Tidal marsh survival in the face of sea level rise (SLR) and declining sediment supply often depends on the ability of marshes to build soil vertically. However, numerical models typically predict survival under rates of SLR that far exceed field-based measurements of vertical accretion. Here, we combine novel measurements from seven U.S. Atlantic Coast marshes and data from 70 additional marshes from around the world to illustrate that—over continental scales—70% of variability in marsh accretion rates can be explained by suspended sediment concentratin (SSC) and spring tidal range (TR). Apparent discrepancies between models and measurements can be explained by differing responses in high marshes and low marshes, the latter of which accretes faster for a given SSC and TR. Together these results help bridge the gap between models and measurements, and reinforce the paradigm that sediment supply is the key determinant of wetland vulnerability at continental scales.

中文翻译：

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协调模型和沼泽易受海平面上升影响的测量

面对海平面上升 (SLR) 和沉积物供应减少，潮汐沼泽的生存通常取决于沼泽垂直形成土壤的能力。然而，数值模型通常预测 SLR 率下的生存率远远超过垂直吸积的基于现场的测量值。在这里，我们结合来自美国大西洋沿岸七个沼泽的新测量值和来自世界各地的另外 70 个沼泽的数据，以说明在大陆尺度上，70% 的沼泽吸积率变化可以用悬浮沉积物浓度 (SSC) 和泉水来解释潮差 (TR)。模型和测量值之间的明显差异可以通过高沼泽和低沼泽的不同响应来解释，对于给定的 SSC 和 TR，后者的增长速度更快。这些结果共同有助于弥合模型和测量之间的差距，