Water level and salinity are important abiotic factors in saline-alkaline wetlands, which have been altered due to climate change and human activities. For saline-alkaline wetland plants, it remains to be revealed whether the most important abiotic factor is water or salt. Therefore, it is valuable to examine plant responses and adaptive strategies to water-salt conditions in saline-alkaline wetlands. We performed a simulation experiment using soil and plants from a typical saline-alkaline wetland. The responses and adaptive strategies of plants, the relationship between abiotic factors and the causal relationships between plant functional traits under the combined effects of water level and salinity of NaHCO₃ and NaCl were studied, taking Scirpus planiculmis as the plant model. The results showed that water level had stronger effects on plant functional traits than salinity and their combined effects, and there was an antagonistic relationship between water level and salinity. The salinity effects disappeared with rising water level. Different plant functional traits among organs showed similar changes with increasing water levels: highest at stressed and suitable conditions and lowest at middle condition, including stem diameter, chlorophyll fluorescence parameters, total sulphur (TS) and total nitrogen (TN) in leaf and the bioconcentration factor (BCF) of TS and TN in leaf, which indicated that environmental stresses force plants to improve their performance to remain similar to the performance in a suitable environment. Based on the structural equation model (SEM), water-salt conditions and photosynthesis influenced the TN, TS, total phosphorus (TP), and N:P ratio of S. planiculmis, stem diameter, root:shoot ratio (R:S ratio) and stem:leaf ratio (S:L ratio) by regulating the BCF and the translocation index (TI) of elements. Therefore, element bioconcentration and translocation are crucial for plant responses to altered water-salt conditions. This study is beneficial for understanding plant response mechanisms and adaptive strategies in saline-alkaline wetlands under climate change and may provide new theoretical evidence for the restoration of degraded wetlands.

水位和盐度是盐碱湿地中重要的非生物因子，由于气候变化和人类活动而发生了变化。对于盐碱湿地植物，最重要的非生物因子是水还是盐仍有待揭示。因此，在盐碱湿地中研究植物对水盐条件的反应和适应策略是很有价值的。我们使用来自典型盐碱湿地的土壤和植物进行了模拟实验。研究了水和NaHCO ₃和NaCl盐度的联合作用下植物的响应和适应策略，非生物因子之间的关系以及植物功能性状之间的因果关系，以Scirpus Planiculmis为食作为工厂模型。结果表明，水位对植物功能性状的影响大于盐度及其综合影响，并且水位与盐分之间存在拮抗关系。随着水位的升高，盐分效应消失了。器官之间不同的植物功能性状随水位的升高表现出相似的变化：在胁迫和适宜条件下最高，而在中间条件下最低，包括茎直径，叶绿素荧光参数，叶片中的总硫（TS）和总氮（TN）以及生物浓度叶片中TS和TN的因子（BCF），这表明环境胁迫迫使植物改善其性能，使其与合适环境中的性能保持相似。根据结构方程模型（SEM），通过调节BCF和元素的易位指数（TI）来确定扁平葡萄球菌，茎直径，根：茎比率（R：S比率）和茎：叶比率（S：L比率）。因此，元素生物富集和转运对于植物对水盐条件变化的反应至关重要。这项研究有助于理解气候变化下盐碱湿地的植物响应机制和适应策略，并可能为退化湿地的恢复提供新的理论依据。