Global warming is expected to drive species toward higher altitudes. Indeed, most documented range shifts are upward, but observed shifts are often far from model predictions, and even downward shifts are common. Can such counterintuitive observations be explained? Metabolic oxygen demand rises with temperature in ectothermic animals, but levels of metabolic sensitivity to temperature increases (Q₁₀) vary among species. Oxygen availability also decreases with altitude, which potentially interferes with the ability of organisms to track their thermal niches upward. Here, I introduce the “metabolic oxygen‐driven altitude shift” (MODAS) framework, which accounts for an overlooked cause of interspecies variation in range shifts. Upward shifts should always occur if it is most important for the species to conserve its pre‐warming temperature. In contrast, if conserving the oxygen demand–supply balance has priority, then downward shifts should occur for species that are less sensitive to temperature increases (low Q₁₀), while excessive upward shifts to lower than pre‐warming temperatures should occur at high Q₁₀.

中文翻译：

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垂直位移的困境：陷入高温和低氧之间

预计全球变暖将把物种推向更高的高度。确实，大多数记录的范围偏移是向上的，但是观察到的偏移通常与模型预测相差甚远，甚至向下偏移也是常见的。可以解释这种违反直觉的看法吗？结温动物的代谢需氧量随温度升高而升高，但代谢对温度的敏感性水平升高（Q ₁₀）因物种而异。氧气的可用性也随着海拔的升高而降低，这可能会干扰生物体向上追踪其热ni的能力。在这里，我介绍了“代谢性氧气驱动的高度变化”（MODAS）框架，该框架解释了范围变化中种间变异的被忽略的原因。如果对物种而言，保持其变暖前的温度最为重要，则应始终发生向上移位。相反，如果保持氧气供需平衡为优先事项，那么对温度升高不太敏感的物种（低Q ₁₀）应发生向下移位，而在高Q下应发生过度升高以低于预热温度的物种。₁₀。