Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa.
UMR 8187 - LOG - Laboratoire d'Océanologie et de Géosciences, Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, Lille, France.
Glob Chang Biol. 2021 Jun;27(11):2549-2560. doi: 10.1111/gcb.15616. Epub 2021 Apr 3.
Temperature extremes are predicted to intensify with climate change. These extremes are rapidly emerging as a powerful driver of species distributional changes with the capacity to disrupt the functioning and provision of services of entire ecosystems, particularly when they challenge ecosystem engineers. The subsequent search for a robust framework to forecast the consequences of these changes mostly ignores within-species variation in thermal sensitivity. Such variation can be intrinsic, but can also reflect species interactions. Intertidal mussels are important ecosystem engineers that host symbiotic endoliths in their shells. These endoliths unexpectedly act as conditionally beneficial parasites that enhance the host's resistance to intense heat stress. To understand how this relationship may be altered under environmental change, we examined the conditions under which it becomes advantageous by reducing body temperature. We deployed biomimetic sensors (robomussels), built using shells of mussels (Mytilus galloprovincialis) that were or were not infested by endoliths, at nine European locations spanning a temperature gradient across 22°of latitude (Orkney, Scotland to the Algarve, Portugal). Daily wind speed and solar radiation explained the maximum variation in the difference in temperature between infested and non-infested robomussels; the largest difference occurred under low wind speed and high solar radiation. From the robomussel data, we inferred body temperature differences between infested and non-infested mussels during known heatwaves that induced mass mortality of the mussel Mytilus edulis along the coast of the English Channel in summer 2018 to quantify the thermal advantage of endolith infestation during temperature extremes. Under these conditions, endoliths provided thermal buffering of between 1.7°C and 4.8°C. Our results strongly suggest that sustainability of intertidal mussel beds will increasingly depend on the thermal buffering provided by endoliths. More generally, this work shows that biomimetic models indicate that within-species thermal sensitivity to global warming can be modulated by species interactions, using an intertidal host-symbiont relationship as an example.
预计随着气候变化，极端温度将加剧。这些极端情况迅速成为物种分布变化的强大驱动因素，有可能破坏整个生态系统的功能和服务提供，尤其是当它们挑战生态系统工程师时。随后，人们寻求一个强大的框架来预测这些变化的后果，但大多忽略了物种对热敏感性的内在变化。这种变化可能是内在的，但也可能反映了物种间的相互作用。潮间带贻贝是重要的生态系统工程师，它们的壳内寄生着共生的内植物。这些内植物出人意料地充当了有条件有益的寄生虫，增强了宿主对强烈热应激的抵抗力。为了了解在环境变化下这种关系可能如何改变，我们研究了通过降低体温而获得优势的条件。我们在欧洲九个地点部署了生物模拟传感器（robomussels），这些传感器是使用未被内植物寄生或被内植物寄生的贻贝壳（Mytilus galloprovincialis）建造的，这些地点横跨 22°的纬度梯度，涵盖了从苏格兰奥克尼群岛到葡萄牙阿尔加维的温度范围。每日风速和太阳辐射解释了受感染和未受感染的 robomussels 之间温差的最大变化；在低风速和高太阳辐射下，差异最大。从 robomussel 数据中，我们推断了 2018 年夏季英吉利海峡沿岸贻贝 Mytilus edulis 大规模死亡期间，受感染和未受感染贻贝之间的体温差异，以量化极端温度下内植物感染的热优势。在这些条件下，内植物提供了 1.7°C 至 4.8°C 的热缓冲。我们的研究结果强烈表明，潮间带贻贝床的可持续性将越来越依赖于内植物提供的热缓冲。更普遍地说，这项工作表明，生物模拟模型表明，物种间的热敏感性对全球变暖的影响可以通过物种相互作用来调节，以潮间带宿主-共生关系为例。
