Frenette Bryan D, Bruckerhoff Lindsey A, Tobler Michael, Gido Keith B
Division of Biology, Kansas State University, 166 Ackert Hall, Manhattan, KS 66506, USA.
Conserv Physiol. 2019 Oct 31;7(1):coz063. doi: 10.1093/conphys/coz063. eCollection 2019.
Earth's atmosphere has warmed by ~1°C over the past century and continues to warm at an increasing rate. Effects of atmospheric warming are already visible in most major ecosystems and are evident across all levels of biological organization. Linking functional responses of individuals to temperature is critical for predicting responses of populations and communities to global climate change. The southern redbelly dace and the central stoneroller are two minnows (Cyprinidae) that commonly occur in the Flint Hills region of the USA but show different patterns of occurrence, with dace largely occupying headwater reaches and stonerollers persisting in both headwater and intermediate-sized streams. We tested for differences between species in critical thermal maximum, energy metabolism, sustained swimming and activity over an ecologically relevant temperature gradient of acclimation temperatures. Typically, metrics increased with acclimation temperature for both species, although stoneroller activity decreased with temperature. We observed a significant interaction between species and temperature for critical thermal maxima, where stonerollers only had higher critical thermal maxima at the coldest temperature and at warm temperatures compared to the dace. We did not find evidence suggesting differences in the energy metabolism of dace and stonerollers. We detected interspecific differences in sustained swimming performance, with dace having higher swimming speed than stonerollers regardless of acclimation temperature. Finally, there was a significant interaction between temperature and species for activity; dace activity was higher at intermediate and warm temperatures compared to stonerollers. We observed subtle interspecific differences in how performance metrics responded to temperature that did not always align with observed patterns of distribution for these species. Thus, other ecological factors likely are important drivers of distributional patterns in these species.
在过去的一个世纪里，地球大气温度上升了约1°C，并且仍在以越来越快的速度变暖。大气变暖的影响在大多数主要生态系统中已清晰可见，且在生物组织的各个层面都很明显。将个体的功能反应与温度联系起来，对于预测种群和群落对全球气候变化的反应至关重要。南方红腹雅罗鱼和中央石滚鱼是两种鲤科小鱼，它们在美国弗林特山区普遍存在，但呈现出不同的分布模式，雅罗鱼主要栖息在源头河段，而石滚鱼在源头和中等大小的溪流中都有分布。我们在一个与生态相关的驯化温度梯度下，测试了这两个物种在临界热最大值、能量代谢、持续游泳能力和活动方面的差异。通常情况下，两个物种的各项指标都随驯化温度的升高而增加，不过石滚鱼的活动能力随温度升高而下降。我们观察到，在临界热最大值方面，物种和温度之间存在显著的相互作用，与雅罗鱼相比，石滚鱼仅在最冷和最暖的温度下具有更高的临界热最大值。我们没有找到表明雅罗鱼和石滚鱼能量代谢存在差异的证据。我们检测到持续游泳表现方面的种间差异，无论驯化温度如何，雅罗鱼的游泳速度都比石滚鱼快。最后，在活动方面，温度和物种之间存在显著的相互作用；与石滚鱼相比，雅罗鱼在中等温度和温暖温度下的活动更为活跃。我们观察到，性能指标对温度的反应存在细微的种间差异，这些差异并不总是与这些物种观察到的分布模式一致。因此，其他生态因素可能是这些物种分布模式的重要驱动因素。
