Mechanistic Modeling of Marsh Seedling Establishment Provides a Positive Outlook for Coastal Wetland Restoration Under Global Climate Change. Issue 22 (11th November 2021)

• Record Type: Journal Article
• Authors: Hu, Zhan; Borsje, Bas W.; van Belzen, Jim; Willemsen, Pim W. J. M.; Wang, Heng; Peng, Yisheng; Yuan, Lin; De Dominicis, Michela; Wolf, Judith; Temmerman, Stijn; Bouma, Tjeerd J.
• Is Part Of: Geophysical research letters. Volume 48:Issue 22(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-11
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2021GL095596
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: While many studies focus on the persistence of coastal wetlands under climate change, similar predictions are lacking for new wetland establishment, despite being critical to restoration. Recent experiments revealed that marsh seedling establishment is driven by a balance between physical disturbance of bed‐level dynamics and seedling root stability. Using machine learning, we quantitatively translate such finding in a new biogeomorphic model to assess marsh establishment extent. This model was validated against multiyear observations of natural seedling‐expansion events at typical sites in the Netherlands and China. Subsequently, synthetic modeling experiments underscored that seedling expansion was primarily determined by controllable local conditions (e.g., sediment supply, local wave height, and tidal flat bathymetry) rather than uncontrollable climate change factors (e.g., change in sea‐level and global wave regime). Thus, science‐based local management measures can facilitate coastal wetland restoration, despite global climate change, shedding hope for managing a variety of coastal ecosystems under similar stresses. Plain Language Summary: Vulnerability of coastal wetlands under climate changes is of global concern due to their valuable services. Thus, restoring coastal wetlands is of widespread importance. However, the key processes controlling wetland vegetation establishment are not clear until recent field and laboratory experiments using marshes as an exemplary system. In the current study, we translate the insights of these recent studies into a new biogeomorphic model to predict marsh establishment extent on a landscape scale. Synthetical model analysis underlines that controllable local conditions are much more important than uncontrollable climate change stressors, thus providing a positive outlook for future coastal wetland restorations. Key Points: Controllable local conditions are more important than uncontrollable global changes for marsh establishment Sediment supply plays a key role in governing seedling establishment occurrence Tuning wave condition and tidal flat shape are effective measures to promote marsh creation