Vegetation-Driven Changes in Soil Salinity Ions and Microbial Communities Across Tidal Flat Reclamation

Area of Science:

• Ecology
• Environmental Science
• Microbiology

Background:

• Tidal flat ecosystems are crucial but vulnerable to land reclamation.
• Soil microbes are vital but sensitive to environmental changes caused by reclamation.

Purpose of the Study:

• Investigate bacterial community dynamics during 50 years of tidal flat reclamation.
• Identify environmental drivers, particularly salinity ions and vegetation, influencing microbial succession.

Main Methods:

• Analyzed bacterial communities across a 50-year reclamation chronosequence.
• Compared three vegetation types: bare flats, reed beds, and rice fields.
• Assessed soil physicochemical properties, including salinity ions, nutrients, and pH.

Main Results:

• Reclamation significantly reduced total dissolved salts and increased nutrients, especially in rice fields.
• Key ions (HCO3-, Cl-, K+) were primary drivers of microbial structure, more so than TDS or pH.
• Bacterial abundance and diversity increased over time, with rice fields exhibiting the highest values after 50 years.
• Specific bacterial phyla (Actinobacteriota, Proteobacteria) and genera showed distinct responses to ion concentrations.

Conclusions:

• Vegetation type and specific salinity ions are critical in shaping microbial communities during tidal flat reclamation.
• A phased vegetation strategy (reeds then rice) can improve soil quality and microbial diversity.
• Findings offer insights for sustainable tidal flat reclamation and management strategies.