Ecological niches of open ocean phytoplankton taxa

Philipp Georg Brun, Meike Vogt, Mark Payne, Nicolas Gruber, Colleen J. O'Brien, Erik T. Buitenhuis, Corinne Le Quéré, Karine Leblanc, Ya-Wei Luo

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Abstract

We characterize the realized ecological niches of 133 phytoplankton taxa in the open ocean based on observations from the MAREDAT initiative and a statistical species distribution model (MaxEnt). The models find that the physical conditions (mixed layer depth, temperature, light) govern large-scale patterns in phytoplankton biogeography over nutrient availability. Strongest differences in the realized niche centers were found between diatoms and coccolithophores. Diatoms (87 species) occur in habitats with significantly lower temperatures, light intensity and salinity, with deeper mixed layers, and with higher nitrate and silicate concentrations than coccolithophores (40 species). However, we could not statistically separate the realized niches of coccolithophores from those of diazotrophs (two genera) and picophytoplankton (two genera). Phaeocystis (two species) niches only clearly differed from diatom niches for temperature. While the realized niches of diatoms cover the majority of niche space, the niches of picophytoplankton and coccolithophores spread across an intermediate fraction and diazotroph and colonial Phaeocystis niches only occur within a relatively confined range of environmental conditions in the open ocean. Our estimates of the realized niches roughly match the predictions of Reynolds' C-S-R model for the global ocean, namely that taxa classified as nutrient stress tolerant have niches at lower nutrient and higher irradiance conditions than light stress tolerant taxa. Yet, there is considerable within-class variability in niche centers, and many taxa occupy broad niches, suggesting that more complex approaches may be necessary to capture all aspects of phytoplankton ecology
Original languageEnglish
JournalLimnology and Oceanography
Volume60
Issue number3
Pages (from-to)1020-1038
ISSN0024-3590
DOIs
Publication statusPublished - 2015

Cite this

Brun, P. G., Vogt, M., Payne, M., Gruber, N., O'Brien, C. J., Buitenhuis, E. T., Le Quéré, C., Leblanc, K., & Luo, Y-W. (2015). Ecological niches of open ocean phytoplankton taxa. Limnology and Oceanography, 60(3), 1020-1038. https://doi.org/10.1002/lno.10074