Modeling silicate–nitrate–ammonium co-limitation of algal growth and the importance of bacterial remineralization based on an experimental Arctic coastal spring bloom culture study
Autor: | Christoph Völker, Tobias R. Vonnahme, Ulrike Dietrich, Martial Leroy, Svein Kristiansen, Dick van Oevelen, H. Rodger Harvey, Silke Thoms, Rolf Gradinger |
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Jazyk: | angličtina |
Rok vydání: | 2021 |
Předmět: |
VDP::Mathematics and natural science: 400::Geosciences: 450::Marine geology: 466
0106 biological sciences 010504 meteorology & atmospheric sciences lcsh:Life 01 natural sciences Nutrient lcsh:QH540-549.5 Phytoplankton Ecosystem Ecology Evolution Behavior and Systematics 0105 earth and related environmental sciences Earth-Surface Processes Ecology 010604 marine biology & hydrobiology fungi lcsh:QE1-996.5 Biogeochemistry 15. Life on land Spring bloom lcsh:Geology lcsh:QH501-531 Productivity (ecology) Arctic 13. Climate action VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Marin geologi: 466 Environmental science lcsh:Ecology Bloom |
Zdroj: | Biogeosciences, Vol 18, Pp 1719-1747 (2021) EPIC3Biogeosciences, 18(5), pp. 1719-1747, ISSN: 1726-4189 |
ISSN: | 1726-4189 1726-4170 |
Popis: | Arctic coastal ecosystems are rapidly changing due to climate warming. This makes modeling their productivity crucially important to better understand future changes. System primary production in these systems is highest during the pronounced spring bloom, typically dominated by diatoms. Eventually the spring blooms terminate due to silicon or nitrogen limitation. Bacteria can play an important role for extending bloom duration and total CO2 fixation through ammonium regeneration. Current ecosystem models often simplify the effects of nutrient co-limitations on algal physiology and cellular ratios and simplify nutrient regeneration. These simplifications may lead to underestimations of primary production. Detailed biochemistry- and cell-based models can represent these dynamics but are difficult to tune in the environment. We performed a cultivation experiment that showed typical spring bloom dynamics, such as extended algal growth via bacterial ammonium remineralization, reduced algal growth and inhibited chlorophyll synthesis under silicate limitation, and gradually reduced nitrogen assimilation and chlorophyll synthesis under nitrogen limitation. We developed a simplified dynamic model to represent these processes. Overall, model complexity in terms of the number of parameters is comparable to the phytoplankton growth and nutrient biogeochemistry formulations in common ecosystem models used in the Arctic while improving the representation of nutrient-co-limitation-related processes. Such model enhancements that now incorporate increased nutrient inputs and higher mineralization rates in a warmer climate will improve future predictions in this vulnerable system. |
Databáze: | OpenAIRE |
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