Baker, KG and Geider, RJ, Phytoplankton mortality in a changing thermal seascape, Global Change Biology, 27, (20) pp. 5253-5261. ISSN 1354-1013 (2021) [Refereed Article]
Copyright 2021 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Predicting spatiotemporal distributions of phytoplankton biomass and community composition heavily relies on experimental studies that document how environmental conditions influence population growth rates. In unicellular phytoplankton, the net population growth rate is the difference between the cell division rate and the death rate. Along with predation and disease, phytoplankton mortality arises from abiotic stress. Although the effect of temperature on the net population growth rate is well understood, studies examining thermally induced death rates in phytoplankton are scarce. We investigated how cell division and death rates of the diatom Phaeodactylum tricornutum varied within its thermal tolerance limits (thermal niche), and at temperatures just above its upper thermal tolerance limit. We show that death rates were largely independent of temperature when P. tricornutum was grown within its thermal niche, but increased significantly at temperatures that approached or exceeded its upper thermal tolerance limit. Furthermore, the sensitivity of mortality increased with the duration of exposure to heat stress and was affected by the pre-acclimation temperature. Heat waves can be expected to significantly affect phytoplankton mortality episodically. The increasing frequency of heat waves accompanying global warming can be expected to drive changes in phytoplankton community structure due to interspecific variability of thermal niches with potential implications for food web dynamics and biogeochemical cycles.
|Item Type:||Refereed Article|
|Keywords:||cell death, global warming, mortality rate, Phaeodactylum tricornutum, thermal acclimation, thermal response, tipping points|
|Research Division:||Biological Sciences|
|Research Field:||Ecological physiology|
|Objective Division:||Environmental Management|
|Objective Group:||Coastal and estuarine systems and management|
|Objective Field:||Assessment and management of coastal and estuarine ecosystems|
|UTAS Author:||Baker, KG (Dr Kirralee Baker)|
|Web of Science® Times Cited:||8|
|Deposited By:||Oceans and Cryosphere|
|Downloads:||2 View Download Statistics|
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