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Dissertation
Resource requirements and competitive abilities of diatoms from the greater Yellowstone ecosystem for silicon and nitrogen
Doctor of Philosophy (Ph.D.), Drexel University
2000
DOI:
https://doi.org/10.17918/00008313
Abstract
The several diatom species used in my study, Asterionella formosa Hass., Aulacoseira subarctica (O. Mull.), Fragilaria crotonensis Kitt. Hass., Stephanodiscus minutulus Kutzing, Stephanodiscus niagarae Ehrenb., and Stephanodiscus yellowstonensis Theriot and Stoermer, were originally isolated from the Lewis, Jackson and Yellowstone lakes. Information on the nutrient kinetics of diatoms under either silicon or nitrogen limitation was obtained for use in a Monod model and in a variable internal stores model of growth. Short-term batch culture growth experiments were fit to the Monod model and long-term semicontinuous culture experiments were fit to the variable internal stores model. The results of both batch and steady state culture methods agree. For Si-limited experiments, S. minutulus is better able to grow at low silicon concentrations than other species, as predicted by its lower K for Si-limited growth. F. crotonensis and A. formosa had the lowest requirement for growth under nitrogen limitation. Nutrient competition experiments were performed in continuous cultures at 15°C and various Si: N ratios. The results generally, but not always, confirmed the predictions based on the Monod relationship for each species. In cultures with all six species silicon-limited (Si: N = 0.25), S. minutulus dominated as predicted. At intermediate Si: N ratios, several species coexisted because each species needs a different resource requirement for either silicon or nitrogen. F. crotonensis dominated as Kilham et al. (1996) predicted at high Si: N ratio when all six species were nitrogen-limited. Clones of these two species (S. niagarae and S. yellowstonensis) isolated for the Yellowstone lakes showed clear differences in their nitrogen physiology, with S. yellowstonensis being able to grow at much lower N levels compared.
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Details
- Title
- Resource requirements and competitive abilities of diatoms from the greater Yellowstone ecosystem for silicon and nitrogen
- Creators
- Heuichan Roh
- Contributors
- Susan Soltau Kilham (Advisor) - Drexel University, Drexel University (1970-)
- Awarding Institution
- Drexel University
- Degree Awarded
- Doctor of Philosophy (Ph.D.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Number of pages
- xii, 120 pages
- Resource Type
- Dissertation
- Language
- English
- Academic Unit
- School of Environmental Science, Engineering, and Policy (1997-2002); Drexel University
- Other Identifier
- 991021889073304721