Phytoplankton competition and resilience under fluctuating temperature.

Autor: Siegel P; School of Life Sciences University of Essex Colchester Campus Colchester UK., Baker KG; School of Life Sciences University of Essex Colchester Campus Colchester UK.; Present address: Institute for Marine and Antarctic Studies University of Tasmania Battery Point Tasmania Australia., Low-Décarie E; School of Life Sciences University of Essex Colchester Campus Colchester UK.; Present address: Biological Informatics Center of Expertise, Agriculture and Agrifoods Canada, Government of Canada Montreal Quebec Canada., Geider RJ; School of Life Sciences University of Essex Colchester Campus Colchester UK.
Jazyk: angličtina
Zdroj: Ecology and evolution [Ecol Evol] 2023 Mar 19; Vol. 13 (3), pp. e9851. Date of Electronic Publication: 2023 Mar 19 (Print Publication: 2023).
DOI: 10.1002/ece3.9851
Abstrakt: Environmental variability is an inherent feature of natural systems which complicates predictions of species interactions. Primarily, the complexity in predicting the response of organisms to environmental fluctuations is in part because species' responses to abiotic factors are non-linear, even in stable conditions. Temperature exerts a major control over phytoplankton growth and physiology, yet the influence of thermal fluctuations on growth and competition dynamics is largely unknown. To investigate the limits of coexistence in variable environments, stable mixed cultures with constant species abundance ratios of the marine diatoms, Phaeodactylum tricornutum and Thalassiosira pseudonana, were exposed to different temperature fluctuation regimes ( n  = 17) under high and low nitrogen (N) conditions. Here we demonstrate that phytoplankton exhibit substantial resilience to temperature variability. The time required to observe a shift in the species abundance ratio decreased with increasing fluctuations, but coexistence of the two model species under high N conditions was disrupted only when amplitudes of temperature fluctuation were high (±8.2°C). N limitation caused the thermal amplitude for disruption of species coexistence to become lower (±5.9°C). Furthermore, once stable conditions were reinstated, the two species differed in their ability to recover from temperature fluctuations. Our findings suggest that despite the expectation of unequal effect of fluctuations on different competitors, cycles in environmental conditions may reduce the rate of species replacement when amplitudes remain below a certain threshold. Beyond these thresholds, competitive exclusion could, however, be accelerated, suggesting that aquatic heatwaves and N availability status are likely to lead to abrupt and unpredictable restructuring of phytoplankton community composition.
Competing Interests: The authors declare no competing interests.
(© 2023 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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