Details

Autor(en) / Beteiligte

• Xin, Pei
• Wilson, Alicia
• Shen, Chengji
• Ge, Zhenming
• Moffett, Kevan B.
• Santos, Isaac R.
• Chen, Xiaogang
• Xu, Xinghua
• Yau, Yvonne Y. Y.
• Moore, Willard
• Li, Ling
• Barry, D. A.

Titel

Surface Water and Groundwater Interactions in Salt Marshes and Their Impact on Plant Ecology and Coastal Biogeochemistry

Ist Teil von

• Reviews of geophysics (1985), 2022-03, Vol.60 (1), p.n/a

Ort / Verlag

Washington: Blackwell Publishing Ltd

Erscheinungsjahr

2022

Quelle

Access via Wiley Online Library

Beschreibungen/Notizen

• Salt marshes are highly productive intertidal wetlands providing important ecological services for maintaining coastal biodiversity, buffering against oceanic storms, and acting as efficient carbon sinks. However, about half of these wetlands have been lost globally due to human activities and climate change. Inundated periodically by tidal water, salt marshes are subjected to strong surface water and groundwater interactions, which affect marsh plant growth and biogeochemical exchange with coastal water. This paper reviews the state of knowledge and current approaches to quantifying marsh surface water and groundwater interactions with a focus on porewater flow and associated soil conditions in connection with plant zonation as well as carbon, nutrients, and greenhouse gas fluxes. Porewater flow and solute transport in salt marshes are primarily driven by tides with moderate regulation by rainfall, evapotranspiration and sea level rise. Tidal fluctuations play a key role in plant zonation through alteration of soil aeration and salt transport, and drive the export of significant fluxes of carbon and nutrients to coastal water. Despite recent progress, major knowledge gaps remain. Previous studies focused on flows in creek‐perpendicular marsh sections and overlooked multi‐scale 3D behaviors. Understanding of marsh ecological‐hydrological links under combined influences of different forcing factors and boundary disturbances is lacking. Variations of surface water and groundwater temperatures affect porewater flow, soil conditions and biogeochemical exchanges, but the extent and underlying mechanisms remain unknown. We need to fill these knowledge gaps to advance understanding of salt marshes and thus enhance our ability to protect and restore them. Plain Language Summary Salt marshes populated by salt‐tolerant plants are commonly found at the land‐ocean interface. As highly productive intertidal wetlands, salt marshes serve a variety of ecological functions. This review covers the current state of knowledge on surface water and groundwater interactions in salt marshes and their impacts on ecology and the environment. A global analysis is provided to understand the distribution, hydrological and ecological functions, status and potential challenges of salt marshes. Surface water and groundwater interactions under different driving forces and factors are discussed and linked to soil conditions and biogeochemical processes. Current approaches including field measurements, radionuclide analyses and numerical modeling provide a guide for applications targeted at specific questions in salt marsh science and management. Knowledge gaps identified by this review suggest needs for further investigations into the complex and dynamic surface water and groundwater interactions and associated biogeochemical processes that characterize salt marshes. Key Points Tides play a primary role in salt marsh surface water and groundwater interactions Surface water and groundwater interactions affect plant zonation, and carbon and nutrient outwelling Future research needs to couple hydrological processes to ecological and geochemical processes