Shifts in growth light optima among diatom species support their succession during the spring bloom in the Arctic

Autor: Dany Croteau, Thomas Lacour, Nicolas Schiffrine, Philippe‐Israël Morin, Marie‐Hélène Forget, Flavienne Bruyant, Joannie Ferland, Augustin Lafond, Douglas A. Campbell, Jean‐Éric Tremblay, Marcel Babin, Johann Lavaud
Přispěvatelé: Institut de biologie physico-chimique (IBPC (FR_550)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Takuvik Joint International Laboratory ULAVAL-CNRS, Université Laval [Québec] (ULaval)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Physiologie des Microalgues (PHYSALG), Physiologie et Toxines des Microalgues Toxiques et Nuisibles (PHYTOX), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut des Sciences de la MER de Rimouski (ISMER), Université du Québec à Rimouski (UQAR), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Mount Allison University, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2022
Předmět:
Zdroj: Journal Of Ecology (0022-0477) (Wiley), 2022-06, Vol. 110, N. 6, P. 1356-1375
Journal of Ecology
Journal of Ecology, 2022, ⟨10.1111/1365-2745.13874⟩
ISSN: 1365-2745
0022-0477
DOI: 10.1111/1365-2745.13874
Popis: 1. Diatoms of the Arctic Ocean annually experience extreme changes of light environment linked to photoperiodic cycles and seasonal variations of the snow and sea-ice cover extent and thickness which attenuate light penetration in the water column. Arctic diatom communities exploit this complex seasonal dynamic through a well-documented species succession during spring, beginning in sea-ice and culminating in massive phytoplankton blooms underneath sea-ice and in the marginal ice zone. The pattern of diatom taxa sequentially dominating this succession is relatively well conserved interannually, and taxonomic shifts seem to align with habitat transitions. 2. To understand whether differential photoadaptation strategies among diatom taxa explain these recurring succession sequences, we coupled lab experiments with field work in Baffin Bay at 67.5°N. Based on field data, we selected five diatom species typical of different ecological niches and measured their growth rates under light intensity ranges representative of their natural habitats. To characterize their photoacclimative responses, we sampled pigments and total particulate carbon, and conducted 14C-uptake photosynthesis response curves and variable fluorescence measurements. 3. We documented a gradient in species respective light intensity for maximal growth suggesting divergent light response plasticity, which for the most part align with species sequential dominance. Other photophysiological parameters supported this ecophysiological framing, although contrasts were always clear only between succession endmembers, Nitzschia frigida and Chaetoceros neogracilis. To validate that these photoacclimative responses are representative of in situ dynamics, we compared them to the chlorophyll a-specific light-limited slope (α*) and saturated rate of photosynthesis (P*M), monitored in Baffin Bay on sea-ice and planktonic communities. This complementary approach confirmed that unusual responses in α* and P*M as a function of light history intensity are similar between sentinel sympagic species N. frigida and natural ice-core communities. While no light-history-dependent trends were observed in planktonic communities, their α* and P*M values were in the range of measurements from our monospecific cultures. 4. Synthesis. Our results suggest that Arctic diatoms species photoadaptation strategy is tuned to the light environment of the habitats in which they dominate and indeed drives the seasonal taxonomic succession.
Databáze: OpenAIRE
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