Tascón-Peña Osvaldo, Cabrerizo Marco J, Pérez-Lorenzo María, Marañón Emilio
Centro de Investigación Mariña da Universidade de Vigo, Illa de Toralla s/n, Vigo 36331, Spain.
Department of Ecology and Animal Biology, Faculty of Marine Sciences, University of Vigo, Campus Lagoas Marcosende, Vigo 36310, Spain.
J Plankton Res. 2025 May 21;47(3):fbaf021. doi: 10.1093/plankt/fbaf021. eCollection 2025 May-Jun.
Thermal fluctuations affect the physiology and ecology of organisms. To date, most studies quantifying the effects of temperature on phytoplankton have used mean constant conditions, thus overlooking the role of short-term thermal fluctuations. Here, we use a multi-trait analysis to quantify how thermal regime (constant vs. fluctuation by ±3°C around mean temperature) alters the effect of temperature (18 vs. 22°C) on the growth, elemental composition, photosynthetic performance and metabolism of five phytoplankton species (, , , sp. and ) during exponential growth and stationary phases. Our results showed a high degree of inter-trait and inter-specific variability in the response to the temperature treatments. The carbon-based growth rates tended to be reduced by thermal fluctuations (by 20-29%), particularly under warming conditions. By contrast, thermal fluctuations increased the photosynthesis rates up to 25%, regardless of the growth phase. The carbon-to-nitrogen and carbon-to-chlorophyll ratios, maximum photochemical yield of photosystem II and relative maximum electron transport rates did not show a clear response to interactions between thermal fluctuations and temperature. These results suggest that, when assessing phytoplankton responses to temperature, it is essential to consider both thermal fluctuations and multi-trait analysis.
热波动影响生物体的生理和生态。迄今为止，大多数量化温度对浮游植物影响的研究都采用了平均恒定条件，从而忽略了短期热波动的作用。在此，我们使用多性状分析来量化热状态（恒定温度与围绕平均温度±3°C波动）如何改变温度（18°C与22°C）对五种浮游植物物种（、、、 属和 ）在指数生长期和稳定期的生长、元素组成、光合性能和代谢的影响。我们的结果表明，在对温度处理的响应中，性状间和物种间存在高度变异性。基于碳的生长速率往往会因热波动而降低（降低20 - 29%），尤其是在变暖条件下。相比之下，无论生长阶段如何，热波动都会使光合速率提高高达25%。碳氮比、碳叶绿素比、光系统II的最大光化学产量和相对最大电子传递速率对热波动和温度之间的相互作用没有明显响应。这些结果表明，在评估浮游植物对温度的响应时，必须同时考虑热波动和多性状分析。
