Climate warming can negatively affect the body size of ectothermic organisms and, based on known temperature–size rules, tends to benefit small-bodied organisms. Our understanding of the interactive effects of climate warming and other environmental factors on the temporal changes of body size structure is limited. We quantified the annual trends in size spectra of 583 stream fish communities sampled for more than 20 years across France. The results show that climate warming steepened the slope of the community size spectrum in streams with limited impacts from other human pressures. These changes were caused by increasing abundance of small‐bodied individuals and decreasing abundance of large‐bodied individuals. However, opposite effects of climate warming on the size spectrum slopes were observed in streams facing high levels of other human pressures. This demonstrates that the effects of temperature on body size structure can depend on other human pressures, disrupting the natural patterns of size spectra in wild communities with potentially strong implications for the fluxes of energy and nutrients in ecosystems.

气候变暖会对变温生物的体型产生负面影响，并且根据已知的温度-体型规则，往往有利于小型生物。我们对气候变暖和其他环境因素对身体尺寸结构的时间变化的相互作用影响的理解是有限的。我们量化了 20 多年来在法国各地采样的 583 个溪流鱼类群落大小范围的年度趋势。结果表明，气候变暖使溪流中群落规模谱的斜率变得陡峭，而其他人类压力的影响有限。这些变化是由于小体型个体数量的增加和大体型个体数量的减少引起的。然而，在面临高水平其他人类压力的溪流中观察到气候变暖对尺寸谱斜率的相反影响。这表明温度对身体尺寸结构的影响可能取决于其他人类压力，扰乱了野生群落尺寸范围的自然模式，对生态系统中的能量和营养物质的流动具有潜在的强烈影响。