Abstract Hydrology is a critical driver controlling mangrove wetlands structural and functional attributes at different spatial and temporal scales. Yet, human activities have negatively affected hydrology, causing mangrove diebacks and coverage loss worldwide. In fact, the assessment of mangrove water budgets, impacted by natural and human disturbances, is limited due to a lack of long-term data and information that hinders our understanding of how changes in hydroperiod and salinity control mangrove productivity and spatial distribution. In this study, we implemented a mass balance-based hydrological model (RHYMAN) that explicitly considers groundwater discharge in the Shark River estuary (SRE, southwestern Everglades) located in a karstic geomorphic setting and influenced by regional hydrological restoration. We used long-term hydroperiod and porewater salinity (PWS) datasets obtained from 2004 to 2016 for model calibration and validation and to determine spatiotemporal variability in water levels and PWS at three riverine mangrove sites (downstream, SRS-6; midstream, SRS-5; upstream, SRS-4) along SRE. Model results agree with a distinct PWS pattern along the estuarine salinity gradient where the highest PWS occurs at SRS-6 (mean: 25, range: 22–30 ppt), followed by SRS-5 (17, 14–25 ppt) and SRS-4 (5, 3–13 ppt). A commensurate increase in PWS over a thirteen-year period indicates a long-term reduction in freshwater inflow coupled with sea-level rise (SLR). Increasing freshwater scenario simulation results show a significant reduction (17–27%) in PWS along the estuary in contrast with a high SLR scenario when salinity increases up to 1.1 to 2.5 times that of control values. Model results show that freshwater inflow and SLR are key drivers controlling mangrove wetlands PWS in this karstic coastal region. Given its relatively simple structure, this mass balance-based hydrological model could be used in other environmental settings to evaluate potential habitat and regime shifts due to changes in hydrology and PWS under regional hydrological restoration management.

中文翻译：

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模拟受水文恢复和气候变暖影响的红树林（美国佛罗里达州大沼泽地）土壤孔隙水盐度

摘要 水文是控制不同时空尺度红树林湿地结构和功能属性的关键驱动因素。然而，人类活动对水文产生了负面影响，导致全球红树林枯死和覆盖面积减少。事实上，由于缺乏长期数据和信息，阻碍了我们了解水周期和盐度的变化如何控制红树林生产力和空间分布，因此对受自然和人为干扰影响的红树林水资源收支的评估是有限的。在本研究中，我们实施了基于质量平衡的水文模型 (RHYMAN)，该模型明确考虑了位于岩溶地貌环境中并受区域水文恢复影响的鲨鱼河河口（SRE，大沼泽地西南部）的地下水排放。我们使用 2004 年至 2016 年获得的长期水周期和孔隙水盐度 (PWS) 数据集进行模型校准和验证，并确定三个河流红树林地点（下游，SRS-6；中游，SRS-5）的水位和 PWS 的时空变化; 上游，SRS-4) 沿 SRE。模型结果与沿河口盐度梯度的明显 PWS 模式一致，其中最高 PWS 出现在 SRS-6（平均值：25，范围：22-30 ppt），其次是 SRS-5（17、14-25 ppt）和 SRS -4 (5, 3–13 ppt)。十三年期间 PWS 的相应增加表明淡水流入量长期减少，同时海平面上升 (SLR)。增加淡水情景模拟结果表明，当盐度增加到 1.1 到 2 时，与高 SLR 情景相比，沿河口的 PWS 显着减少（17-27%）。控制值的5倍。模型结果表明，淡水流入量和 SLR 是控制该岩溶沿海地区红树林湿地 PWS 的关键驱动因素。鉴于其相对简单的结构，这种基于质量平衡的水文模型可用于其他环境设置，以评估由于区域水文恢复管理下水文和 PWS 的变化而导致的潜在栖息地和制度变化。