothetical pelagic food web is described, consisting of at least five different trophic pathways from phytoplankton to pelagic fish. It is suggested that coastal waters probably have all the different pathways, and the relative importance and efficiency of the different pathways will determine the total fish production in an ecosystem. DA - 1988 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1988 T1 - A size-based model of carbon and nitrogen flows in plankton communities TI - A size-based model of carbon and nitrogen flows in plankton communities UR - http://hdl.handle.net/11427/22132 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/22132
dc.identifier.vancouvercitationMoloney CL. A size-based model of carbon and nitrogen flows in plankton communities. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 1988 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/22132en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Biological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherPlankton - Mathematical modelsen_ZA
dc.subject.otherMarine plankton - Mathematical modelsen_ZA
dc.subject.otherFood chains (Ecology) - Mathematical modelsen_ZA
dc.subject.otherCarbonen_ZA
dc.subject.otherNitrogenen_ZA
dc.titleA size-based model of carbon and nitrogen flows in plankton communitiesen_ZA
dc.typeDoctoral Thesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnamePhDen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
thesis_sci_1988_moloney_coleen_lyn__.pdf
Size:
5.14 MB
Format:
Adobe Portable Document Format
Description:
Download
Collections
PhD / Doctoral