Resilience of seagrass populations to thermal stress does not reflect regional differences in ocean climate

1. The prevalence of local adaptation and phenotypic plasticity among populations is critical to accurately predicting when and where climate change impacts will occur. Currently, comparisons of thermal performance between populations are untested for most marine species or overlooked by models predicting the thermal sensitivity of species to extirpation. 2. Here we compared the ecological response and recovery of seagrass populations (Posidonia oceanica) to thermal stress throughout a year-long translocation experiment across a 2800 km gradient in ocean climate. Transplants in central and warm-edge locations experienced temperatures >29 ºC, representing thermal anomalies >5ºC above long-term maxima for cool-edge populations, 1.5ºC for central and <1ºC for warm-edge populations. 3. Cool, central and warm-edge populations differed in thermal performance when grown under common conditions, but patterns contrasted with expectations based on thermal geography. Cool-edge popul...1. 种群间局部适应（local adaptation）与表型可塑性（phenotypic plasticity）的普遍存在，是精准预测气候变化影响发生时间与空间分布的关键前提。当前，多数海洋物种的种群间热性能（thermal performance）比较研究尚未开展，或是被预测物种热敏感性灭绝风险的模型所忽略。 2. 本研究依托横跨2800公里海洋气候梯度的为期一年移植实验，对比了海草物种波西多尼亚海草（Posidonia oceanica）的种群对热胁迫的生态响应与恢复过程。中部与暖边缘区域的移植体所处水温超过29℃，其热异常幅度较长期最高温分别超出冷边缘种群5℃、中部种群1.5℃，而暖边缘种群的热异常幅度则不足1℃。 3. 在同质园（common garden）条件下培养时，冷边缘、中部与暖边缘种群的热性能存在显著差异，但其变化模式与基于热地理分布的预期并不一致。冷边缘种群...