Resilience of Phragmites australis Communities Under Climate Change: Simulating the Coupled Effects of Salinity Intrusion and Moisture Conditions in Coastal Wetlands

Under global climate change, coastal wetlands face severe dual stress of salinization and drought, whose coupling drives wetland degradation. As a key species, Phragmites australis maintains wetland function, but its community resilience mechanism to salinity‐moisture coupling remains unclear. We developed a dynamic growth model for P. australis under these stresses, calibrated and validated via indoor controlled experiments and field surveys. Three scenarios (drought + high salinity, moist + low salinity, flooded + moderate salinity) quantified non‐linear impacts on biomass. The model showed high accuracy ( R = 0.97, RSR = 0.2452, IOA ≥ 0.97). Scenario simulations revealed: moist + low salinity yielded the highest biomass peak (~2000 g/m 2 ) with gentle decline; flooded + moderate salinity had a slightly lower peak (~1900 g/m 2 ) and faster decline; drought + high salinity showed the lowest peak (~1800 g/m 2 ) and most rapid post‐September decline. This study overcomes static model limitations, providing a scientific tool for adaptive restoration of wetland P. australis communities.