Tidal freshwater forested wetlands (TFFWs) commonly occur along coastal rivers; however, sea level rise and changes to river discharge may impact these wetlands. Information that characterizes the hydrology and salinity regime of the TFFW zone is needed to assess risk and predict future viability. A combination of field data and modeling were used to characterize TFFW hydrology, salinity, and vegetation along two distributaries (the East River and St. Marks River) of the Apalachicola River in west Florida, USA. Six gaging stations were established (three per river) roughly equidistant along the TFFW tidal gradient to monitor salinity and water levels at the river-wetland interface. Eighteen 500-m² forest survey stations (nine per river) were also established roughly equidistant between (and including) the upper and lower gaging stations to measure canopy trees (> 2.54 cm DBH) and calculate species importance values (IV₂₀₀). Field measures, along with other monitoring and model data, were used to develop a 30-year salinity record (1985–2015) for each gaging station based on an artificial neural network (ANN) model. Optimal ANN models for each TFFW gaging station were selected based on Akaike’s Information Criteria, and 30-year mean daily salinity was interpolated to all forest survey stations based on river distance. Important input variables for the ANN models included daily Apalachicola River discharge, Apalachicola Bay tidal stage, and bay salinity, among others. Based on 30-year salinity models, mean daily salinity ranged between 0.30 and 0.63 ppt at the downriver stations of East and St. Marks Rivers, respectively, to 0.14 and 0.14 ppt at the upriver stations, respectively. Results showed a predictable reduction in mean salinity and salinity ranges further upriver at both rivers; however, the St. Marks River showed a distinct inflection point in reduced salinity compared with the East River. Evaluating tree species IV₂₀₀, there was a shift to species indicative of non-tidal conditions midway up the study reach of the St. Marks River while tidal species remained prominent throughout the East River study reach. Comparison of salinity, tidal reach, and species IV₂₀₀ for each river suggests hydrology may be the most important contributor to the downriver extent of TFFWs while salinity may be an important driver of TFFW community composition.

潮汐淡水森​​林湿地（TFFWs）通常发生在沿海河流沿岸。但是，海平面上升和河流流量的变化可能会影响这些湿地。需要具有表征TFFW区水文和盐度状况的信息，以评估风险和预测未来的生存能力。结合现场数据和建模，对美国西佛罗里达州阿帕拉奇科拉河的两个支流（东河和圣马克斯河）沿线的TFFW水文，盐度和植被进行了特征描述。沿TFFW潮汐梯度大致等距地建立了六个测量站（每条河三个），以监测河流-湿地界面的盐度和水位。18个500-m ²还建立了森林测量站（每条河流9个），它们在上下测量站之间（包括其上下）大致相等的距离，以测量冠层树木（> 2.54 cm DBH）并计算物种重要性值（IV ₂₀₀）。基于人工神经网络（ANN）模型，现场测量以及其他监测和模型数据被用于为每个计量站建立30年的盐度记录（1985-2015年）。根据Akaike的信息标准，为每个TFFW测量站选择了最佳的ANN模型，并根据河流距离将30年的平均每日盐度插值到所有森林测量站。ANN模型的重要输入变量包括每日阿帕拉奇科拉河流量，阿帕拉奇科拉湾潮汐阶段和海湾盐度等。根据30年的盐度模型，东部和圣马克河下游河段的日平均盐度分别为0.30和0.63 ppt，上游河段的日平均盐度分别为0.14和0.14 ppt。结果表明，两条河流的平均盐度和盐度范围都可以预期地降低。然而，与东河相比，圣马克斯河在盐度降低方面表现出明显的拐点。评估树种IV_200年，在圣马克斯河研究范围的中途出现了指示非潮汐条件的物种转移，而在整个东河研究范围内，潮汐物种仍然很突出。比较每条河流的盐度，潮差和IV ₂₀₀物种，表明水文学可能是TFFW下游范围的最重要因素，而盐分可能是TFFW群落组成的重要驱动力。