The impact of light intensity and daylength on silacate and nitrate competition among marine phytoplankton
Sommer, U. (1994). The impact of light intensity and daylength on silacate and nitrate competition among marine phytoplankton. Limnol. Oceanogr. 39(7): 1680-1688
In: Limnology and Oceanography. American Society of Limnology and Oceanography: Waco, Tex., etc. ISSN 0024-3590; e-ISSN 1939-5590, more
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Keywords |
Algae Aquatic communities > Plankton > Phytoplankton Biological competition > Interspecific competition Chemical compounds > Silicon compounds > Silicates Cyanobacteria Environmental factors Environments > Aquatic environment > Marine environment Luminous intensity Microorganisms > Bacteria Nitrates Nutrients Photoperiods Thallophyta Marine/Coastal |
Abstract |
I tested the extent to which differences in light supply could influence the outcome of nutrient (Si and N) competition between marine phytoplankton. Competition experiments were performed with 11 species of marine phytoplankton at Si: N ratios from 16 to 124: 1, light intensities from 28 to 225 μmol quanta m−2 s-1, and three different daylengths. Thus, light supply was the composite result of two components: photoperiod and intensity. Diatoms were dominant competitors at higher Si: N ratios, nonsiliceous flagellates at lower ones. Light had no impact on the transition from flagellate to diatom dominance along the Si: N gradient. However, species within those groups were separated along the light gradient. Contrary to theoretical expectations, changes in light intensity and changes in daylength led to similar shifts in species dominance. Therefore, it was possible to describe the light climate by the integral parameter «daily light dose» |
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