School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK.
Department of Biological, Geological and Environmental Sciences, University of Catania, Catania, 95128, Italy.
New Phytol. 2020 Jun;226(5):1312-1324. doi: 10.1111/nph.16453. Epub 2020 Feb 29.
As climate change transforms seasonal patterns of temperature and precipitation, germination success at marginal temperatures will become critical for the long-term persistence of many plant species and communities. If populations vary in their environmental sensitivity to marginal temperatures across a species' geographical range, populations that respond better to future environmental extremes are likely to be critical for maintaining ecological resilience of the species. Using seeds from two to six populations for each of nine species of Mediterranean plants, we characterized patterns of among-population variation in environmental sensitivity by quantifying genotype-by-environment interactions (G × E) for germination success at temperature extremes, and under two light regimes representing conditions below and above the soil surface. For eight of nine species tested at hot and cold marginal temperatures, we observed substantial among-population variation in environmental sensitivity for germination success, and this often depended on the light treatment. Importantly, different populations often performed best at different environmental extremes. Our results demonstrate that ongoing changes in temperature regime will affect the phenology, fitness, and demography of different populations within the same species differently. We show that quantifying patterns of G × E for multiple populations, and understanding how such patterns arise, can test mechanisms that promote ecological resilience.
随着气候变化改变了温度和降水的季节性模式，在边缘温度下的发芽成功率将对许多植物物种和群落的长期生存变得至关重要。如果种群在其对跨越物种地理范围的边缘温度的环境敏感性方面存在差异，那么对未来环境极端变化反应更好的种群可能对维持物种的生态恢复力至关重要。我们使用来自地中海植物的 9 个物种的每一种的 2 到 6 个种群的种子，通过量化在极端温度下和在代表土壤表面以下和以上的两种光照条件下的发芽成功率的基因型-环境互作（G×E），来描述种群间环境敏感性的变化模式。在对高温和低温边缘温度进行测试的 9 个物种中的 8 个中，我们观察到了在发芽成功率方面存在显著的种群间环境敏感性差异，而且这种差异通常取决于光照处理。重要的是，不同的种群通常在不同的环境极端条件下表现最好。我们的结果表明，不断变化的温度模式将以不同的方式影响同一物种内不同种群的物候、适应性和种群动态。我们表明，通过量化多个种群的 G×E 模式，并了解这些模式是如何产生的，可以检验促进生态恢复力的机制。
