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Full-Text Articles in Life Sciences
Saturating Growth Rate Against Phosphorus Concentration Explained By Macromolecular Allocation, Gabrielle Armin, Jongsun Kim, Keisuke Inomura
Saturating Growth Rate Against Phosphorus Concentration Explained By Macromolecular Allocation, Gabrielle Armin, Jongsun Kim, Keisuke Inomura
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
The saturating relationship between phytoplankton growth rate and environmental nutrient concentration has been widely observed, yet the mechanisms behind the relationship remain elusive. Here, we use a mechanistic model of phytoplankton and show that the saturating relationship between growth rate and phosphorous concentration can be interpreted by intracellular macromolecular allocation. At low nutrient levels, the diffusive nutrient transport linearly increases with the phosphorous concentration, while the internal phosphorous requirement increases with the growth rate, leading to a non-linear increase in the growth rate with phosphorous. This increased phosphorous requirement is due to the increased allocation to biosynthetic and photosynthetic molecules. …
Saturating Relationship Between Phytoplankton Growth Rate And Nutrient Concentration Explained By Macromolecular Allocation, Jongsun Kim, Gabrielle Armin, Keisuke Inomura
Saturating Relationship Between Phytoplankton Growth Rate And Nutrient Concentration Explained By Macromolecular Allocation, Jongsun Kim, Gabrielle Armin, Keisuke Inomura
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
Phytoplankton account for about a half of photosynthesis in the world, making them a key player in the ecological and biogeochemical systems. One of the key traits of phytoplankton is their growth rate because it indicates their productivity and affects their competitive capability. The saturating relationship between phytoplankton growth rate and environmental nutrient concentration has been widely observed yet the mechanisms behind the relationship remain elusive. Here we use a mechanistic model and metadata of phytoplankton to show that the saturating relationship between growth rate and nitrate concentration can be interpreted by intracellular macromolecular allocation. At low nitrate levels, the …
The Simulated Biological Response To Southern Ocean Eddies Via Biological Rate Modification And Physical Transport, Tyler Rohr, Cheryl S. Harrison, Matthew C. Long, Peter Gaube, Scott C. Doney
The Simulated Biological Response To Southern Ocean Eddies Via Biological Rate Modification And Physical Transport, Tyler Rohr, Cheryl S. Harrison, Matthew C. Long, Peter Gaube, Scott C. Doney
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
We examine the structure and drivers of anomalous phytoplankton biomass in Southern Ocean eddies tracked in a global, multiyear, eddy-resolving, 3-D ocean simulation of the Community Earth System Model.We examine how simulated anticyclones and cyclones differentially modify phytoplankton biomass concentrations, growth rates, and physical transport. On average, cyclones induce negative division rate anomalies that drive negative net population growth rate anomalies, reduce dilution across shallower mixed layers, and advect biomass anomalously downward via eddy-induced Ekman pumping. The opposite is true in anticyclones. Lateral transport is dominated by eddy stirring rather than eddy trapping. The net effect on anomalous biomass can …
Eddy-Modified Iron, Light, And Phytoplankton Cell Division Rates In The Simulated Southern Ocean, Tyler Rohr, Cheryl S. Harrison, Matthew C. Long, Peter Gaube, Scott C. Doney
Eddy-Modified Iron, Light, And Phytoplankton Cell Division Rates In The Simulated Southern Ocean, Tyler Rohr, Cheryl S. Harrison, Matthew C. Long, Peter Gaube, Scott C. Doney
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
We examine the effects of Southern Ocean eddies on phytoplankton cell division rates in a global, multiyear, eddy‐resolving, 3‐D ocean simulation of the Community Earth System Model. We first identify and track eddies in the simulation and validate their distribution and demographics against observed eddy trajectory characteristics. Next, we examine how simulated cyclones and anticyclones differentially modify iron, light, and ultimately population‐specific cell division rates. We use an eddy‐centric, depth‐averaged framework to explicitly examine the dynamics of the phytoplankton population across the entire water column within an eddy. We find that population‐averaged iron availability is elevated in anticyclones throughout the …