A consumer\'s guide to phytoplankton primary productivity models

LIMNOLOGY AND

November 1997 Volume 42

OCEANOGRAPHY Lmnol Oceanogr, 42(7), 1997, 1479-1491 0 1997, by the American Society of Limnology

and Oceanography,

Number 7

Inc

A consumer’s guide to phytoplankton primary productivity models Michael J. Behrenfeld and Paul G. Falkowski Department of Applied Science, Oceanographic and Atmospheric Sciences Division, Upton, New York 11973-5000

Brookhaven National Laboratory,

Abstract We describe a classification system for daily phytoplankton primary productivity models based on four implicit levels of mathematical integration. Depth-integrated productivity models have appeared in the literature on average once every 2 years over the past four decades. All of these models can be related to a single formulation equating depth-integrated primary production (2 PP) to surface phytoplankton biomass (C,,,J, a photoadaptive variable (PhO,,), euphotic depth (Z,,), an irradiance-dependent function (F), and daylength (DL). The primary difference between models is the description of F, yet we found that irradiance has a relatively minor effect on variability in X PP. We also found that only a small fraction of variability in 2 PP can be attributed to vertical variability in phytoplankton biomass or variability in the light-limited slope for photosynthesis. Our results indicate that (1) differences between or within any model category have the potential to improve estimates of X PP by