Department of Integrated Modelling, Leibniz Centre for Tropical Marine Research, Bremen, Germany.
Department of Physics & Earth Sciences, Jacobs University Bremen, Bremen, Germany.
PLoS Comput Biol. 2022 May 9;18(5):e1010099. doi: 10.1371/journal.pcbi.1010099. eCollection 2022 May.
The symbiotic relationship between corals and photosynthetic algae is the foundation of coral reef ecosystems. This relationship breaks down, leading to coral death, when sea temperature exceeds the thermal tolerance of the coral-algae complex. While acclimation via phenotypic plasticity at the organismal level is an important mechanism for corals to cope with global warming, community-based shifts in response to acclimating capacities may give valuable indications about the future of corals at a regional scale. Reliable regional-scale predictions, however, are hampered by uncertainties on the speed with which coral communities will be able to acclimate. Here we present a trait-based, acclimation dynamics model, which we use in combination with observational data, to provide a first, crude estimate of the speed of coral acclimation at the community level and to investigate the effects of different global warming scenarios on three iconic reef ecosystems of the tropics: Great Barrier Reef, South East Asia, and Caribbean. The model predicts that coral acclimation may confer some level of protection by delaying the decline of some reefs such as the Great Barrier Reef. However, the current rates of acclimation will not be sufficient to rescue corals from global warming. Based on our estimates of coral acclimation capacities, the model results suggest substantial declines in coral abundances in all three regions, ranging from 12% to 55%, depending on the region and on the climate change scenario considered. Our results highlight the importance and urgency of precise assessments and quantitative estimates, for example through laboratory experiments, of the natural acclimation capacity of corals and of the speed with which corals may be able to acclimate to global warming.
珊瑚和光合藻类之间的共生关系是珊瑚礁生态系统的基础。当海水温度超过珊瑚-藻类复合体的热耐受极限时，这种关系就会破裂，导致珊瑚死亡。虽然通过生物体水平的表型可塑性来适应是珊瑚应对全球变暖的重要机制，但对适应能力的基于群落的转变可能会为珊瑚在区域尺度上的未来提供有价值的指示。然而，可靠的区域尺度预测受到珊瑚群落适应速度的不确定性的阻碍。在这里，我们提出了一种基于特征的适应动态模型，我们将其与观测数据结合使用，以首次粗略估计群落水平上珊瑚适应的速度，并研究不同全球变暖情景对热带地区三个标志性珊瑚礁生态系统的影响：大堡礁、东南亚和加勒比海。该模型预测，珊瑚适应可能通过延迟某些珊瑚礁（如大堡礁）的衰退提供一定程度的保护。然而，目前的适应速度不足以使珊瑚免受全球变暖的影响。基于我们对珊瑚适应能力的估计，该模型结果表明，所有三个地区的珊瑚丰度都将大幅下降，范围从 12%到 55%不等，具体取决于地区和所考虑的气候变化情景。我们的研究结果强调了通过实验室实验等精确评估和定量估计珊瑚自然适应能力以及珊瑚适应全球变暖速度的重要性和紧迫性。
