Tidal wetlands support plant communities that facilitate carbon storage, accrete soil, and provide habitat for terrestrial and aquatic species. Climate change is likely to alter estuaries through sea-level rise and changing precipitation patterns, although the ecological responses are uncertain. We were interested in plant responses to physiological stress induced by elevated water salinity and flooding conditions, which may be more prevalent under climate change. . We used a greenhouse experiment and factorial flooding (1, 12, 24, and 48 % time) and salinity (0, 5, 15, 30 PSU) treatments to evaluate the productivity responses of three emergent herbaceous species (Carex lyngbyei, Triglochin maritima, and Argentina pacifica) common to tidal marshes of the Pacific Northwest, USA. We measured weekly changes in plant height and final above and belowground biomass for all species after 10 weeks. Increased salinity reduced final above and belowground biomass significantly in all three species, with A. pacifica responding the most, followed by C. lyngbyei and T. maritima. Increased flooding also reduced total biomass in A. pacifica and T. maritima. There was a significant response in C. lyngbyei aboveground biomass and A. pacifica height to the flooding-salinity interaction. These results indicate emergent plant community composition may change in response to novel climate conditions in estuaries, driven by distinct physiological tolerances to salinity and flooding, and highlight the importance of considering multiple climate drivers when projecting ecosystem change. This may be especially true for estuaries that currently have prolonged freshwater phases like those in the Pacific Northwest.

潮汐湿地为植物群落提供了支持，这些群落促进了碳的储存，积聚了土壤并为陆生和水生物种提供了栖息地。尽管生态反应尚不确定，但气候变化可能会通过海平面上升和降雨模式变化而改变河口。我们对植物对盐分升高和水淹条件引起的生理胁迫的响应感兴趣，这在气候变化下可能更为普遍。。我们使用了温室试验，因子洪水（1、2、24和48％的时间）和盐度（0、5、15、30 PSU）处理来评估三种新出现的草本物种（Carex lyngbyei，Triglochin maritima，和阿根廷太平洋）常见于美国西北太平洋的潮汐沼泽。在10周后，我们测量了所有物种每周的植物高度变化以及最终的地下和地下生物量。盐度的增加在所有这三个物种中显着降低了最终的地上和地下生物量，其中A. pacifica响应最大，其次是C. lyngbyei和T. maritima。洪水泛滥也减少了太平洋A. apacifica和T. maritima中的生物量。lyngbyei地上生物量和A. pacifica有显着反应盐度相互作用的高度。这些结果表明，由于对盐分和洪水的独特生理耐受力，新兴的植物群落组成可能会随着河口新的气候条件而发生变化，并突出了预测生态系统变化时考虑多种气候驱动因素的重要性。对于目前淡水阶段延长的河口（例如西北太平洋地区的河口）尤其如此。