Inter-Research > MEPS > v489 > feature  
Marine Ecology Progress Series

via Mailchimp
MEPS - Vol. 489 - Feature article
Inorganic nitrogen and phosphorus control the competition between diazotrophs and ordinary phytoplankton, which in turn drives ambient nutrient concentrations; diazotrophs are strong competitors for P, as they can invest more energy into its acquisition. Image: M. Pahlow

Pahlow M, Dietze H, Oschlies A


Optimality-based model of phytoplankton growth and diazotrophy


The supply of fixed inorganic nitrogen (DIN) and phosphorus (DIP) to the ocean surface drives the interaction between ordinary and diazotrophic phytoplankton, described here by an optimality-based chain model. Competition between both groups controls ambient DIN and DIP concentrations. Conditions favourable for diazotrophy emerge from trade-offs among cellular energy and resource requirements for N, P and C acquisition. The model constructed by Pahlow and co-workers predicts that diazotrophs are strong competitors for DIP, as they can devote more resources to P acquisition than ordinary phytoplankton organisms, which must invest more of their resources in DIN uptake and assimilation. Therefore, the authors argue that diazotrophy is most advantageous under conditions of oligotrophy, particularly in P.


Inter-Research Science Publisher is pleased to make this Feature Article openly available for viewing by our readers.


Abstract   Back to contents page   Link to full PDF