State Key Laboratory of Estuarine and Coastal Research, Institute of Eco-Chongming, East China Normal University, 200062, Shanghai, China.
School of Forest Sciences, University of Eastern Finland, 80101, Joensuu, Finland.
Sci Rep. 2018 Feb 5;8(1):2441. doi: 10.1038/s41598-017-18721-z.
The ecophysiological characteristics of native Phragmites australis and exotic Spartina alterniflora grown under waterlogging and salinity were investigated to explore their adaptation potential to sea level rise. The seasonal course of phenotypic traits, photosynthetic activity and chlorophyll fluorescence parameters of P. australis did not change remarkably under shallow flooding, whereas these variables were sensitive to increasing salinity. Waterlogging exacerbated the negative effects of salinity on shoot growth and photosynthetic activity of P. australis, and the combined stresses led to an absence of tassel and reproductive organs. By contrast, S. alterniflora performed well under both stresses and showed an obvious adaptation of salt secretion with increasing salinity. Light salinity was the optimal condition for S. alterniflora, and the tassel growth, chlorophyll content and fluorescence characters under moderate stresses did not differ notably. The Na and Cl concentrations in leaves of both species increased, and the K content decreased in response to salinity. Under moderate and high saline levels, the ion concentrations in S. alterniflora were maintained at relatively consistent levels with increased salt secretion. We expect the degradation of P. australis and further colonization of S. alterniflora under prolonged flooding and saltwater intrusion from sea level rise on the coastline of China.
本研究调查了本土芦苇（Phragmites australis）和外来互花米草（Spartina alterniflora）在淹水和盐胁迫下的生理生态特征，以探讨它们对海平面上升的适应潜力。在浅水淹没条件下，芦苇的表型特征、光合活性和叶绿素荧光参数的季节性变化并不显著，而这些变量对盐度增加敏感。淹水加剧了盐度对芦苇地上部生长和光合作用的负面影响，复合胁迫导致抽穗和生殖器官缺失。相比之下，互花米草在两种胁迫下表现良好，表现出明显的盐分泌适应能力，随着盐度的增加而增加。低盐度是互花米草的最佳条件，中度胁迫下的抽穗生长、叶绿素含量和荧光特性差异不显著。两种植物叶片中的 Na 和 Cl 浓度增加，K 含量随盐度增加而减少。在中度和高盐度下，互花米草通过增加盐分泌，将离子浓度维持在相对稳定的水平。我们预计，在中国沿海地区，随着海平面上升导致的长时间淹水和海水入侵，芦苇将退化，互花米草将进一步定殖。
