Food web consequences of thermal asymmetries
Food web consequences of thermal asymmetries
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DOI：
10.1111/1365-2435.14091
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发表时间：
2022-06-01
影响因子：
5.2
通讯作者：
Dell, Anthony, I
中科院分区：
文献类型：
--
作者：
Gibert, Jean P.;Grady, John M.;Dell, Anthony, I
了解食物网将如何应对全球气温上升是一个紧迫的问题。温度对食物网的影响可能是由消费者和资源的热敏感性差异或热不对称所支撑的。我们确定了热性能曲线上升部分不对称的三个来源：热调节组之间的热间变化，热调节组内的热内变化以及不同生态速率对温度的响应速率依赖的变化。我们使用了一个大型的热敏感性经验数据集来探索在真实的消费者-资源互动中普遍存在的热不对称。然后我们发展理论来说明食物网温度反应是如何由这些热不对称的大小和方向介导的。我们使用这个模型来显示食物网可能对当前预期的变暖做出反应的情况，以及可能不是这种情况的情况。我们的研究结果表明，温热间、温热内和速率相关的不对称可能在天然食物网中很常见。我们展示了所有的热不对称如何在营养水平上对物种丰度以及食物网中最大营养位置产生重要影响。不对称的方向（即哪个物种的反应更强烈）和它们的大小（热反应的差异）决定了食物网的温度反应，并且，与目前的预期一致，顶级捕食者的丰度几乎总是随着温度而下降，即使最大营养位置可能会增加。虽然我们的模型表明食物网的温度反应可以变化，但这种变化的大部分可以通过考虑热不对称性来解释。我们的研究为在实验室、实验和观测环境中观察到的广泛变化的食物网效应提供了新的数据和理论见解，并阐明了在不断变化的世界中，捕食者和猎物的热生态如何影响整体食物网的反应。在《华尔街日报》博客上阅读免费的《简明语言摘要》。
Understanding how food webs will respond to globally rising temperatures is a pressing issue. Temperature effects on food webs are likely underpinned by differences in the thermal sensitivity of consumers and resources, or thermal asymmetries. We identify three sources of asymmetry in the rising portion of thermal performance curves: inter-thermy variation across thermoregulatory groups, intra-thermy variation within a thermoregulatory group and rate-dependent variation in how different ecological rates respond to temperature. We use a large empirical dataset on thermal sensitivities across thermoregulatory groups to explore how prevalent thermal asymmetries are in real consumer-resource interactions. We then develop theory to illustrate how food web temperature responses are mediated by the magnitude and direction of these thermal asymmetries. We use this model to show possible conditions under which food webs could respond to warming as currently expected, and when that may not be the case. Our results suggest that inter-thermy, intra-thermy and rate-dependent asymmetries are likely common in natural food webs. We show how all thermal asymmetries have important effects on species abundances across trophic levels as well as the maximum trophic position in the food web. Both the direction of the asymmetries (i.e. which species respond more strongly) and their magnitude (the difference in thermal responses) determine the temperature response of the food web and, consistent with current expectations, top predator abundance almost always declines with temperature, even though maximum trophic position may increase. While our model shows that food web temperature responses can be varied, much of this variation can be explained by considering thermal asymmetries. Our study provides new data and theoretical insights into the widely varying food web effects of warming observed in laboratory, experimental and observational settings, and clarifies how predator and prey thermal ecology may influence overall food web responses in a changing world. Read the free Plain Language Summary for this article on the Journal blog.