Abstract Plant adaptation to sea level rise has important implications for conservation and shoreline protection; however, it has received little attention. Here I explored adaptation of one of the dominant plants in European saltmarshes to sea level rise and whether this adaptation is mediated by successional stages. Different successional stages have distinct characteristics such as nutrient availability. I collected Elytrigia atherica from high and low marsh at early, intermediate, and late successional stages. Individuals of E. atherica were randomly assigned to two groups, one group was grown under optimal conditions, the other under permanent inundation, simulating an increased future sea level. Phenotypic traits, biomass, and chlorophyll fluorescence were measured. Also, genetic differentiation, genotype diversity, and its relationship with trait variation were tested. Results show that under the optimal conditions, E. atherica originated from the low marsh increased root biomass, while reducing vegetative growth, and photosynthetic efficiency compared with those from the high marsh regardless of successional stages. These results indicate that E. atherica may adapt to lower marsh. However, under permanent inundation, no significant trait differentiation of E. atherica from the high and low marsh was found. No genetic differentiation was found, and genotype diversity was not correlated with trait variation. Results suggest low-marsh ecotypes may exist, possibly due to adaptive maternal effects; however, they are not necessarily better adapted to sustained inundation. Results suggest that increased sea level rise may impose a great threat to coastal vegetation.

中文翻译：

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优势植物的低沼泽生态型可能无法更好地适应海平面上升

摘要 植物对海平面上升的适应对于保护和海岸线保护具有重要意义；然而，它很少受到关注。在这里，我探讨了欧洲盐沼中一种主要植物对海平面上升的适应，以及这种适应是否由演替阶段介导。不同演替阶段具有不同的特征，例如养分有效性。我在早期、中期和晚期演替阶段从高低沼泽中采集 Elytrigia atherica。E. atherica 的个体被随机分配到两组，一组在最佳条件下生长，另一组在永久淹没下，模拟未来海平面的上升。测量了表型性状、生物量和叶绿素荧光。此外，遗传分化、基因型多样性、并检验其与性状变异的关系。结果表明，在最佳条件下，与来自高沼泽的E. atherica相比，无论演替阶段如何，低沼泽地的E. atherica增加了根生物量，同时降低了营养生长和光合效率。这些结果表明 E. atherica 可能适应较低的沼泽。然而，在永久性淹没条件下，高低沼泽地未发现 E. atherica 的显着性状分化。未发现遗传分化，基因型多样性与性状变异无关。结果表明可能存在低沼泽生态型，这可能是由于适应性母体效应所致；然而，它们不一定能更好地适应持续的淹没。