Data from: Incorporating thresholds into understanding salinity tolerance: a study using salt-tolerant plants in salt marshes

Although salinity in many ecosystems such as salt marshes can be extremely high, an asymmetry in salinity range between experimental studies (relatively narrow) and field conditions (potentially broad) has strongly affected current understanding of plant salinity tolerance. To improve understanding, it is thus important to examine plant tolerances over a broad range of salinities and identify potential tolerance thresholds. We examine tolerances of two widely-distributed marsh plants, Suaeda salsa and Salicornia europaea, to salinities ranging from 0 to 100 g kg-1, and determine survival, above- and below-ground biomass after eight weeks of salinity treatment. Both species, especially Sa. europaea, have much broader salinity tolerances than other plants previously examined, 2) plant survival, above- and below-ground biomass have remarkably different responses to salinity, and 3) there is a non-linear, threshold response of S. salsa to salinity, above which S. salsa survivorship drastically decreases. These results provide multiple important insights. Our study suggests that the potential for using these halophytes to revegetate and restore salt-affected land may be greater than previously thought, and highlights the importance of studying multiple plant responses. Importantly, our study calls for a better integration of thresholds into understanding plant salinity tolerances and their applications.尽管盐沼等诸多生态系统的盐度可处于极高水平，但实验研究（盐度范围相对狭窄）与野外实际环境（盐度范围潜在宽泛）之间的盐度范围不对称性，已对当前学界关于植物耐盐性的认知产生了显著影响。为深化相关认知，有必要在宽泛的盐度梯度下开展植物耐盐性评价，并明确潜在的耐盐阈值。本研究针对两种广布盐沼植物——盐地碱蓬（Suaeda salsa）与欧洲海蓬子（Salicornia europaea）展开耐盐性测试，设置0至100 g kg⁻¹的盐度梯度，在盐胁迫处理8周后测定其存活率、地上与地下生物量。研究得到三项核心发现：其一，两个物种（尤其是欧洲海蓬子）的耐盐范围远宽于此前已报道的其他植物；其二，植物存活率、地上及地下生物量对盐度的响应模式存在显著差异；其三，盐地碱蓬对盐度呈现非线性阈值响应，当盐度超过该阈值后，其存活率会急剧下降。上述研究结果提供了多项重要科学启示。本研究表明，利用这类盐生植物（halophytes）开展盐渍化土地植被重建与生态修复的潜力，可能远超此前的预期，同时凸显了多维度测定植物响应指标的重要性。尤为关键的是，本研究呼吁在植物耐盐性认知及其应用研究中，更好地整合阈值维度的考量。