The physiological response of picophytoplankton to temperature and its model representation

Stawiarski, Beate, Buitenhuis, Erik T. and Le Quéré, Corinne (2016) The physiological response of picophytoplankton to temperature and its model representation. Frontiers in Marine Science, 3. ISSN 2296-7745

[img]
Preview
PDF (Published manuscript) - Published Version
Available under License Creative Commons Attribution.

Download (1MB) | Preview

Abstract

Picophytoplankton account for most of the marine (sub-)tropical phytoplankton biomass and primary productivity. The contribution to biomass among plankton functional types (PFTs) could shift with climate warming, in part as a result of different physiological responses to temperature. To model these responses, Eppley's empirical relationships have been well established. However, they have not yet been statistically validated for individual PFTs. Here, we examine the physiological response of nine strains of picophytoplankton to temperature; three strains of picoprokaryotes and six strains of picoeukaryotes. We conduct laboratory experiments at 13 temperatures between –0.5 and 33°C and measure the maximum growth rates and the chlorophyll a to carbon ratios. We then statistically validate two hypotheses formulated by Eppley in 1972: The response of maximum growth rates to temperature (1) of individual strains can be represented by an optimum function, and (2) of the whole phytoplankton group can be represented by an exponential function Eppley (1972). We also quantify the temperature-related parameters. We find that the temperature span at which growth is positive is more constrained for picoprokaryotes (13.7–27°C), than for picoeukaryotes (2.8–32.4°C). However, the modeled temperature tolerance range (ΔT) follows an unimodal function of cell size for the strains examined here. Thus, the temperature tolerance range may act in conjunction with the maximum growth rate to explain the picophytoplankton community size structure in correlation with ocean temperature. The maximum growth rates obtained by a 99th quantile regression for the group of picophytoplankton or picoprokaryotes are generally lower than the rates estimated by Eppley. However, we find temperature-dependencies (Q10) of 2.3 and of 4.9 for the two groups, respectively. Both of these values are higher than the Q10 of 1.88 estimated by Eppley and could have substantial influence on the biomass distribution in models, in particular if picoprokaryotes were considered an independent PFT. We also quantify the increase of the chlorophyll a to carbon ratios with increasing temperature due to acclimation. These parameters provide essential and validated physiological information to explore the response of marine ecosystems to a warming climate using ocean biogeochemistry models.

Item Type: Article
Additional Information: © 2016 Stawiarski, Buitenhuis and Le Quéré. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Uncontrolled Keywords: picophytoplankton,picoeukaryotes,eppley,phytoplankton growth rates,temperature tolerance,phytoplankton size scaling,physiological parameterization,chlorophyll a to carbon ratio
Faculty \ School: Faculty of Science > School of Environmental Sciences
Related URLs:
Depositing User: Pure Connector
Date Deposited: 24 Sep 2016 00:54
Last Modified: 22 Jul 2020 01:04
URI: https://ueaeprints.uea.ac.uk/id/eprint/60268
DOI: 10.3389/fmars.2016.00164

Actions (login required)

View Item View Item