Cabrerizo Marco J, Marañón Emilio
Departamento de Ecología y Biología Animal, Universidade de Vigo, Facultad de Ciencias del Mar, Campus Lagoas Marcosende s/n, 36310 Vigo, Spain.
Centro de Investigación Mariña da Universidade de Vigo (CIM-UVigo), Illa de Toralla s/n, 36331, Vigo, Spain.
Fac Rev. 2021 Jan 29;10:9. doi: 10.12703/r/10-9. eCollection 2021.
Warming can cause changes in the structure and functioning of microbial food webs. Experimental studies quantifying such impacts on microbial plankton have tended to consider constant temperature conditions. However, Jensen's inequality (or the fallacy of the average) recognizes that organism performance under constant conditions is seldom equal to the mean performance under variable conditions, highlighting the need to consider fluctuations over a range of time scales. Here we review some of the available evidence on how warming effects on the abundance, diversity, and metabolism of microbial plankton are altered when temperature fluctuations are considered. We found that fluctuating temperatures may accentuate warming-mediated reductions in phytoplankton evenness and gross photosynthesis while synergistically increasing phytoplankton growth. Also, fluctuating temperatures have been shown to reduce the positive warming effect on cyanobacterial biomass production and recruitment and to reverse a warming effect on cellular nutrient quotas. Other reports have shown that fluctuations in temperature did not alter plankton responses to constant warming. These investigations have mostly focused on a few phytoplankton species (i.e. diatoms and haptophytes) in temperate and marine ecosystems and considered short-term and transient responses. It remains unknown whether the same responses apply to other species and ecosystems and if evolutionary change in thermally varying environments could alter the magnitude and direction of the responses to warming observed over short-term scales. Thus, future research efforts should address the role of fluctuations in environmental drivers. We stress the need to study responses over different biological organization and trophic levels, nutritional modes, temporal scales, and ecosystem types.
升温会导致微生物食物网的结构和功能发生变化。量化此类对微生物浮游生物影响的实验研究往往考虑的是恒温条件。然而，詹森不等式（或均值谬误）表明，在恒定条件下生物体的表现很少等同于在可变条件下的平均表现，这凸显了在一系列时间尺度上考虑波动的必要性。在此，我们回顾一些现有证据，这些证据表明当考虑温度波动时，升温对微生物浮游生物的丰度、多样性和代谢的影响是如何改变的。我们发现，温度波动可能会加剧升温介导的浮游植物均匀度和总光合作用的降低，同时协同增加浮游植物的生长。此外，温度波动已被证明会降低升温对蓝藻生物量产生和补充的积极影响，并逆转升温对细胞营养配额的影响。其他报告表明，温度波动并未改变浮游生物对持续升温的反应。这些研究大多集中在温带和海洋生态系统中的少数浮游植物物种（即硅藻和定鞭藻），并考虑了短期和瞬时反应。对于其他物种和生态系统是否也有相同的反应，以及在热变化环境中的进化变化是否会改变在短期尺度上观察到的对升温反应的幅度和方向，目前尚不清楚。因此，未来的研究工作应关注环境驱动因素波动的作用。我们强调有必要研究不同生物组织和营养级、营养模式、时间尺度和生态系统类型的反应。
