Unvegetated corridors nonlinearly regulate hydrological connectivity and sediment delivery in a microtidal marsh
Wang, D.; Bai, J.; Schoutens, K.; Wang, J.; Wang, W.; Gu, C. (2026). Unvegetated corridors nonlinearly regulate hydrological connectivity and sediment delivery in a microtidal marsh. Catena 269: 110129. https://dx.doi.org/10.1016/j.catena.2026.110129
In: Catena. Elsevier: Cremlingen. ISSN 0341-8162; e-ISSN 1872-6887, more
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| Author keywords |
Hydrological connectivity;Connectivity efficiency;Nonlinear;Sediment deposition;Vertical bed level change;Unvegetated corridor;Interior marsh resilience;tidal marsh;vegetation;accretion;morphology;mangrove;estuary |
| Authors | | Top |
- Wang, D.
- Bai, J.
- Schoutens, K., more
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| Abstract |
Microtidal marsh resilience to sea-level rise depends on biogeomorphic feedbacks linking vegetation, hydrodynamics, and sediment distribution. In microtidal systems, the invaded Spartina alterniflora as an ecosystem engineer alters flow pathways and traps sediment near channel margins, thereby restricting sediment delivery to interior marsh platforms typically covered by native species, such as Suaeda salsa. Yet how targeted vegetation management regulates hydrological connectivity and re-establish these feedbacks to support marsh adaptation remains poorly understood. Here, we conducted a field-based manipulation experiment in a Spartina alterniflora-invaded microtidal marsh in the Yellow River Delta, China. Unvegetated corridors of varying widths were constructed to connect the tidal channel with interior Suaeda salsa marsh platforms. We quantified hydrological connectivity and sediment redistribution using flow velocities, sediment deposition, and bed level change, and introduced a new metric defined as connectivity efficiency. Our results showed that unvegetated corridors enhanced hydrological connectivity, reducing sediment accumulation near channel fringes while increasing sediment accretion in interior marshes. Corridor width exerted a nonlinear control on connectivity: wide corridors (e.g., 20 m) facilitated greater overall sediment deposition across the marsh platform, whereas intermediate corridors (e.g., 4 m) achieved the highest efficiency in transferring sediment to interior platforms. Corridor creation initially suppressed Suaeda salsa due to increased hydrodynamic disturbance, but subsequently promoted its partial recovery in the subsequent year under improved accretional conditions. Our findings highlight that spatially explicit manipulation of hydrological connectivity can effectively regulate sediment delivery and mediate biogeomorphic feedbacks in microtidal marshes. This process-based understanding provides a mechanistic basis for connectivity-oriented management strategies to enhance microtidal marsh resilience under sea-level rise. |
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