To save saltmarshes and their valuable ecosystem services from sea level rise, it is crucial to understand their natural ability to gain elevation by sediment accretion. In that context, a widely accepted paradigm is that dense vegetation favors sediment accretion and hence saltmarsh resilience to sea level rise. Here, however, we reveal how dense vegetation can inhibit sediment accretion on saltmarsh platforms. Using a process‐based modeling approach to simulate biogeomorphic development of typical saltmarsh landscapes, we identify two key mechanisms by which vegetation hinders sediment transport from tidal channels toward saltmarsh interiors. First, vegetation concentrates tidal flow and sediment transport inside channels, reducing sediment supply to platforms. Second, vegetation enhances sediment deposition near channels, limiting sediment availability for platform interiors. Our findings suggest that the resilience of saltmarshes to sea level rise may be more limited than previously thought.

中文翻译：

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茂密的植被阻碍沉积物向盐沼内部输送


为了保护盐沼及其宝贵的生态系统服务免受海平面上升的影响，了解盐沼通过沉积物堆积而升高海拔的自然能力至关重要。在这种情况下，一个广泛接受的范式是茂密的植被有利于沉积物的堆积，因此盐沼对海平面上升的恢复力较强。然而，在这里，我们揭示了茂密的植被如何抑制盐沼平台上的沉积物积聚。使用基于过程的建模方法来模拟典型盐沼景观的生物地貌发育，我们确定了植被阻碍沉积物从潮汐通道向盐沼内部输送的两种关键机制。首先，植被将潮汐流和泥沙输送集中在河道内，减少了平台的泥沙供应。其次，植被增强了河道附近的沉积物沉积，限制了平台内部沉积物的可用性。我们的研究结果表明，盐沼对海平面上升的恢复能力可能比之前想象的更为有限。