Weitz Group @ Georgia Tech Theoretical Ecology and Quantitative Biology



A discrepancy between Michaelis-Menten based nutrient uptake model predictions and nitrogen to phosphorus stoichiometry in the surface ocean

TitleA discrepancy between Michaelis-Menten based nutrient uptake model predictions and nitrogen to phosphorus stoichiometry in the surface ocean
Publication TypeJournal Article
Year of Publication2010
AuthorsBallantyne F, Menge DNL, Weitz JS
JournalLimnology and Oceanography
Volume55
Start Page997
Pagination997-1008
Abstract

We derive a simple prediction about euphotic zone N: P stoichiometry from a large class of models that use saturating nutrient uptake functions to characterize N and P acquisition by phytoplankton. The prediction is: At an ecological steady state, the ratio of phytoplankton N: P to inorganic N: P in the euphotic zone equals the ratio of phytoplankton maximum uptake rates of N and P. We estimate this predicted ratio using nutrient uptake parameters measured in laboratory growth experiments and compare the predicted ratio to empirical observations from long-term sampling in the Atlantic and Pacific oceans. The model predictions for the ratio of phytoplankton N: P to inorganic N: P are at odds with the majority of data from extensive long-term sampling in the Atlantic and the Pacific oceans. This discrepancy calls into question the scope of applicability of ecosystem models that explicitly describe phytoplankton growth as a function of N and P availability. We discuss efforts to resolve this discrepancy, including the need for performing more comprehensive N and P uptake experiments and by reexamining models of nutrient uptake.

URLhttp://www.aslo.org/lo/toc/vol_55/issue_3/0997.html
AttachmentSize
fb_dm_jsw_lando2010.pdf878.25 KB