Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
Biol Lett. 2021 Mar;17(3):20200873. doi: 10.1098/rsbl.2020.0873. Epub 2021 Mar 17.
Montane reptiles are predicted to move to higher elevations in response to climate warming. However, whether upwards-shifting reptiles will be physiologically constrained by hypoxia at higher elevations remains unknown. We investigated the effects of hypoxic conditions on preferred body temperatures (T) and thermal tolerance capacity of a montane lizard () from two populations on the Qinghai-Tibet Plateau. Lizards from 2600 m a.s.l. were exposed to O levels mimicking those at 2600 m (control) and 3600 m (hypoxia treatment). Lizards from 3600 m a.s.l. were exposed to O levels mimicking those at 3600 m (control) and 4600 m (hypoxia treatment). The T did not differ between the control and hypoxia treatments in lizards from 2600 m. However, lizards from 3600 m selected lower body temperatures when exposed to the hypoxia treatment mimicking the O level at 4600 m. Additionally, the hypoxia treatment induced lower critical thermal minimum (CT) in lizards from both populations, but did not affect the critical thermal maximum (CT) in either population. Our results imply that upwards-shifting reptiles may be constrained by hypoxia if a decrease in T reduces thermally dependent fitness traits, despite no observed effect on their heat tolerance.
高山爬行动物预计将随着气候变暖而向更高海拔迁移。然而，向上迁移的爬行动物是否会因高海拔地区的低氧而在生理上受到限制仍不清楚。我们研究了低氧条件对青藏高原两个种群高山蜥蜴（）的最佳体温（T）和耐热能力的影响。海拔 2600 米的蜥蜴分别暴露在模拟海拔 2600 米（对照）和 3600 米（低氧处理）的 O 水平下。海拔 3600 米的蜥蜴则分别暴露在模拟海拔 3600 米（对照）和 4600 米（低氧处理）的 O 水平下。在海拔 2600 米的蜥蜴中，对照和低氧处理组的 T 没有差异。然而，当暴露在模拟海拔 4600 米的 O 水平的低氧处理中时，海拔 3600 米的蜥蜴选择了更低的体温。此外，低氧处理降低了两个种群蜥蜴的临界最低体温（CT），但对两个种群的临界最高体温（CT）没有影响。我们的研究结果表明，如果 T 的降低降低了与温度相关的适应特征，那么向上迁移的爬行动物可能会受到低氧的限制，尽管没有观察到对它们耐热性的影响。
