Global warming is altering both phytoplankton-experienced temperature and light-exposure duration through shifting their niches from low to high latitudes. We explored the growth, physiology, and compositions of a smaller Thalassiosira pseudonana and a larger Thalassiosira punctigera, temperate marine centric diatoms, in responses to a matrix of temperatures (12, 15, 18, and 21 °C) and photoperiods (light:dark cycles of 4:20, 8:16, 16:8, and 24:0). Both T. pseudonana and T. punctigera grew faster under medium temperature and longer photoperiod, under the expected optimal instantaneous light intensity. The biovolume-based pigments content of T. pseudonana responded largely to temperature, while that of T. punctigera responded more to photoperiod duration than to temperature. In T. pseudonana, shortest photoperiod enhanced cellular protein content and alleviated their temperature dependency. Continuous growth light reduced the photosynthetic capacity of T. pseudonana at the lowest temperature and reduced that of T. punctigera across temperatures. Moreover, we found the increasing temperature linearly increased the dark respiration rate (Rd) and molar ratio of carbon to nitrogen (C:N) of T. pseudonana but decreased that of T. punctigera, with the scattered effects of photoperiod. Our results demonstrated that responses of diatoms Thalassiosira across photoperiods and temperatures vary with species and possibly with cell size, suggesting that the poleward shift of the niches of phytoplankton in nature might cause a change in community structure.

全球变暖通过将生态位从低纬度转变为高纬度来改变浮游植物的温度和光照持续时间。我们探索了温度，温度（12、15、18和21°C）和光周期（光：暗）的作用下，较小的拟南芥和较大的拟南芥，温带海洋中心硅藻的生长，生理和组成。4：20、8：16、16：8和24：0的周期）。两个T. pseudonana和T.茶色增长快介质温度和更长的光周期下，预期的最佳瞬时光强度下。的基于biovolume颜料含量T. pseudonana很大程度上回应了温度，而中T. punctigera对光周期持续时间的反应比对温度的反应大。在假单胞菌中，最短的光周期增加了细胞蛋白含量并减轻了它们的温度依赖性。持续增长的光降低的光合能力T. pseudonana在最低温度和减少了的T.茶色跨越温度。此外，我们发现了增加的温度线性增加暗呼吸速率（Rd）和碳与氮的摩尔比：的（C N）T. pseudonana但降低其的T.茶色，与光周期的散射效果。我们的结果表明硅藻Thalassiosira的反应 跨光周期，温度随物种和细胞大小而变化，这表明自然界中浮游植物生态位的极移可能导致群落结构发生变化。