Anthropogenically driven habitat changes caused a directional reorganization of macrobenthic functional structure

Coastal habitat transformations, including ecological restoration, biological invasion, and shoreline engineering, have become major drivers of ecological change in intertidal ecosystems worldwide. However, their functional consequences for macrobenthic communities remain insufficiently understood. We investigated macrobenthic communities across six representative intertidal habitats in Yueqing Bay and evaluated functional trait composition, functional diversity, functional beta diversity decomposition, and applied RLQ and fourth-corner analyses to identify the environmental drivers of functional traits. Habitat modification selectively favored distinct ecological strategies and resulted in pronounced functional reorganization of macrobenthic communities. Long-term transplanted mangrove forests were characterized by higher proportions of long-lived and infaunal taxa, accompanied by reduced functional space. In contrast, Spartina alterniflora marshes supported higher proportions of epifauna taxa and maintained the larger functional space and stronger turnover-driven functional replacement. Artificial seawalls similarly favored long-lived and sensitive taxa, whereas natural rocky reefs were dominated by short-lived and herbivorous communities. Sediment texture and nutrient conditions jointly mediated trait-environment coupling. These results indicate that multiple anthropogenic pressures directionally restructure macrobenthic functional organization through distinct environmental filtering pathways, highlighting the importance of considering functional responses when evaluating the ecological consequences of coastal habitat transformation.