Scale-dependent biogeomorphic feedbacks control the tidal marsh evolution under Spartina alterniflora invasion.

Area of Science:

• Ecological modeling
• Biogeomorphology
• Invasive species ecology

Background:

• Biogeomorphic feedbacks are crucial for pioneer species in tidal environments.
• The impact of invasive species on salt marsh succession, considering hydro-geomorphology and ecoengineering, is poorly understood.

Purpose of the Study:

• To develop a bio-hydrogeomorphic model for tidal platform evolution and vegetation distribution under invasive Spartina alterniflora.
• To understand the biogeomorphic impacts of invasive species throughout the invasion process.

Main Methods:

• Developed a bio-hydrogeomorphic model.
• Conducted field observations in the Yellow River Delta, China.
• Analyzed tidal channel formation along an elevation gradient.

Main Results:

• Spartina alterniflora invasion shifted salt marshes from stabilized to self-organized systems via geomorphic-biological feedback.
• Tidal channel initiation in low-elevated zones was driven by patch-scale feedbacks during early invasion.
• Landscape-scale feedbacks dominated channel incision in higher zones during the mature phase, influenced by tidal prism and organism traits.

Conclusions:

• Scale-dependent feedbacks and variations in ecoengineering capacity determine morphological changes in invasive ecosystems.
• Findings offer insights into the biogeomorphic impacts of invasive species and inform conservation strategies for native ecosystems.